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Join this family as they document every animal on their journey through the zoo.

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Animals of the National Zoo, Washington DC.mp4

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Phone: 202-633-3055
Email: ZooSCBICommunications@si.edu

Welcome to the newsroom for the Smithsonian's National Zoo and Conservation Biology Institute. If you are a reporter and would like to arrange an interview or get more information on the Zoo's animals and conservation science research, or request photos or video, please contact the communications team to facilitate your request. Before calling to discuss stories on some of the most-covered topics, media are encouraged to look over online resources for details on the Zoo's giant pandas, Asian elephants, and the Smithsonian Conservation Biology Institute.

To be added to the Zoo's press release distribution list, please fill out the contact form on the right side of this page and use the subject line: "add to distribution list."

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Phone: 202-633-3055 Email: ZooSCBICommunications@si.edu Welcome to the newsroom for the Smithsonian's National Zoo and Conservation Biology Institute. If you are a reporter and would like to arrange an interview or get more information on the Zoo's animals and conservation science research, or request photos or video, please contact the communications team to facilitate your request.

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Bio.2.1.4 Explain why ecosystems can be relatively stable over hundreds or thousands of years, even though populations may fluctuate(emphasizing availability of food, availability of shelter, number of predators and disease).

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Bio.2.1.4 Explain why ecosystems can be relatively stable over hundreds or thousands of years, even though populations may fluctuate(emphasizing availability of food, availability of shelter, number of predators and disease).

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Bio.2.1.1 Analyze the flow of energy and cycling of matter (such as water, carbon, nitrogen and oxygen) through ecosystems relating the significance of each to maintaining the health and sustainability of an ecosystem.  

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Bio.2.1.1 Analyze the flow of energy and cycling of matter (such as water, carbon, nitrogen and oxygen) through ecosystems relating the significance of each to maintaining the health and sustainability of an ecosystem.  

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Bio 2.1.3 Explain various ways organisms interact with each other (including predation, competition, parasitism, mutualism) and with their environments resulting in stability within ecosystems.

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Bio 2.1.3 Explain various ways organisms interact with each other (including predation, competition, parasitism, mutualism) and with their environments resulting in stability within ecosystems.

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Today you are a zoologist working with environmental engineers at the zoo. Your mission is to teach the engineers about the various aquatic animals below to ensure that their enclosures meet all of their needs for survival. The following animals have been selected for your review because they rely on very specific water conditions to live. A Google Form will be used to help you store information moving forward. Click on each animal's profile as a way to share more info. about them. It will be helpful if you keep both the Padlet and Google form windows open at the same time. Thank you and Good luck!

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Bio.2.1.2 Analyze the survival and reproductive success of organisms in terms of behavioral, structural, and reproductive adaptations.

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Bio.2.1.2 Analyze the survival and reproductive success of organisms in terms of behavioral, structural, and reproductive adaptations.

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Driving Questions:                                                                   * How can zoologists and environmental engineers apply what they know about natural habitats to construct the best possible living environment for each animal within a zoo?                                                                                                                                                      * How can understanding interdependence within an ecosystem ensure that all animal’s needs are met within a zoo? 

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Driving Questions:                                                                   * How can zoologists and environmental engineers apply what they know about natural habitats to construct the best possible living environment for each animal within a zoo?                                                                                                                                                      * How can understanding interdependence within an ecosystem ensure that all animal’s needs are met within a zoo? 

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Looking for a panda, a cheetah, or perhaps a piranha? The Zoo map can help guide your Zoo adventure.

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Physical Description

North American river otters, also called Canadian otters, have long, muscular, streamlined bodies with short legs and fully webbed feet bearing non-retractable claws. Their small heads widen to long necks and shoulders, and they have flattened, well-muscled tails. These otters have brown-to-gray fur, and their undersides are a lighter, silvery shade. Their dense, short under-fur is overlain by darker, coarse guard hairs that help repel water.

The river otter's eyes and ears are located high on its head for surface swimming. A third eyelid, or nictitating membrane, protects the eye and allows the otter to see when swimming underwater. The otter's ears and nostrils close underwater.

River otters have long, stiff and highly sensitive facial whiskers that aid in locating and capturing prey. The otters typically capture prey in their mouths but occasionally use their thumbs and forepaws to grasp and manipulate prey. Like other carnivores, their teeth are well adapted for grinding and crushing.

The tail is highly muscular and comprises up to 40 percent of the otter's total body length. With the tail's strong, undulating movement, a river otter propels itself through the water as fast as 8 miles (13 kilometers) per hour and can easily dive to 36 feet (11 meters) or more. River otters use their powerful hind feet to help with propulsion and their small, dexterous front feet for paddling through the water.

Adult river otters weigh 10 to 33 pounds (4.5 to 15 kilograms) and are about 2.5 to 5 feet (76 to 152 centimeters) in length. Females are roughly one-third the size of males.

Native Habitat

River otters are found throughout most of North America from the Rio Grande to Canada and Alaska, except for in arid deserts and the treeless Arctic. They live in riparian zones, often in the same areas as beavers. Their aquatic habitats can be both marine and fresh water: streams, rivers, lakes, ponds and marshes.

They prefer unpolluted water with a minimal human disturbance. An extremely adaptable animal, otters tolerate hot and cold climates, as well as high elevations and lowland coastal waters.

Communication

River otters exhibit a variety of vocalizations, ranging from whistles and buzzes to twitters, staccato chuckles, chirps and growls. When threatened or frightened, they emit a hair-raising scream that can be heard up to 1.5 miles (2.4 kilometers) across the water.

River otters leave scent marks on vegetation within their home range. Scent marking is done by either urinating/defecating or by emitting a strong, musky odor from the paired scent glands near the base of the tail.

Food/Eating Habits

River otters eat mostly aquatic organisms, including fish, frogs, crayfish, turtles, insects and some small mammals. They hunt singly or in pairs and although otters generally forage in water, they are equally at home on land, sometimes traveling between 10 and 18 miles (16 and 29 kilometers) in search of food.

North American river otters get their boundless energy from their very high metabolism, which also requires that they eat a great deal during the day. At the Smithsonian's National Zoo, they eat a prepared meat diet and several types of fish. They also receive mice, carrots, hard-boiled eggs, clams, crayfish, dry kibble, crickets and live fish for variety and enrichment.

Social Structure

A North American river otter's home range can be as large as 30 square miles (78 square kilometers), but a typical territory is 3 to 15 square miles (4.8 to 24 square kilometers). That home range shrinks drastically during breeding and rearing season.

While river otters tend to live alone or in pairs, they often socialize in groups and are known for their playful behavior. Their long, agile bodies enable them to quickly twist , turn, roll and dive, and they are frequently seen sliding or burrowing in the mud or snow. There is evidence that river otters' play activities strengthen social bonds, improve hunting techniques and scent mark territories. They spend a significant portion of the day scent marking territory by urinating, defecating, scratching and rubbing their scent glands on rocks and trees.

Reproduction and Development

Information about river otter breeding and reproductive and social behavior is varied due to the difficulty of studying these animals in the wild. Some studies indicate that river otters pair for only a few months during the breeding season and have no further strong bonds. Other research maintains that river otters mate for life.

Different studies have placed the breeding season in winter, late spring and summer. What is clear is that there is a delayed implantation of nine to 11 months, with actual gestation taking about 60 days. Otter births occur most frequently in March or April.

Female otters prepare dens that they keep scrupulously clean. The den is usually dug into the bank of a stream but can be an old beaver's lodge, muskrat house or hollow tree. Young are born between April and May and arrive silky black, blind, toothless and totally helpless. They weigh about 4 to 6 ounces (113 to 170 grams) at birth and measure 8 to 11 inches (20 to 28 centimeters). The male otter is generally chased away until the young are weaned and old enough to leave the riverbank, at which time they may return and help raise the pups.

River otters stay in family groups during the summer and early fall. Pups grow rapidly and emerge from the den at about 2 months of age. At this point, they eat solid food but are not completely weaned for another month or two. While young otters swim naturally, the mother must coax them into the water for their first swim. They remain as a family unit for seven to eight months or until the birth of a new litter. Otters reach sexual maturity at 2 to 3 years of age.

Provided it survives its first year of life, a typical North American river otter will live to the age of 12, with some surviving longer. The oldest living river otter on record was 27 years old.

North American river otters are likely the most numerous of the otter species. Because they are at the top of their food chain, they have few predators. However, water pollution, uncontrolled trapping and severe habitat loss have reduced the number of river otters.

For years, river otters have been hunted for their fur, and their pelts are still an important source of income for many people in Canada. As recently as the mid-1980s, more than 30,000 pelts were harvested annually. Today, accidental trappings in beaver traps constitute the most otter fatalities.

Regionally extinct throughout the Midwest and heavily populated areas in the east, several states have recently begun reintroduction programs. It is encouraging to note that with these conservation programs, regulations on trapping and the improvement of water quality, the river otters are finally making a comeback in certain wetland areas.

Because they have a low tolerance for polluted water, river otters are considered by some naturalists to be a good indicator, or "keystone," species of the quality of aquatic habitats. They are found at the top of the food chain, and there is some evidence that their birth rates are reduced when pollution levels-including toxic chemicals, heavy metals, pesticides and agricultural wastes-build up.

River otters have been blamed for decimating game fish populations and are seen as a pest to eradicate by many game fishermen. Recent research, however, indicates that otters prefer slower moving, easier to catch fish, such as suckers and catfish found along river bottoms, and pose no threat to game fish.

Help this Species

Organize or attend a stream, river, lake or other waterway cleanup in your area to preserve aquatic habitats for local species.

Are you a hunter? You can be an incredible ally for conservation! Check the conservation status of the animals you hunt and use methods that don't impact other animals.

Protect local waterways by using fewer pesticides when caring for your garden or lawn. Using fertilizers sparingly, keeping storm drains free of litter and picking up after your pet can also improve watershed health.

Two male otters, a father and son pair named Emmett and Potomac, live on American Trail.

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The North American river otter is the most abundant otter species, but surprisingly little is known about its life in the wild. These otters are frequently observed playing and sliding together.

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Physical Description

Harbor seal coloration can vary greatly from white or light gray with dark spots to dark brownish black with light spots depending on where in their range they are found.

Adult male harbor seals weigh between 120 and 300 pounds (55 to 130 kilograms) and are between 5 and 6 feet (1.5 to 1.8 meters) long. Adult females are slightly smaller than their male counterparts weighing between 100 and 190 pounds (45 to 87 kilograms) and averaging between 4 and 5 feet (1.2 to 1.5 meters) long.

Native Habitat

Harbor seals have the widest distribution of any seal and can be found in both the North Atlantic and Northern Pacific oceans. On the West Coast of North America, their distribution spans from the Southern Arctic (Yukon to northern Alaska) down the California coastline and on the East Coast from South Greenland, the Hudson Bay and down the coastline to the Carolinas.

Harbor seals can be found anywhere from cool, temperate waters to cold, arctic and sub-arctic coasts. They spend half their time on land resting, breeding and raising their young on both rocky and sandy beaches. Harbor seals do not migrate and will remain in the same general area unless searching for food requires them to move. Some recent tagging studies have shown that juvenile animals may travel greater distances.

Communication

Harbor seals spend most of their time staying alert for predators such as polar bear, orca and even sharks. Regardless of whether it is alone or in a group, a harbor seal will let out an alarm call if danger appears to be near and flee the area, usually by diving into the water.

Harbor seals use vocalizations to warn other seals about danger, fend of danger, establish hierarchy, and keep mothers and their pups together.

Food/Eating Habits

Harbor seals, like other pinnipeds have adaptations that allow them to dive and conserve oxygen while under water. Harbor seals are generally able to dive to depths of 500 feet (152.4 meters) but depths of up to 1,460 feet (446 meters) have been recorded. They can remain submerged for up to 30 minutes at a time although the average dive lasts less than three minutes given that most prey items live in shallower depths.

Before a deep dive, harbor seals will exhale to reduce the amount oxygen in their lungs, relying instead on oxygen stored in their blood and muscle tissues. Blood is shunted away from the extremities and is concentrated on maintaining the core functions of brain heart, and lungs where it is needed. Harbor seals will also slow their heart rates from upwards of 80 (averaging between 80 and 120) beats per minute to as few as three or four. After surfacing, the seal's heartbeat accelerates rapidly for a short time.

Harbor seals have a higher metabolic rate than other mammals of comparable size. This allows them to generate heat to keep warm-usually about one degree warmer than the surrounding temperature of the water. A thick layer of insulating blubber provides thermoregulation as well as a nutrient reserve during fasting periods. During the winter months, the blubber layer can account for up to 30 percent of a harbor seal's body mass. Other adaptations to prevent heat loss to the environment include the ability to shunt blood vessels in their extremities and skin to conserve heat at their core.

Harbor seals are opportunistic feeders and eat mainly fish: rockfish, herring, cod, mackerel, flounder and salmon. They will also eat squid, clams, octopus, crayfish, crab and shrimp when available. Harbor seals wait until the tide comes in to feed and some may even follow fish runs with the high tides in spring. These seals that follow fish runs for food will wait to return to the coastal waters in the fall. Harbor seals frequently swallow their food whole.

At the Smithsonian's National Zoo, harbor seals are offered herring, capelin, squid, butterfish and mackerel.

Social Structure

Although harbor seals are mainly a solitary species, they can be extremely gregarious, especially on land and during breeding season. Due to their naturally solitary lifestyle, they can become very antagonistic towards each other when groups of several hundred congregate together on shore during the breeding season. Many individuals take part in biting, head butting, snorting, growling, flipper waving and other behaviors to keep others away from them.

Reproduction and Development

Seals molt following the pupping season. During this time, they remain hauled out on the shore to avoid heat and energy loss.

Male harbor seals are generally promiscuous, mating with multiple females in a breeding season. Males initiate mating by chasing, neck and flipper biting, and embracing. When approached, females respond by growling, head thrusting and flipper waving. Copulation usually takes place in the water, which occurs very shortly after weaning young conceived during the previous breeding season. Several hundred animals will move ashore at one time for breeding season which ranges from March to August.

The peak of harbor seal births vary widely between areas. Harbor seals can be born as early as February in Baja California and as late as July in Europe. Mothers will give birth to one pup after an 11-month gestation period. Harbor seal pups average 2.5 to 3 feet (75 to 100 centimeters) in length and weigh average between 22 and 26 pounds (10 to 12 kilograms) at birth. Mothers nurse their pups for about four weeks after birth. Although a pup can immediately swim on its own after birth, a pup will often stay on its mother's back while she dives and remain very close to its mother until it matures. Harbor seals reach sexual maturity between 3 and 7 years of age.

Harbor seals in the wild can live between 25 and 30 years and for over 30 years in human care.

On a global scale, harbor seals benefit from large and stable populations that do not qualify them under a threatened category. However, the International Union for Conservation of Nature still recommends the protection and observation of this species from a conservation standpoint. Historically, harbor seals have suffered population drops due to viral diseases similar to distemper, water pollution and habitat loss. Harbor seals are also threatened by humans through hunting and commercial fishing practices. Harbor seals have learned how to steal fish from fishing nets, resulting in damage to nets angering fishermen and fisheries in these areas. Harbor seals also consume the fish in these areas leaving fisheries with lower yields. Other threats include over-fishing in an area which results in a loss of resources.

In the Unites States, harbor seals are protected under the Marine Mammal Protection Act of 1972. With the exception of licensed hunting, this Act protects from all other threats including importation of parts or products from all seals. From a conservation standpoint, the adherence to legal protection as well as the safe-keeping of our waterways will help harbor seals to survive in their current habitats without fear of hunting, pollution or habitat loss.

One male harbor seal, Luke, lives at the mixed-species seal exhibit along with the gray seals.

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Also known as the common seal, harbor seals spend half their time in the sea and half on land. They have the widest distribution of any seal and live in both the North Atlantic and Northern Pacific oceans. Harbor seals can be found anywhere from cool, temperate waters to cold, arctic and sub-arctic coasts.

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Physical Description

Males have a distinctively arched Roman nose, which gives them their other common name of horsehead seal. Males have massive shoulders and necks with the skin bunched in large folds or wrinkles. Females lack the distinctive nose of the male and are more delicately featured. Coat color varies greatly from gray to brown, but most have darker backs than bellies. Bulls have a dark background color with lighter, irregular spotting seen mostly on the belly. Cows have a lighter background color with darker patches and spots. Gray seals lack extremely dense underfur that distinguishes the eared seals; they only have a few secondary hairs as opposed to the 50 or so found in fur seals.

Gray seals have many adaptations for their aquatic lifestyle. Their limbs are shortened with the digits elongated and encased in cartilage and connective tissue to form flippers. Their streamlined, torpedo-shaped body has strong, bulky shoulders and tapers to the tail. Seals generally have more bulk overall in the torso than sea lions, partially due to their method of swimming propulsion. Seals use their rear flippers and the back half of the body in a sculling motion. Gray seals have relatively short front flippers with five prominent claws and have the ability to curl these flippers to tear food or grasp terrain.

On land, seals move in caterpillar fashion alternately shifting weight from their chest to their pelvic region, or they will roll to their desired destination. They appear quite clumsy and slow but can overtake a running human over a short distance.

In water, gray seals make up for their clumsy appearance on land. A flexible body allows them to twist and turn easily while pursuing prey. Their front flippers act as rudders, but are kept tucked away close to the body when not in use. They are able to obtain speeds of 14 to 23 miles per hour (23 to 37 kilometers per hour), but normally cruise at six miles per hour (10 kilometers per hour) or less. They tend to exhibit deliberate and sluggish behavior to conserve energy, and are usually either traveling between haul-out spots, making feeding trips of short duration or resting. They often use an upright stance while resting in the water, called bottling.

Water is an efficient conductor of heat and seals must be able to regulate body temperature. A layer of blubber, or fat, insulates the trunk of their body while the circulation system has the ability to shunt the blood supply to the extremities and the outer surface of the body. As a result, they can haul out on ice and not melt it. Gray seals' dense fur gives them some protection from the cold as well as trapping a layer of water next to the skin that warms to body temperature. They also have a relatively small body surface area in proportion to their volume, reducing the amount of heat lost to the surroundings. They thermoregulate by behavioral means through methods such as changing position in the sun, moving to damp places or shallow pools, and altering activity levels.

Adult males are about 7.5 feet (2.3 meters) in length and can weigh over 750 pounds (339 kilograms). Females are smaller with lengths about 6.5 feet (2 meters) and weigh up to about 575 pounds (170 kilograms).

Native Habitat

Gray seals are found on both sides of the North Atlantic in temperate and subarctic waters. They prefer remote rocky coasts with small islands and reefs. The beaches they inhabit may be rocky, sandy or ice pack. Gray seals migrate far from their rookeries when not breeding or molting.

Communication

Gray seals have numerous vocalizations, many of which are used during their highly social breeding season. Males jackhammer, hiss and growl to display dominance and aggression. They exhibit behaviors such as neck darts and open-mouthed threats as forms of non-vocal communication. Non-receptive females caterwaul or hoot at persistent males. Flipper slapping and scratching are common signs of irritation. Little is known about gray seals' sense of smell, but it should be noted that bulls produce strong odors during breeding season and that mothers identify their pups by scent. Olfactory, visual and acoustic cues are all part of the mother-pup recognition system. Tactile communication occurs as well, demonstrated through whisker greetings.

Food/Eating Habits

As predators, seals have excellent senses. Their eyesight is particularly well developed since they spend much time underwater with reduced light levels. On the surface, their pupil contracts to a tiny pinhole to protect the retina from any intense glare. They see better underwater than in air. Gray seals also hear better in their underwater environment and can perceive sound at a greater range of frequencies than humans. Lack of any external ear flaps and a heavy wax coating in their auditory canal reduces their ability to perceive sound in the air. Their ears are valvular and close when in the water. Their nostrils are also valvular and are closed at rest. The vibrissae located on the head are extremely sensitive and enable seals to capture prey in total darkness by feeling the currents created by their prey.

Gray seals have been documented as eating 29 different species of fish and invertebrates including herring, cod, mackerel and squid. They sometimes eat commercially valuable species, which makes them unpopular with fishermen. They regularly dive 230 feet (70 meters) for food, but are capable of diving much deeper.

At the Smithsonian's National Zoo, they are fed a combination of thawed frozen herring, capelin, butterfish, squid and mackerel twice a day. They receive vitamin supplements daily to replace any nutrients lost during the fish freezing process.

Social Structure

Gray seals are gregarious social animals that haul out close to one another and form large aggregations during the pupping, breeding and molting seasons.

Reproduction and Development

Breeding season differs among the populations, with the Northeast Atlantic group pupping mostly on land in September through November, the Northwest Atlantic group pupping on land and ice from late December to early February, and the Baltic group pupping on ice from February to March. About a month before pupping, large numbers of cows and bulls congregate offshore of the rookery. The birth of the first pups signals the males to come ashore. Instead of holding territories, the males compete for proximity to the females and their pups. Bulls display, vocalize, and fight, often trying to interrupt each other during copulation. Their large size and massive necks provide them with some protection from each other's shoving and biting. During the initial stages of the breeding season, bulls control large areas with many females. Once mating begins, the bulls become distracted and younger, smaller bulls can establish themselves on the fringes of the group. They mate mainly on land, though they can sometimes mate in the water.

Females give birth to a single pup of which they are very protective. Lactation lasts roughly three weeks and during this time, the mother spends most of her time in close proximity to her pup. Pups feed for about five minutes every five hours and gain weight rapidly on the high-fat milk. Once the pup is weaned, the cow comes into estrus and solicits attention from the bull. The fertilized egg develops into a blastocyst after which it remains dormant for two to four months before attaching to the uterine wall. This delayed implantation ensures that birthing occurs at the right time each year. Females then return to the sea to regain their physical condition before molting.

At birth, pups are about three to 3.5 feet (90 to 105 centimeters) long from nose to tail tip and weigh about 33 pounds (15 kilograms). They have a cream-colored natal lanugo coat that molts at two to three weeks. Pups gain about five pounds (2.3 kilograms) per day from their mother's rich milk, but gain little if any in length. At weaning, pups are completely abandoned by their mothers and fast from one to four weeks before they start feeding on their own at sea.

Neither bulls nor cows eat during the breeding season and both experience significant losses in weight and physical condition. Following breeding season, all gray seals return to the sea and begin their migrations. Young animals may travel as far as 30 miles (48 kilometers) in a day. Gray seals regain their physical condition before their annual molt. Adults probably return to their birthplace once sexually mature, which is age three to five years for females and six years for males.

Gray seals live an average of 35 years in human care while wild bulls average 25 and wild cows average 35. The oldest recorded in the wild is 46 years.

Gray seals' natural predators are sharks and orcas. Disease and parasites are also natural threats. Although gray seals are not hunted for their fur and there is no longer a market for seal oil, people continue to be the greatest threat to these animals. Entanglement in and ingestion of plastics results in unknown numbers of gray seal deaths. They are inadvertently caught in fishing nets, particularly drift nets, resulting in their deaths. The impact of overfishing in gray seals' natural hunting grounds has not been determined. They are unpopular with fishermen as these seals are known to consume commercially valuable fish.

At the seal exhibit, visitors can meet gray seal females Kjya, Kara and Birdie, as well as a male Gunther. Gunther has a Species Survival Plan recommendation to breed with Kjya and Kara. Birdie is Kara's offspring and was born on Jan. 21, 2017.

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Physical Description Males have a distinctively arched Roman nose, which gives them their other common name of horsehead seal. Males have massive shoulders and necks with the skin bunched in large folds or wrinkles. Females lack the distinctive nose of the male and are more delicately featured.

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Physical Description

Sea lions, along with fur seals, are considered eared seals. Their visible ear flaps distinguish them from true seals. They also use their fore flippers to propel themselves through the water, whereas true seals rely primarily on their back flippers to swim.

Males are generally a dark chestnut brown, although some males have lighter coloring on their head, muzzle, sides, hind and belly. Females and juveniles are usually tan. Both sexes have a sleek, single hair coat, which also distinguishes them from true seals.

At about 5 years old, males develop a noticeable crest that runs lengthwise along the top of their skull creating a high, domed forehead. The fur on this crest usually becomes increasingly lighter as a sea lion ages.

California sea lions lack the "mane" that gives sea lions their name. They also have a more slender neck than some species and a dog-like head.

California sea lions have many adaptations for their aquatic lifestyle. Their limbs are short with elongated digits encased in cartilage and connective tissue to form flippers. They have strong, bulky shoulders and their streamlined, torpedo-shaped bodies taper to the tail.

Their front flippers are especially long and are used for propelling them through the water. Their back flippers are used as rudders and have three claws for grooming.

On land, these sea lions move by rotating their rear flippers under their bodies and supporting their body weight on all four flippers. Although California sea lions appear clumsy when moving on land, their movement through the water appears almost effortless.

The flexibility of their bodies allows them to make tight, twisting turns as they play or pursue fish, and they can quickly reach speeds of 25-30 mph (40-48 kph) while hunting, avoiding predators or simply playing.

A layer of blubber, or fat, insulates the sea lion's body, and the circulatory system can shunt the blood supply to the extremities and outer surface of the body. Meanwhile, a layer of fur traps water next to the skin nad warms it to body temperature. The California sea lion's small body surface in proportion to its volume also reduces the amount of heat lost to its surroundings.

Overheating can often be a problem for California sea lions, and they use behavioral means to cool off, such as resting with a flipper in the water, flipping sand over their back or flipper fanning in the water.

Adult males are about 8 feet (2.4 meters) long from nose to tail and weigh an average of 600 pounds (272 kilograms). In preparation for the breeding season, their weight often increases up to 1,000 pounds (454 kilograms).

Adult females are significantly smaller and slimmer than males. They are about 6 feet (1.8 meters) long and weigh an average of 220 pounds (100 kilograms).

Native Habitat

The three species of California sea lion are divided by geographical divisions - the Pacific coast, the Gulf of California and the Galapagos Islands. These sea lions are currently found in the eastern North Pacific from British Columbia to Baja California, the Gulf of California, and in a separate population on the Galapagos Islands.

The population in Japan is now considered extinct. The U.S. population of California sea lions is estimated at 210,000. Population estimates in other areas are considered unreliable.

California sea lions are not typically found more than 10 miles (16 kilometers) from the Pacific coastline. They usually congregate on islands and remote shorelines when not in the ocean. Many have habituated to human presence and haul out on manmade structures, such as piers and buoys.

Communication

As social animals, California sea lions spend much time communicating with each other. From alarm barks and growls to bleats and roars, California sea lions are one of the noisiest pinniped species. They have numerous vocalizations used not only on land but underwater as well.

Males typically patrol their aquatic and terrestrial territories and bark or roar to warn intruders away - sometimes even barking underwater. During these patrols, they display to other males in the vicinity. These behaviors are vital to maintaining a territory and include barking, head shaking, oblique stares and lunges at the opponent's flippers.

Females use specific calls to identify their pups. Following birth, the cow and pup spend time nuzzling and vocalizing to each other. This process imprints on their memories exactly what one another smells and sounds like. While the calf is still nursing, the cow alternates between feeding her pup and hunting for food. When a cow enters the water to hunt, her pup joins with other pups in the pod.

Once back from her feeding trip, the mother calls her offspring using a pup attraction call and the pup answers with its own unique bleat. The mother then confirms her pup by smell, leads it to a sheltered spot and nurses it.

Visual signals are an important part of sea lion nonvocal communication. Whiskers are used for greeting one another and, in conjunction with smell, allow bulls to determine the sexual receptivity of cows. Bulls produce strong smells when in rut, presumably important in breeding behavior.

Food/Eating Habits

These predators have excellent senses. Their eyesight is well developed, because they spend a lot of time underwater with reduced light levels. At the surface, where there is brightness and glare, the sea lion's pupil can contract to a tiny pinhole, protecting its sensitive retinas.

Though the sea lion's ear flaps are small, it can hear quite well both above and below the surface. Its ears are also valvular and close underwater. Sea lions often vocalize underwater and are able to easily locate sound sources.

Their sensitive whiskers, called vibrissae, can rotate forward and detect the slight movements of fish swimming nearby, enabling California sea lions to find and capture prey in total darkness.

California sea lions seem to have an acute sense of smell. Their nostrils are closed at rest and have to be opened to take a breath.

They are generalist feeders, eating herring, rockfish, anchovies and other fish, krill, and invertebrates, such as squid and octopus. They typically feed toward the top of the water column but can dive as deep as 1,000 feet if necessary.

At the Smithsonian's National Zoo, they eat thawed frozen squid, capelin, herring, butterfish and mackerel. They also get vitamin supplements daily to replace any nutrients lost in the food during the freezing process.

Social Structure

California sea lions are gregarious, social animals and gather during the breeding season, preferring sandy beaches for their rookeries. Females gather on the rookeries where they are sociable and noisy but relatively indifferent to the males until they are ready to mate.

Males are polygamous, mating with more than one female, and maintain territories during the breeding season of May to August, with territorial behavior peaking in late June and early July.

Most territories include access to the water's edge and often extend into the water, allowing bulls a chance to cool off. Bulls patrol their territories, barking incessantly to advertise their presence and using formalized movements to mark boundaries.

For bulls, bigger is better; they spend months gaining weight. A large amount of blubber provides extra insulation and nutrition, helping them to remain in control of their territory. Large size can be threatening to a would-be competitor and an advantage in combat. If necessary, bulls fight to defend their territories. These battles can be so intense that pups are sometimes trampled to death in the chaos.

Reproduction and Development

California sea lion females are receptive to mating about three weeks after giving birth to a calf. Male California sea lions hold their territories for an average of 27 days, making it counterproductive to establish territories before the females arrive. They do not set up well-defined territories until after the first pups are born.

Females give birth to a single pup and are protective of them for several days, moving the pups around with them. Females then begin to leave their pups for increasing lengths of time. Within two weeks, females come into estrus and solicit attention from bulls.

After copulation, the fertilized egg develops into a blastocyst, remaining dormant for several months before attaching to the uterine wall. This delayed implantation ensures that birthing occurs at the right time each year. Pups are about 2.5 feet (75 centimeters) long, nose to tail tip, and weigh about 18 pounds (8 kilograms) at birth. They are chestnut brown in color.

Young pups suckle at frequent intervals throughout the day, but by 3 weeks old are left alone for increasing amounts of time. Pups gather in groups, called colonies, and spend their time resting, exploring the rookery or playing in tide pools. They nurse anywhere from six months to a year, until the arrival of the next pup. Females reach sexual maturity at 4 or 5 years and males at 5 to 6 years in human care.

California sea lions live 15 to 20 years in the wild and average 25 to 30 years in human care.

California sea lions' natural predators are sharks and orcas, or killer whales. Disease, parasites and the weather system El Nino also take their toll. California sea lions are protected under the Marine Mammal Protection Act, which makes it illegal to harm them. Still, some are killed each year by fishermen who regard the animals as competition and a threat to their livelihood. In 2003, the California sea lion population size was estimated at 237,000 to 244,000.

Entanglement in and ingestion of plastics in the ocean is another serious threat to these animals. Habitat destruction, pollution and diminished food supply through overfishing are hazards faced by marine life in general. Toxic algae blooms fed by agricultural run-off and other pollution can lead to the poisoning of marine mammals by a chemical called domoic acid, which can cause brain damage.

Water quality is vital to a sea lion's well being, as blubber can hold pollutants. Many studies show concentrations of pollutants such as DDT and PCBs incorporated within the bodies of fur seals and sea lions. The levels of these toxins increases with age in males but drops sharply after maturity in females. This suggests the transfer of these pollutants during lactation to offspring.

Help this Species

Organize or attend a stream, river, lake or other waterway cleanup in your area to preserve aquatic habitats for local species.

Avoid single-use plastics, such as plastic bottles, bags and utensils. Choosing reusable options instead can help reduce plastic pollution.

Try fundraising for conservation organizations in new and fun ways. You could donate your birthday to conservation, host a bakesale to benefit wildlife or Adopt a Species!

Protect local waterways by using fewer pesticides when caring for your garden or lawn. Using fertilizers sparingly, keeping storm drains free of litter and picking up after your pet can also improve watershed health.

Four female sea lions, named Sidney, Summer, Calli and Celia, and one male sea lion, named Charger, live on American Trail. Calli gave birth to Celia in June 2019. The pup made its public debut at American Trail in September 2019.

Calli and Summer are not related but have similar stories - both were orphaned as young pups. Calli's mother died shortly after she was born, and Summer was abandoned by her mother. In June 2005, Pacific Marine Mammal Center in Laguna Beach, California, rescued Calli and Summer. There, animal care staff hand-raised them. They came to the Smithsonian's National Zoo in 2006.

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Physical Description Sea lions, along with fur seals, are considered eared seals. Their visible ear flaps distinguish them from true seals. They also use their fore flippers to propel themselves through the water, whereas true seals rely primarily on their back flippers to swim.

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Physical Description

Beavers have a yellowish brown to almost black coat; a broad, flat scaly tail; large orange incisors; webbed rear feet and digitated front paws.

Beavers, having dual habitats, move between aquatic and terrestrial environments. Their stocky bodies have large volume to surface area ratios, giving them great ability to conserve warmth. On land, beavers are extremely awkward, making them vulnerable to attack from predators. However, in water, beavers swim up to 6 miles per hour (10 kilometer per hour) and, because of their over-sized lungs, can stay submerged for up to 15 minutes while traveling over one half mile.

The incisors, the long, dark orange visible teeth, are self-sharpening and can cleave a willow the size of a person's finger in a single bite. Incisors grow throughout a beaver's life and, through daily use, are continuously worn down. If the incisors become too long, they prevent the mouth from closing enough for the grinding molars to meet, possibly causing starvation. Beavers seem to have a smile upon their face because of lips that appear too small. The lips do not close over the incisors, but are pulled tightly behind them. This is an important adaptation to the aquatic side of their life, permitting them to work underwater without their mouth filling with water.

Their nose is equipped with a pair of slap valves that close when beavers dive, swim, or work underwater. The skin around the nose is bare, enhancing a beaver's tactile sense and gathering more information than if the nose were covered with fur.

Whiskers help detect objects near the sides of a beaver's face and head, which is especially helpful in narrow passageways and dark water.

The eyes have a thin, transparent membrane, called a nictitating membrane, which is pulled over the eyeball for underwater work. A beaver's sight is good only for short distances and at close range.

The ears are external, small and rounded and have valves that close for underwater work. The beaver's auditory sense is well developed which is important for hearing another beaver's danger signal-a tail slap on the surface of the water.

The front feet are small, dexterous, and well adapted to work on land. Beavers walk on five digits, grasp sticks with their front paws, and have well developed digging claws. They hold their food with their front paws and eat corn-on-the-cob style. The hind feet are quite different and are webbed for swimming. The hind feet are larger than the front and totally void of fur except on the dorsal surface. The hind feet also have a preening toe, the second from the inside, with a unique double toenail. The preening toe serves as a comb and prevents the fur from matting while maintaining waterproofing and insulating properties. These flexible toes are also used to remove burrs and parasites from the fur. Beavers are meticulous in keeping their fine, soft fur waterproofed.

The tail varies in shape from short and broad to long and narrow and is an individual and family trait. In general, it is about two inches (5 cm) thick at the base and about 0.24 inches (0.6 cm) thick at the tip. It is practically hairless and covered with black scales. There is a sharp demarcation between the fur and the scales, 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 and to signal danger when slapped on the water. 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. The beaver's vertebrae continue into and almost to the end of the tail.

North American beavers are the largest rodents in North America and the second largest in the world (capybaras of South America being the heaviest). They weigh between 35 and 65 pounds (16 to 30 kilograms), with 110 pounds (50 kilograms) the heaviest on record. Beavers are 3 to 4 feet (1 to 1.2 meters) long and one to one and a half feet (0.3 to 0.5 meters) tall.

Native Habitat

Beavers are found throughout North America with the exception of the California and Nevada deserts and parts of Utah and Arizona. They live in ponds, lakes, rivers, marshes, streams and adjacent wetland areas.

Beavers are one of the few animals that actually change their habitat; they build watertight dams of sticks woven with reeds, branches, and saplings, which are caulked with mud. Dams reduce stream erosion by forming slow-moving ponds. These ponds serve as habitat for a wide range of small aquatic life as well as providing 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 rise 6.5 feet (2 meters) or more and can reach widths of 39 feet (12 meters). A 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 may be four feet (1.2 meters) wide and two feet (0.6 meters) high, insulated by walls one-third of a meter 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.

Communication

Beavers employ a variety of communication signals. One method is slapping their tails on the water to communicate an alarm signal. Usually performed by an adult, it alerts others in the area to seek refuge in deep water and may also frighten the predator.

Beavers also communicate with beavers outside the family unit by depositing scents around the edges of their territory. Beavers are unique among rodents in that they actually build scent mounds which are heaps of mud, sticks, and grass up to a third of a meter high and about a meter wide on which they deposit scents from their anal glands. Within the lodge, beavers employ various vocalizations (the voice box is quite rudimentary though) and postures to communicate with family members. At the Zoo, they have been heard occasionally hissing if they are unhappy.

Beavers have important castor and oil glands near the anus. Castor, a very pungent, thick liquid, is produced for scent marking and is vital in leaving a long lasting odor. The oil glands produce the oil used to waterproof a beaver's fur. The oil is slightly different between the sexes and is used in reproductive communication.

Food/Eating Habits

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. In cold climates, they spend the winter inside their lodge chamber, feeding on branches they have stored on the muddy pond floor as a winter food supply. The water acts as a refrigerator, keeping the stems cold and preserving the nutritional value.

At the Smithsonian's National Zoo, they are fed once a day a diet of mixed vegetables, rodent chow and a healthy supply of wood.

Social Structure

Beavers form strong family bonds. They are social animals and each group is made up of one breeding pair, the kits of the year, and the surviving offspring from the previous year, called yearlings. There also may be one or more sub-adults, 2 years or older, of either sex from previous breeding seasons which generally do not breed. In winter, they live together in their lodge and share food from the common larder (stored food supply). Their family life is exceptionally stable and is based on a hierarchy in which adults dominate yearlings and yearlings dominate kits. Physical aggression is rare and vocalizations, gestures and postures are used within the lodge to communicate issues of dominance status within the group.

Reproduction and Development

Beavers pair for life. They breed in the water from January to late February and females give birth in spring to kits that weigh about one pound (0.5 kg). Kits are born with their eyes open and are completely covered with fur. They take to the water inside the lodge within one half hour after birth. They are skillful swimmers within a week but are too buoyant to dive. Kits typically stay close to their mother in the lodge for the first few weeks, nursing frequently and gaining considerable weight. Females have four nipples and sometimes sit upright to nurse. There is evidence of teat sharing among kits, which may explain the high survival rate of all members of a large litter. Kits nurse for about six weeks and all members of the family share in bringing solid food to them. 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 kits until they are, usually, driven away just before the birth of a new litter.

Sleep Habits

Beavers are mainly nocturnal throughout their range. However, in regions where ponds freeze over throughout the winter season, beavers may stay in their lodges or under the ice using their fat reserves and feeding off the cache they've gathered. In the lodge and underwater, light levels remain constant and low during the 24-hour day, so that sunrise and sunset are not apparent. In the absence of solar "cues," activity is not synchronized with the solar day. The circadian rhythm, or regular day cycle, breaks down, and beaver "days" become longer, varying in length from 26 to 29 hours. At the Zoo, beavers usually wake up in the early evening, around 4pm

North American beavers typically live 10 to 15 years. The oldest on record is 30 years in human care.

Beavers are a classic story of American conservation at its worst and at its best. During the early 19th Century, the single most valuable commodity in most of North America was beaver pelt. Much of the exploration of the New World developed from the fur trade and wars were even fought over access to beaver trapping areas, including the French and Indian War. Beaver fur was in constant demand for robes, coats, clothing trim, and top hats (called beavers). Beaver fur was fashionable in European capitals and some of America's great financial empires and real estate holdings were founded on the profits of beaver fur. With trapping totally unregulated well into the 20th Century, beavers all but disappeared from most of their original range.

Now protected from over exploitation, beavers have reestablished themselves over most of the continent, and have even become an agricultural pest in some regions. Beaver dams can change a farmer's stream into mud or swamp. Dams may also flood stands of commercial timber, highways, and croplands and may block the upstream run of spawning salmon. However, beaver dams are also important. They maintain an ecological balance by controlling run off, erosion and floods and keep the water table high enough to support rich vegetation. Beavers have also supplied people with information on swimming techniques, dam building, engineering, natural fortification, and flood control.

Beavers are still harvested for their fur and meat, but are actively managed throughout most of their range. The beaver's main predator, besides humans, is the wolf. Other predators include coyotes, wolverines, bears, foxes and lynxes.

Two male North American beavers named Chipper and Birch live on American Trail.

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Physical Description Beavers have a yellowish brown to almost black coat; a broad, flat scaly tail; large orange incisors; webbed rear feet and digitated front paws. Beavers, having dual habitats, move between aquatic and terrestrial environments. Their stocky bodies have large volume to surface area ratios, giving them great ability to conserve warmth.

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Physical Description

Males and females are similar in plumage; the head is white with a pale yellow wash on the crown; the long bill is grayish; back, rump, and tail are streaked with gray and dark brown; the breast and belly are a blackish-brown; eyes pale yellow; and legs and feet are black.

Immature pelicans have brownish-grey necks and white underparts. They will gradually acquire their adult plumage over a period of about three years. The brown pelican's most distinguishing feature is a long beak measuring approximately 9 inches (23 centimeters) in length with a hooked tip and large pouch beneath. The huge naked skin pouch suspended from the lower half of the hooked bill holds two or three times more than the bird's stomach-about one gallon of water and fish. Pelicans hold their catch and let the water drain from the corners of their mouths before they swallow. Fish are never carried in the pouch, but in the gullet or esophagus. The pouch is also pulsated in extreme heat to allow cooling.

In flight, brown pelicans are easily identified by a pattern of a few flaps followed by gliding.

Brown pelicans are the smallest species of pelican. Both males and females are 3 to 5 feet (0.9 to 1.5 meters) long and weigh over 7 pounds (3 kilograms).

Native Habitat

Of the seven or eight species of pelican, the brown pelican (also called the American brown pelican or common pelican) can be found from Virginia, south to the mouth of the Amazon River in Brazil, from central California to south-central Chile and the Galapagos Islands, and in Alabama, Louisiana and Texas along the Gulf Coast.

Communication

Adult brown pelicans make very few vocalizations. Occasionally, they will make a low croak. Nestlings squeal.

Food/Eating Habits

Brown pelicans use their pouch, swimming ability, and extremely keen eyesight to catch fish. Flying over the ocean, they can spot a school of small fish from heights of 60 to 100 feet (30 m). After spotting the fish, the pelican folds back its wings and dives deep into the water, submerging completely or partially before emerging with a mouthful of fish. Air sacs beneath the pelican's skin cushion the impact and help it resurface.

Brown pelicans are the only species of pelican that hunts with such dramatic plunging dives. Other pelican species fish by swimming on the surface of the water, which is also a method sometimes used by juvenile brown pelicans. Their pouch, which they use as a dip net, holds the catch of fish until the water (as much as 3 gallons) is squeezed out. The pouch itself can hold three times more fish than the stomach. While fish is being held in the pouch, gulls often hover above or even sit on the pelican's bill ready to steal a fish or two. Once the water has drained from the pouch, the pelican swallows the fish. The pouch also serves as a cooling mechanism and as a feeding trough for young pelicans.

Brown pelicans feed on mid-sized fish and some invertebrates. They require up to 4 pounds of food per day. Their diet consists mainly of menhaden, herring, sheepshead, pigfish, mullet, grass minnows, top minnows and silversides-all fish considered commercially unimportant.The brown pelicans' diet at the Smithsonian's National Zoo consists of thread herring. They are also given vitamin supplements based on the amount of fish they eat.

Social Structure

Pelicans are social and gregarious. Males and females, juveniles and adults, congregate in large flocks for much of the year. In level flight, pelicans fly in groups, with their heads held back on their shoulders, the bills resting on their folded necks. They may fly in a "V," but usually in regular lines or single file.

Reproduction and Development

During breeding season in March or April, males pick a nesting sites and perform an "advertising" display that attracts females. On the Southeast coast, it is often in mangroves that pelicans build their flimsy nests of sticks, reeds, bones and seaweed. On islands without predators, they often build nests on the ground, which may be a shallow depression lined with a few feathers and a rim of soil up to 10 inches, or a large mound of soil and debris with a cavity on top. They nest in colonies, and are sensitive to disturbance by tourists and fisherman while breeding.

Brown pelicans lay two to three chalky, white eggs and incubation lasts about 28 to 30 days. Both parents take turns incubating and feeding the young by regurgitation. Fledging requires 63 to 76 days, possibly longer in tree nests. They perform little-to-no post-fledging care, depending on the length of time the young spent in the nest. Sexual maturity is reached after two to five years.

Brown pelicans typically live 25 to 30 years.

The brown pelican has few natural enemies. Flooding or hurricanes sometimes destroy ground nests, but the biggest threat comes from humans. In the late 19th and 20th centuries, pelicans were hunted for their feathers to adorn women's clothing and hats. During the food shortages of World War I, fisherman claimed that pelicans were depleting resources from the commercial fishing industry and slaughtered them by the thousands. Their nests were also frequently raided for eggs.

In the 1940s, the pesticide DDT began to be widely used and cause a decline in the pelican population due to eggshell thinning. In 1903, President Roosevelt designated Florida's Pelican Island as the first national wildlife refuge, which helped to reduce the killing of pelicans for their feathers. In addition, passage of the Migratory Bird Treaty Act in 1918 gave protection to pelicans and other birds. Studies proved that pelicans were not harming the commercial fishing industry, which helped to stop the killing of pelicans by fishermen.

In 1970, the U.S. Fish and Wildlife Service listed the brown pelican as an endangered species meaning that it was considered in danger of extinction through all or a significant part of its range.

In 1972, the Environmental Protection Agency banned the use of DDT in the U.S. and placed heavy restrictions on the use of other pesticides. Since the banning of DDT, there has been an increase in nesting success. The brown pelican was the first bird species to recover from the effects of pesticides.

In November 2009, the brown pelican was delisted and removed from the Endangered Species list.

Today, abandoned fishing lines, other marine debris, and overhead wires still pose a threat to the brown pelican. In Florida, at least 500 pelicans are killed each year from entanglement in fishing gear. The brown pelicans on American Trail are rehabilitated birds, injured in this fashion.

American Trail has one female brown pelican, Scout, and two male brown pelicans, Pappy and Huey, who share their habitat with the sea lions. The three pelicans were named by veterans in the Zoo family. Pappy is named after Major Gregory "Pappy" Boyington, a Marine and flying ace in WWII. Scout was named after the job one of our own veterans had in the military, scout sniper. And Huey is named after the military helicopter.

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A beautiful and unexpectedly graceful bird, brown pelicans live along both coasts of North America. Once threatened by DDT, they were one of the first species to recover from the effects of the pesticide and be removed from the Endangered Species List.

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These freshwater rays live in the Amazon River system, one of the only species of rays to live in fresh, rather than salt, water. Though a docile species, they are responsible for more injuries to humans each year than any other Amazonian animal.

Their conservation status is currently unknown. However, due to the fact that fresh water stingrays live in a concentrated environment, scientists believe they might be endangered. They are not typically hunted for food but are becoming popular in the aquarium trade. Since 2002, the Zoo has been highly successful in breeding freshwater stingrays. The young stingrays are initially placed in 150-gallon "nursery tanks" until they reach a size where they can defend themselves, whereupon they are moved to a larger pool. Stingrays at the Zoo are often sent to other sites around the country for breeding. Unlike other public aquariums, visitors cannot touch the stingrays at the Zoo because they are capable of stinging. Unlike other institutions, the Zoo does not cap, trim or surgically remove the stingrays' spines.

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These freshwater rays live in the Amazon River system, one of the only species of rays to live in fresh, rather than salt, water. Though a docile species, they are responsible for more injuries to humans each year than any other Amazonian animal.

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Physical Description

The yellow-spotted turtle has a domed and dark colored shell. They have yellowish-orange head markings. There is usually a single barbel on the chin. These side-necked turtles cannot retract their head into their shell. Hatchlings have very obvious yellow spots on their heads, which shrink as they grow. Males keep some of the yellow spotting; females lose their spots altogether.

The average adult length is 15 to 27 inches (38 to 69 centimeters), with females outgrowing males. Adult males weigh 1 to 2 pounds (0.5 to 1 kilograms) and females weigh 2.5 to 6.5 pounds (1 to 3 kilograms).

Native Habitat

Yellow-spotted Amazon River turtles are native to the Amazon River basin and can be found in the Amazon and Orinoco river systems in Venezuela, eastern Colombia, eastern Ecuador, northeastern Peru, the Guianas, Brazil and northern Bolivia.

These turtles spend time basking along the riverbanks and in the calm waters of big rivers and streams. They avoid fast-moving waters.

Food/Eating Habits

They are omnivorous, feeding on both vegetation and small animals. They have also been known to occasionally use an inertial feeding mechanism to extract fine particulate matter from the water surface.

The turtles are fed fruits and vegetables at the Smithsonian's National Zoo.

Reproduction and Development

Mating season varies depending on location, but nesting has been recorded for most months of the year. The clutch size averages between 15 and 25 eggs but as many as 40 are possible.

A male yellow-spotted side-necked turtle courts a larger female by nipping at her feet and tail. A few weeks later, in the evening, the female lays about two dozen (20 to 30) hard-shelled, slightly elongated eggs in a shallow nest she has dug on the riverbank. The nest is about 26 centimeters deep and contains seven to 52 eggs, depending on female body size. The babies, which are slightly larger than a quarter, hatch out in a little over two months.

Sleep Habits

The turtles are diurnal, meaning they are most active in mid-morning and afternoon.

The oldest known yellow-spotted Amazon River turtle living in human care reached 23 years of age. They can live up to 70 years.

The indigenous Yekuana Indians, who eat these turtles and their eggs, are now trying to hunt the turtles sustainably. The 12 main nesting sites of these turtles are now protected from poachers by armed guards.

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A long-lived turtle native to the Amazon River, only the males and juvenile females have yellow head markings. They are considered vulnerable due to hunting, but the indigenous Yekuana Indians, who eat these turtles and their eggs, are now trying to hunt the turtles sustainably.

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Twig catfish grow to between 5 and 7 inches (12.7 to 17.8 centimeters) in length.

Native Habitat

Twig catfish have a relatively broad distribution. They are found in the Amazon, Orinoco and Panara rivers as well as coastal rivers of the Guyana Shield. These catfish prefer an environment with a substrate comprised of submerged dead leaves and sticks which helps them stay well camouflaged.

Food/Eating Habits

Twig catfish use dozens of small, uniquely specialized spoon shaped teeth to rasp at wood and algae, their primary source of nutrition. Consuming wood as a primary energy source is extremely rare among vertebrates. Fish in the genus Farlowella are the only known fish evolved to do this.

At the Smithsonian's National Zoo, they are fed a gel diet as well as produce including zucchini and cucumbers. They also enjoy eating all the plants in their exhibit.

Reproduction and Development

An oviparous species, twig catfish lay their eggs in a single layer on vertically situated rocks and vegetation. They do not attempt to hide their eggs in caves or crevices, instead opting to lay them in open water. Males guard fertilized eggs.

Twig catfish are named for their long, thin bodies that resemble a twig or stick. Their noses are pronounced, and their bodies are generally brownish, with two lateral dark stripes running from head to tail. The body is protected by bony plates called "scutes." Thanks to their body shape and coloring, twig catfish can hide easily among sticks, leaves and other vegetation rather convincingly. There is some sexual dimorphism, with females generally having a smaller rostrum and generally rounder in shape when compared to males.

There is no current research being conducted on twig catfish at the Zoo. Their status in the wild is unknown. Catfish in the genus Farlowella are generally considered to be relatively common; however, there is little known about each distinct species.

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Twig catfish, named due to their resemblance to twigs, are found throughout the Amazon, Orinoco and Panara rivers, as well as rivers of the Guyana Shield. They are one of the only fish known that have evolved to eat wood as a primary energy source.

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The sunbittern is an elegant bird with long features and plumage decorated in orange, brown and white. Native to tropical habitats in Guatamala and northern Brazil, they are typically found in lowlands, foothills and well-wooded banks of streams and creeks.

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The sunbittern is an elegant bird with long features and plumage decorated in orange, brown and white. Native to tropical habitats in Guatamala and northern Brazil, they are typically found in lowlands, foothills and well-wooded banks of streams and creeks.

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Physical Description

The mouth is at the top of the body of the fish and opens in three pieces. Many oral bones bear teeth, including the jaw, palate, tongue and pharynx. Very large, pearly-silver scales cover their bodies. These scales shift to shades of red, blue and green as the fish ages. They have dorsal and anal fins that are almost fused with the caudal fin. Males are slenderer and have a longer anal fin. Arowanas have two barbells at the extremity of the lower jaw. While the adults are silver, juveniles have blue glints and a yellow-orange bar.

Arowanas are long fish capable of reaching lengths of over 39 inches (100 centimeters).

Native Habitat

Arowanas are native to the Amazon drainage system and the western Orinoco, Rupununi and Essequibo systems of the Guianas. They live in both the whitewater and blackwater floodplains of the Amazon. In both types of water, they are most abundant in the flooded areas.

Food/Eating Habits

Arowanas are omnivorous, with a tendency to feed on fish at the surface. The superior position of the mouth allows them to capture their prey while swimming from below. They have a unique predatory behavior in that they usually stay parallel to a downed tree to hide before attacking prey, which usually involves jumping out of the water. They can catch large insects, other fish, crabs, snails, snakes and small birds in low hanging branches.

At the Smithsonian's National Zoo, arowanas are fed a mixed diet that includes aquatic gelatin diet, smelt, shrimp and a variety of invertebrates like insects and worms.

Reproduction and Development

Arowanas spawn at the beginning of the flood season, which is usually in December and January. Females produce a small number of large eggs. Males carry the eggs, larvae and early juveniles in their mouths until the yolk sac has been absorbed, which takes about two months.

In human care, arowanas have lived beyond 10 years of age.

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Physical Description The mouth is at the top of the body of the fish and opens in three pieces. Many oral bones bear teeth, including the jaw, palate, tongue and pharynx. Very large, pearly-silver scales cover their bodies. These scales shift to shades of red, blue and green as the fish ages.

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Physical Description

Red-bellied piranhas are red on their undersides from chin and cheeks to belly. The head and body are various shades of gray; their sides are flecked with bright silver scales. The piranha's distinctly rounded and snub-nosed profile serves a function.

Beneath the high forehead are powerful muscles that attach to a short, stout lower jaw fitted with triangular, razor sharp teeth, which interlock neatly with a matching set above. This design allows piranhas to bite down with incredible force and shearing ability. However, these formidable teeth are not usually visible, being covered by thick, fleshy lips.

Food/Eating Habits

In the wild, a good portion of their diet consists of fins nipped from the tails of larger fish. Additional items on a piranha's menu can include bits of flesh, whole small fish, insects, aquatic invertebrates and occasionally, plant material in the form of figs and other ripe fruit.

At the Smithsonian's National Zoo, red-bellied piranhas receive a gelatin diet (a mixture of greens, proteins and micronutrients in a gelatin base), smelt, shrimp, herring and earthworms.

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True to their name, red-bellied piranhas have red undersides. Their bodies are gray and flecked with bright, silver scales. Native to the Amazon River basin, these fish are important scavengers. They tend to travel in schools of 20 or more.

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The plecostomus, also called the suckermouth catfish, is found in fresh and brackish water and prefers fast-flowing streams and rivers with pebbly substrate. Their coloring depends on their surroundings and environment. They are sometimes referred to as "janitor fish" for their ability to clean tank algae.

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The plecostomus, also called the suckermouth catfish, is found in fresh and brackish water and prefers fast-flowing streams and rivers with pebbly substrate. Their coloring depends on their surroundings and environment. They are sometimes referred to as "janitor fish" for their ability to clean tank algae.

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Banded leporinus are torpedo-shaped, striped yellow and black freshwater fish found primarily in the creeks and streams of the Amazon River basin in Brazil, Columbia and Venezuela where they feed on plants, fruits and leaves.

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Freshwater fish with silver bodies and colorful fins, flagtail characins-also called kissing prochilodus-live in the Amazonia River system.

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The black pacu is a large, non-aggressive, fruit-eating species of fish found in the upper Amazon River basin.

Pacu are caught for food in South America and are bred in fish farms for food and the pet trade. Many species of pacu are imported for the aquarium trade as piranha. This confusion often leads to release in non-native waters as they quickly outgrow their aquariums. Pacu have been introduced to United States in rivers from Washington to Florida.

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The black pacu is a large, non-aggressive, fruit-eating species of fish found in the upper Amazon River basin. Pacu are caught for food in South America and are bred in fish farms for food and the pet trade. Many species of pacu are imported for the aquarium trade as piranha.

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Native to the streams of the Amazon River basin, the arapaima is a massive yet sleek and streamlined, freshwater fish, growing to weigh about 200 pounds and be 7 to 8 feet long. It can breathe air, allowing it to survive in pools with low water levels or decaying vegetation.

In the 1970s, the arapaima population began to decline due to overfishing until it went commercially extinct near major Amazonian cities. Pesticides and the amount of other animals dependent on aquatic habitats have also contributed to their decline. A favorite food amongst the Amazonian natives, the arapaima is harpooned not only to be eaten but also for its scales, which can reach 4 inches (10 centimeters) in length and are used for jewelry. Their bony tongues can also be used as a scraper. In Brazil, commercial fishing of wild arapaima is banned, but they are being bred with some success in indoor ponds in Germany and artificial lakes in Peru. In 2011, arapaima (known as paiche in Peru, where it has been farm-raised and certified sustainable), appeared on the menu of several prominent U.S. restaurants.

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Native to the streams of the Amazon River basin, the arapaima is a massive yet sleek and streamlined, freshwater fish, growing to weigh about 200 pounds and be 7 to 8 feet long. It can breathe air, allowing it to survive in pools with low water levels or decaying vegetation.

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Physical Description

An African clawed frog's body is flattened with a smaller, wedge-shaped head. The positioning of the eyes and nostrils on the top of the head, along with camouflaged skin, help this species hide from predators, such as herons. The smooth skin is often multicolored with blotches of greenish-gray or brown on its back. The underside is off-white with a yellow hue. African clawed frogs have the ability to change their appearance to match their background, becoming darker, lighter or mottled.

The frogs' front limbs are small with non-webbed fingers used to push food into the mouth. Their hind legs are large and webbed, and the three inside toes on either foot have "claws," which are not true claws but cornified tips. Although an adept swimmer, the African clawed frog is clumsy on land and crawls rather than hops.

African clawed frogs also have a lateral line system that is very sensitive to vibrations, enabling them to detect predators and prey in murky water. The lateral line is visible as a series of white stitch marks along each side of the frog.

The Pipidae family of frogs is unique in that members lack a tongue and a visible ear. The males also lack vocal cords. Instead of moveable eyelids, a horny, transparent covering protects their eyes.

Males weigh 2 ounces (60 grams), and are about 2 to 2.5 inches (5 to 6 centimeters) long. Females are much larger, weighing approximately 7 ounces (200 grams) and are about 4 to 4.5 inches (10 to 12 centimeters) long. Females also have cloacal extensions at the end of their abdomen.

Native Habitat

These frogs live along the African Rift Valley south of the Sahara Desert in east and southern Africa, as well as in South Africa, Namibia and Angola. As an invasive species, they are now found in freshwater areas all over the world, including the United States, Chile, France, Indonesia, Portugal, United Kingdom and Italy. Rarely found in running streams, the African clawed frog prefers warm, stagnant pools and quiet streams, thriving in temperatures from 60 to 80 degrees Fahrenheit. Almost totally aquatic, it only leaves the water when forced to migrate to another pond. It is a highly opportunistic species and can easily colonize newly created water bodies.

Communication

Despite their lack of vocal cords, males can vocalize to attract females. Rapid muscle contractions in the throat produce a clicking noise, to which the female responds with either an acceptance call (a rapping sound) or a rejection call (slow ticking sound). A female only rarely answers the male's call.

Food/Eating Habits

As tadpoles, African clawed frogs are exclusively filter feeders. Adult frogs become scavengers, eating living, dead or dying arthropods and other pieces of organic waste, including aquatic insect larvae, water insects, crustaceans, small fish, tadpoles, worms and freshwater snails. They have a voracious appetite and will attack anything that passes by. Extremely sensitive fingers, an acute sense of smell and its lateral line system help to locate food. A special pump helps individuals suck food into their mouths. The claws on their hind feet tear apart larger pieces of food.

Reproduction and Development

These frogs are sexually mature in 10 to 12 months. Mating can take place during any time of year but is most common from early spring to late summer, depending on location, and can take place up to four times a year. Despite their lack of vocal cords, males vocalize to attract females.

Mating usually occurs at night in stagnant water, and lasts three to four hours. The males clasps a female around the pelvic region, a form of amplexus (a common mating position in which the male grabs the female from behind), in opposition to the normal axillary, or front limb, amplexus. As amplexus is formed, the female lays 500 to 2,000 eggs. Sticky jelly around the eggs causes them to adhere to objects such as sticks, stones and other substrate underwater. Eggs hatch within one week and tadpoles are slightly less than 1/5 of an inch (2/5 of a centimeter) long. The total change from egg to small frog takes about six to eight weeks. Adults exhibit no parental care.

African clawed frogs can live up to 15 years.

African clawed frogs are a very successful and adaptable species with a wide distribution and presumed large population.

These frogs have been used extensively as laboratory research animals, mostly in the field of vertebrate embryology because females are prolific egg layers and the embryos are transparent, making it easy to observe its development.

During the 1940s, female African clawed frogs were used as indicators of human pregnancy. Female frogs were injected with urine of a human female, and the injected frog would start producing eggs if the woman was pregnant. With the adoption of modern-day pregnancy tests, many African clawed frogs were released all over the world, creating an invasive species problem in some areas and possibly spreading the chytrid fungus. Seemingly, the disease does not detrimentally affect populations of African clawed frogs.

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African clawed frogs are native to eastern and southern Africa and parts of western Africa. They have been used extensively used for research, and are considered an invasive species on four continents, due to their release into the wild from research laboratories.

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Food/Eating Habits

Using its spoon-like bill to scoop prey up from shallow water, the roseate spoonbill's diet typically includes minnows, small crustaceans, insects and bits of plants. They feed in the early morning and evening hours in both fresh and saltwater wetlands. It is believed the roseate spoonbill receives its bright coloring from the pigments of the crustaceans that it eats.

At the Smithsonian's National Zoo, they are fed flamingo pellets, sea duck pellets and insects.

Reproduction and Development

Typically roseate spoonbills do not breed until their third year. To attract one another, courtship displays include ritualized exchanges of nest material, dancing and clapping. Female spoonbills create deep, well-constructed nests out of sticks using materials brought to them by males. The Florida population usually nests in red and black mangroves sometimes with wood storks, while the Texas and Louisiana populations often nest on the ground in offshore island mixed colonies with gulls, terns and herons.

A female lays a clutch of one to five eggs. Both parents share incubation duties, which last about 22 to 24 days. A newly hatched chick has mostly pink skin with a sparse covering of white down. The parents feed the chick by dribbling regurgitated material into the baby's upturned bill. After one month, the chick will begin to exercise by clambering through the branches or foliage surrounding the nest, and by six weeks, it will have developed wing feathers large enough for flight.

Between 1850 and 1890, the number of roseate spoonbills dropped dramatically as hunters began killing the birds for their feathers, which they sold for use in the construction of ladies' fans and hats, as well as for their meat. By the 1930s, the population dropped to a low of 30 to 40 breeding pairs nesting in a few small colonies on the keys of Florida Bay. The species eventually began to rebound, especially in isolated areas, once they gained full legal protection from hunting.

Now the birds' main threat is the destruction of their natural habitat. The ground nesting colonies in Texas and Louisiana are vulnerable to predators making their way in from the shore islands. Often this forces entire colonies to shift locations, sometimes to more vulnerable sites. Some populations show high levels of pesticides in their eggs, but they do not appear to be significantly impacted by egg shell thinning.

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Food/Eating Habits Using its spoon-like bill to scoop prey up from shallow water, the roseate spoonbill's diet typically includes minnows, small crustaceans, insects and bits of plants. They feed in the early morning and evening hours in both fresh and saltwater wetlands.

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See what the animals are up to in real time.

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See elephants, lions and naked mole-rats on animal cams streaming live, 24/7 from the Smithsonian's National Zoo and Conservation Biology Institute.

Download Animal Cam Bingo Cards (link opens in new window). These activities are designed to engage learners of all ages in looking closely and thinking deeply about animal behavior and habitats. Welcome to the wild side of learning!

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The Zoo's animal webcams are some of the most famous on the internet. Tune in to watch the Zoo's elephants, lions and naked mole-rats - live, 24/7!

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Main webpage for the zoo

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Snot otter, devil dog, or hellbender? Whatever name you call them, they are largest salamander in the Americas. Check out how animal keeper Matt Neff cares for and studies these unique salamanders!

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Always free of charge, the Smithsonian's National Zoo is one of Washington D.C.'s, and the Smithsonian's, most popular tourist destinations, with more than 2 million visitors from all over the world each year. The Zoo instills a lifelong commitment to conservation through engaging experiences with animals and the people working to save them.