Reptile Species

Reptiles are a fascinating part of the animal kingdom, from a tiny gecko to an alligator or crocodile. They are often intimidating-looking, with a lumbering gait and large teeth-but they typically use avoidance tactics to defend themselves.


Traditionally, reptiles have been classed with amphibians in Linnaeus’ Systema Naturae. However, fossil and molecular data indicate that birds, crocodiles, and lepidosaurs (snakes and lizards) are closer relatives.

Spectacled Caiman

The Spectacled Caiman (Caiman crocodilus) is a smaller relative of the American Alligator and a member of the Alligatoridae family. It is native to southern Mexico and northern Argentina where it can grow to over 2 meters (8 ft) in length. It is a wetlands predator and thrives in freshwater marshes, heavily vegetated ponds and lakes, and canals. Caimans display a wide range of coloration, from pale yellowish to olive green with black or variable crossbanding. They are able to change their skin color to match their environment, which is why they are so well camouflaged. Their long snouts are characterized by a curved bony ridge (infra-orbital bridge) between the eyes, which give them the spectacled appearance that lends their name.

This caiman hunts primarily by ambushing its prey from a concealed position. Its diet consists of a variety of aquatic invertebrates (insects, crustaceans, and mollusks) as well as fish, amphibians, reptiles, birds, and mammals. If the environment becomes too harsh, the caiman will burrow into mud and remain dormant until conditions improve.

At Lincoln Park Zoo, we prioritize the individual well-being of all animals in our care. Spectacled caimans are no exception, and we are working to ensure that this species has the best chance of surviving in the wild. We have a captive breeding program, and the Zoo is also involved in conservation efforts in its natural habitat in South Florida.

Thorny Devil

The Thorny Devil (Moloch horridus) is a lizard with an intimidating array of spines and spikes. Its unique appearance is a defence mechanism that scares off predators. It also camouflages well and uses deception as a means of evading prey. It has a spiny “false head” on the back of its neck that it lowers to show potential predators before dipping its real head, which is made of soft tissue.

A solitary and non-territorial lizard, the thorny devil is adapted to desert habitat with sandy soil. It is found in sand plains and sand ridge deserts of Australia’s mallee belt and deep interior.

Its scales are ridged, allowing it to collect moisture from the desert’s cold nights. The lizard then channels the water through existing grooves on its skin surface to its mouth, where it is swallowed. It can also drink from damp surfaces such as puddles, rain or dew.

During the day, thorny devils spend time within a shrub complex where they sleep and bask in the sun. They can remain sedentary or wander to a different area in search of food and mates. Mating behaviour is poorly known but limited observations indicate males seek out females by bobbing their heads and waving their legs. They fall and roll to throw off males that are unreceptive. Mating occurs during the late winter and early summer and females lay between 3 to 10 eggs in a burrow 30 cm underground. The eggs incubate for three to four months before the young start eating.


The Gharial is the largest and longest-lived of all crocodile species. Males grow between 15 and 20 feet (5 to 6.1 meters) long, while females are generally slightly shorter. Their elongated snouts are well-adapted for hunting fish in rushing waters. Gharials hunt from ambush, keeping still until a fish swims close enough to attack. Their sharp teeth face outward rather than downward and are curved backward like a pin cushion, making them easier to snap shut on their prey and stab.

Unlike other crocodilian species, gharials do not have powerful legs for walking on land. Instead, they move by sliding along their bellies. Gharial skin is a good camouflage, and its markings and coloration help blend it into the environment. The eyes have a reflective layer behind them called the tapetum lucidum that assists in vision at night.

Gharials are highly efficient predators in their watery habitat and may live up to 100 years old. However, they are classified as Critically Endangered by the International Union for Conservation of Nature, as their population in the wild has dropped by up to 98 per cent since the 1940s due to traditional medicine hunting and significant changes to their natural habitats.

As a result of these threats, only about 250 gharials remain in the wild today. They are being heavily poached for their skins and meat, as well as their eggs and snouts, which are used in various traditional medicines. In response, WWF-India has initiated rear-and-release programs that are reintroducing captive-bred gharials into the wild.


The tegu is the largest reptile species native to South America. Its body is covered with a mottled pattern of black and white bands. The coloration fades to a emerald green as hatchlings become adults. Its tail is banded yellow and black and can be used as a weapon in self-defense or to distract an enemy. The tegu’s tail is powerful enough to swipe at an aggressor and can inflict a serious wound. The tegu is diurnal and spends the day alternating between basking to regulate its body temperature and searching for food.

Tegus are natural predators and opportunistic feeders that consume a wide range of plant matter, eggs, fruit, insects, mollusks, small mammals and other reptiles. They have been documented consuming gopher tortoise and American alligator eggs in Florida and are also known to consume pet food left outdoors.

Although tegus prefer warmer climates, they have been shown to survive in slightly colder environments by adjusting their body temperatures and brumating, a hibernation-like state. They are one of the few partially endothermic reptiles that can do this.

The tegu has several traits that make it an excellent invader, including a high reproductive output, large size, rapid maturation and long lifespan in the wild. In addition, its ability to adapt its metabolism and brumate allows it to persist in a variety of environments.