The cool, clear, fast-flowing rivers and streams of the Eastern United States are home to a unique species. It is the third largest salamander in the world and it lives almost exclusively in the water – it is known most commonly as the Hellbender.
The hellbender’s flattened body shape and head plus its slimy skin help it move through the fast flowing waters that it needs to survive. Though it possesses lungs, hellbenders take in up to 95% of their oxygen through capillaries in their skin. Hellbenders skin has many folds and wrinkles along the surface, most notably along the sides of the body. These wrinkles create more surface area for the intake of oxygen. Their lungs are used primarily for buoyancy.
The have a strong, thick tail that aids in swimming and propulsion through the water though often they will walk on the river bottom. Their short limbs and webbed feet each have toe pads that help them maintain traction and grip on the slippery surfaces below.
A hellbender spends most of the daytime hours lying concealed beneath large smooth river rocks – it emerges at night to hunt. Exclusively a carnivore, it’s favorite food is crayfish. Hellbenders uses a suction feeding behavior to help uproot crayfish from the muddy river bottom. In addition to crayfish, they are also known to eat insects, small fish and even other, smaller hellbenders.
First discovered in the Allegheny Mountain portion of the Appalachian chain of the eastern United States, hellbenders are sometimes known as the the Allegheny Alligator. Other regional names include “devil dogs”, “lasagna lizards” and “snot otters.” There are two subspecies of the salamander, the Eastern Hellbender and the Ozark Hellbender which is found only in parts of Arkansas and Missouri.
Growing up to 30 inches long and weighing up to 5 pounds, the hellbender is North America’s largest salamander species – only the Japanese and Chinese salamanders are larger: each able to grow to nearly 6 feet long. Typically hellbenders are reach a length between 12 and 15 inches long.
Their skin is usually a yellowish to olive brown color, though sometimes they may be grey or even black. It is covered in a mucus layer that may aid in avoiding or detering prey.
Like snakes, hellbenders possess the Jacobson’s organ in the roof of their mouth that aids in chemical detection and smell. They can detect certain native fish species – both prey and predator.
Like sharks, hellbenders also utilize a lateral line system of sensors along it’s body to detect vibrations from movement in the water around them as well as light detection, and water pressure. They have lidless eyes but relatively poor vision, relying more on smells and movement detection to hunt and evade prey such as small-mouth bass and trout.
Hellbenders live solitary, territorial lives only coming together for breeding season between September and November. Males will select a hollowed out area beneath river rocks for the female to lay up to 500 eggs. Males will guard the nest until the larva hatch. Like many other amphibians, the larva are fully independent upon hatching.
Hellbenders reach maturity between 5 and 8 years old and can live up to 15 years in a healthy, native habitat – some hellbenders in managed care have lived twice as long.
As a primary consumer of crayfish and as a food source for larger fish, the hellbender is vital to a balanced ecosystem among the many streams and rivers of the eastern United States. Their dependence on clean, clear and heavily oxygenated flowing water also make them a key indicator species for the habitats where they exists.
Unfortunately due to pollution and toxins entering many waterways, as well as man-made dams interfering with steady water flow and limiting the animals abilities to reach one another during mating season – the hellbenders numbers are on the decline.
Accredited zoological facilities such as the Buffalo Zoo, Bronx Zoo and the Cincinnati Zoo currently participate in conservation programs to oversee breeding and reintroduction of hellbenders back into their native, fresh water habitats.
Found throughout most of North America except the desert regions of the Southwest – Beavers inhabit ponds, lakes, rivers and streams, marshes and adjacent wetland areas.
North American beavers have stocky bodies with shades of brown to almost black coat of fur and a broad, flat, scaly tail. The stocky body build enables the beaver to conserve heat.
A signature mark of the beaver is its prominent front teeth. These long, visible incisors grow continuously throughout its life and are worn down through daily use. These teeth are self-sharpening and can cut through a branch the size of a person’s finger in a single bite. Without the self-sharpening properties and constant work the incisors can become too long, which can prevent the beaver’s mouth from closing enough for its grinding molars to meet, which could lead to starvation. A beaver’s teeth are orange in color due to the high levels of iron in their enamel. The iron provides for much stronger teeth that are also more resistant to acids and tooth decay.
Beavers are herbivores, eating leaves, woody stems and aquatic plants. Their chief building materials are also their preferred foods: poplar, aspen, willow, birch and maple. Beavers are mainly nocturnal creatures – though with very little light inside their dens, their activities are not always synchronized with normal day and night cycles.
Beavers regularly move between land and water environments. Their small front feet are well adapted to working on land. They walk on five digits, grasp sticks with their front paws and have well-developed digging claws. Their larger hind feet are webbed for swimming and lack fur except on the top surface.
The hind feet also have a preening toe, the second from the inside, with a unique double toenail. Beavers are meticulous groomers. They use the preening toe as a comb to prevent their fine, soft fur from matting to maintain its waterproofing and insulating properties. These flexible toes also remove burrs and parasites.
On land, a beaver’s movements can be rather awkward and slow, making them vulnerable to predators. In the water, however, beavers can swim up to 6 mph. Their large lungs allow them to stay submerged for up to 15 minutes while traveling over half a mile.
Whiskers help detect objects around a beaver’s face and head, which is especially helpful in narrow passageways and dark water. The beaver’s eyes have a thin, transparent membrane, called a nictitating membrane, which aids in visibility and protection underwater – though a beaver’s sight is good only for short distances and at close range. Beavers have external, small and rounded ears with valves that close while submerged – they have a well developed sense of hearing which aids in detecting possible predators such as coyotes, wolverines and bears.
The shape of the beaver’s tail is unique to an individual but similar among related animals – varying from short and broad to long and narrow. It is hairless and covered with black scales. There is a distinct line between the fur covered body and tail with the fur remaining at full length and density right up to this line.
The tail is used as a rudder in swimming, as a balance prop while working on land. The beaver’s tail is also used for communication – they will often slap their tail on the water’s surface to signal danger when threatened. Beavers will also store fat in their tails, eating more in the fall so they can survive off the fat stored in their tails through winter if food is not available.
Beavers are one of the few animals that modify the habitat where they live. Known for building watertight dams of comprised of sticks woven with reeds, branches and saplings, which are then caulked with mud.
These dams reduce stream erosion by forming slow-moving ponds which serve as habitats for a wide range of small aquatic life and also provide water and food for much larger animals. By building dams, beavers create new habitats that can support an incredibly diverse biological community.
Beavers also build dome-like lodges that can rise 6 feet or more and can reach widths more than 35 feet across. Each beaver lodge can have one or more underwater entrances and living quarters are located in the top of the lodge above the water line.
Often built away from the shore, these lodges form islands that can only be entered from underwater. The lodge chamber is insulated by walls sometimes more than a foot thick and ventilated by a small air hole in the roof called a “chimney.” Typically, the floor is covered in wood shavings to absorb excess moisture and provide bedding. Beavers spend the summer and fall building dams and gathering and storing food for the winter.
Beavers are the largest rodents in North America and the second largest in the world (South America’s capybaras being the heaviest). Beavers are 3 to 4 feet in length and weigh between 35 and 65 pounds. According to the Smithsonian’s National Zoo the heaviest beaver on record weighed 110 pounds.
Newborn beavers – called kits – weigh about 1 pound. They take to the water inside the lodge within a half hour after birth. They are skillful swimmers within a week but are too buoyant to dive at this age. They typically stay close to their mother in the lodge for the first few weeks. Often a female beaver will sit upright to nurse.
On land, mothers often carry kits on their broad tails, sometimes even walking erect and holding them in their paws. In the water, kits may rest upon their mother’s back. The young remain with their parents for two years, helping with lodge maintenance and raising the next generation of kits until they are, usually, driven away just before the birth of a new litter.
Beavers form strong family bonds. They are social animals, and each group is made up of one breeding pair – believed to mate for life, the newest born kits and the surviving offspring from the previous year, called yearlings. There may also may be one or more sub-adults, 2 years or older, of either sex from previous breeding seasons. These sub-adults generally do not breed.
In winter, these family groups live together in their lodge and share food from the common supply. Their family life is based on a hierarchy in which adults dominate yearlings and yearlings dominate kits.
North American beavers typically live 10 to 12 years. The oldest on record lived 30 years in human care.
Some call it the thunderbird. Seen as a symbol of power by Native American tribes, the greatly respected creature was believed to bring thunder with the beating of it massive wings: the California condor.
Once known as California turkey vultures, California condors are a huge species of vulture with a wingspan of up to nearly 10 feet and weigh around 18 pounds, males are typically larger than females. They are the largest flying land bird in North America and only one of two condor species in the world – the Andean condor of South America being the other.
Adults are mostly black with white, triangular patches on the underside of their wings. Their head is bald and pink or orange in color. Juveniles are brown, the triangle markings on their wings have dark patches and their head is black.
Their wings are designed for soaring rather than flapping flight. By riding air currents they can soar for hours without even beating their wings. They have been observed flying at altitudes of 15,000 feet and at speeds of up to 55 mph! Though they spend more time roosting than flying.
All vultures play a vital role in their ecosystem by eating carrion – the remains of deceased animals – this helps reduce the spread of disease among other animals and people. Like other vultures, California condors are scavengers; they don’t hunt other animals. They’ll eat anything from dead rodents and deer to stranded marine mammals. They’ll will often gorge themselves on 2-3 pounds of food at a time and can even go several days without eating. The condor seems to prefer fresh carcasses.
California condors don’t have a good sense of smell like turkey vultures do, instead they use their excellent eyesight to find a meal.
They have a hooked beak that’s used for tearing meat. While they possess long talons, they have relatively weak feet. Due to their beak shape and talons they were once classified as falcons.
Their featherless head helps prevent the rotting food from sticking to them. After they eat, they’ll rub their head on grass or rocks or bathe in water to clean themselves.
Their bald head may also aid in regulating their body temperature and vultures are known to urinate on their legs to cool down – a process called “urohydrosis”.
These birds don’t have a voice box or vocal cords and can only grunt and hiss.
They may gather in large groups around roosts, feeding and bathing sites.
They are generally monogamous, and may mate for life. However if one mate dies the other will typically find a new mate in a year or two. They start breeding at 6 years of age.
California condor females only lay one egg at a time, but may lay a second as a replacement if the first is lost. The exhibit a very slow reproductive cylce as pairs only average one chick every 2 years. Both parents incubate the egg and take care of the chick.
Incubation lasts nearly two months. The chick will use the sharp point on its beak, called the egg tooth, to pip open the egg shell, but it can take hours or several days to completely hatch. Chicks may fledge as early a 5 months old.
California condors can live up to 60 years. They can live in a wide range of habitats, such as mountainous areas, forests, oak savannas, grasslands and seashores.
The California condor once lived along the pacific coast of North America, from British Colombia to Baja California, though fossils suggest they once lived as far as what is now Florida and New York.
Habitat loss, poaching and lead poisoning are some of the things that lead to the drastic decline of these incredible birds.
California condors nearly went extinct in the 1980’s. Only 22 individuals remained – 20 in the wild and 2 in captivity. Wild eggs were collected and artificially incubated and in 1983, the San Diego Zoo became the first facility in the world to hatch a California Condor in managed care.
In 1987 the last bird was brought into human care. A captive breeding program was started in order to hopefully save the species from extinction.
Some chicks have been hand raised by animal care specialists using a puppet that resembles an adult condor. This minimizes the chance of the chick imprinting on humans.
By the 1992 captive-bred condors were being released into wild. The birds have also been trained to avoid power lines and people. More than 40 wild condors have produced viable offspring.
Though it has been banned, DDT still posses a threat as condors may eat the remains of contaminated marine mammals. And they still face threats like habitat loss, lead poisoning and micro-trash. Lead poisoning is a big problem for condors. Carcasses of animals that have been shot with lead bullets and left behind can be a tempting meal for these scavengers.
The condors may also mistake pieces of plastic, glass or metal as bone fragments which they often gather for their chicks.
Due to the ongoing and exhaustive work of several zoological and avian care facilities, there are now more than 460 California condors in the world with more than half living out in the wild in Southern California, Arizona, Utah and Baja California, Mexico and their numbers are increasing. Key facilities at the forefront of the California condor conservation include the Los Angeles Zoo, Oregon Zoo, Idaho’s Peregrine Fund and the San Diego Zoo.
The thunderbird is once again soaring high over North America as another success story – highlighting the importance of supporting your local zoo and their research and conservation programs.
Special thanks to the following organizations for their education, research and conservation programs that provided information for this episode:
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