shelter – Discover-Nature

Heat Effects

The midwestern United States is experiencing a heat dome this week. This is the result of a high pressure system hundreds of miles across and moving very slowly. Air in the upper atmosphere of a heat dome is already warm, but is still cooler than the air below, and cooler sir sinks towards the Earth’s surface. As the air moves downward, it compresses air molecules together releasing heat, making the lower layers even hotter and drying out the area as moisture evaporates. With little or no moisture, no clouds form to relieve the heat and dry conditions.

^{Heat Dome over Eastern US by National Weather Service, Jun 26 2025}

Humans have a variety of ways to cope with high heat including being less active, drinking plenty of fluids, and remaining in shady or air-conditioned areas. Wildlife still has to get food and water every day and may have fewer opportunities available to them to avoid the high heat. Let’s look at how the heat is affecting a few of the backyard species common in the Midwest.

^{Photinus pyralis, Big Dipper firefly by Terry Priest}

Fireflies are cold-blooded, or ectothermic, and prefer warm and humid areas. They come out in the early evening and as their bodies warm, they become more active, flying and flashing more frequently, communicating with other fireflies to find a mate. Eggs are laid soon after mating, but these will perish if they do not remain hydrated. Turning off outdoor lighting for a few hours in the evening and maintaining taller, well-watered vegetation will help fireflies during hot and dry conditions.

^{American Toad by Brad Carlson, Mar 2012; and Bullfrog at Waterfall Place by DonArnold, 2022}

Frogs and toads are also ectothermic and require heat from the environment to live. Species worldwide, including American toads and bullfrogs in our area, find temperatures in the 70s to be ideal. As temperatures move into the mid-80s, these species and others are prone to dehydration and heat stress. In addition, they normally look for shady and humid areas to regulate their body temperatures, but the lack of moisture in a heat dome does not make those niches easy to locate. Maintaining shady, well-watered areas of the garden provides refuge for many amphibian species.

^{Cardinal looking to stay in the shade by Don Arnold, 2023}

Birds are often affected by extreme heat. Most birds have lower body temperatures than the outside air. This allows birds to easily dissipate heat from high energy activities, such as flight. Once the outside air gets above a hundred degrees, birds cannot lose heat to the atmosphere and become severely compromised by heat and dehydration. Rapid open-mouthed breathing, changing eating times to early or late in the day, sitting with wings outstretched, or exhibiting poor balance are all signs of heat stress in birds. Providing shady, undisturbed areas and readily available water sources gives birds the opportunity to move around less and stay hydrated.

Wild animals have to deal with weather extremes just as we do. Come to the Jurica-Suchy Nature Museum or a nature center near you to learn more about providing opportunities for wildlife to survive heat, drought, and other environmental conditions.

Salamanders

Salamanders are in the order of amphibians named Caudata, which includes mudpuppies, newts, and sirens. There are about 760 species of salamanders worldwide and 121 species are endangered. With the exception of a few in the Amazon basin, they are found only in the northern hemisphere. They live in habitats that provide sufficient humidity levels to keep their skin moist, from sea level to nearly 15,000 feet in altitude.

^{Northern zig-zag salamander, Plethodon dorsalis, by John P Clare, 2016}

^{Marbled salamander, Ambystoma opacum, by Jupiterimages, PhotoImages}

The smallest species are lungless salamanders of southern Mexico, growing to an inch in length. The largest species are the Chinese great salamanders, about six feet in length. They are often mistaken for lizards, having smooth or bumpy skin, but can be easily identified by their total lack of scales. All salamanders have a tail which is rounded in terrestrial species but slightly flattened and often crested in aquatic species. Most salamanders are grey, brown, or white, but a few terrestrial species are brightly colored. Cave dwelling salamanders often lack all pigment and appear pinkish-white in daylight.

^{* Western lesser siren, Siren intermedia nettingi, by Peter Paplanus, 2013}

^{Long-tailed salamander, Eurycea longicauda longicauda, by Meghan Alessi, Getty Images}

Salamanders, other than cave-dwellers, tend to have well-developed eyes. Research shows they are very attuned to differentiating brightness, but cannot see colors. Their eyes are large and provide nearly 360 degrees of view. Salamanders have no external ears, but can detect vibrations received through their jaw bones. Although some species can emit small squeaks, salamanders have no vocal chords or voice box and do not use vocal communications. Their sense of smell is well-developed and plays an important part in locating prey and mates.

^{* Hellbender, Cryptobranchus alleganiensis}
^{alleganiensis, by Jason Ondreicka, Getty Images}

^{Cave salamander, Eurycea lucifuga, by Alfred Crabtree, 2012}

Salamanders may have functional lungs, non-functioning lungs, or no lungs. All species have the ability to exchange gases directly through their skin and the membranes inside their mouth and throat, but this also requires that the skin remain moist at all times. Terrestrial salamanders depend on moisture found in deep leaf litter, holes in trees in temperate zones, or moisture collected in bromeliads growing on trees in tropical zones.

^{Four-toed salamander, Hemidactylium scutatum,}
^{by Jason Ondreicka, Getty Images}

Salamanders have three sets of glands located under the skin, covering their entire body. Mucous glands secrete a sticky liquid that is spread over their body keeping the skin from drying out. When salamanders are in the water, the mucous acts as a lubricant, enhancing their swimming ability. A second set, called the granular glands, produce toxins and odors unique to each species that helps to deter predators and attract mates. A third set of glands is a mixture of the first two, doing a little bit of the work of each.

^{Small-mouthed salamander, Ambystoma texanum,}
^{by Jupiterimages, PhotoImages}

^{Tiger salamander, Ambystoma tigrinum tigrinum, by John P Clare, 2013}

Salamanders are not as noticeable as many other species. They prefer secrecy and out-of-the-way hiding places. Most species are active at dusk and into the nighttime. All salamanders are carnivorous, feeding on small crustaceans, insects, spiders, and their favorite food – worms. Predators include snakes, lizards, fish, birds, and small mammals. Salamanders defend themselves by exhibiting threatening poses and emitting toxins, many with a bad odor. As a last defense, they may voluntarily lose their tails to a predator, a trait known as autotomy. A new tail can be grown within a few weeks.

Salamanders are easy to care for and their habitats are easily duplicated making them widely distributed in the pet trade and for use in laboratories. Additional conservation impacts come from habitat fragmentation, or habitat degradation, or habitat loss due to draining of wetlands and forest clearing.

^{Northern slimy salamander, Plethodon}
^{glutinosus glutinosus,}
^{by Jason Ondreicka, Getty Images}

^{Red-backed salamander, Plethodon cinereus cinereus, by Steve Byland, Getty Images}

In Illinois, we have 20 species of salamanders, pictured throughout this blog. Seventeen are terrestrial and three are aquatic (*). Consider coming to the Jurica-Suchy Nature Museum or a nature museum near you to learn more about salamanders in your area.

Spotted salamander, Ambystoma maculatum, by Louisianatreefarmer, Getty Images
Blue-spotted salamander, Ambystoma laterale, by Jason Ondreicka, Getty Images
Central newt, Notophthalmus viridescens louisianensis, by Andrew DuBois, 2016
Dusky salamander, Desmognathus fuscus conanti, by Jason Ondreicka, Getty Images
* Mud puppy, Necturus maculosus maculosus, by Andrew Hoffman, 2010
Three-toed salamander, Amphiuma tridactylum, by Peter Paplanus, 2016
Southern two-lined salamander, Eurycea cirrigera, by Peter Paplanus, 2021
Mole salamander, Ambystoma talpoideum, by Andrew DuBois, 2016
Dark-sided salamander, Eurycea longicauda melanopleura, by Andrew Hoffman, 2010

Insects Over Winter

It is starting to get chilly in the Midwest as we head toward winter. Insects also recognize the shorter daylight hours and dropping temperatures. They use two main strategies to cope with winters: freeze avoidance and freeze tolerance. Avoidance may require travel or a dry place to stay warm. Tolerant insects can stay here and control their body’s response to freezing temperatures. Staying in place has several advantages including being able to emerge early in spring, allowing those insects to feed before predators are out.

^{Clockwise from upper left: Monarch butterflies on migration by Dopeyden, Getty Images; Cecropia moth cocoon by Sylvie Bouchard, Getty Images; Milkweed bugs by Rick Wood, Rick Wood’s Images; Four-lined plant bug, Poecilocapsus lineatus, by Heather Broccard-Bell, Getty Images Signature; Common pill-bug by Ines Carrara, Getty Images}

Those insect groups that opt for traveling to warmer climates often make a one-way trip. Monarchs are one of the best known insect migrators. Monarchs east of the Rocky Mountains leave in early fall to arrive at overwintering sites in the mountains of Mexico. Their offspring return to the southern U.S. in spring to breed, and this second generation returns to the East and Midwest over the following summer. Monarchs west of the Rockies overwinter in Baja, California, and many of the same individuals that fly south do return, but their trip is considerably shorter allowing time for breeding during summer months in the northwest U.S.

^{Honeybees in hive by OK-Photography, Getty Images}

Many different species of insects can control or stop ice formation in their bodies. Honeybees cluster together and shiver, generating enough body heat to keep the air above freezing in their hive. Other insects get rid of all the food and water in their bodies, becoming dehydrated and unable to freeze. Some species can control where ice crystals may form in their bodies, and prevent their formation inside cells that would cause harm to the insect. Insect species that retain some water use cryoprotectants, chemicals resulting from large amounts of sugar. One such chemical is glycerol, which lowers the freezing temperature of water and other liquids.

^{Dragonfly larva with fish by Mauribo, Getty Images Signature}

^{Fast running stream by Mburnham, Getty Images}

Some insects remain active throughout the winter. Aquatic insects in immature stages can easily spend the winter in fast moving or deeper water that does not freeze. Some insects move inside warm and protected places like attics, sheds, and gaps in house walls. They also overwinter in tree cavities, under bark, inside dead plants, and in old burrows. Allowing vegetation with hollow stems to stand through the winter will provide many populations a safe place to spend the season.

The insect version of hibernation is called diapause, when growth and development is halted until longer daylight hours prevail. Late winter weather patterns with warm periods interspersed with cold periods endanger many species. Another change we have experienced in recent years involves warm temperatures lasting later in fall and starting earlier in spring. These changes interrupt the historical natural cycles, causing insects and other animals to abort hibernation and actively look for food or mates. Food plants do not produce enough to support animal populations, or another cold period returns, and species are not able to adapt, and often perish.

^{A garden in winter by Vermontalm, Getty Images; Snag and deadwood in winter by BayDavn0211, Getty Images; Spring garden and returning insects by Anthony Lerma, Getty Images}

Insects are a vital part of healthy habitats, providing pollination services and food to many species. We can help overwintering insects by leaving dead stalks standing until late spring to provide safe habitat. Leaves left piled up provide nutrients, insulation, and a place of shelter. Uncovered soil can also host ground nesters such as native bees. Snags and logs provide lots of cavities protected from the weather. Selecting some plant species that bloom early or late in the year will provide additional food at those times. Growing plants in clusters enables insects to find all they need in one place. With a little planning, everyone’s backyard can be an inviting habitat for insects year-round.

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

Beat The Heat

This week, the weather has been hot for the upper Midwestern U.S. with temperatures topping out above 100°F. Combined with high dew points in the mid-70s, the heat index temperature was upwards of 110°F. Here are some ways that plants and animals keep cool in the extreme heat.

^{Mojave Desert by LezusRocks, Getty Images}

^{Kit fox at entrance to desert den by Stevelenzphoto, Getty Images}

Desert environments, where hot conditions exist daily, are home to numerous animal species that live underground. Heat from the sun penetrates soils and sand layers for several inches, but at 20″ below the surface of the sand in the Mojave Desert, temperatures are fairly constant around 86°F while the surface may be over 110°F. Few large mammals are known to use burrows, although kit foxes and humans are two examples. Basements and lower levels in buildings are often preferred areas on hotter days.

^{Shaded walk in the woods by Felixmizioznikov, Getty Images}

Shade from trees is highly effective in creating cooler areas. Leaves are lighter in color than most soils and paved areas, and leaves reflect much of the sun’s radiation upwards, away from the shady area underneath. Denser foliage and rough leaf textures enhance the cooling effect. Under a shade tree, temperatures may drop up to ten degrees and other surfaces no longer exposed to direct sunlight, including our skin, may be 20 to 40 degrees cooler.

^{African elephant by Petr Polak, Getty Images: Black-tailed jackrabbit by Rancho_Runner, Getty Images; Fennec fox by Nattanan726, Getty Images}

Vasodilation occurs when blood vessels near the skin’s surface expand so more blood flows next to the skin. Many animals living in hotter climates, including fennec foxes, black-tailed jackrabbits, and African elephants, have large ears with broad, flat surfaces devoid of hair, fur, or other insulation. The ear’s large surface area is covered by a thin layer of skin and blood vessels. During hot weather, heat carried in the blood through the ear is readily lost to the outside environment, providing a cooling effect for the rest of the body.

^{Large crowd by Shaunl, Getty Images Signature}

Evaporative cooling is another method through which heat can be dissipated from a body. Trees use this method by losing water vapor through their leaves during photosynthesis, cooling the air under the leaves. Humans employ this method in a process called sweating. We lose warm water through skin pores directly to the air around us. Sweating also moistens our skin’s surface, indirectly providing additional cooling as air moves across the skins surface and wicks away additional heat. An important aspect enhancing the effectiveness of this method is our posture. Being supported by two legs, rather than four, exposes much less surface area to the direct rays of the sun, and much more surface area to air currents.

^{Forest path by Inga Nielsen, Getty Images}

While sweating is good for cooling, it is removing water from the body, which must be replaced for the process to continue. Exposure to today’s temperature extremes may result in a loss of three gallons of water or more from an average-sized human. As you are out enjoying nature during hot days, remember to keep hydrating to stay cool and keep other bodily systems healthy.

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}

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}

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.

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.

^{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.

Junco Winter Adaptations

Juncos spend the winter spread across the United States. They spend summers at breeding areas in southern Canada, and in fall males migrate to the northern states while females migrate farther south. Males have several adaptations that allow them to more easily survive in colder climates, and allow them to return early to breeding areas to claim the best territory for attracting a mate among the females that come back a few weeks later.

^{Male dark-eyed junco, Junco hyemalis by Christian Gott, dec 2022}

^{Female dark-eyed junco, Junco hyemalis by Joseph Higbee, Dec 2014}

Junco males are small, round-bodied birds with a slate gray back and are larger and weigh more than females. According to Bergmann’s Rule, large bodies have a smaller surface area relative to their volume, and are therefore able to retain more heat than longer or skinnier bodies. Being able to retain more heat for longer periods, an average-sized male junco can go two hours longer without food than an average female, and a large male may go more than ten hours longer between meals. This can be an essential factor when living through a colder period.

^{A cozy tree cavity by Steve Valasek, Apr 2014}

^{Accommodations for one… by Hedera Baltica, May 2016}

Tree cavities provide excellent places to shelter in winter. At night and in severe weather, juncos seek a small, tight space big enough for a single bird that provides protection from wind and moisture. During daytime hours, while foraging, juncos can often be found in conifer trees whose year-round needles provide a windbreak and a place to remain out of sight of predators.

^{Male junco with fluffed-out feathers by Ken Gibson, Dec 2016}

Juncos have a normal body temperature of 107˚F, well above the average outside temperature on a winter day which could be between -10˚F and +20˚F. Maintaining body heat requires a high-caloric diet to create the heat and resources to not allow the heat to escape. Birds have muscular control over their feathers and are able to fluff them, trapping air next to their skin. Preening is a daily activity where oil secreted from a gland above the tail is rubbed on all of their feathers providing a moisture barrier that keeps water, snow, and cold winds away from their skin. Both feathers and trapped air make up two layers of insulation that work efficiently to retain body heat.

During extreme weather, it may be advantageous to remain sheltered and inactive when the amount of calories burned to get a meal is more than the calories in the meal. When sheltering for longer periods, juncos may intentionally lower their body temperatures a few degrees, entering a state of torpor. This state lasts for only a few hours, but saves enough energy so that the bird does not need to forage for an extended period during a day. Using muscular control, birds can generate body heat by contracting and releasing their muscles, similar to shivering in mammals, and bring their body temperatures back to normal and resume daily activities.

^{Juncos feeding on ground by mwms1916, Apr 2015}

^{Juncos feeding on ground feeder by synspectrum, Nov 2015}

Northern U.S. flocks of juncos in winter are 70% or more males, while most females spend winters in the southern U.S. This is also true for several other species that migrate with juncos including tree sparrows, song sparrows, and mourning doves. Juncos will be leaving in late winter to return to breeding grounds across Canada, but for the coming few months we will certainly enjoy their presence in our area.

Desert Habitat, pt.3

In the past two blogs, we have explored deserts and the plants which inhabit them. Animals native to these habitats have general adaptations for coping with temperature extremes, aridity, and finding water, food, and shelter. Strategies include hunting during cooler hours including at dawn, dusk, or overnight; obtaining water from sources other than standing water; burrowing underground to avoid temperature spikes and solar radiation; ability to conserve water in their body; ability to dissipate body heat; and being well-camouflaged. Look for each of these adaptations in the following species that live in our desert regions.

Greater roadrunner, Geococcyx californianus, by Tony Cyphert, Sep 2018

Ord’s Kangaroo Rat, Dipodomys ordii, by Andy Teucher, Jun 2005

The greater roadrunner, Geococcyx californianus, can only fly for several seconds at a time, but can reach speeds up to 17mph when running. They hunt early in the morning, retiring to shade when temperatures heat up mid-morning. Water requirements are met from foods including grass and prickly pear cactus, plus prey that includes lizards, scorpions, and rattlesnakes. Roadrunners do not urinate, but can excrete salt and save the water. They have an un-feathered area under their chins used to dissipate body heat. Ord’s kangaroo rat, Dipodomys ordii, is another species that gets all of their water requirements from the seed they eat. Individuals live in underground burrows, coming out only at night to feed. They conserve water in their bodies and do not sweat or pant. They have many predators, but with a 9-foot jump and excellent hearing, they are hard to catch. Seeds are collected and stored in their burrows, and they will gain 50% more water from the underground humidity before being eaten.

Horned Toad, Phrynosomasp., by TJFrom AZ, May 2009

Gila monster, Heloderma suspectum , by Karla Kishinami, Apr 2012

Horned toads, Phrynosoma spp., are small, ant-eating lizards with thick scales to conserve water and deter predators. To escape a predator, these animals can squirt a directed stream of blood from their eyes up to five feet away. They are sandy-colored with undefined outlines allowing them to easily hide amid rocky outcrops. Normally active during the day, they can retreat to burrows or under rocks if temperatures become too hot. During winter, horned toads will spend a period of inactivity, called brumation, in underground burrows. The Gila monster, Heloderma suspectum, is another lizard with armor protected skin marked with black and pink coloration that camouflages them well in sandy soils. They shelter from daytime heat under rocks and shrubs, emerging in early morning or evening to hunt small mammals, lizards, insects, and bird eggs. One of only two venomous reptiles in North America, their venom adversely affects their prey’s nervous system. The short, thick tail stores water in fatty tissue for use when needed.

Tarantula, Aphonopelma sp., by Saguaro National Park, Nov 2020

Western coral snake, Micruroides euryxanthus, by Ashley Wahlberg, Apr 2016

The tarantula, Aphonopelma spp., shelters in deep burrows lined with silk to prevent the sand from caving in. They are nocturnal hunters of insects, arthropods, and small lizards with a bite that delivers a small amount of venom to stun their prey. Venom immediately starts to break down tissue to liquify the meat, allowing the spider to use sucking mouth parts to draw in its meal. The Western coral snake, Micruroides euryxanthus, is brightly colored with red-white-black-white banding and venom that is twice as deadly as most rattlesnakes. They are very secretive, living under rocks or buried in the sand. Coming out at night or on some overcast days, they hunt for lizards and other snakes. Venom causes rapid paralysis and respiratory failure, although due to their small size and small amount of venom injected, they are not a threat to humans.

Like many environments, a healthy desert community exists when plants, animals, and habitat are all present and undisturbed. With much of the life in deserts underground, walking off trails and driving off roads can negatively impact what is under the surface. Removing plants and rocks used for water and shelter is equally damaging. I encourage you to get out, observe, and enjoy this unique habitat, or research many of the fun and interesting adaptations at a local natural history museum.

^{Pictures above clockwise: Bark scorpion by Josh More, May 2014; Cactus wren by Mick Thompson, Feb 2019; Jackrabbit, by Mark Gunn, Mar 2014; Javelina, Sonora Desert, by Richard Bonser, Jan 2005; Tarantula hawk wasp by Jim Mulhaupt, May 2010; Sonoran mud turtle by Grigory Heaton, Sep 2022; Round tailed ground squirrel by Wendy Miller, May 2022; Hoary bat by Michael Pennay, Sep 2009; Cactus deermouse by J.N.Stuart, Oct 2011}