reproduction – Discover-Nature

Camels

Camels, known as the “ships of the desert” for the many unique attributes that allow them to live in a harsh environment, originated 40 million years ago in North America, but are no longer found there. Today, there are three recognized species, the dromedary camel, Camelus dromedarius, living in North Africa, the Middle East and western India; the domesticated Bactrian camel, Camelus bactrianus, living across central Asia, and the wild Bactrian camel, Camelus ferus, living in the deserts of northwest China and southwest Mongolia. Wild dromedary camels are extinct, and the population of wild Bactrian camels is critically endangered with less than 700 individuals competing with livestock for food and clean water.

^{Dromedary camel distribution map by EBKWiki, Nov 2024; Wild Bactrian camel distribution map by Oona Räisänen & IUCN, Nov 2010; Bactrian camel distribution map by EBKWiki, Nov 2024}

Camels at shoulder height are about seven feet tall, with a life expectancy of 40-50 years. Bactrian camels are much heavier and stockier, weighing up to 2,200 pounds, almost twice as much as a dromedary camel. Camels range from tan to dark brown in color with heavy, thick fur. They do not have hooves, but walk on two toes, widely split apart. Dromedary camels have a wide, soft pad of skin covering their toes, while Bactrian camels have a firmer foot, and both types of feet work effectively to keep camels from sinking into the sand. Both legs on one side move together allowing them to cover long distances and achieve short bursts of speed up to 40mph. When facing into the wind, camels use their double row of eyelashes, the hair covering their ears, and the ability to completely close their nostrils as protection from blowing sands.

^{Bactrian camel by J.Patrick Fischer, Dec 2011; Dromedary camel by Agadez, Mar 2008; Wild Bactrian camel by Paul Korecky, Sep 2017}

Camels are well-suited to their desert environment, having several adaptations for water conservation and the ability to go long periods without drinking. They can live 4-5 days in severe heat before dehydration becomes a problem. If temperatures are mild, the animal is not working, and it is getting sufficient water from its food sources, a camel can survive up to 10 months without drinking, allowing them to forage deep into the desert.

^{Dromedary camel kneeling by jjmusgrove, Feb 2023}

Camels need to drink once every ten days. They can lose up to 30% of their body weight in dehydration without discomfort. They are able to reduce urinary output by 80% when needed, and feces are always dry. When water is available, they can drink 25 to 30 gallons in a few minutes. Excess water is stored in their red blood cells. A camel’s hump is used to store fat, which can be reabsorbed for energy when food is scarce. Camels are able to adjust their internal body temperature by 10 or more degrees throughout the day. Being able to raise its internal temperature as the environment gets hotter allows the animal to tolerate the heat without the need to sweat, something they rarely do. Thick wool coats protect them from direct sunlight and heat. Even in a reclining position, their folded legs prevent the body from touching the hot surface and allow cool air to pass underneath.

^{Dromedary calf suckling mothers milk by Garrondo, Dec 2004}

Camels reach full size at about seven years old, but they are old enough to breed at three to four years old. One adult male with several females and young form a stable family group. Babies are born after a 13-14 month gestation period and weigh about 80 pounds at birth; they are able to walk within 30 minutes of being born. Their mother produces nine pounds of milk per day, and calves are dependent on her milk for 12-18 months. Camels are primarily herbivorous, consuming a wide variety of vegetation including plants with thorns and dry plants that other livestock will not touch. Their upper lip is split in two, with each side able to move independently, allowing them to easily grasp many types of vegetation. Their feeding habits help keep fast growing plants in check, and seeds consumed by camels moving great distances are widely spread over the desert.

^{Camel caravan entering Timbuctu by RAS News & Events}

Camels have a naturally docile disposition and humans have been domesticating them for over 10,000 years. Many desert cultures are dependent upon these bonds. Modern forms of transportation have replaced some aspects of the human-camel relationship, but camels are still bred as pack animals and for milk, meat, hair, and camel racing. Dromedary camels account for about 95% of the world camel population; and as pack animals, they can carry 200 pounds for 30 miles. Camel hair is often used to make textiles including clothing, tents, and bedding. Outer guard hairs are waterproof, while soft inner hair is used for premium goods. Camel milk is a staple for drinking, but is just as often used to make yogurt, cheese, and ice cream. Their meat is rich in protein, vitamins, and essential nutrients.

Camels have some of the most unique adaptations found in the animal world, allowing them to survive comfortably in a very harsh habitat. You can learn more and see camels at most zoos.

Red Panda

The red panda, Ailurus fulgens, a small mammal closely related to weasels and raccoons, is found in the Himalayan and Tibetan mountain ranges of Nepal, Bhutan, and southern China. There are two subspecies, the Himalayan red panda and the Chinese red panda, differentiated by slight skull and color variations. They were isolated almost 200,000 years ago by glaciation in the Brahmaputra River Valley.

Red pandas live in steeply sloped, heavily forested areas where bamboo grows in dense thickets and there is easy access to water. Their habitat ranges in altitude from 6,500 feet to over 14,000 feet, in a temperate area with average temperatures in the upper sixties (Fahrenheit). These mountain ranges contain many protected pockets of forest, interconnected with wildlife corridors through unprotected country. Some areas overlap habitat where the Giant Panda lives, and the two species must share the bamboo in these locations.

_{Red panda, Ailurus fulgens, by Pixabay 27707, Sep 2015}

_{Red panda, Ailurus fulgrens, climbing at Taronga Zoo, by Charles Wong}

The red panda has a round head with a short snout and white fringed, triangular ears. Adults are 24″ long and weigh about 15 pounds. Their fur is dense, reddish-brown and covered with dark guard hairs. A black belly and legs, with a white muzzle and alternating red and buff rings along an 18″ tail, ensures that the red panda is well camouflaged in a forested area covered in red moss and white lichen. They have five curved claws on each foot that can be partially retracted in addition to flexible joints in their pelvis and hind limbs and an elongated wrist bone ending in a false thumb. All of these adaptations allow for a great range of motion when climbing and moving about the forest.

_{Red panda, Ailurus fulgens, mom and newborn by Rainer Halama, Jul 2013}

Red panda, Ailurus fulgens, twittering

The red panda lives in solitude, except during mating season in late winter when they cautiously seek out mates, resting and feeding near one another for short periods. Mating occurs on the ground, and gestation lasts 13 weeks, but can be prolonged up to 24 weeks at the discretion of the mother. The female selects a den site, building a nest of sticks, leaves, grass, and moss. Litters are between 1 and 4 babies weighing only 3 to 4 ounces at birth. Babies are born covered in fur for warmth, but blind for their first 18 days. They depend on their mother for everything for three to five months, and will not leave home until a year has passed.

_{Red panda, Ailurus fulgrens, sunbathing by Su-May, Sep 2011}

_{Red panda, Ailurus fulgrens, Conservation of energy by Tina R Tiller}

Red pandas move easily through the trees as well as over open ground. Trees next to bamboo stands provide places to sit higher up and eat, but the forest also provides shelter, an escape route from potential predators, and branches to sunbathe on in colder weather. If temperatures become too bitter, red pandas can lower their metabolic rates, curl into a tight ball, and sleep for a few hours to conserve warmth and energy. Bamboo makes up a large part of their diet, but it is supplemented with fruits, flowers, eggs, small mammals and birds. They prefer to eat early in the morning and late in the afternoon, while intermittently sleeping during the remaining hours.

_{Chinese red panda, Ailurus fulgens, named Kinta at Nogeyama Zoo, by Toshihiro Gamo}

Red pandas are on the endangered species list with decreasing populations near 10,000 in the wild. Their primary predators include leopards and jackals, which they can escape from using their climbing skills and agility through rocky and forested areas. But their main threat comes from poachers who prize their fur and bushy tails for the hat making industry and habitat destruction and land development that is steadily cutting large forests into small, isolated acreages. Red pandas have been well studied and are a favorite species at many zoos. Consider getting out this year to see them and learn more at a zoo near you.

Great Horned Owls

The great-horned owl, Bubo virginianus, is native to much of the Americas, including most of North America and Central America and about half of South America. It is the second heaviest owl in North America, right behind the snowy owl, Bubo scandiacus, weighing up to five-and-a-half pounds with a wingspan between three and five feet.

^{Great-horned owl, Bubo virginianus, by Andy Reago&Chrissy McClareen, Aug 2012}

^{Range and distribution of Great-Horned Owl, Bubo virginianus by BirdLife International, 2014}

Feathers cover the entire body, including their feet, and are varying shades of browns and grays. Their backs and heads are mottled or barred in several patches. This coloration, especially when coupled with mostly nocturnal activities, provides excellent camouflage. Their ‘horns’ are actually feathers sticking upwards on either side of their heads. These are called plumicorns, but their function is not well understood. The feather structure of the wing allows owls to fly silently and includes a serrated leading edge to disrupt turbulence and softer feathers behind to help deaden sound.

^{Great horned owl plumicorns by Jean-pol Grandmont, Aug 2013}

^{Great horned owl wing structure by Peter K. Burian, Aug 2015}

The owl’s ears are covered by feathers, but are not symmetrical with one being higher on the side of the head than the other. This arrangement provides the owl with the ability to triangulate sounds and precisely locate prey in the dark or when prey is hidden, such as when an animal is moving about under a layer of snow. Their flattened face, shaped as a round disc, also helps to direct sound to their ears. Like all owls, their eyes are fixed in the sockets, but the bird can swivel its head almost 180° to either side allowing it to see in all directions.

^{Great horned owl talons by Curtis Bouvier, May 2010}

Great horned owls hunt from a perch, observing the area below them before diving swiftly and silently from far above. Their diet consists of small mammals, birds, amphibians, and a variety of snakes. Their talons are powerful and deadly, with a grip comparable to much larger birds such as golden eagles. Most prey is killed by being pierced or crushed in the talons. Owls may hunt and kill for more than their immediate needs and will cache their kills for future meals.

Great horned owls are not migratory. When an owl is ready to mate, courtship occurs in late fall and pairs mate for life, establishing a territory together in which they will live their entire lives. Most territorial defense is through hooting at a transgressor, but rare physical confrontations have been observed. If an owl cannot establish its own territory, it will live in silence among the fringes of other territories.

^{Great-horned owl juveniles, Bubo virginianus, by Alan Vernon, Jun 2010}

^{Great horned owl female & juvenile on nest by John Kees, Apr 2012}

Males are responsible for picking a nest site, almost always taking over a nest constructed by another species. Mated pairs breed once every two to three years, laying from one to six eggs. Egg laying occurs between late February and early April. The female alone incubates the eggs, never leaving the nest, while the male hunts and brings her food. After about 33 days, the eggs hatch. Young owls will start to fly after seven weeks, but take a full month or more to become proficient.

^{Great horned owl calling, Bubo virginianus, by Michael & Katie LaTour, Jan 2019 (at 0:02, 0:10)}

^{Great-horned owl pair calling by Bushman, Dec 2013 (at 0:18, 0:41, 0:51, 1:22)}

Owls are more often heard than seen. Although the females are larger than males, females have a smaller voice box and thus a higher pitched hooting call ending with a slight rising note. Juveniles can make hissing or screeching sounds and are often misidentified as barn owls, Tyto furcata.

You can learn more about these magnificent birds at the Jurica-Suchy Nature Museum. Make a reservation to come see us by visiting our website at: https://ben.edu/campus-links/jurica-suchy-nature-museum/ (click on Register to Visit the Museum).

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.

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.

7 of the 15 hummers that breed in North America:
- Anna’s Hummingbird, Calypte anna, by Alan Scmierer-USFWS, Mar 2007
- Black-chinned Hummingbird, Archilobus alexandri, by Paul Crook-USFWS, Jun 2024
- Blue-throated Hummingbird, Lampornis clemenciae, by Alan Schmierer-USFWS, Jun 2024
- Broad-billed Hummingbird, Cynanthus latirostris, by Alan Scmierer-USFWS, Mar 2022
- Buff-bellied Hummingbird, Amazilia yucatanensis, by Alan Scmierer-USFWS, Jan 2010
- Broad-Tailed Hummingbird, Selasphorus platycercus, by Tom Koerner-USFWS, Feb 2024
- Allen’s Hummingbird, Selasphorus sasin, by Wendy Miller-USFWS, Jun 2024

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.

Remaining 8 species that breed in North America:
Calliope Hummingbird, Selasphorus calliope, by Barbara Wheeler-USFWS, Nov 2021
Costa’s Hummingbird, Calypte costae, by Wendy Miller-USFWS, May 2020
Rivoli’s Hummingbird, Eugenes fulgens by Doug Greenberg-USFWS, Aug 2017
Lucifer Hummingbird, Calothorax lucifer, by Jim Gain-USFWS, Mar 2022
Ruby-throated Hummingbird, Archilobus colubris, by Alan Scmierer-USFWS, Jun 2024
Rufous Hummingbird, Selasphorus rufus, USFWS, Jun 2024
Violet-crowned Hummingbird, Amazilia violiceps, by budgora, Mar 2014
White-eared Hummingbird, Basilinna leucotis, by Alan Scmierer-USFWS, Mar 2022

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.

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.

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.

Extinct & Endangered – pt.2

The International Union for Conservation of Nature (IUCN) gathers data through research and field projects on all known species of plants and animals. They work to educate people on conserving nature and sustainably using natural resources. The IUCN publishes a document known as The Red List providing the conservation status of all species. There are nine possible levels including Least Concern, Near Threatened, Vulnerable, Endangered, Critically Endangered, Extinct in the Wild, Extinct, Data Deficient, and Not Evaluated.

An endangered species is one that is likely to become extinct in the near future, either world-wide or locally in a known range. Critically endangered species are at extreme risk of extinction in the immediate future. A species is vulnerable when its population and breeding numbers are at risk, but have a chance to improve. Several factors considered are the current population size, how fast the population has increased or decreased over a short period of time, whether breeding rates are high or low, and what threats exist from habitat loss, poaching, and invasive species.

^{Eskimo curlew, Numenius borealis, @ Field Museum of Natural History by James St. John, Oct 2014}

The Eskimo curlew, Numenius borealis, spends northern hemisphere summers breeding on the Alaskan and western Canadian tundra. As the weather turns colder, they migrate to Argentina by flying east to the Atlantic Ocean, and then south. Although nests are built on open ground, they are difficult to find and study. Food includes berries, insects, and snails, but incubation and rearing habits have never been clearly identified. During migration in the mid-1800s, populations would darken the skies as tens of millions of birds followed the warmer weather. Eskimo curlews were hunted on both continents year-round. If a bird was wounded, the other flock members would circle back, becoming additional targets for hunters. Development cuts up large breeding areas to smaller sections reducing food sources and enabling predators to severely impact populations. The species is listed as critically endangered, although there has not been a confirmed sighting since 1963.

^{Proboscis Monkey, Nasalis larvatus, by Chris Smallwood, Jul 2013}

^{Proboscis Monkey, Nasalis larvatus, female with young by Martha de Jong-Lantink, Jun 2020}

The proboscis monkey, Nasalis larvatus, another endangered species, is found mostly in the mangrove forests in Borneo; it is one of the largest monkeys native to Asia. Living in swamps and lowland areas along rivers, they are excellent tree climbers and swimmers, having the ability to swim underwater for short distances. Their large noses, smaller in females and upturned in juveniles, are thought to make their calls louder and more attractive to the opposite sex. They communicate through a variety of calls to signal alarm and threat warnings, and to keep infants and group members close. Rapid loss of habitat to logging and oil palm plantations, plus hunting for their meat, considered a delicacy in some areas, have reduced populations by more than half in the last fifty years.

^{Whooping Crane, Grus americana, by Trish Gussler, May 2018; Whooping Crane, Grus americana, by Diana Robinson, Mar 2018; Whooping Crane, Grus americana, by Evangelio Gonzalez, Dec 2018}

The whooping crane, Grus americana, is one of only two crane species native to North America, and it remains on the list of endangered species although it may be starting a comeback. Birds build a nest on a slight rise in a marsh where one or two eggs are laid. Normally only one egg survives, and the juvenile stays with the parents for six to eight months. Populations were never large, but prior to European settlement, there were an estimated 10,000 birds. Hunting for meat and feathers, in addition to predation and habitat loss, drastically reduced population size from the mid 1800s to the early 1900s. Through several programs of captive breeding, wetland management, and extensive efforts to assist the juveniles in learning migration routes by following ultralight aircraft, populations have rebounded to about 600 today.

^{JSNM Extinct Endangered display; JSNM Eskimo curlew, Numenius borealis; JSNM Proboscis monkey face, Nasalis larvatus; JSNM Proboscis monkey, Nasalis larvatus; all pictures by DonArnold, Feb 2024}

In the final blog on this topic, we will take a look at a few success stories – species that have recovered with populations that continue to get stronger. Many nature museums have information and extinct species on display to learn from. All of the above species, and more, can be found at the Jurica-Suchy Nature Museum, so please stop by, or visit a local nature museum where you live.

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.

^{Jellyfish & jacks by melissaf84, Getty Images, Coral Sea; Whelks by Pack-Shot, Getty Images; Reef crab by JohnAndersonPhoto, Getty Images, Lembeh Strait, Indonesia; Posidonia seagrass meadow by Arnaud Abadie, Getty Images Signature, Mediterranean Sea}

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.

^{Pics 1&2: Green sea turtle, Chelonia mydas, by DonArnold, JSNM 2023; Pics 3-6: Hawksbill sea turtle, Eretmochelys imbricata, by DonArnold, JSNM 2023; Pic 7: Loggerhead sea turtle, Caretta caretta, by DonArnold, JSNM 2023}

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.

^{Hawksbill portrait, Eretmochelys imbricata, by Sheraca, Dec 2014; Hawksbill sea turtle, Eretmochelys imbricata, by Goug Finney, Sep 2019}

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.

^{Kemp’s ridley sea turtle, Lepidochelys kempii, by USFWS, Sep 2010}

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.

^{Green sea turtle, Chelonia mydas, by Florida Fish&Wildlife}

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.

^{Leatherback sea turtle, Dermochelys coriacea, by Claudia Lombard, USFWS, Jun 2011}

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.

^{Olive ridley sea turtle, Lepidochelys olivacea, by Charles Peterson, Head Start Programs, Oct 2002}

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.

^{Loggerhead sea turtle, Caretta caretta, & epibionts by actor212, Aug 2017}

Puffins

Puffins are part of the Alcidae family of seabirds along with murres, guillemots, auklets, murrelets, and 25 recently extinct species. All members of the family can fly and are excellent divers and swimmers. Three species are found in the North Pacific Ocean including the tufted puffin, Fratercula cirrhata, horned puffin, Fratercula corniculata, and rhinoceros auklet, cerorhinca monocerata. The Atlantic puffin, Fratercula arctica, is the only species found in the North Atlantic Ocean.

^{Images clockwise: Atlantic puffin, Fratercula arctica, portrait by stockomotion, Getty Images Signature; Horned puffin, Fratercula corniculata, showing horns over eye by webguzs, Getty Images; Tufted puffin, Fratercula cirrhata, on the water by Bruce Block, Getty Images Signature; Rhinoceros auklet, Cerorhinca monocerata, by nikkigensert, Getty Images}

The rhinoceros auklet was thought to have been misidentified when it was first discovered and named. However, DNA testing has shown that all four puffin species have a common auklet ancestor. Puffin species have short, stocky wings and tails, with darker gray-to-black plumage on top of their heads and backs and lighter whitish-to-brown plumage on their faces and underparts. Their bills change color during breeding seasons to display several stripes of red, orange, yellow, and black.

Tufted puffin, *Fratercula cirrhata*, breeding coloration by MrDaz, Getty Images Signature

Short wings require the birds to beat them quite fast to fly, about 400 beats a minute, but they achieve speeds of 45 to 55 mph in flight. Short wings are used as powerful flippers underwater along with feet used as rudders. Puffins can dive to 200 feet or more catching a dozen or more small fish and invertebrates as they swim through the water. A uniquely designed hinge on their bill allows the top and bottom bill to meet at several different angles so the bird can add more fish without losing its grip on any that are already caught.

^{Images clockwise: Horned puffin, Fratercula corniculata, with fish catch in Alaska by Gerald Corsi, Getty Images; Atlantic puffin, Fratercula arctica, with catch by Daniel Jara, Getty Images; Rhinoceros auklet, Cerorhinca monocerata, with seven fish Andrew Reding, Jul 2010}

Puffins spend winters at sea, far from land, floating on the surface or pursuing prey. Breeding season occurs in late spring, and most adult birds come together, forming large colonies containing breeding and non-breeding individuals. Non-breeding birds spend hours each day exhibiting a behavior called wheeling flight – flying figure eights over the cliffs where the colony is located. After finding a mate, puffins form long-term pair bonds. After breeding, pairs may split up when out at sea, but often return the next breeding season to find the same mate and nesting site. Puffins breed in large colonies on coastal cliffs of offshore islands. Only one egg is laid and both parents incubate the egg and feed the chick. Chicks fledge at night, and juveniles spend the first five years out at sea before returning to the breeding colonies.

^{Horned puffin, Fratercula corniculata, nesting on Latrabjarg Cape, Vestfirdir, Iceland by Nikolay Tsuguliev, Getty Images}

^{Atlantic puffin roost by Shankar S., May 2016}

Puffins are not considered endangered, but are starting to encounter trends affecting the continuity of their successful breeding. Warming waters in the oceans are reducing populations of fish that breed and live in cold water areas, that are the favorite prey of the auk family. Threats on the mainland of Iceland, historically one of the largest breeding colonies, include being hunted by mink introduced in the 1930s, so most colonies are now located on offshore islands. Hunting for feathers, eggs, and meat has been sustainable on island ranges for hundreds of years. However, hunting on the American mainland during the late 1800s and early 1900s eradicated the population at one point. In the last 50 years, about 50,000 birds have returned to protected areas in Maine. Their biggest natural predator is the great black-backed gull which dive-bombs and picks off birds near shore during breeding periods.

^{Tufted puffin, Fratercula cirrhata, spreading its wings by TiannaChantal, Getty Images}

Puffins have an average lifespan of over thirty years, spending most of their lives out at sea. Reproduction rates are low with only one chick born each year to a pair of puffins, but a breeding pair may produce twenty chicks in their lifetimes and threats from natural predators are small. Puffins are favorite species in many zoos and some aquariums. Learn more by visiting a local institution or take a virtual tour from a live webcam at: https://explore.org/livecams/puffins/puffin-loafing-ledge-cam.

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, 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.

^{Red Admiral butterfly on buttonbush by DonArnold, Jul 2023; Honney bee on buttonbush by DonArnold, Jul 2023; Long-tongued tiger swallowtail on buttonbush by Owen Sholes, Getty Images}

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.

Ferns

Ferns are a group of well-known plants that first developed during the carboniferous period about 350 million years ago when the climate was stable, warm, and wet. Ferns were globally abundant in woodlands and marshlands providing suitable habitat for them.

Ferns were the first group of plants with vascular systems. Vascular plants utilize tube-like structures, called xylem tissue and phloem tissue. Water and minerals are moved from roots to fronds (leaves) through the xylem tissues and are used in photosynthesis to create food that is distributed throughout the rest of the plant in phloem tissues. Vascular systems also provide internal support so these plants can stand upright on their own.

^{Fertile fronds, Christmas fern in Sheipsit State Forest, CT by Holcy, Getty Images}

Early scientists noted that ferns came back every year, but produced no flowers or seeds. In 1669, it was discovered that spores grew on the surface of the fronds, but it was not until the mid-18th century that the entire reproductive process was understood. Spores are one-celled organisms that start to develop in springtime. They appear by the thousands as small green bumps on the undersides of fronds. As summer progresses, the sporangia, a capsule that contains the spore, turns brown. Clumps of these are called sori, and can easily be observed on fern fronds. In late summer, when the sporangia mature, they open and release their spores. Some plants will forcefully shoot their spores away from the fronds and some will open and let the spores drift away, caught by any small breeze.

^{Polystichum richardii in Stanley Park, Akaroa by Jon Sullivan, Aug 2006}

^{Lady fern sporangia by Kerry Woods, Mar 2013}

Most spores will not land in a spot with favorable growing conditions (fertile soil and water), but the spore may remain viable for up to a year, should conditions change. Spores do not contain a small plant like a seed does. A spore starts as a one-celled organism that grows by dividing itself in two during the first phase of reproduction called the gametophyte generation. As this division continues, a small structure called a prothallium grows, getting its nutrients directly from contact with water. Two more structures develop. The archegonium contains an egg, and the antheridium contains sperm. When water is present, the sperm will swim to the egg, fertilize it, and eventually a new, self-supporting plant grows.

^{Crozier shaped fronds by Ray Hems, Getty Images Signature}

The fern develops underground over the winter. In spring, when ground temperatures have risen, fernlets will push tightly coiled fiddleheads through the soil into the open air. A fiddlehead, also called a crozier, is a group of young, coiled fronds (leaves) of a fern. As the fern grows, the upper and lower surfaces of the fronds grow at different rates, and the fiddlehead uncoils, straightening out into several fronds. The plant is entering the second phase of reproduction, known as the sporophyte generation, where spores will be grown on the undersides of the fronds.

^{Green Boston fern frond, Nephrolepsis exaltata by Noppharat05081977 Getty Images}

^{Staghorn fern frond veins by IveehCoombs_Photography, Getty Images}

^{Staghorn ferns by Eyepark, Getty Images}

Ferns can also reproduce through cloning. The walking fern, Asplenium rhizophyllum, grows long fronds that eventually bend over and touch the ground. Wherever a tip touches moist soil, new roots are sent out, and a cloned plant develops. The Boston fern, Nephrolepsis exaltata, grows runners – leafless stems that branch out horizontally. Wherever they come in contact with moist soil, roots are sent out to clone another Boston fern. The staghorn fern, Platycerium sp, grows buds on its roots. As the soil around the plant is moistened by water containing nutrients, a new plant pushes upward through the soil from each bud.

^{Walking fern, Low Tatras mountains, Slovakia by Vrabelpeter1, Getty Images}

Ferns grow well in a variety of habitats. Many species prefer damp woodlands, but some grow on cliff faces or in rocky, dry locations. Be sure to watch for various species of ferns when you are out walking. A good field guide can help with fern identification and provide distinguishing information on this amazing plant group.

Bird Eggs

It is spring in the northern hemisphere, and many birds are claiming territories, finding mates, and establishing nesting sites. Raising new families will take most of the summer and early autumn. As we watch birds who have laid their eggs, it may seem that not much happens until the young hatch, but there is lots of activity taking place.

^{RWBB calling by mirceax from Getty Images}

An ovum, the female reproductive cell, starts its journey to become an egg in the oviduct where it is fertilized by stored sperm from a male and encased in a glob of protein-filled gelatin to form a yolk. Additional proteins, known as the albumin or egg white, are added to nourish the embryo as it grows inside the egg. Calcium carbonate, a mineral added by special cells in the bird’s uterus, encloses the gelatin-like mass of protein and embryo, slowly hardening into the egg’s shell. Egg shells are not completely solid, but are perforated with many minute holes that allow air to reach the developing embryo. Pigmentation is squirted onto the shell adding color and pattern to the outside. A coating of protein determines the outer texture of the egg which may be smooth, glossy, dull, rough, or powdery.

^{Egg collection, Jurica-Suchy Nature Museum, Benedictine University, Lisle by DonArnold}

The total number of eggs laid at one time is called a clutch and some bird species lay only one a year, but many species produce two, or more, annually. A consistent number of eggs is found in each clutch, although additional clutches in the same year may contain fewer eggs. Eggs vary widely in size, shape, and color among various bird species. Egg shapes may be determined by the location of the nest. Cavity nesters tend to have rounded eggs, while cliff dweller’s eggs are often oval with a broad end on one side and a pointed end on the other to prevent the egg from rolling very far. Where a clutch has a greater number of eggs, pointed shapes fit into smaller spaces enabling the mother to easily cover them all when sitting on the nest.

^{Nesting female hummingbird by jaypiercestorffphoto}

Incubation is the process of keeping the eggs warm. An adult usually develops a brood patch underneath its belly where feathers and down disappear and blood vessels close to the skin’s surface can warm the area that is in direct contact with the eggs. Incubation periods are consistent in each species, but may be lengthened by abnormal cold spells.

^{Blue robin eggs in nest by Dennis Flarsen, Pixabay}

^{Western bluebird eggs by Summit to Seashore Birding, Sep 2007}

Color is added into the shell material before it hardens. Colors may vary in hue and saturation on individual eggs, and the deepest hues are often found at the largest end. Pigments are chemicals with complex molecular structures that produce color when mixed with water. Birds have two pigments: reddish-brown hues and bluish-green hues. Here are several theories as to why eggs have markings, but exact reasons are not known.

Heavier pigments are often found in birds that lay their eggs in open, exposed environments, and the markings may serve as camouflage. Many cavity nesters lay white eggs, which are well hidden from other birds, predators, and the sun. Some eggs laid in exposed nests may still be brightly colored, but covered by the female most of the time.

^{Quail eggs showing pigmentation by Piyachok from Getty Images}

Darker colors and markings are often found among species that breed in cooler climates. Pigments are known to absorb UV radiation from the sun and not allow it to harm a developing embryo. But, light absorption by an area of pigmentation generates more heat inside the shell, which may also be harmful. Pesticides and other chemicals in the environment can cause thinning of the shell casing, making them more susceptible to breakage. Pigments tend to gather at weaker spots in the shell casing and have been shown to strengthen the shell.

Several aspects of bird egg development are not yet understood, and many theories are under investigation. An interesting question currently under review is whether a bird, or another animal such as a predator, sees different aspects of the light spectrum than humans. If so, what do birds see when they look at an egg? A new bird’s life starts in an egg, a small and wonder-filled package that has been much studied and yet still presents many unanswered questions.

To learn more, consider visiting your local nature museum.

The Jurica-Suchy Nature Museum at Benedictine University in Lisle, Illinois, has an extensive egg collection displayed by clutch size and covering almost 200 bird species.

Frog Calling

Spring has arrived bringing rising temperatures, warm winds, and spring rains to the upper Midwest. This is the time of year when many amphibians, most notably salamanders, frogs, and toads, start their annual breeding periods. Illinois has nineteen native frog species. They are secretive and difficult to find most of the year; but spring is the season for mating, and males will leave their woodland homes and make their way to the nearest pond on nights when temperatures stay in the forties or above.

Frogs use a variety of different calls. Advertisement calls, the loudest calls voiced by male frogs, advertises their presence and availability to potential mates. The courtship call, a slight variation of the advertisement call, is used as a female gets close to direct her to the exact location where the male is waiting. If a male mounts an unreceptive female, or mounts another male, which can happen by mistake in the dark, a release call is emitted to inform the male to stop and look for another potential mate. Aggressive calls may be used by one male towards another who gets too close. And if any frogs are attacked by a predator, a loud distress call is made. This may be to startle the attacker or warn other frogs in the area.

^{Waterfall Glen gray tree frogs calling by DonArnold, 2022}

Calls are created by filling the lungs with air, and then blowing out a steady stream of air over the vocal chords. When calling, the mouth and nostrils are normally closed. The air is passed from the lungs, over the vocal chords in the larynx and into the air sac under the mouth. This air sac, shown in many frog pictures, amplifies the sound to help it carry farther. Calling requires considerable energy and may increase the metabolic rate, the rate at which calories are used, from ten to twenty times the resting rate of an individual. For frogs with breeding periods lasting many weeks, the expenditure of calories will cause a male to lose a significant amount of body weight.

^{NoName Marsh, Boreal Chorus & Spring Peeper by DonArnold, Mar 2022}

Many different species of frogs lay their eggs in the same ponds. Males arrive early in the evening and begin advertising, while females arrive a bit later and identify a potential mate based on his call. When a gravid female approaches, the male clasps her from on top and holds on. After a time, the female releases her eggs in the water, and the male immediately fertilizes them by releasing sperm into the water around the egg sac. Depending on the species, all of the eggs may be deposited in one egg sac or in several separate egg sacs. Egg laying can last several minutes to several hours. After each group of eggs is laid, the male and female may separate or rest for a brief period and then move to another spot to deposit more eggs.

Their skin is moist and cool to the touch. It is permeable, allowing air to pass directly through it into their circulatory system, helping to remove some of the workload from the lungs and heart. This can be especially useful during inclement weather. However, the skin’s permeability makes them susceptible to drying out, so they live in or close to water or high humidity environments. Their lifestyle includes being active mostly at night or on overcast days when it is cooler and more humid.

^{From left: Spring peeper calling by Andrew Hoffman, Jan 2000; Ornate chorus frog calling by FWC Fish & Wildlife, Jan 2014; Green tree frog calling by Eyeweed, Dec 2009}

Many frog populations have been impacted by losses of both wetland and forest habitat. Wetlands are used for breeding and forests provide sheltered areas with shade, ground cover, and higher humidity than areas open to bright sunlight. During spring evenings or overcast days, listen closely as you pass by these shady areas and nearby ponds to catch sound or sight of these wonderous small creatures.

At The Waterhole

Last week, we discovered adaptations that allow elephants to deal with gravity and heat. Asian elephants live mostly in tropical forests that are warm from plenty of sunlight, although very little light reaches through the canopy to the forest floor. Rainfall may be intermittent, and shade-tolerant vegetation changes with a lack or an abundance of water. African savannas have lots of grasslands with a few trees and shrubs. They have distinct wet and dry periods, but grasses grow deep root systems that sustain them throughout the year. African woodlands are more open than Asian forests allowing a variety of trees and shrubs that grow well in full sunlight.

Elephants live in large groups, called herds, led by the strongest adult female. The herd members include all the females plus any males who not yet teenagers. The matriarch knows where to find food and water. She is aggressive when it comes to protecting the rest of the herd and is always the first to confront any threat. Males grow into bulls and will start to fight other males in their teen years. Once this aggression starts, the matriarch will kick the young bull out of the family. Bulls travel alone or together with other bulls, but it is a dangerous time for them because they do not have the support and knowledge of the matriarch for finding food and water.

_{^{The Herd by WLDavies, Getty Images Signature}}

Elephants are old enough to mate in their mid-teens. Pregnancy lasts 18-22 months, and each cow has a baby once every five years until they are in their forties. The herd is very social and several females take care of each calf. Water holes are places where the herd engages in many social activities. Elephants use water to drink, to swim and play in, and to bathe. However, bathing for an elephant means getting dirty, not clean. Elephants stir up the edges of a water hole to create mud to wallow in. Or they will cover themselves with water followed by dirt sprayed on their bodies with their trunks. Dried mud provides cooling from the sun and keeps biting insects away from tender skin. Elephants love water and bathe often, helping to keep skin moisturized.

Lovely mud by bucky_za, Getty Images Signature

Food eaten daily includes about 300 pounds of grass, tree bark, fruit, and other green vegetation. Elephants also need salt to supplement their diet. Their tongues are too short to lick anything not in their mouth, so they use their tusks to dig furrows in the ground and pile up soil and stones. Large stones can be placed into their mouth to lick salt from, and small stones are ground up by their huge molars. Food eaten daily includes about 300 pounds of grass, tree bark, fruit, and other green vegetation.

African elephants are larger than Asian elephants and males are larger than females in all species. Asian elephants average life span is about 80 years in the wild, while African elephants live only 60 years. They are excellent swimmers, often submerging their whole body underwater except for their trunks, which are used as snorkels to breathe. On land, they are slow moving, but can run short distances at better than 20 mph. They use many vocalizations to communicate such as grunts, rumbles, trumpets, screams, and purrs, and they can use their trunks to modulate sounds.

A thousand years ago, ivory was a hot commodity, and hunters exterminated elephants in North Africa. In the last century, after remaining populations were severely depleted by the late 1800s, many countries banned the trade of ivory. Elephants are recovering today, but poaching continues to be a serious threat. As more humans have moved into their native ranges, existing populations have to live in smaller areas. At their rate of food consumption, vegetation does not have enough time to grow back, and herds today are experiencing food shortages. Several conservation organizations are working to provide land for the establishment of wider ranges, care for orphaned elephants, and combat poaching.

You can see and learn more about these wondrous animals at your local zoo or natural history museum.

^{Clockwise above: African bush elephants by designerpoint, Pixabay; Masai Mara elephants by tankbmb, Getty Images; African elephant by Donvanstaden, Getty Images; Friends by cocoparisienne, Pixabay; Asian elephant by miharing, Getty Images}

Duck Potato Salad

Walking around a freshwater marsh, we can observe dozens of plants and animals. Daily sunlight provides hours of energy, but it is only usable by the plants, which create their own food in a process called photosynthesis. Plants may be fully submerged, floating, or living above the water’s surface, but all are vital components of the food supply.

^{Marsh panorama by Beyond_Invisible, Getty Images}

Just as animals breathe, plants also need to exchange gases, taking in carbon dioxide and releasing oxygen. Plants living in a marsh, where they are fully or partially saturated with water, have developed several strategies for the gas exchange process. Spongy tissue is a universal adaptation of marsh plants. Both stems and leaves contain large airspaces surrounding food producing cells which are well distributed throughout the plant. Airspaces also keep the plants lightweight and enable stems, leaves and flowers to float on or reach above the water’s surface.

Floating wisps of green algae are primitive plants that have been on earth for over two billion years and are the basic food source for all life in the marsh. Millions of microscopic animals, crustaceans, insects, and small fish depend directly on green algae for their food. Green algae lack stems, leaves and flowers, but grow as long chains of nearly identical cells. Some algae are microscopic, some can be easily observed as green strands on or below the water’s surface and some grow to several hundred feet in length.

^{Duckweed forest pond by Sunsju, Aug 2019}

Duckweeds refer to a group of tiny, flowering plants that float on the surface of wetland areas. They reproduce by dividing their cells. This is a rapid process taking from 16 to 48 hours. In optimal growing conditions, with plenty of sunlight and nutrients available, the surface area of a pond can be covered in a very short period of time. Several species of pond plants grow long, narrow leaves with soft, nourishing cells providing a easy-to-eat and tasty treat for marsh dwellers. With large airspaces, these plants are able to stay afloat no matter how long they grow.

^{Spatterdock by Kirill Ignatyev, Jul 2011}

Plants with floating leaves, such as spatterdock, must have a method for preventing excess water from entering leaves and stems when they exchange gases. Plants have stomata, openings in the leaf where gases are exchanged. In terrestrial plants, stomata are located on the undersides of leaves to prevent rain from entering the opening. Floating leaves have stomata on the upper side of the leaf, providing far less exposure to water.

^{Water marigold by Gennady Alexandrov, May 2014}

Water marigold has two types of leaves, one that grows on the stem above the water’s surface and another that grows on the submerged stems. Leaves growing in air take in carbon dioxide and release oxygen through their stomata. Submerged leaves have very thin cell walls and exchange the same gases directly with the water surrounding them.

^{Arrowhead with bulb, -duck potato’, lower right, by Andriy Nekrasov, Getty Images}

Arrowhead is firmly anchored in the bottom of ponds, and has stems, leaves, and flowers growing above the surface. It reproduces by both seeds grown from pollinated flowers and bulbs grown on submerged stems. Bulbs remain submerged, attached to the stem and grow until they are mature enough to anchor themselves in the bottom silt and start another plant. While growing, the bulbs are very tasty and are a favorite food of many duck species, earning the nickname duck potatoes.

^{Wild celery, Vallisneria americana, by Schizoform, Jun 2022}

Wild celery produces both male and female flowers. Female flowers are attached to long stems that float on the water’s surface. Male flowers break off underwater and float to the surface unattached, where they are blown around until they meet a female flower, transferring pollen by contact. The pollinated flower coils downward back under the surface where the seeds develop and are released into the water to start a new plant wherever they land on the silt bottom.

Marsh plants come in many forms and each is well adapted to the unique conditions of the habitat in which they live.