Range:

All continents except Europe and Antarctica

Habitat:

Wetlands

It’s a croc!

Cold-blooded, thick skinned, and egg-laying, the ancient order of crocodilians strikes terror in the hearts of many and respect in others—or perhaps a bit of both. The fact is, crocodilians—alligators, crocodiles, caimans, and gharials—are a misunderstood group of animals, most of which face serious threats to their habitat as well as being hunted for their skin by humans. Of the 23 species of crocodilians, 7 are critically endangered, and nearly all are at risk in some part of their range.

A brief history lesson

Appearing about 230 million years ago, the hearty crocodilians have survived nearly every earthly scenario, though human activities are proving their most formidable challenge yet! They have outlived dinosaurs, ice ages, and more, yet they have changed very little over time. The only reptiles older than crocodilians are turtles, tortoises, and tuatara. Interestingly, crocodilians are more closely related to birds and dinosaurs than most living reptiles. Scientists have placed crocodiles and alligators in different families (Crocodylidae and Alligatoridae) based on key differences between them.

Caimans are also a type of alligator, but gharials are in a family of their own called Gavialidae. The U.S. is home to the American alligator and a small population of American crocodiles.

Crocodilians keep growing all their lives.
A crocodilian’s tongue doesn't move—it's attached to the bottom of its mouth.
All crocodilians store fat in their tails, so they can go for quite a while without eating, if necessary—as long as two years for some big adults.
Male gharials grow a conspicuous, rounded bulge made of cartilage at the end of their snout as they mature. While most human males would not want a large bulb on the end of their nose, gharials find it very desirable.
Once listed as endangered in 1967, today the American alligator is the most numerous species of crocodilian on the planet. A limited harvest of the animals raised on “alligator farms” to produce food and leather products is allowed.
Saltwater crocodiles are the largest of all the crocs and are at home in both fresh water and salt water habitats, often swimming along coastlines.
The black caiman is the largest of the alligators. It lives in South America’s Amazon River Basin.
Chinese literature and art dating back to ancient times depicts dragons that could be based on the Chinese alligator.
Some caiman species often build their nests next to termite mounds; it is thought the heat produced by the termites helps to incubate the caiman’s eggs.
The mugger crocodile is the only croc species that breeds twice a year, laying a clutch of eggs 30 to 57 days apart.
American alligators are the largest reptiles in North America, with males reaching up to 14.8 feet (4.5 meters) in length and 1,000 pounds (454 kilograms).
Which crocodile is usually featured in Tarzan movies? The Nile crocodile.
What is the group name for alligators? A congregation.

See six species!

Visitors to the San Diego Zoo and Safari Park have a unique opportunity to experience the mystery and grace of six different crocodilian species. The Park has two American alligator ambassadors: Myakka and Bayou. They are part of the Wildlife Education Department and can be seen walking on a leash, seeking out warm basking areas. These animals are excellent ambassadors for wildlife as they give our guests a chance to see them up close and learn about the important roles they play in the ecosystem.

At the Zoo, you’ll discover African dwarf crocodiles, Johnston’s crocodiles (or Australian freshwater crocs), slender-snouted crocodiles, and gharials, all in Lost Forest. Keepers work diligently and patiently with these intelligent animals, training them to respond to various commands that make everyone’s life safer and less stressful.

Reptile Walk

In the Zoo’s new Reptile Walk, you’ll find two female Chinese alligators, a critically endangered species. The Zoo expects to become a breeding facility for this most endangered of all crocodilian species and we are awaiting a breeding recommendation from the Association of Zoos and Aquarium's Species Survival Program.

Dwarf crocs

The Zoo’s reptile keepers share information about the dwarf crocodile during training presentations for guests. The training methods are all based on positive reinforcement, rewarding desired behavior like responding to their name, touching a target, and coming out of the water, and simply ignoring undesirable behavior. The crocs catch on quickly to commands, which are then used to separate the animals, give injections, and safely get them into a crate when necessary. Don’t let the dwarf name fool you—these crocs are still astonishingly strong, even at a “dwarfed” length of 6 feet (3 meters), so safety remains a priority.

We send our reptile keepers to Crocodilian Biology and Management school in Florida as part of their training to ensure they have the most up-to-date information available.

Slenter-snouted crocs

Slender-snouted crocs, located next to the Zoo’s pygmy hippos, are much larger than the dwarf variety, and the females in the enclosure each respond to their own color-coded target (yes, they see in color!) on the end of a pole. Their keeper goes into the exhibit, stands on the beach, calls one of the croc’s name, and smacks the colored target on the surface of the water (a cue that crocodilians easily respond to). Soon, a croc silently glides to the surface and lunges out of the water to capture its prey—a tasty fish. Keepers say these animals are so intelligent that they have to change up the routine daily. The crocs seem to enjoy learning things, especially on warm days when they are more active. The Johnston’s crocodiles, found along the Zoo’s Tiger Trail, favor a sit-and-wait hunting strategy, snatching prey with a lightning-fast sideways movement of the head.

New gharials!

May 16, 2012, was a huge day for the Reptile Department at the San Diego Zoo: we received 10 young Indian gharials from our partners, the Madras Crocodile Bank Trust and Centre for Herpetology in India. This import has been very significant to the Species Survival Plan for gharials, as this new group of animals means the addition of new genetics and a younger demographic for zoo collections. Our Zoo is one of only seven North American zoos to house gharials. Head down the Tiger Trail at the Zoo to see these amazing young crocodilians for yourself!

American alligator

Of the 23 crocodilian species, 12 are in need of conservation help. Many croc species are hunted by people for their skins to make shoes and luggage, and some have suffered from a loss of habitat. But there are conservation success stories, too. The American alligator was listed as endangered in 1967, after being heavily hunted for its hide and meat, and its numbers plummeted to about 200 animals. But through captive breeding (farming) and conservation of wild populations, these alligators were declared “fully recovered” by 1987. Today, they are found in the southeastern United States, and hunting these animals is tightly regulated.

Crocodile Specialist Group

Efforts by the Crocodile Specialist Group, affiliated with the International Union of Conservation of Nature, are now under way to help other crocs that are still in trouble. The group’s Human-Crocodile Conflict Working Group currently monitors Nile crocodile attacks on humans and livestock in Africa. In China, a breeding center has been established to help the critically endangered Chinese alligator and has begun releasing captive-bred alligators into wild habitats and monitoring the results. In India, juvenile mugger crocodiles raised in captivity are being released to restock rivers.

Help for gharials

San Diego Zoo Global continues its efforts to help gharials. Habitat destruction and environmental degradation have eliminated this species across much of its historical range. This species has experienced a decline of 96 to 98 percent over a 3-generation period since 1946, and its population has been reduced to a very small number of widely spaced subpopulations of fewer than 235 individuals. The drastic decline in the gharial population can be attributed to a variety of causes, including over-hunting for skins and trophies, egg collection for consumption, use in native medicines, and killing by fishermen. Hunting is no longer considered to be a significant threat; however, the wild population of gharials has undergone a drastic decline of about 58 percent between 1997 and 2006.

The last remaining strong-hold for gharials is the Chambal National Sanctuary, a river nearly 250 miles long, in north India that feeds into the Ganges River. Current conservation measures include protection of nests from predators and raising hatchlings in captivity until they reach a size that we hope gives them greater survivorship when released into the wild. We partner with the Madras Crocodile Bank Trust and Centre for Herpetology (MCBT), one of the largest reptile zoos in the world and one of the oldest nongovernment environmental organizations in Asia. San Diego Zoo Global manages the Gharial Conservation Fund, through which we are able to support much-needed gharial research and conservation efforts in the field. We plan to continue to partner with the MCBT and other zoos for the conservation of this amazing species.