Reptiles are air-breathing vertebrates that have lungs, internal fertilization and scaly skin. Unlike mammals and birds, most reptiles are cold-blooded.
They can’t generate heat to stay warm or cool themselves, so they depend on the sun and shade to control their body temperature. They also don’t have feathers or fur to provide insulation.
Komodo dragons (Varanus komodoensis) are large lizards that prey on mammals, birds and other reptiles. They also scavenge for carcasses and play a key role in their ecosystems by regulating populations of smaller animals.
The dragon’s jaws are able to swallow entire prey items without choking, thanks to the presence of special ligaments that prevent the mouth from closing prematurely. Its teeth are a combination of sharp serrated edges and smooth cusps. They are able to cut through tough bone, flesh and shell.
Once it finds a prey item, the lizard catches it by ambush or stalks it. When it attacks, it typically rakes its teeth through the animal’s flesh, causing bleeding and impairing blood flow, which helps to weaken the victim and facilitates digestion. Its blood contains a group of proteins known as cationic antimicrobial peptides, which offer a powerful defense against bacteria and may help fight antibiotic-resistant strains.
Young dragons eat mainly snakes, birds and reptiles, but once they reach maturity, they can hunt larger animals as big as water buffalo. They can even scavenge for meat from the carcasses of dead creatures, if necessary. In addition, they can run swiftly for short distances and detect potential prey with a sharp sense of smell. They can detect the scent of an animal from as far away as 985 feet (300 m) by licking their forked tongues against trees or rocks, touching the tips of their tongues to the roofs of their mouths and checking which one has more concentrated “smell.” They are notoriously cannibalistic, and males squabble aggressively over females and their offspring.
Leatherback Sea Turtle
The largest of all sea turtles, the leatherback has a unique rubbery skin and seven distinct ridges on its carapace. Their streamlined shape and powerful front flippers allow them to swim long distances over open ocean and against strong currents. These turtles have a wide range and are found throughout the world’s tropical and subtropical oceans. They are true denizens of the deep, diving to depths over 1000 meters, and can tolerate colder water temperatures than other sea turtle species. They primarily feed on jellyfish, and their throat cavity and scissor-like jaws have spines that help them swallow the soft-bodied prey.
Leatherbacks are monogamous and return to their nesting beaches year after year. Females lay as many as 100 eggs, but only a small percentage hatch. Hatchlings have to fend for themselves once they leave the nest, and are vulnerable to predators and natural disasters. Any that survive to adulthood have overcome enormous odds.
Leatherbacks are listed as Endangered in the United States and Vulnerable globally. Their main threats are incidental take in commercial fisheries and marine pollution (including plastic bags that the turtles mistakenly ingest, thinking they are jellyfish). In addition to these dangers, climate change is also an issue as warmer waters cause beach erosion and erode the sand where the leatherbacks nest. This also alters the migratory habits of the turtles and their food sources, and makes it harder for them to find safe nesting areas.
The boa constrictors of the world are ambush predators, circling and lying in wait for their prey. Once a suitable animal approaches, they grab it with their front teeth and then kill it by squeezing its body until all of its blood stops flowing. Boas can wrap their bodies around animals as large as pigs, and they can also unhinge their jaws to swallow them in larger pieces.
These snakes live in a variety of habitats, including rainforest, but they tend to choose areas with a low concentration of available prey and plenty of hiding places where predators are unlikely to find them. Their skins are a protective covering with scales that allow them to camouflage in their surroundings, and they can even use sound to warn predators of danger, producing a loud hiss when threatened.
Boas are ovoviviparous, which means they lay their eggs inside themselves and then the young hatch alive. They are a fairly active species, but as they get older and become more heavy-set, they spend less time on the ground and more time in trees. Once they reach sexual maturity at about 2 or 3 years of age, females will bear litters of up to a dozen babies.
Adult boas usually weigh 10 to 16 feet (3 to 5 m) and are tan, light brown, grayish brown, or cream colored with dark, hourglass-shaped saddles on their bodies that fade into reddish bands toward the tail. They often have lighter splotches on their sides and necks, and their heads are tannish with darker markings around the eyes. As they grow, the young of some subspecies (Boa constrictor occidentalis) can become nearly black with aging.
Crocodiles are prehistoric animals that have been around for 200 million years and are classified in the same group of dinosaurs as Archosaurs. They have evolved little since then and are still considered apex predators and can be found in fresh and salt water. They are incredibly strong, with streamlined bodies that allow them to move through the water quickly and trap prey.
They can eat fish, birds, frogs, turtles, and mammals. Crocodiles also have special sense organs in their head, body, and tail that work like motion detectors to help them find prey. They can even hold their breath underwater for an hour! However, they can’t run or walk on land very fast and get tired easily.
Their lifespan depends on where they live and how much activity they participate in. In captivity, they have been known to live up to 70 years. They mate between January and February and breed in fresh or salt water depending on the species. They are usually nocturnal, but will come out during the day to soak up some sun and have their snouts cleaned.
People often confuse crocodiles with alligators as they look similar, but there are some differences. The best way to distinguish between a male and female crocodile is by looking at their snouts. Males have a wide gap, while females have a narrow one. The temperature of the nest can also be an indication of whether it is a boy or girl – low temperatures tend to produce females while high ones will result in boys.