The High Life, animal species

In the last blog, we investigated the conditions and constraints of living at high altitudes, generally above 10,000 feet.  A few physiological adaptations listed included enhanced breathing and blood supply to get more oxygen to the body, internal temperature regulation allowing some mammals to adjust to a colder environment, and smaller plants requiring less moisture and having a short growing season. 

Common springtail, Orchesella cincta, by Mvuijlst, Feb 2009
Springtail, Isotoma caerulea, by Andy Murray, Jul 2014

The Himalayan jumping spider, Euophrys omnisuperstes, is generally found above 22,000 feet, living among rock crevices and feeding on stray insects blown upward by rising mountain winds.  The spider also feeds on springtails, Collembola, once considered an insect but now classified as a free-ranging hexapod.  These tiny organisms have antifreeze compounds in their blood, enabling them to live in higher, colder habitats. 

Reptiles from four lizard species have been found living in higher elevations.  Two species of iguana in the genus Liolaemus live in Bolivia; a third iguana species, Liolaemus tacnae, lives in Peru; and an Asian lizard, Phrynocephalus erythrurus, lives on the Tibetan plateau.  All were found between 16,000 feet and 18,000 feet, but very little is known about them since these areas are difficult to access for study.

Golden eagle, Aquila chrysaetos, by Giles Laurent, Dec 2021; Andean condor, Vultur gryphus, by Bastihitzi, May 2013; Alpine chough, Pyrrhocorax graculus, by Jim Higham, 2008

Birds can be found living near mountain tops year-round.  The Alpine chough, Pyrrhocorax graculus, lives in social flocks from the Alps to the Himalayas.  Standing 15″ high with a 30″ wingspan, they have black feathers with distinct yellow beaks and red legs.  They eat insects and berries in summer, but have become well-adapted to scavenging in winter, especially around ski resorts.  The Andean condor, Vultur gryphus, another social bird, roosts on cliffs and outcrops above 16,000 feet.  The steep terrain provides additional protection from potential predators.  Golden eagles, Aquila chrysaetos, are found world-wide in many habitats.  In the mountains, they hunt marmot, hare, and young goats at lower elevations, but nest in eyries, large cliff-hugging nests at higher elevations.  With wingspans up to seven feet, they can dive at speeds of up to 150mph over unsuspecting prey.

Left top to bottom: Common crane, Grus grus, by Savithri Singh, Feb 2020; Whooper swan,Cygnus cygnus, by KyoichiNarukami, Japan, Jan 2012; Bar-headed goose, Anser indicus, by J.M.Garg, India, Mar 2000; Ruppell’s Griffon Vulture, Gyps rueppellii, by Lip Kee, Kenya, Aug 2008

High altitude bird species with physiological adaptations for breathing and blood supply include those whose migration routes take them over the world’s highest mountain ranges.  Ruppell’s Griffon Vulture, Gyps rueppellii, with an 8-foot wingspan, has been observed at altitudes exceeding 36,000 feet over the Ethiopian Highlands of Central Africa.  The common crane, Grus grus, lives across eastern Europe and northern Asia, migrating over the Alps to Africa, India and southern China.  The bar-headed goose, Anser indicus, and the whooper swan, Cygnus cygnus, both live in south Asia and migrate over the Alps to central and sub-Arctic Asia to breed. 

Above: Large-eared pika, Ochotona macrotis,
by Karunakar Rayker, Ladakh India, Feb 2008
Right: Snow leopard, Panthera uncia, by Vassil, Aug 2007

The heights of the Himalayas support mammals that can concentrate their hemoglobin and allow the blood to carry more oxygen, avoiding issues with hypoxia, a shortage of usable oxygen in the body.  Species with this physiological adaptation include large-eared pika, Ochotona macrotis, living above 7,700 feet up to 20,000 feet; wild yak, Bos mutus, which have larger heart and lungs than domesticated yaks; and the snow leopard, Panthera uncia, living above 3,000 feet up to 18,000 feet.  The snow leopard has short, heavily furred limbs and a long, heavy tail for use as a blanket.  Its large nasal cavity and strong chest allows more oxygen to be taken in with each breath.

Ethiopian wolf, Canis simensis, by Charles J. Sharp, Ethiopia, Dec 2017; Mountain goat, Oreamnos americanus, by Darklich14, Colorado, Aug 2009; Tibetan argali, Ovis ammon, by DonArnold, Jurica-Suchy Nature Museum, Mar 2026; Guanaco, Lama guanicoe, by Charles J. Sharp, Chile, Oct 2025; Yellow-rumped leaf-eared mouse, Phyllotis xanthopygus, drawing by Charles Darwin, 1832

Mountain goats, Oreamnos americanus, can climb steep cliff faces with hooves that grip ledges and rock surfaces in the Rocky Mountains.  The yellow-rumped leaf-eared mouse, Phyllotis xanthopygus, feeds on grains, seeds, roots, and insects in the Andean Mountains of Chile, living at altitudes to 22,000 feet.  Guanaco, Lama guanicoe, a member of the camel family, lives in the Andes up to 13,000 feet and has about four times as many red blood cells as a human does.  The Ethiopian wolf, Canis simensis, is an endangered species living up to 15,000 feet in central Africa with populations fragmented by pressure from human farming activities.  Tibetan argali, Ovis ammon, is a wild sheep found in the Altai Mountains of Mongolia up to 19,000 feet.  The ewes and lambs prefer steep, treacherous slopes as protection against predators.

Scientists continue to study species in these habitats to learn more about their specific adaptations and survival abilities in a harsh environment.  You can learn more by visiting zoos or nature museums near you to investigate these fascinating species.

Spring Migration

Meteorological spring starts Sunday, and we are already starting to hear the calls of early migratory birds, heading north from southern wintering grounds, working to establish territory their among the best nesting sites available. 

Red-winged blackbird, Agelaius phoeniceus, singing by Rhododendrites, May 2023

Some birds, including red-winged blackbirds, Agelaius phoeniceus, get their cue to start spring migration as temperatures get warmer.  These species head to prairies, forests, and wetlands to claim a location they can protect, call for a mate, and establish a nesting site with good protection and food sources.  Other birds, including many warbler species, return in spring when daylight hours lengthen.  Generally flying at night, they use star positions and the Earth’s magnet field to guide them.  If nights are stormy or heavily overcast, early morning may find hundreds of them waiting in fields for clear skies.  Birds may also stop for a day or two in areas located on the southern shores of any large body of water to rest and feed before crossing.

Red-winged blackbird, Agelaius phoeniceus, flock at sunset by Jerry Segraves
North America flyway map by USFWS

Bird species around the world generally follow established flyways, established routes over specific locations between their southern and northern territories.  Many migration routes do not follow a straight path.  Some species have historical stopover or feeding locations that provide a rest point along the way.  Other species may not be able to cross a mountain range; or a large body of water can act as a barrier for land birds, but may be a required food source for wetland birds.

Arctic tern, Sterna paradisaea, adult & juvenile by Charles J Sharp, Aug 2025
Arctic tern, Sterna paradisaea, in flight by Charles J Sharp, Aug 2025

Long distance migration routes are most common for birds wintering in subtropical and tropical areas and breeding in the northern hemisphere.  Long migrations in the southern hemisphere are far less common because there is less land near the South Pole to support breeding activities.  The record holder for migration distance is the Arctic tern, Sterna paradisaea, overwintering in Antarctica and breeding in Arctic locations, a round trip between 30,000 and 55,000 miles.  Some shorter migrations are between upper and lower altitudes in mountainous regions.

Penguin migration map by Fred Cooke
& Jenni Bruce, Aug 2011
Dusky grouse male, Dendragapus obscurus, displaying by US NPS

Most birds migrate in flocks, which reduces the energy needed to fly long distances and provides added protection against predators.  Penguins migrate without flying.  Most penguin species swim between locations, covering up to 1,000 miles round trip.  A few species cover long distances on foot, including dusky grouse, Dendragapus obscurus, in the Rocky Mountains which walk from lower to higher elevations.  However, a flock may encounter unfavorable weather or flying conditions that causes a large number of birds to stall in one location, introducing other risks including depleted food sources and predation by land-based animals.

At the Jurica-Suchy Nature Museum, we host a nature walk every other week to observe changes in our campus including the birds that are moving through the area.  There are many birding groups worldwide that provide opportunities to observe and learn about migratory birds in every location.  Consider joining a group, or take your own bird walk as we have clear days and warming temperatures and see who’s on the move in your area.

Forest Floor

Two main types of forests grow in the regions between the tropics and the poles, deciduous forest and coniferous forest.  A majority of energy from sunlight is captured by the canopy vegetation, with little leftover to reach the forest floor.  And yet, the lowest level of the forest has an abundance of food and organisms.

Deciduous species are mainly hardwoods including oak, birch, maple, ash, beech, and hickory.  These trees have leaves that are broad and flat, designed to catch sunlight.  Conifer forests are made up mostly of softwood tree species from the pine and fir families.  Most conifers have leaves that are long, thin, and needle-like, a compact form of leaf that is often waxy and designed to withstand the rigors of an environment that is cold and dry for long periods.

Chlorophyll is a chemical that is synthesized by plants and gives leaves and needles their characteristic green color.  Plants use chlorophyll to absorb energy from sunlight and use that energy to power the process of photosynthesis which creates carbohydrates, providing food for the rest of the plant.  Senescence, the process that occurs when a plant stops making chlorophyll, happens as seasons change and day length shortens while temperatures fall.  As chlorophyll is removed, leaves and needles lose their green hues and show their underlying colors of browns, reds, and oranges even as they die and fall to the forest floor.

Fallen leaves create a thick layer of litter, broken down by a rich variety of decomposers including mosses, fungi, insects, and other invertebrates.  Decaying vegetation releases nutrients back into the soil to be used once more as food for other forest plants.  The annual leaf fall adds an estimated 2,600 pounds of vegetation per acre back into forest habitats worldwide.

In deciduous forests, all of the leaves typically fall in late autumn opening up the forest floor to sunlight in early spring.  A group of plants known as spring ephemerals take advantage of this sunlight to quickly flower, bloom, and reproduce before leaves re-appear and shade once more rules the forest floor.  In conifer forests, where shade is ever-present, flora is restricted to shade-loving species such as ferns and fungi.  In addition, fir and pine tree needles are high in acid content and their leaf litter is only broken down by a relatively few fungi species over long periods of time.

All forest floors are rich with many organisms present throughout the year.  Invertebrates including insects, fungi, and small mammals spend their entire lives living in the leaf litter.  Detritus from leaf fall provides food and nutrients throughout the year to the plants and other organisms living in these wonderful habitats.  As you walk the forests, no matter what the season, think about all of the life going on around you each day on the rich woodland floor.

American Asters

As we enter early autumn, it is late in the growing season for the central United States, and many insect species are still actively looking for pollen and nectar as they get ready for winter.  Migrating birds and species that overwinter here are also seeking daily meals.  Fall flowering plant species are much fewer in number than summer blooming species, but include varieties of American asters, Symphyotrichum spp.; goldenrod, Solidago spp.; black-eyed Susans, Rudbeckia spp.; coneflower, Echinacea spp.; sedum, Sedum spp.; and anise hyssop, Agastache spp.

American Aster by Andrew McKinlay, Aug 2013; Anise hyssop by Steve Guttman, Oct 2011; Black-eyed Susan by Jodi Grundig, Aug 2009; Coneflower by Bonnie Leer, Jul 2008; Goldenrod by Cathy Baird, Aug 2013; Sedum by Eleanor Martin, Jul 2009

In this blog, we take a look at American asters, which make up a genus of over 100 species of perennial plants, all of which are native to North America.  Asters like full or partial sun and reach heights of between one and six feet.  They display a variety of colors from white to blue to purple.  They do best in wet soils.  Asters are often grown in pots or used in borders, as well as being found in a variety of wild habitats including forests, savannas, prairies, and wetlands.

American painted lady on Pacific aster by TJ Gehling, Oct 2023; Gulf fritillary on white aster by Vicki DeLoach, Ot 2012; Leaf cutter bee, Megachile spp, on New England aster, by GreenRavenPhotography, Sep 2016; Metallic green bee on white aster by Jacqui Trump, Oct 2021; Pecks skipper, Polites peckius, on smooth blue aster, Symphyotrichum laeve, by Tom Potterfield, Sep 2016

These asters are an excellent source of nectar and pollen sought by both long-tongued and short-tongued bees, butterflies, wasps, and beetles.  All parts of the plant are edible, although some species may contain mild toxins, making the animal eating it ill.  Leaves and stems are eaten by grouse, turkey, chipmunks, mice, and deer.  The abundant seeds are available long after most other flower seeds have been consumed or buried.  Large quantities of seeds are eaten by migrating bird species including dark-eyed junco, Junco hyemalis; indigo bunting, Passerina cyanea; American tree sparrow, Spizelloides arborea; and American goldfinch, Spinus tristis.

American goldfinch, Spinus tristis, by F Delventhal, Jul 2022; American tree sparrow, Spizelloides arborea, by Tom Benson, Nov 2018; Dark-eyed junco, Junco hyemalis, by Stan Lupo, Mat 2020; Indigo bunting, Passerina cyanea, by Mitchell McConnell, Apr 2013

Asters are sometimes referred to as a keystone species.  Keystone species can be either plants or animals that are essential to maintaining the health and functions of the entire ecosystem to which they belong.  The introduction or loss of a keystone species may significantly affect an entire ecosystem in either positive or negative ways.  Populations of other organisms may be altered, habitat changes can be observed, and biodiversity can rapidly change.  American asters, along with the other late blooming flower species, are an important food source late in the growing season for maintaining a healthy population of pollinators, migrating birds, and over-wintering wildlife.

To learn more about seasonal changes and how our native species are adapted to handle these conditions, consider a visit to the Jurica-Suchy Nature Museum or a nature center near you.

Squirrels of Illinois

Squirrels are members of the family Rodentia, along with about 40% of all mammals species including mice, rats, voles, beavers, muskrats, guinea pigs, and hamsters.  Rodents are characterized by the two front teeth on both the upper and lower jaws that grow continuously their entire lives. 

Note incisors on left strike against each other to remain sharp; Molars grow in back of mouth

Rodent dental system by V. Leche, professor Stockholm hogskola

Guinea pig incisors by Morbakka, Oct 2024

Squirrels in Illinois can be found in forested areas as well as urban communities.  They all use their long tails for balance when climbing trees or resting on branches as well as running along branches, wires, and tops of walls.  Squirrels are excellent climbers and can jump up to ten feet.  They are able to gnaw and chew through almost any non-metal material.

Grey squirrel jumping to a fence top by AJ, Nov 2017

Most species are solitary dwellers, but not territorial, able to live on their own, but in close association with other squirrels, rarely fighting for territory, food, or mates.  They breed twice each year, once in winter and once in early summer.  Two to four young are typically born and can fend for themselves after about two months.  The young will often stay with the mother until the next litter is born. 

Squirrels use tree cavities for raising young and for protection from predators, but most of the time they live in nests built of twigs and leaves high up in a tree.  Nests are normally located near readily available water.  They eat a variety of foods including nuts, berries, acorns, fruit, buds, fungi, seeds, and insects. 

Fox squirrel by Corey Seeman, Jan 2023
Fox squirrel by Corey Seeman, Jan 2020

The fox squirrel, Sciurus niger, is the largest species in Illinois at about 22″ in length and weighing up to two pounds.  Their fur is reddish-brown, with lighter shades on ears, bellies, and tail edges.  They are common in urban areas, but are often found where there are no gray squirrels.  Fox squirrels are most active in the early morning and late evening and are excellent swimmers.

Grey squirrel by Zoblinski,
Getty Images
Leucistic (white) grey squirrel
by Pete Weiler, Pexels
Melinistic (black) grey squirrel
by Tom GV, Getty Images

The Eastern gray squirrel, Sciurus carolinensis, is slightly smaller at about 18″ long and weighs about a pound.  They have short, gray fur, but are often subject to genetic variations that result in different colored fur.  Common variants in Illinois include melanistic or black squirrels, leucistic or white squirrels, and albino squirrels.  Eastern gray squirrels are abundant in urban areas and large forested tracks.  However, there are very few forests left in Illinois to support these animals.

Red squirrel by Christopher Defalco, Pexels

Red squirrels, Tamiasciurus hudsonicus, are small, about a foot long, weighing about a half pound.  They have reddish-brown backs with white bellies and a dark orange stripe down their back in summertime. Red squirrels are found only in the northeast quarter of the state in large forested areas.  They are diurnal, active in early morning and late evening.

Southern flying squirrel by EEI_Tony, Getty Images

The Southern flying squirrel, Glaucomys volans, is the smallest species at about nine inches, weighing only two ounces.  They have gray-red-brown backs with white bellies and are nocturnal, making them difficult to observe.  Flying squirrels have large eyes to see better at night and a long, flattened tail that is used as a rudder when airborne.  A flap of skin runs between the front and back legs on either side of their body and is stretched taut when their legs are spread, providing the ability to jump from a high place and glide down to a lower place.  Unlike other squirrel species, flying squirrels share a communal nest during most of the year.

Northern flying squirrel by Dopeyden, Getty Images______While this is not the species found in Illinois, flight patterns are very similar…

Squirrels play an important part in forest and urban tree regeneration.  They bury acorns and other nuts in warmer months for winter food stores, but usually bury many more than they actually consume.  The remainder are left to germinate, resulting in many new trees each year.  Squirrels are fun to observe and can provide enjoyment and an opportunity to learn about wildlife behaviors.  Come down to the Jurica-Suchy Nature Museum or a nature center near you to learn more about these amazing animals.

Pamir Wildlife

The Pamir Mountains form the western edge of the Tibetan Plateau.  A pamir is a high-altitude valley or plateau surrounded by mountains.  Many valleys in this range exceed 14,000 feet in altitude, and peaks reach well above 20,000 feet, making these some of the highest mountains on the Euroasian continent.  The area contains the major center of glaciation in this part of the world, and all of the nearby mountain ranges are still being forced upwards by movement of the Indian-Australian tectonic plate pushing northward under the continent.

Pamir Knot, Hindu Kush satellite image by Jeff Schmaltz, NASA
Pamir Mountains by Amanov Dmitry, Jun 2014

Wildlife in the Pamir region is well-adapted for high altitudes, long, cold winters, and short growing seasons.  Mountain people use the land for grazing large herds of domesticated sheep and yaks, but grazing space must also be shared with wild sheep, wild yaks, dozens of bird species, over 700,000 insect species, and many large predators.  Let’s look at a few of the more notable species.

Himalayan vulture, Gyps himalayensis, on Rupin Pass trail by SahanaM, Oct 2018
Himalayan vulture, Gyps himalayensis, by OK-Photography, Getty Images

The Himalayan vulture, Gyps himalayensis, inhabits the pamirs up to 18,000 feet.  These birds easily soar on warm thermal updrafts, but are not capable of long distance flight.  They are often found basking in the sun on high, rocky perches.  Traveling in large flocks, they follow grazing herds, keeping watch for dead animals.  They can be aggressive to most other predators at a kill site, but give way to snow leopards, wolves, and cinereous vultures.  The biggest threat to current populations is from drug overdoses of diclofenac, an anti-inflammatory drug that has been heavily used to treat injury in domesticated herds.

Herd of Marco Polo sheep in the Tien Shan mountains, by okyela, Getty Images
Marco Polo sheep, taken at Berlin Zoo by Cloudtail, Aug 2018

The Marco Polo sheep, Ovis ammon polii, is the largest sheep in the world, with large, spiral horns reaching six feet in length, with spans up to five feet across.   They feed in the early morning and spend the remainder of the day basking quietly in sunny grassland.  Their feet and hooves provide sure footing among sharp ridges and loose scree, and they spend nights sleeping among large boulders for protection.   As the climate has warmed, there has been a loss of snowpack, resulting in less available fresh water for drinking and growing thick grasslands.  These factors are driving the sheep to lower altitudes where they are more susceptible to predators including gray wolves, red fox, and brown bear.

Snow leopard, Panthera uncia, by Irbis1983
Snow leopard, Panthera uncia, by Bernard Landgraf, Jan 2005

Snow leopards, Panthera uncia, have seen a steady decline with a current population of fewer than 10,000.  Their thick fur, gray/white with black rosettes, provides great warmth in colder altitudes, but is prized by poachers, who constitute their main threat.  They are solitary animals, active for several brief periods daily, and dependent on healthy populations of ibex and sheep to eat.  Powerful legs and furred paws enable them to pursue prey, in any weather, across rocky mountain terrain.  After making a kill, they move the carcass to a protected area to eat.  At one time, these predators were hardly ever seen, but overgrazing has caused humans to move domesticated animals into areas where snow leopards normally hunt, providing more opportunities for these predators to be killed by protective herdsmen.

Wild yak, Bos mutus, by Adarsh Thakuri, Jun 2008
Wild yak, Bos mutus, by the Editors of Encyclopedia Britannica

Wild yak, Bos mutus, can live in extreme conditions at altitudes up to 20,000 feet.  They are large animals standing 6′ tall, weighing 1500 pounds, with black horns spanning six feet.  Black, long, fine hair hangs all the way down to their feet, providing warmth for the body and legs.  Yaks are very social, forming large herds of several hundred animals.  They graze in two groups, with the females typically found about 300′ higher in altitude than the males.  Females with young often keep to high, steep slopes where predators, including wolves and bears, are less prone to roam.  Wild yaks readily hybridized with domesticated species, resulting in a natural spread of the gene pool.

Apollo swallowtail butterfly, Parnassius apollo, by Hectonichus, 2007
Clouded Apollo swallowtail butterfly, Parnassius apollo, by Zeynel Cebeci, Adana Turkey, May 2016

Butterflies are another common inhabitant of high-altitude mountain regions, particularly from the genus Parnassius, known as the snow Apollo swallowtail family.  They are color adapted with dark bodies and wing bases that readily absorb heat from the sun providing a source of quick energy.  Their normal ranges are found above 14,000 feet, and they are active for only 2-3 months annually, during the short summer season.  Dozens of species have been identified with many having very small populations, numbering only a few hundred individuals.  Poaching for collectors remains their main threat.

At the Jurica-Suchy Nature Museum, we have many of these and other species on display in our mountain region diorama.  Consider a visit to learn more about the wildlife of high-mountain plateaus worldwide.

High-altitude species from around the world on display at the Jurica-Suchy Nature Museum include: Marco Polo argali sheep, Alaskan brown bear, bighorn sheep varieties, mountain goat.

Bearing Up In Winter

American black bears, Ursus americanus, live in several habitats in North America including forests, beaches, and  alpine regions.  However, their diet, home range, and sleeping pattern are unique to each individual bear.  Winter behavior is determined by temperature and available food in their immediate area.

Black bear on the shoreline on Vancouver Island, BC by Miharing, Getty Images Signature
Black bear in first snow by KenCanning, Getty Images Signature

Bears are omnivores, eating a variety of plants, insects, fish, small animals, carrion, and human garbage.  In colder months, the lack of readily available food and falling temperatures drive bears into dens to hibernate until warmer temperatures return.  Typical den sites include hollow logs, under tree root masses, and rocky crevices or caves.  Black bears, especially in areas of the Smoky Mountains where extreme temperature drops do not occur, will make dens in tree cavities high off the ground.  Bears are not true hibernators and may be awake or even leave the den on days with warmer temperatures.

Black bear in rock crevice den by
Nastasic, Getty Images Signature
Black bear den under root mass by
Blazer76, Getty Images

Once they move into a den, bears can lower their body temperature by eight to twelve degrees and burn body fat to satisfy all of their energy requirements.  They do not eat, drink, urinate, or defecate while in the den, although they do wake occasionally to shift their resting position.   Bears remain in hibernation while cold temperatures persist.  In Alaska’s interior, this may be up to seven months, while in southern and coastal areas hibernation might last only two to three months.  In late summer and fall, bears eat 50 to 80 pounds of food and add three to six pounds of fat each day in preparation for winter.

Black bears are solitary animals, coming together only in summer to mate, a bi-annual activity for adult females.  Females are able to delay implantation of the fertilized eggs until after they are in the den for the winter.  Cubs are born after eight weeks, in mid-winter.  They weigh less than half-a-pound and are hairless and helpless.  An average litter of one to three cubs will nurse from their mother for three to six months and will be nearly five pounds each as they emerge from the den in late spring.  Cubs stay with mom for about 18 months, learning to fend for themselves, and will reach an average of 80 pounds by the end of their first year.

Black bear den with female and nursing cubs by National Park Service

Unless the bear is a pregnant female or the weather conditions are extreme, if there is food available, there is no need to hibernate.  Zoo bears historically do not hibernate.  However, many zoos are changing their practices by reducing meal sizes so their bears do enter hibernation for short periods.  Studies show that this leads to fewer problems with overweight bears, and allows pregnant females the quiet time needed for cubs to develop naturally.

Black bear cubs in spring in Glacier Bay National Park by National Park Service
Black bear female nursing cubs by Alan D Wilson, 2010

Scientists are studying several health issues important to both bears and humans.  Bears lose about 25% of their muscle mass during an extended hibernation, but emerge from the den with strong bones and good physical abilities.  As humans become less active due to aging or other circumstances, they lose almost 60% of muscle and bone mass in the same period.  Loss of bone mass, termed osteoporosis, accounts for over half of the bone fractures in adults over fifty years of age.  Studies on how bears conserve and reuse proteins during hibernation, and use fat for energy, may provide insights into helping people to maintain their strength and health as they age or become less active.

At the Jurica-Suchy Nature Museum, you can learn more about black bears, grizzly bears, and polar bears.

Baleen Whales

There are over 90 species of whales roaming every ocean habitat.  There are two broad classifications of whales, baleen whales and toothed whales.  Baleen whales lack teeth.  When they open their mouths, a membrane made of keratin, called baleen, stretches from the upper to the lower jaw.  This allows water to flow through its porous structure while trapping fish and zooplankton, small sea creatures, by the mouthful.  Toothed whales have actual teeth and they hunt fish, squid, and other animals of the sea.

Clockwise above- Baleen by Paigefalk, Getty Images Signature; Humpback whale (baleen) by Craig Lambert, Getty Images; Orca whale (toothed) by Schmid-Reportagen, Pixabay

There are 15 species of baleen whales compared to 77 species of toothed whales.  Baleen whales are generally larger, with the blue whale being the largest whale in our oceans.  Most baleen whales are migratory, moving between cold, polar waters that support large populations of prey and warmer waters that they use for breeding.  While warm water environments support less prey, they have fewer predators and other risks, allowing newborn youngsters to grow and learn to defend themselves before migrating back to richer feeding grounds.

Humpback mother & calf by Lauren Baer, Getty Images

Consider the Sei whale, one species of baleen whale from the Rorqual family that is known for their slender, pointed heads and fins.  They are one of the smallest baleen whales, growing to about 40′ in length as an adult.  Exact population numbers are not known, but it is estimated there are about 60,000 Sei whales worldwide.  Each Sei whale eats about one ton (2,000 pounds) of food each day, including krill, fish, and squid.  One ton holds close to a half million krill, a small crustacean weighing about 2 grams.  The entire population of Sei whales alone is consuming roughly 20 billion krill or other small fish each day!

Group of Antarctic krill by Noyan Yilmaz
Baleen whale eating by Julian Allchin, Getty Images

Whales, hummingbirds, humans, frogs, and rabbits are all tetrapods, animals whose ancestors had legs.  Nearly all of the bones in one species can be found in each of the others, a condition called homology.  This is the result of divergent evolution where organisms from the same common ancestor evolve and accumulate differences, often resulting in an entirely new species. These differences are selected based on both biotic and abiotic factors in the habitat.  Whales have the same shoulder-arm-hand structure inside their side fins as a human arm.  While our hands and arms let us reach, grasp, and throw an object in the air, a whale’s fin delivers a powerful push through the water they live in.

Whale fin to human arm bone structure homology by DonArnold, 2024

Humpback pushing with fin by Yann-Hubert, Getty Images Pro; Human arm throwing a ball by South Agency, Getty Images Signature

At the Jurica-Suchy Nature Museum, you can observe and learn more about homologous structure from our Sei whale / human arm skeleton comparison.  Plus we have more to show you concerning whales and other marine species from around the world.  Read more about whales on the following sites:

Autumn Foods

Meteorological fall began September 1st, marking the beginning of cooling temperatures that lead into winter, the coldest time of the year in the northern hemisphere.  As the days begin to cool, many plant species are producing ripe fruits and seeds and starting the process of going dormant until next spring’s warming temperatures and longer days signal a beginning of the next growing cycle.  Some animals, especially birds, travel long distances, migrating to areas that stay warm throughout the year.  Those who stay through the coldest months depend on having food sources available even while plants are dormant.

Grey-headed coneflower seed head by Laura Fischer Photography

The best winter food sources for wildlife are native plants with berries and seeds available throughout the colder months.  Birds including woodpeckers, robins, waxwings, bluebirds, thrushes, chickadees, quail, and thrashers rely on robust insect populations in summer.  In winter, when insects are no longer available, having another food source such as seed heads and berries left standing in your garden fulfills this need while adding visual interest and wildlife watching opportunities for you.

Food items shown above: Acorns on forest floor by Liz West, Oct 2006; Shellbark hickory nuts by HeikeRau, Getty Images; Pine cones with seeds by GordonImages, Getty Images

Several tree families including pine, hickory, oak, and cherry offer fruit and nuts lasting through the winter.  Along with grass and wildflower stems, trunks and branches also provide habitat for insect eggs and larva that will emerge in the spring.  Over winter, insects in these stages are available as food for foraging species that use beaks and claws to dig them out.  Stems growing close together provide additional benefits as thickets that provide protection against cold winds and harsh weather and hiding places that are safe from other predators.

Berries & Seeds above: Aster seeds by David Hansche, Getty Images; Sunflower at sunset by Hazal Ak, Getty Images; Wild elderberries by StargateChris, Getty Images; Thistle seeds by JTCanada, Getty Images

Sunflowers, elderberries, and serviceberries are important food sources for fall migrators and winter inhabitants, providing fat and energy to stay warm and active.  Aster, thistle, and conifer seeds released throughout the colder months are a favorite food source for finches and other small perching birds.  Oak acorns, beechnuts, and hickory nuts are eaten by many woodland animals including squirrel, chipmunk, deer, wild turkey, fox, and quail.

Wildlife enjoying an offering: Blue tit on suet by Hedera.Baltica, Dec 2022; Lunch by Audrey, Feb 2008; Pine siskins on thistle by Yooperann, May 2015; Purple finches by Stan Lupo, Oct 2016

Some of these animals also forage through our backyards in winter as many berry producing plants in the wild are stripped bare during late autumn and early winter.  Backyard plantings and feeders provide important supplementary food sources for these animals.  A variety of species to consider planting include American persimmon, blackberry, blueberry, elderberry, raspberry, cranberry, paw-paw , and prickly pear cactus, holly, sumac, hackberry, viburnum, hawthorn, bayberry, red cedar, and juniper.  You can learn more under Garden For Wildlife on the National Wildlife Federation website at https://www.nwf.org/Garden-for-Wildlife/Food.

Nature journaling is a great way to track your observations and learn more through later research

Opportunities to observe wildlife in your own backyard can be an exciting way to learn.  Try tracking which plants are being eaten and at what times during the changing seasons.  Record the weather conditions during those periods to learn what foods are relied upon during colder, harsher winter weather.  Try a variety of suet, seed and nut varieties in feeders to attract a range of animals to your backyard for fun wildlife watching and education.

Hummingbirds

It is getting to the end of summer, and many bird species that winter in Central and South America will soon be starting their migrations.  Of the 320 species of hummingbirds, 15 spend the summer breeding in North America, from the Gulf Coast states to southern Canada, before returning to winter habitat farther south.  Only one species, the Ruby-Throated Hummingbird, Archilochus colubris, breeds east of the Mississippi River. 

Hummingbirds have a very high metabolism with a normal heart rate of 250 beats per minute that accelerates to almost 1250 beats per minute when in flight.  They consume large amounts of nectar each day to get enough sugar to support their energy requirements.  Several small grooves running the length of their tongue funnel nectar into their throat by capillary action, a force that causes liquid to rise in a small tube without needing to use air to suck the liquid in.  They also eat any small invertebrate to fulfill protein, vitamin, and mineral needs.  Hummingbirds snatch insects mid-air while in flight, poach them from spider webs, and glean tiny moth caterpillars from new leaves and branch tips.  Another foraging method uses the blast of air beneath their powerful wings to roll over leaves on the forest floor, revealing the insect life below.

Anna’s hummingbird catching insects by Stan Lupo, Jul 2023

Hummingbirds do not bond with a mate.  Females establish a territory that optimizes the available nectar and offers multiple nest sites.  Males establish a territory based on encountering as many females as possible.  Both will defend their areas from other hummingbirds, as well as other nectar feeders including butterflies and bees.  Daily feeding starts on the outer edge of their territory to chase out any overnight interlopers and ends with nectar sources deep inside the area’s interior.  Males will breed with as many females as possible.  Females may have more than one brood of eggs each year, either concurrently or one brood following another.

Nests are about 2″ in diameter, built of small twigs, lined with soft plant material, and covered on the outside with greenish-gray lichens.  Nests are bound to branches with spider silk, usually in a forest clearing.  The lichens provide camouflage by making the nest appear as a large knot when seen from below.  Females reach breeding age at the end of their first year, and can breed throughout their lifetimes.  They construct one or more nests, each containing two white eggs, the size of peas, which are incubated by only the female for 14 to 16 days.  The male takes no part in raising the young birds, coming together with the female only during mating. 

Allen’s Hummingbird nest, by Mike’s Birds, Mar 2013
Ruby-throated hummingbird on nest with lichen, by Lorie Shaull, Jul 2020

Hummingbirds found in the western portions of North America travel overland migration routes.  However, midwestern and eastern birds fly non-stop over the Gulf Of Mexico.  A hummingbird can increase its fat reserves and double its body weight in the 7 to 10 days prior to the overseas trip.  Through studies using banded birds, we have learned that they fly alone, normally at night, along with large flocks of other birds.  Young birds, making the trip for the first time, can successfully navigate the migration route with no prior training.  Their guidance system, how it works, and how it is learned are all still a mystery.

No hummingbird species are listed as endangered.  However, hybridization among species is common, and their small size and great speed make them very difficult to count and track.  Little data is available about population size changes and movements; however, more birds have been found over-wintering as far north as the Gulf Coast states of North America.

At the Jurica-Suchy Nature Museum, we have numerous bird specimens on display, including hummingbirds.  We welcome you to come in and learn more about these amazing creatures.

Oak Tree Habitat, pt.3

In the past couple of blogs, we learned that oak trees are a keystone species in their habitat, especially for the vast network of relationships between oaks and insects.

Ladybug on oak tree leaf by EMFA16, Getty Images
Leaf litter and under-bark room for rent, by Wayne S. Grazio, Nov 2013
Insect holes & homes on cork oak, Quercus suber, by Bloor4ik, Getty Images

Oak trees and their surroundings provide shelter and food from leaves, wood, bark, sap, flowers, pollen, and acorns to thousands of species of insects and other invertebrates.  Shelter is provided on the tree, inside cavities or other fissures, among the leaf litter, and around the root systems.  As oaks age, there are more opportunities for shelter and food, including after branches or the whole tree dies and falls to decay on the forest floor.

Chickadee nest by Jack VandenHeuval, Getty Images
Chickadee eating a caterpillar by Bettina Arrigoni, May 2018

Over 900 caterpillar species have been identified in oak habitats, more than three times the number found in forests dominated by maple trees.  Canopy leaves and branches provide shelter and nesting opportunities for dozens of bird species who find a ready source of food within the insect populations.  Ninety percent of bird species feed insects, especially caterpillars, to their young.  The Carolina Chickadee feeds four to six chicks for 16 days before they fledge.  Mealtimes require 400 to 500 caterpillars each day. 

Aphids and ants by oday222, Getty Images Pro
Philodromus praedatus spiders live mainly in mature oak trees, by Nikk, May 2016
Oak gall by Michael Boubin, Getty Images

Several species of flies and wasps lay their eggs on oak trees, stimulating a growth hormone in the tree to grow a gall, an outgrowth of bark, around the eggs.  When the larvae hatch, secretions from the gall feed the larvae, and the gall provides protection to the developing insects.  The abundance of insects attracts other invertebrates from higher up on the food chain.  Spiders frequently inhabit mature oak trees hunting and feeding on many of the insect species.  Aphid colonies are often found on oak trees, but cause little damage to the tree.  Aphids feed on the sap from the tree and secrete a sticky, sugary substance called honeydew, a favorite food for ants.  The ants protect the aphid colonies, keeping them underground during inclement weather and herding them up the tree in summer to ensure the aphids are well fed to keep producing more honeydew.

Fall webworm, Hyphantria cunea, by Anita Gould, Sep 2015; Polyphemus moth caterpillar, Antheraea polyphemus, by Ed Uthman, Sec 2018; Speckled wood caterpillar, Pararge aegeria, by Dean Morley, May 2013; Linden looper caterpillar, Erannis tillaria, by sankax, Jun 2009

Insects and oak trees have created an environment rich in food for many of its inhabitants.  According to Doug Tallamy, a leading entomologist at the University of Delaware, “caterpillars transfer more energy from plants to other animals than any other type of creature.”  The loss of habitat for insects puts considerable strain on all other environments, including ones supporting ourselves.  Insects do most of the work of pollination, allowing plants to reproduce.  They also provide for quick decomposition and the return of nutrients to the soil for growing new plants.  Insects are a driving force of the world’s food webs and are necessary for a healthy environment.

Morning in an oak forest by Slatan

There are over 400 species of oaks worldwide, with about one quarter found in North America.  As we have briefly touched upon in this series of blogs, oak trees provide opportunities for healthy habitats for many other species.  For information and further discussion on the relationships between caterpillars and oak trees, please see The Nature Of Oaks, by Doug Tallamy.

Oak Tree Habitat, pt.2

In the last blog, we discussed oak trees as a keystone species, substantially affecting the types and abundance of other species in their habitat.  There are 400-500 species of oaks worldwide, supporting an extraordinary 2,300 wildlife species not including fungi, bacteria, and other microorganisms.  Oak trees in all stages of life and death have numerous biotic relationships with wildlife.

Badger in tree cavity by Byrdyak, Getty Images||Golden millipede in Lagos by efeghali, Getty Images||Neanura springtail by Henrik_L, Getty Images||Pileated woodpecker in oak tree by mtruchon, Getty Images||Slug & rollie pollies by Sonya Kate Wilson, Getty Images||Wood Mouse in tree cavity by byjohn, Getty Images

Fungi are often identified as attacking oak trees, but they can have very beneficial relationships.  Fungi growing in the ground assist an oak tree in getting nitrogen, phosphorous, and other nutrients out of the soil, and in return get carbon and energy from the sugars in the tree’s sap.  Oaks provide a place to live for over 700 species of lichens, plus uncounted liverworts and mosses.  Lichens covering the oak’s surface help to keep them free of fungal infections and invasive insects.  Liverworts and mosses help oaks to retain water and release it into the soil over a long period of time.  As oak limbs fall and decay, water retention softens the wood providing food and habitat for decomposers.

Green moss on oak tree by tntemerson, Getty Images
Fungi on oak tree stump by Rixie
Lichen & peat moss on oak by Sean Gardner, Getty Images

Fallen oak leaves are slow to decompose due to their tannin and lignin content, both preservative compounds.  Leaf litter, composed of several layers of fallen leaves, becomes habitat for many millions of species including millipedes, springtails, woodlice, slugs, beetles, ants, and other organisms that feed on decaying plants.  Through their activities, the creatures of the leaf litter help to return nutrients to the trees.

Oak forest leaf litter by Tina_C_Olsen, Getty Images

Acorns, with high amounts of fats, proteins, and carbohydrates, are one of the healthiest and most sought after foods in the woodland.  White oaks, living between 200 and 300 years, will produce about 3 million acorns during their lifetime.  Many bird species eat acorns, but oak trees enjoy a special relationship with blue jays, whose beaks are strong enough to pry an acorn open.  In autumn, blue jays enjoy feeding on acorns, but also cache them for winter, burying several at a time under a few inches of soil in various locations up to a mile from the originating tree.  Although blue jays cache large quantities of acorns, they can only remember and retrieve about 25% of them, allowing many new oak trees to grow and spread into new areas.

Blue jay with red oak acorn by mirceaux, Getty Images

Oak trees support 31 mammal species who consume acorns for food, use the tree for shelter, or use the surrounding habitat for hunting.  Gray squirrels and red squirrels favor acorns in the autumn and throughout the winter from caches hidden in nearby locations.  They remember far more cache locations than blue jays, but there are still uneaten acorns that will germinate in spring to start new trees.  Acorns are also a favorite food for badger, deer, wild board, and wood mouse. 

Gray squirrel eating acorn by viktor2013, Getty Images
Red squirrel with acorn by Neil_Burton, Getty Images

Oak trees offer shelter for many species.  Squirrels often build their nests high up among the leaves that provide protection from weather and predators.  Dead branches, especially those with cavities, may remain on the tree for many years, providing excellent roost sites for bats.  Open limbs, leafed areas, and cavities all provide nest sites for a variety of birds.  In addition, the many insects drawn to oak trees provide a ready source of food for all of these nesters.  Humans have been acorn consumers for millennia.  Raw acorns, high in tannin content, can be toxic in larger quantities; but, properly prepared, acorns are high in calories, vitamin C, starch, magnesium, calcium, phosphorous, and antioxidants.  They have been a food staple in many cultures and can be found in the records of ancient Greeks, Iberians, Japanese, and English.

Oak trees have many direct and indirect relationships with insects, which we will explore in the next blog.

Oak Forest by warmcolors, Getty Images

Oak Tree Habitat, pt.1

Oak trees, genus Quercus, have over 400 species worldwide, but almost one-third are threatened with extinction.  They are a keystone species, playing a central role in supporting the entire habitat in which they live.  They maintain the structure and stability within their ecosystem, substantially affecting the types and abundance of other species.  Oaks make up only 2% of plant species, but they directly support more than 30% of all plants and animals.

A great oak in Nottingham Forest by Peter Shaw, Getty Images

Oak trees live from a few decades to several centuries.  The Great Oak, Quercus agrifola, a species of Coast Live oak in California, is estimated to be over 2,000 years old.  Oaks clean the air by absorbing pollution and sequestering carbon.  They provide shelter, food, shade, and help to reduce erosion.  Humans get food from the acorns, dyes from the tannin, and wood for construction, ships, and barrels, plus cork for stoppers and oak chips for smoking meat, fish, and cheese.

Red oak with new leaves, Quercus rubra, by aleroy4, Getty Images
Oak forest leaf litter in winter by Whiteway, Getty Images Signature

In spring, tender new leaves containing fresh sap are consumed by a variety of insects.  In fall, older leaves will fall to the ground, but are slow to decompose, building up many layers of leaves over time which provide shelter for small woodland ground dwellers and food for decomposers. 

Branches of red oak with catkins, Quercus rubra,
by anmbph, Getty Images
Texas Red Oak female flowers, Quercus buckleyi by Doug Goldman, USDA-NRCS National Plants Data Team

Oak trees have both male and female flowers.  Male flowers grow in early spring in long clusters hanging from tree limbs.  The pollen is a favorite food for a large variety of insects, especially bees.  Pollen is released slowly, over several weeks, to be blown by the wind to the female flowers, which appear as tiny, red flowers near the tips of twigs and new shoots.  Female flowers are eaten by insects and are a favorite of red and gray squirrels.  Oak flowers are one of the earliest food sources for animals in spring, and must be abundant on every tree so that some are able to survive to produce acorns, the seeds of the oak tree.

Bur Oak acorns, Quercus macrocarpa; Northern Red Oak acorns, Quercus rubra; Live Oak acorns, Quercus virginiana by Steve Hurst, ARS Systematic Botany and Mycology Laboratory, USDA-NRCS PLANTS Database;

In late summer, after pollination, the female flower will produce a large, green nut called an acorn, which will mature in autumn, turn brown, and fall from the tree.  Acorns are a nutritious food source for many animals, being high in energy, carbohydrates, and fat.  In the eastern U.S., many species are dependent on acorn production, and the amount of available acorns significantly influences population sizes.  Some acorns will find suitable ground for sending out a root and starting a new tree, but most will be eaten.  Masting, an over-abundance of acorns, occurs every few years.  It is thought that masting creates a better chance for new oak trees to grow by overwhelming the animal populations’ need for food.  As a secondary result, animal populations may expand immediately following a mast year, only to have higher than normal mortality when food resources return to normal for the following years.

Bur Oak bark, Quercus macrocarpa by Herman, D.E., ND State Soil Conservation Committee, USDA-NRCS PLANTS Database
Dead oak log in Bialowieza Forest by Nirian, Getty Images Signature

Oak roots grow close to the ground’s surface and extend well beyond the circumference of the tree’s crown.  A complex network of fungi live on the roots and provide additional nutrients to the tree, keeping both species healthy.  As the trees grow and age, roots and bark develop crevices and holes in their surfaces, or chunks may become loose, providing niches for plants and animals to shelter and grow.  Exposed wood gradually dies and decays providing even more habitat and food for decomposers and the other wildlife that live on them. 

In our next post, we will take a look at some of the many species that oak trees directly and indirectly support with shelter, food, and breeding opportunities.

The Woodlands at the Turning, an Illinois oak savannah, by Justin Kern, Nov 4, 2013

Cicadas

Cicadas are found in habitats with deciduous trees on every continent except Antarctica.  There are about 3,000 species worldwide; and 170 make their home in North America, including several species divided into three groups with 13-year or 17-year life cycles, found exclusively in the eastern and central United States.  The map below shows where various groups are located. 

USDA Forest Service brood map of all periodical cicadas

Cicadas hatch from eggs laid in tree branches.  After dropping to the ground and burrowing into the soil, they spend the majority of their lives as a nymph living underground.  Using their rostrum, a long, sharp rigid structure that can penetrate the outer layer of tree branches and roots, they feed on the sugar and water flowing through the xylem tissue of the tree.  Species classified as annual cicadas actually live from one to nine years, some emerging each summer.  They are active for four to six weeks to mate, lay eggs, and then they die.

Look closely to see the rostrum sticking out in front of the nose

Magicicada after emerging from final molt by Karly Tuminello

Cicadas have wide set eyes, short antennae, and large, clear wings with membranes clearly visible.  The surfaces of their outer wings are covered by small, blunt, waxy spikes.  They are water repellant, keeping the insect dry.  These spikes can also break up and kill any potentially harmful bacteria landing on the surface.

Magicicada species showing short antennae & clear wings by Karly Tuminello

Beneath the wings are muscular structures called tymbals which can be flexed creating a sound like banging a drum.  The buzzing sound commonly associated with cicadas is a result of rapidly flexing these muscles.  Tymbals are found on both sexes, and are used to hear sound as well as produce sound.  Males often form large groupings to enhance their sound and attract more females to a single location. 

Magicicada waiting for wings to harden after molting by Karly Tuminella

Nymphs start to emerge when underground soil temperatures are above 64⁰F, usually in late May in the northern hemisphere.  Males emerge about two weeks before females.  After emerging, the nymph will find a suitable perch and molt to reveal a fully winged adult; then spend from one to six days waiting for their wings to harden.  Males fly up into nearby deciduous trees to find a suitable mating perch and begin calling to attract a female, which will join the male after her molt is complete.  After mating, the female lays about 600 eggs.  She cuts 25 to 30 small slits in branches and deposits about 20 eggs in each where they will remain for six to ten weeks before hatching.  Both sexes may mate several times with different partners, although most only mate once.

Cicada’s mouth parts are strong enough to pierce tree bark, but they do not bite or sting, although they may pierce human skin if handled roughly.  They do not pose any danger to humans and have not been known to carry any harmful disease.  They feed on sap, not foliage, so they pose no threat to mature trees.  Younger or smaller trees with only a few branches may be overwhelmed by the many slits made by a female laying a full brood of eggs.  Lots of slits may cause scarring that could kill smaller branches.

Empty cicada husks provide food for many species by Karly Tuminello

Cicadas and their empty husks do provide food for many predators including birds, fish, mammals, herps, and other insects.  The emergence of the periodical cicadas will provide a feast for their predators, whose populations will boom next year before being reduced by less available food over the following several years.  One theory for why there are periodical species concludes that cicadas emerging in mass numbers can overwhelm the predators need for food, allowing a great number of cicadas to breed and maintain their own high population.  Other theories also exist to explain this natural phenomenon, but whatever the reason, they are harmless insects with a very interesting life cycle for us to observe this year.

Rodents

Rodentia are the largest order of mammals in the world, encompassing over 40% of mammal species.  A rodent is characterized by having two pairs of large front teeth, one pair in each of the upper and lower jaws.  These are called incisors and are used for gnawing vegetation.  They have no canine teeth, leaving a large gap between the four front teeth and their molars in the back of the mouth.  Rodents can be found in all types of habitat everywhere in the world except Antarctica, New Zealand and a few oceanic islands.

Capybara, Hydrochoerus hydrochaeris, use calls to warn others of danger and to find their young including purring, barking, cackling, whistling, whining, grunting, and chattering.

Capybara by Dick Culbert, Gibsons, B.C. Canada, May 2014

The largest rodent is the capybara, Hydrochoerus hydrochaeris, growing up to 140 pounds.  But a majority of species are small animals, under 4 ounces, with bulky bodies, short limbs, and long tails.  Compared to their overall size, the body’s surface area is large and contributes to a greater loss of heat than larger animals.  To combat this, rodents create more body heat by being constantly active.  They consume large quantities of food to meet high energy needs.  Many species are active year-round, coming out during early morning and late evening hours to feed.  Animals living in habitats with extreme temperatures may hibernate to escape the cold or estivate to escape the heat.  These species conserve energy by adjusting their body temperatures to within a few degrees of the air temperature and slow other bodily functions, requiring less food and more rest.

Beaver skull by Don Arnold, Apr 2023

North American beaver, Castor canadensis, hone their upper teeth into efficient biting tools and defensive weaponry.

North American beaver, Castor canadensis, by Steve, Washington D.C., Jul 2008

Incisors grow constantly their entire lives.  The front surface is protected by a hard enamel shell.  The back surface of the upper pair is soft and easily wears away from the constant rubbing of the lower teeth as vegetation is bitten off and chewed.  This creates a chisel like edge on the top teeth that is an excellent cutting surface.  Teeth are used to gnaw vegetation, dig burrows, and for defense, if attacked.  If an animal does not gnaw enough vegetation, the growth rate of the teeth becomes greater than what is being worn away and health problems can develop leading to the inability to eat.  This most often occurs in captive animals who are not provided with sufficient quantities of harder vegetation.

Fox squirrels, Sciurus niger, scamper up tree trunks, along branches, and are able to leap to nearby trees, in addition to being fast on the ground and good swimmers.

Fox squirrel, Sciurus niger, by Karly Tuminello, Jul 2020

Food is mainly seeds, leaves, fruit and small invertebrates or insects.  A internal structure called a caecum contains bacteria that assists in breaking down plant material into digestible form.  Several rodents have eyes that protrude in a half dome from their head allowing them to see both ahead and behind.  This wide field of vision allows the animal to easily detect predators.  Their daytime eyesight is poor, but they can detect ultra-violet light, allowing excellent vision during twilight hours when they are most often active.  Most rodents live in large social groups, but forage individually, using a wide variety of alarm calls to keep others informed when danger is near.

Naked mole-rats, Heterocephalus glaber, have strong jaws that use one-quarter of all the muscle tissue in their body.

Naked mole-rats, Heterocephalus glaber, by Roman Klementschitz, Wien, Dec 2003

Humans often consider rodent species to be harmful pests.  While they may carry bacteria and cause nuisance problems, they are also beneficial by eating weed seeds and insects, keeping populations of many pest species in check.  Rodents are widely used in human culture as food, clothing, pets, and laboratory animals for research.  Visit a museum or nature center to learn about the many fun facts of each family in this amazing group of animals.

Kangaroo rats, Dipodomys sp, hop to move around but can jump 6 to 9 feet, and they get all their water from the seeds they eat.

Kangaroo rat, Dipodomys, by U.S. Fish & Wildlife, Sep 2005

Extinct & Endangered – pt.3

An endangered species is one that is likely to become extinct in the near future, either worldwide or locally in a known range.  In some instances, these species may be saved through habitat conservation, breeding assistance, and education.  This final installment on Extinct & Endangered will take a look at three species in North America that have benefited greatly from such efforts.

The Gila Monster, Heloderma suspectum, is the only venomous lizard native to the United States and is listed as near threatened.  Their ranges are quite small, covering 700 to 3000 square feet.  They spend most of their lives in underground burrows, and they are only regularly outside for a couple of hours each day during their mating season, from March to May.  Gila monsters hunt small animals, and prey is eaten alive, head first.  Venom is delivered through their saliva as the prey is chewed and acts to slow the prey’s reactions.  While venom is not deadly to humans, it can cause swelling and severe pain. 

Gila Monster, Heloderma suspectum by Erin Donalson, Getty Images
Gila Monster, Heloderma suspectum by Shoemcfly, Getty Images

Gila monsters pose no direct threat to humans, usually living in remote areas, but still have a fearsome reputation that contributes to illegal hunting of the species.  They were the first venomous animal in the United States to get legal protection from being collected, killed, or sold.  As development threatens areas where the Gila monster is found, conservationists are moving populations to preserves where there is minimal interactions with humans.  Breeding numbers in the wild are still robust, although captive breeding efforts have been started in zoos across North America.  Education and preservation of appropriate habitat has so far kept this species off the endangered lists.

The black-footed ferret, Mustela nigripes, is listed as endangered, but increasing in population.  Their native range includes southern Canada and the northern United States, but habitat loss and disease have reduced populations to only a few hundred.  They are a playful member of the weasel family, using several vocalizations for communication including barks, chattering, and chuckling.  They are nocturnal and rarely seen in the daytime.  Prairie dogs, hunted in underground burrows at night, are their exclusive food source.

Black-footed ferret, Mustela nigripes, portrait by Delecrouix, Getty Images Pro
Black-footed ferret, Mustela nigripes, at prairie dog burrow by kahj19, Getty Images

The species was declared extinct in the late 1960s until a dozen individuals were found in Wyoming in the early 1980s.  Deliberate extermination of prairie dog colonies, because they are considered a nuisance species, has had a significant impact on black-footed ferret populations.  Habitat protection and captive breeding programs have been successful at boosting population numbers.  There are now about 300 black-footed ferrets living in Wyoming and other sites in the north central and southwestern United States where individuals have been released.  Habitat loss and disease are still constant threats, and scientists estimate that about 3,000 individuals will be required to save the species from extinction.

The California Condor, Gymnogyps californianus, the largest bird in North America, formerly nested in caves in high cliff faces along the southern California coast until real estate development claimed all of their habitat.  In the 1980s, as the last 34 birds were captured, the species was declared extinct in the wild. 

California Condor, Gymnogyps californianus, tagged, in flight by OldFulica, Getty Images

Condors are slow flyers, soaring in great circles, searching for carcasses of dead animals to eat.  They eat until they are full, and can go about two weeks between meals.  Juveniles may take several months to learn to fly and land gracefully, without crashing.  Condors reach reproductive maturity at four to six years of age, and can live over fifty years.  After mating, females lay only one egg, and mating may not take place every year.

California Condor, Gymnogyps californianus, Grand Canyon by Blewulis, Getty Images Pro

Even with slow reproduction rates, efforts to expand the population by hand-rearing and re-introduction to unaffected habitat have resulted in close to 450 birds back in the wild in California, Utah, Arizona, and the Baja.  Still listed as an endangered species, the California condor is making great progress in rebuilding its population.

California Condor, Gymnogyps californianus by DonArnold, Mar 2024
Introduction to Extinct & Endangered at Jurica-Suchy Nature Museum by DonArnold, Mar 2024

Extinct and endangered species can be found in every habitat and location worldwide.  Many are being helped by direct action with hand-rearing and habitat protection.  Indirect action through new laws, conservation support, and education has also had a positive effect.  Many of these species are on display at various nature museums including the Jurica-Suchy Nature Museum.  Plan a visit soon to learn more.

Sea Turtles

Sea turtles live in every ocean environment around the world, nesting on tropical and subtropical beaches, and migrating long distances.  They spend their entire lives at sea except when females come ashore to lay their eggs.  They have been on earth for over 100 million years, surviving the period when most dinosaurs and other reptiles died out 65 million years ago.

Coral reef & hawksbill sea turtle by jakubgojda, Indian Ocean, Maldives

Sea turtles are large, air-breathing reptiles with upper (carapace) and lower (plastron) shells.  Six of the seven species are covered by hard scales called scutes.  Although none have teeth, jaws are suited to each species specific diet.  Sea turtles do not have ears, but there are eardrum openings covered by a flap of skin.  Their sense of smell is excellent as is their underwater vision, although they are nearsighted when out of the water.  Along with a streamlined body, they possess powerful legs and claws for swimming, diving, and catching food.

Green turtle eating seagrass by LauraDin, Getty Images
Green sea turtles, Chelonia mydas, on coral reef by Artush, Alam, Egypt

Sea turtles, along with manatees, are excellent caretakers of seagrass beds and coral reefs, habitats that are vital to the reproduction of fish, shellfish, and crustaceans.  Seagrass, one of their favorite foods, grows faster and stronger with daily trimming from turtle munching.  Coral beds, vulnerable to collapse and suffocation under mass quantities of sponges and small crustaceans, benefit from sea turtles that eat several hundred of these animals each day.

Olive ridley digging egg chamber by JHVEPhoto, Getty Images, Costa Rica
Green sea turtle hatchlings by Penny Britt, Getty Images

After reaching sexual maturity, which takes from 15 to 50 years, depending on the species, female sea turtles return every two to five years to the beach where they were born to lay their eggs.  On average, they dig three to seven nests and place about 100 eggs in each.  Baby sea turtles break out of their egg and instinctively flee for the lighter colored horizon where the ocean meets the beach.  They spend several years in the open ocean feeding and growing before venturing into shallower waters to eat, mate, and reproduce.  Only about one in a thousand babies will grow to be an adult.  Most are prey for birds, crabs and fish, but many are killed by humans for food, medicines, and religious ceremonies.  Nesting site habitat destruction and turtles caught as part of the fishing industry also play a part in population decline.

Females lay all of their eggs on land, but nesting sites and the best feeding sites may be thousands of miles apart.  Sea turtles are found throughout the world’s oceans following concentrations of jellyfish, sponges, and crustaceans found in coral reefs and seagrass beds.  Leatherback females have been tracked making migrations of over 12,000 miles between nest sites and the best annual feeding grounds during non-breeding seasons.

Read facts on each species in the sidebar, shown below.  Come to the Jurica-Suchy Nature Museum where we have loggerhead, hawksbill, and green sea turtles on display to learn more about these creatures and their hidden realms.


Sea turtle species…

There are seven species of sea turtles in the world.  All are experiencing dwindling populations from various threats.  Two are critically endangered: the hawksbill sea turtle and the Kemp’s ridley sea turtle.  Two are endangered: the green sea turtle and the flatback sea turtle.  Three are listed as threatened: the leatherback sea turtle, the olive ridley sea turtle, and the  loggerhead sea turtle.

Hawksbill sea turtles, Eretmochelys imbricata, have a narrow head allowing access to tight spaces in coral reefs, the usual spot to find sponges.  They consume 1,000 pounds of sponges annually, keeping coral reefs free from suffocation by the sponges.  These turtles are medium size at 2′-3′ and 100-200 pounds.  Females nest on beaches among rocky areas 3-4 times in a season and lay 140-200 eggs in each nest.

Kemp’s ridley sea turtles, Lepidochelys kempii, are the smallest species at 2′ in diameter and 75-100 pounds.  Kemp’s ridley turtles have made a huge recovery from the 1960s, when there were about 200 individuals left, to almost 9,000 today.  This is due to changes in Mexico’s laws, where 95% of their nesting takes place, to protect nest sites from disturbance.

Green sea turtles, Chelonia mydas, grow to 4′ and 500 pounds.  They are herbivores with a finely serrated beak for biting seagrass and scraping algae from hard surfaces.  This is the only species known to come onshore to bask in the sun.  They are named for the color of their fat, not their shell.

Flatback sea turtles, Natator depressus, have a flattened carapace, unlike other turtles.  They are medium sized at 3′ and 200 pounds.  Found only in Australia, they do not migrate.  Females lay only about 50 eggs in a nest, but nests are well spread out, helping to better protect their eggs.  Their biggest threat is being preyed upon by saltwater crocodiles.

Leatherback sea turtles, Dermochelys coriacea, are the largest species at 4′-8′ and 500-2,000 pounds.  They consume mostly jellyfish, daily eating their own weight in food.  They have no scutes, but are covered by a flexible, leathery skin that allows them to dive up to 4,000 feet deep searching for prey.  These turtles have thermoregulatory adaptations that allow them to hunt in very cold waters from Alaska to Chile, and they regularly make the longest migration of any vertebrate animal, traveling over 12,000 miles annually.

Olive ridley sea turtles, Lepidochelys olivacea, are small at 2′ and 75-100 pounds.  They are the most abundant of all species.  On certain beach sites, nesting females form an arribada, a grouping of all the females offshore who all come ashore at the same time to nest and lay eggs.  Females on other sites may nest alone.  Arribadas are particularly vulnerable to mass mortality events, but these are rare and  population numbers remain consistent.

Loggerhead sea turtles, Caretta caretta, grow to 4′ and 200-400 pounds.  Their very large heads and jaws can easily crush hard shells, allowing them to eat crabs, conches, and whelks.  They have the largest concentration of nests annually, including 30,000 at a single Mediterranean location.  Their shells provide space for 50 to 100 epibionts: plants and invertebrates that live permanently attached to their shells.

Carnivorous Plants

Plants and insects have myriad relationships to one another.  Some are mutually beneficial, as when plants offer nectar to feed insects which in turn pollinate the plants.  Other relationships only benefit the insects when they feed on leaves, stems, and roots.  For carnivorous plants, preying on insects to fulfill their need for nitrogen and other nutrients benefits only the plants.

Venus flytrap, Dionaea muscipula by Len Worthington, Aug, 2016

Pitcher plants are carnivorous, living in bogs and fens found in warm weather areas.  In North America, most species are found along the southeastern coastal states from Texas to West Virginia.  Bogs are depressions filled with rain or melted snow, while fens are similar but get their water from surface or groundwater.  Both types of wetlands are low in oxygen and nitrogen, very acidic, and often quite cold.  These characteristics slow down the rate of decay in the vegetation of the wetland, further reducing the availability of nitrogen which is a vital component of chlorophyll, the compound used by plants, along with water, carbon dioxide, and energy, to photosynthesize sugar for food. 

Carnivorous plants use several strategies to attract and trap insects.  Pitfall traps have slippery faced leaves forming a funnel with a pool of digestive enzymes waiting at the bottom.  Downward facing hairs on the leaves make it harder for insects to climb out.  Some plants use an opposite strategy and cover their leaf surfaces with a sticky secretion, trapping any insects that land on them.  Still others have a leaf-like structure made of two halves that snap together when an insect lands on an inner surface, trapping the insect inside.  In both of the last two instances, digestive enzymes are then released to cover, kill, and break down the insect body for absorption by the plant.

White-topped pitcher plant, Sarracenia leucophylla, traps separated from flowers by NC Orchid, Apr 2016
Two-spotted bumblebee, Bombus bimaculatus by Judy Gallagher, Jun 2022

Carnivorous plants are insect pollinated and must be able to attract pollinators without trapping them.  All of the plant species go through a dormant period as seasonal temperatures get cooler.  Traps die back and are regrown when warmer weather returns.  In several species, flowers bloom and attract pollinators with nectar, completing fertilization before traps develop.  Other plants separate the flowers and traps by a physical distance.  Traps usually lie close to ground level to attract crawling insects, and flowers are grown on top of tall stalks to attract flying insects.  A third method is to make the flowers less attractive to potential prey, and make the traps less attractive to potential pollinators.  This is achieved by using different colors, patterns, and scents on flowers and traps.

Metallic green sweat bee, Agapostemon sericeus by Dann Thombs, Aug 2008
Cobra lily, Darlingtonia californica by Charles Peterson, Mar 2018

Whether you are growing these unique plants at home or viewing them in a botanical garden or out in the wild, some of the plants and their pollinators to watch for include the white-topped pitcher plant, Sarracenia leucophylla  and the two-spotted bumblebee, Bombus bimaculatus; the cobra lily, Darlingtonia californica and the mining bee, Andrena nigrihirta, Tracy’s sundew, Drosera tracyi and the metallic green sweat bee, Agapostemon sericeus, and the Venus flytrap, Dionaea muscipula and any of the hoverfly species, Toxomerus sp.

Bog landscape by Chris Moody, Jun 2009

Buttonbush

Over the past several days, there has been a lot of activity in our backyard pollinator garden in the area surrounding the buttonbush, Cephalanthus occidentalis.  This native shrub is a multi-stemmed flowering species that can grow from 3′ to more than 12′ tall.  It needs lots of sunshine and prefers moist soils.  Found in many habitats including sub-tropical swamps, shrub swamps in the northeast and upper Midwest, and southern and northern floodplain forests east of the Mississippi, this species prefers swampy backwater areas, marshes, wet meadow and bogs.

Buttonbush, Cephalanthus occidentalis, scaly bark by Lalit Mohan Sethee, Getty Images
Buttonbush, Cephalanthus occidentalis, whorled leaves by loonyhiker, Oct 2010

Newer stems are green, but quickly turn dark brown to almost black, becoming scaly with age.  Leaves are opposite or whorled around the stem, each one protruding at a slightly different angle than the one above.  It is thought that this arrangement provides maximum exposure of the plant’s total leaf surface to the sun.

Buttonbush flowers by DonArnold, Jul 2023
Bumblebee on buttonbush by DonArnold, Jul 2023

The flower clusters appear as small balls between 1/2″ and 1″ in diameter, with over 200 spikes poking outward covering their entire surface.  Each spike is actually an individual flower.  Flowers are closely grouped together and exude an intense, sweet fragrance.  The plant reproduces through a two-stage cycle where pollen is produced and falls onto the immature pistil.  As visiting insects brush through the closely grouped flowers, pollen rubs off onto their bodies.  Once the pollen is gone, the pistil matures and becomes sticky at the end.  As other insects arrive, pollen from other plants is picked up by the sticky end to pollinate the plant. 

After pollination is complete, and the flowers drop off the plant, the ball-shaped seedhead turns completely brown.  Unless it is brushed off by a passing animal or it is eaten, the seedhead may remain with the plant through the entire winter season, dropping off in spring.  Seeds will often disperse into wetland areas, floating to shore.  Each seed ball contains two nutlets.

Pollinators include many long-tongued insect species especially bumblebees, honey bees, tiger swallowtail butterflies and black swallowtail butterflies.  In addition, over two dozen bird species utilize the shrub for food, shelter, and nest building material – most notably are wood ducks that use the plant’s structure to shelter their young.  Amphibians and reptiles hide among clusters of buttonbush in wetland areas for protection during the breeding season.  Several honey-producing bee species are attracted to its pollen and nectar.

Buttonbush, Cephalanthus occidentalis, by NC Wetlands, Aug 2018

With more than a dozen buttonbush species worldwide, it is an easy plant find and get close to for observing its flowers and fruits, as well as the behaviors of the many animal species that frequent this shrub.

Oak-Hickory Forest

Oak-hickory forests makeup one-fourth of all the woodlands in the eastern United States.  At the end of the last ice age, oaks were only found in the Appalachian Mountains and the driftless section where glaciers did not form in southwestern Wisconsin.  In the last 15,000 years they have repopulated the land from the Mississippi River to the Atlantic coastline.

Clockwise from top left: Quercus alba, white oak by Chris Andrei, Getty Images; Quercus palustris, northern pin oak by Michel VIARD, Getty Images; Quercus rubra, northern red oak by ValerijaP, Getty Images; Fraxinus pennsylvanica, green ash by Garsya, Getty Images; Carya ovata, shagbark hickory by Elmar Langle, Getty Images; Prunus serotina, black cherry tree by Ina Hensel, Getty Images

Oak-hickory forests are an open woodland community where trees make up less than 10% of the plant life.  Species of both the red oak and the white oak groups dominate these wood including Northern red oak, Quercus rubra, black oak, Quercus velutina, white oak, Quercus alba, and bur oak, Quercus macrocarpa.  Two members of the hickory family, shagbark hickory, Carya ovata, and bitternut hickory, Carya cordiformis, are also found in abundance.  These forests are rich with several other tree species most notably red maple, Acer rubrum, sugar maple, Acer saccharum, black cherry, Prunus serotina, black walnut, Juglans nigra, and green ash, Fraxinus pennsylvanica.

Arisaema triphyllum berries by ES3N, Getty Images
Arisaema triphyllum, jack-in-the-pulpit by Holcy, Getty Images

The open structure of the forest supports a large variety of other plants that offer food, shelter from predators and weather, and places to raise a family.   Food sources are plentiful including fruit-bearing plants of the genus Vaccinium, which includes blueberries and raspberries, and vines from the genus Vitis, which includes several species of wild grape.  Bloodroot, Sanguinaria canadensis, and Jack-in-the-pulpit, Arisaema triphyllum, along with several clovers, attract birds and insects that attract larger predators, creating a rich forest community.  It is estimated that oak-hickory forests support over 300 animal species including birds, mammals, insects, reptiles and amphibians.

Oak woodland by fotoVoyager, Getty Images Signature

Oak trees provide a haven for wildlife.  Acorns, the fruit of an oak tree, are large and heavy, so they do not spread far from the tree.  They offer good nutrition and are a favorite of many wildlife species, whether eaten immediately or cached and eaten over time.  Oak trees retain their dead leaves throughout the winter, not letting them fall until early spring.  The leaves provide shelter from wind and rain, as well as hiding many smaller birds and mammals from airborne predators.  Oak trees have craggy bark providing shelter for insects and other small animals including many amphibian species that overwinter under the bark.

After dying, oak leaves retain tannin, a chemical that slows down their decay.  As leaves build up on the forest floor year after year, they create thick layers used by amphibians, reptiles, small mammals, and insects for shelter from predators and weather.  In winter, the leaf layer provides insulation from the snow and cold, allowing small animals to move around under the snow, hunting for food, or moving to other sites.  However, the leaves can be advantageous to some predators, as well.  Owls, and other nighttime hunters, have excellent hearing and can easily detect the sounds from crackling leaves as prey attempts to hide and flee.

Gnarled tree with large cavity from wepix, Getty Images Signature
Nature lives forever in fallen trunks by Oleksiy Brunets, Getty Images
Tree cavity by rdou, Getty Images

Many tree species are susceptible to dry rot of their interior wood, and none more-so than members of the red oak family.   This provides natural cavities for woodland species.  Woodpeckers, owls, chickadees, and nuthatches, plus squirrels, raccoons, bats, amphibians, and reptiles all use cavities for shelter and protection.  Almost 40% of animal species inhabiting oak-hickory forests will use cavities at some point in their lifetimes.  As trunks and branches decay and fall to the forest floor, they create opportunities for food and shelter.  In addition, animals drawn to these spaces provide food for larger predators.

As you walk through forested areas over the summer, take note of the tree species and the overall structure you observe  Can you spot holes in trees, logs laying on the forest floor, and thicker layers of leaf cover?  Are the woods open where you can see possible lanes of movement?  What plants have fruit or seeds?  Keeping a journal of observations helps us to identify the changes and enjoy these rich habitats.

Dry oak forest in springtime by Meinzahn, Getty Images
Swamp oak forest in springtime by Aleksander, Getty Images

Summer Berries

Across the northern hemisphere, as spring moves into summer, animals are able to find more food sources.  Amelanchier and mulberry trees are two fruit-bearing plants that are favorites of many bird and mammal species, including humans.

Amelanchier trees by Leonora Enking, Apr 2010
Mulberry flower by Sueviews, May 2006
Amelanchier grandiflora flower by Kurt Stuber, 2004

Amelanchier is a genus of 30 species of pome-bearing fruit trees in the family Rosacea.  This family includes several other fruit-bearing trees including apples, pears, and plums.  The tree is a favorite for landscapers with its many white flowers covering the tree in early spring and its brilliant hues of red and orange in the autumn.  Amelanchier can be a single stem or a multi-stemmed plant and will grow in almost any soil type, but the ideal habitat is partly sunny, well-drained areas of open woodland.

Amelanchier are known by many names.  Serviceberry comes from the fact that when the plants are in bloom, the ground is thawed enough to hold funeral services.  In the Cree Indian language, it is known as saskatoon, a name still commonly used in western North America.  Shadblow, in old English, refers to a time when the bloom indicated the shad were running.  Juneberry refers to the time of year when the berries ripen.

Amelanchier fruit by Oregon State University, Jul 2013; Immature mulberry fruit by Geo Lightspeed7, Apr 2022; Unripe white mulberries by Petru Dimitriu

Serviceberry fruit is slightly larger than a blueberry and tastes of blueberry, lightly peppered with strawberry and almonds.  The berries are light green when young and gradually grow plump and sweet as they ripen to dark red and purple.  They are a favorite of many bird species including robins and cedar waxwings in my area.  Fruit is rapidly eaten as soon as it starts to darken, and almost none is left to fully ripen unless the tree is covered with netting.

Cardinal eating mulberry by Carolyn Lehrke, Jun 2015
Robin and mulberries by Zone~V, Jan 2016

Mulberry trees, of the genus Morus, have 64 species worldwide, and are another important summer food source. Red mulberry, Morus rubra, is the only one native to the United States.  White mulberry, Morus alba, is native to South Asia but can be found on many continents, and it is considered an invasive in parts of Brazil and the U.S.  All species grow quickly when they are young, reaching heights of nearly 80 feet.

Mulberry trees can be easily grown from either seed or a plant cutting.  The market for their fruit is worldwide with some places, such as the U.S., importing millions of pounds each year.  While easy to grow, establishing a viable crop for market has many difficulties.  Trees do not produce fruit for the first ten years, and their highest yields are when the trees are 30-80 years old.  The fruit is a favorite of many bird and mammal species, and is often eaten well before it is ripe enough to pick.  Leading producers are Turkey and Iran who have been growing mulberries for several centuries.

Pick your own mulberry by Katarina, May 2014
Mulberry cobbler by Eden, Janine and Jim, Jun 2021
Mulberry jam by Amanda Slater, Jul 2021

Plump, juicy, and sweet berries from both plants are high in vitamin C and iron.  Fruits can be eaten straight from the trees or used in a variety of recipes.  Other parts of these plants contain a milky sap that is mildly toxic to animals and humans if ingested.  The wood is hard, tight-grained and heavy, with many of the same qualities as oak.  It is used in furniture and fence posts.  Historically, it has been used for arrow shafts and body armor.  Amelanchier leaves and bark may be dangerous to cattle, sheep, and goats if consumed in large quantities.  The white mulberry, Morus alba, is an important tree for the silk industry.  The leaves of this species are the only food source for the silkworm, Bombyx mori; its cocoons are used to produce silk. 

Silkworm, Bombyx mori, on Morus alba by Gorkaazk

As you walk woodland areas near your home, watch for berry-loaded trees in your neighborhood.  Keep track of each time you see them and what stage the berries are in – and how many are left on the tree.  See if you can observe and learn more about who is eating this sweet, juicy food source of summer.

Bee An Early Pollinator

There are over 20,000 species of bees world-wide, and more species are found every year.  Bees are important pollinators, especially in early springtime.  Other pollinator species abound, and all are important to the life-cycle of flowers, but bees are thought to increase seed production by about 70%.

Dandelions on day 100 by Mike Deal, Apr 2010

The bees we see in our gardens are all adults, emerging from their nests between early spring and late summer.  The first to emerge are the bumblebees.  They have wingbeats of about 200 strokes per minute and a metabolic rate that is double that of a hummingbird, allowing them to generate plenty of body heat to stay warm during cool spring weather.  Orchard bees are the next out as soon as daily temperatures stay in the mid-50s.  Native honeybees may also come out at about this time, but imported bees cannot fly in temperatures less than 60˚F.  Early blooming flowers including dandelion, jewelweed, aster, goldenrod, and clover, are important sources for pollen and nectar in spring.

Honeybee covered in zucchini pollen by John Kimbler, Getty Images

As crop plants start to flower, including fruit trees and vegetables, a large pollinator workforce is needed.  Almost one-third of the food consumed by humans comes from plants requiring pollination.  As pollen is collected by bees, the grains are spread over the bee’s body, allowing some of those grains to rub off and pollinate subsequent plants as the bee follows a route visiting various flowers.  Adult bees feed mostly on nectar, eating very little of the pollen they collect.  Pollen is brought to the nest to feed their young.

Bumblebee in flight with loaded corbicula by mirceax, Getty Images

Honeybees and bumblebees have a bare spot on their back leg called a corbicula, surrounded by inward curving hairs.  As pollen is collected from each flower, it is scraped into this holding area, which may amount to 20% of their body weight while in flight.  After landing, a bee grips a flower tightly with its jaws and legs.  Snuggling close to the anthers, the bee vibrates and dances to disrupt the pollen inside and let it fall onto their bodies.  They proceed to groom all the pollen grains into the corbicula before moving onto the next blossom.  When the corbicula full, the bee will fly straight to the nest, unload all of the pollen, and return immediately to where they left off to collect more. 

Honeybee collecting pollen into scopa by baianliang, Getty Images Signature

Other bees store pollen in scopa, tufts of hair on their legs and abdomens.  As pollen covers the bee during its flower visits, the four front legs are used to scrape the pollen down past their abdomen where the two back legs pack it into the scopa.  Some bees may carry the pollen dry, and others may mix in a little nectar to form a dough-like substance that easily sticks to their body hair.

Brown honeybee heading into narrow opening by Gregory Johnston

Buzz pollination video @ This Vibrating Bumblebee Unlocks a Flower’s Hidden Treasure |  Deep Look

Pollen collection has resulted in the development of several adaptations found among many bee species.  Electrostatically charged body hair attracts pollen.  The charge is a result of air moving across the body while the bee is in flight.  When plants are small enough that only the bee’s head fits inside, hooked hairs on faces and under chins allow easy pollen collection.  Some plants keep pollen in anthers, long tubes that must be turned upside down and shaken to release the pollen.  Many bee species use buzz pollination, hanging onto the anthers to tip them, then vibrating their wing muscles to loosen the pollen, allowing it to fall on themselves.

Red head bee, Pachyprosopis eucyrta, licking up nectar by Jean&Fred Hort, Mar 2014

Nectar provides carbohydrates in the form of sugars and amino acids.  Bees use their tongues to lick it  or suck it up.  Several species have longer tongues for use on deep-necked flowers.  Honeybees collect nectar and bring it back to their hives to store it.  Over time, some of the water content evaporates, forming honey.  This is used as food over winter or at times when other food is scarce.  Some bumblebees have been shown to also collect and return nectar to the hive, but don’t create true honey.  This nectar is used as nourishment for the hive-bound queen only, not as a food source for the entire colony.

As we begin to see the many blossoms of spring and summer, remember that adult bees are only out in our gardens for a short period of their lives.  We can assist their work as pollinators by allowing early spring flowers to finish their blooms before cutting them down.   

Bumblebee on flower from skitterphoto, Pixabay
Bumblebee collected pollen by vinkirill, Getty Images

Maple Trees

Maple trees in the northern U.S. are coming into bloom at this time of year.  Maples bloom in late winter and early spring, and the flowers come in green, yellow, orange, and red hues.  There are about 130 species worldwide, and except for one species, all are found in the northern hemisphere across Asia, Europe, Africa, and North America.  Thirteen maple trees are native to North America, and we will take a look at a few of the more common ones.

Holland Red Maple Swamp, Wisconsin State Natural Area by Joshua Mayer, May 2012

Several species are large trees, reaching from 40′ to 65′ in height with 20″ to 60″ diameter trunks.  Trunks are dark grayish-brown with ridged bark.  Crowns appear generally rounded and root systems are widely spread.  Maple trees do well in most habitats, particularly moist to wet soil, along streams or in bottomlands. 

Sugar maple in spring by J Stephen Conn, Jul 2007

Sugar maple, Acer saccharum, is well known for its maple syrup, marketed world-wide.  When temperatures drop below 40˚, maple trees stop growing and excess starch is stored until temperatures start to rise again.  Enzymes in the tree change the starch into sugar which is carried by tree sap flowing through the xylem and phloem cells, located just beneath the bark.  A tap gently pounded through the bark intercepts some of the sap and collects it into buckets.  It takes 40 gallons of sap to produce one gallon of maple syrup.  Historically, the wood was used for railroad rails, plow blades, and wagon wheels.  After burning, its ashes are rich in potash and make excellent fertilizer as well as an additive for soap and pottery glazing.

Maple tree tapping by PublicDomainPictures , Pixabay

Black maple, Acer nigrum, is a close relative to the sugar maple, and these two species easily hybridize.  Both species are shade tolerant, often found growing together for several years as understory trees.  Sap from black maple trees may also be used in maple syrup production.  Black and sugar maples are hardwoods, stronger and harder than other maple species, and valued for use as basketball court and bowling alley floors, workbenches, cutting boards, and baseball bats.

Bowling alley by vtwinpixel, Getty Images; Maple & other baseball bats by Comstock Images: Maple workbenches from thelinke, Getty Images Signature

Red maple, Acer rubrum, provides food from seeds, buds, and flowers for squirrels, chipmunks, deer, moose, and elk.  In winter, stumps and small twigs are an important food source for rabbits.  Pollen is produced early in the spring and is a much needed food source at this time of year for bees and other pollinators.  Red maple is also attractive to insects and fungi, which invade the wood and create many open cavities in trunks and large branches, favored as nesting sites for wood ducks and other species.

Red maple buds & flowers by Martin LaBar, March 2010
Baby squirrel in maple tree by William Krumpelman, Getty Images

Red maple has several qualities that have made it a widely used ornamental tree.  It grows well in shady sites; it is tolerant of flooding and water-logged soils; it is one of the first to colonize disturbed sites and anchor the soil, and it has a rapid growth rate, colorful flowers and foliage, and lives 75 to 100 years.  Maple flavored drinks, such as tea, are made from inner bark scrapings.  Bark is also used in the production of ink and black or brown dyes.  The wood is used for smoking meat and in the production of some whisky varieties.

Silver maple, Acer saccharinum, is a fast growing tree with a root system attracted to any source of water.  It is easily grown in shady areas and wet soils, make it a well-liked ornamental tree.  However, it causes many sewer and drain issues in urban settings in its search for water.  The wood is hard but very brittle, and branches easily break in heavy winds.  This often results in trunks having hollow cavities used for shelter by various animal species including wood ducks and squirrels.  Seeds are abundant and are a favorite for birds and small mammals.  The sap makes a delicious syrup, but requires twice as much volume as sugar maple trees, making it not commercially viable.

Maple tea by Masyusha, Getty Images
Two maple whiskys by JeffWasserman

Box elder, Acer negundo, is another maple species that is often found near water.  This tree easily tolerates drought and extreme cold, although the wood is weak compared to other maple species, and branches often break when subjected to heavy loads of snow and ice.  Box elder produces abundant seeds late in the year that provide a great winter food source for mice, squirrels, and seed-eating birds.  Branches are small in diameter, so it is not often used for lumber, but it has several uses as pulp wood for producing crates, boxes, and composite wood panels.

Under the spreading maple by Jo Zimny, Oct 2020

As you are out walking in your area, be sure to look for the many species of maple trees that grow in yards and woodlands, often distinguished by bright flowers, abundant seeds, and lively green foliage.  Also, be sure to take the chance to observe their spectacular fall foliage later in the year.

Boreal Forest in Winter

The boreal forest is the largest tract of woodland on earth covering 11% of all land area, half again as large as the Amazon rainforest.  It stores 30% of the sequestered carbon on earth.  The area also contains a mosaic of wet meadows, ponds, lakes, marshes, and bogs interlaced among the trees.  Tree species include many conifers, dominated by spruce, plus aspen, birch, willow and alder.  The animal life is abundant, with every species that was there before European settlement still remaining.

Boreal Forest panorama by Mliberra, getty Images

The boreal forest is distinguished by short, hot, wet summers and long, dry, cold winters.  When the last glaciers retreated northward, many holes and fissures were left behind.  As the ice melted, all of these depressions were filled with water.  The underlying geology is mostly granite shield, a rock layer that holds the water in and contains few minerals that dissolve in water, yielding very clear water that does not promote algae or bacteria growth.  Most lake life is found in the shallow, warmer edges which also provide support to nearly all of the land-based fauna.

From upper left clockwise: Alder tree by Mantonature, Getty Images Signature; Spruce trees by Hannu Koskela, Getty Images; Willow tree by smarko , Pixabay; Aspen trees by Adamisovitsch, Getty Images

Winter time presents many challenges including less sunlight, colder temperatures, less available water, less food and shelter, and increased severe storms.  Animals that are active daily have higher energy requirements in winter.  They must often change their dietary sources to whatever is available in winter.  Grey squirrels and beavers cache food during warmer periods.  Birds eat foods higher in calories such as nuts, seeds, dried fruit, and insects found under tree bark.  When changes are consistent from year to year, species develop adaptations to meet the requirements of each season and are able to live comfortably throughout the year.

Shelter becomes not only a place to hide from predators, but also provides protection from weather  extremes.  Snow of different thicknesses and weight covers the landscape.  Snow is also a great insulator, keeping cold winds away from exposed skin.  There is normally a layer of air between the ground and the snow cover immediately above.  Temperatures in this space are warmer than the exposed air above the snow creating a winter habitat that is vitally important for many species.  Mice and voles create burrows under the snow where they can huddle together for added warmth.  Similarly, air pockets surrounded by a heavy growth of conifer needles create spaces above the snow cover for birds and some larger mammals to shelter.  And many larger species will nestle into the snow pack to shelter from storms and wind.

Spruce grouse by Impr2003, Getty Images
Willow ptarmigan by Alex Berger, Mar 2022

Spruce grouse, Canachites canadensis, and willow ptarmigan, Lagopus lagopus, are not able to fly more than several yards.  They grow feathers on their feet to insulate them and aid in traction.  Grouse use the air layer at ground level to shelter in.

Portrait of a snowshoe hare by Jim Cumming, Getty Images
Canada lynx by Carol Gray, Getty Images

Ptarmigan, along with snowshoe hares, Lepus americanus, and short-tailed weasels, Mustela erminea, all change color to pure white to hide from predators.  Snowshoe hare and Canada lynx, Lynx canadensis, have very large feet that aid in walking on snow without sinking in.  Arctic fox, Vulpes lagopus, are winter specialists with compact bodies and short legs and ears that limit their exposure to cold, and large, furry paws that enable them to walk on top of the snowpack.  With their long, bushy tails wrapped around their heads, they can withstand winds and temperatures to fifty below zero.

Arctic fox by Diapicard, Pixabay
Stayin’ warm, Arctic fox by PEDRE, Getty Images Signature

You can learn more about this cold but wondrous habitat by searching online for boreal forest, referring to the southern portions of the habitat, or taiga, referring to the northern portions.  Also, look for information concerning seasonal adaptations for species in your own area, or visit a local natural history museum such as the Jurica-Suchy Nature Museum in Lisle, Illinois.