American Alligator

 

American AlligatorDinosaurs still walk the earth in Oklahoma. Southeast Oklahoma to be exact and they swim more often than they walk. Remaining unchanged for 65 million years, the American alligator is Oklahoma’s representative from the Triassic period. They are actually more closely related to birds, which are direct descendants of dinosaurs, than they are to modern reptiles like lizards.

Fully grown male alligators typically reach 13 to 15 feet and females reach lengths of just under 10 feet. Adults tend to be a grayish-black in color with lighter colored bellies. The young can be more colorful with yellow or white highlights. The whole body is armored with large, bony plates. Eyes, ears and nostrils are near the top of the head, with valves to close the ears and nostrils when the alligator is submerged. A transparent eyelid allows them to see underwater. While they move with serpentine grace in water, they are less graceful on land. They either lumber along, or raise themselves off the ground and move at speeds up to 20 miles per hour for a short distance.

Their large, strong mouths have 80 teeth, and are used to capture, crush and dismember their prey. Alligators cannot chew, so they swallow their food whole or in chunks. They often lose teeth in encounters with prey but they are quickly replaced. Each tooth contains a small replacement tooth within its pulp cavity and examination sometimes reveals a further tiny tooth ready to erupt within that.

The American alligator’s breeding season usually begins around May and lasts for six to eight weeks. They mate underwater during the last several days of their courtship season. Females construct the nests in June and July on mounds of high banks. The construction of the nest provides a constant temperature for the 20-30 eggs so that the female doesn’t have to sit on the nest like her avian cousins.

Sex of the hatchlings is determined by the temperature of the eggs during incubation. Temperatures greater than 91 degrees produce males, temperatures less than 85 degrees produce females and temperatures in between produce both sexes. Hatching occurs in mid-August after about 65 days of incubation. When the hatchlings break out of their eggs, they make a distinctive call and the female digs up the eggs. Female alligators are very protective of their offspring, which may stay near her for more than two years. They are very vulnerable to predation by raccoons, otters, herons, snakes, fish, bullfrogs and other alligators.

Juveniles eat a wide variety of small invertebrates, particularly insects, and small fish and frogs. As they grow larger, their diet increases to include larger prey. Eventually, large adults can tackle nearly all aquatic and terrestrial prey that comes within range, although their diet mostly includes fish, turtles, small mammals, and birds.

Alligators can often be found basking with just their eyes, nostrils and snouts above the water primarily in freshwater swamps and marshes, but also in rivers, lakes and smaller bodies of water. In Oklahoma they are found in Red Slough Wildlife Management Areas and the Little River National Wildlife Refuge. Though they have been found in other counties, Choctaw County and McCurtain County claim the highest number of the scaly predators. It is unlikely that they could survive the winter any further north.

Alligators hibernate in burrows, also known as “alligator holes,” when the average temperature falls below 75 degrees. Even outside their burrows, however, they can tolerate limited periods of freezing conditions. Known as the “icing response,” they submerge their body but keep their nostrils projecting above the water surface, so that when the surface freezes they can still breathe. Essentially their upper body becomes trapped in the ice.

Anyone who wants a chance to see walking, or swimming, history can make a trip to the southeast corner of Oklahoma on a warm summer day. Though rarely glimpsed, you just might see Oklahoma’s resident dinosaurs basking lazily in the sun.