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Alligators, Crocodiles, and Hippo’s. Crocodilians. Alligators, caimans, crocodiles and gharails are jointly referred to as CROCODILIANS. Crocodilians. skin. Crocodilians. They control the depths at which they float by controlling the amount of air they retain in their bodies .
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Crocodilians • Alligators, caimans, crocodiles and gharails are jointly referred to as CROCODILIANS
skin Crocodilians They control the depths at which they float by controlling the amount of air they retain in their bodies
American AlligatorsPhysical Traits • Belongs to the family Alligatoridae • American Alligator (Alligator mississipiensis) inhabits the Southeastern United States from North Carolina to Florida and west to the lower Rio Grande. • Chinese Alligator (Alligator sinensis) is found in the Yangtze River Valley of China
American Alligator Physical Traits • Elongated armored, lizard-like bodies with muscular flat tails • Broad head with a long, wide, rounded, shovel-shaped snout (shorter than a crocodile). Nostrils at the end to allow breathing while submerged under water.
Alligators Physical Traits • Their eyes and nostrils close by reflex when the animal goes underwater. • They have a transparent third eyelid, or nictitating membrane, that covers the eye as the animal moves through the water. • Valves to close the ears and nostrils when it is submerged
Alligators Physical Traits • Four short legs – five toes on the front feet and four on the rear • Skin on their backs is armored with rows of bony plates called osteodermsor scutes • Average adult size – 8.2 feet for females and 11.2 feet for males • Can weigh more than one ton
AlligatorsReproduction • Sexual maturity depends on the size of the alligator – about 6 feet. Wild alligators will be about 10-12 years old. For alligators raised in captivity it will be much sooner • Mature alligators seek open water areas in April and May – courtship and breeding season • Males roar during the mating season, but the normal vocalization is a hiss.
AlligatorsReproduction • After mating females move into marsh areas to nest in June and early July • Females construct mounded nests of available vegetation. They lay between 35-50 eggs (There may be as few as 1 or as many as 88) • After laying eggs the female covers the eggs with a layer of vegetation
AlligatorsReproduction • There is a 65-day incubation period. Females stay nearby their nests and defend their eggs against predators such as raccoons. Only fifty percent of the eggs will survive. • Females are territorial and will guard and defend their nests.
AlligatorsReproduction • Eggs hatch in mid August – mid September. The young alligators make high-pitched grunting sounds from within the egg. Females respond by using their mouths to remove the nesting materials covering the young thus liberating 6-8 inch hatchlings
AlligatorsReproduction • Hatchlings remain in groups called pods at least through the first winter and may stay near the nest site for 2-3 years • First 2 years of life is the most critical. Birds, raccoons, bobcats, otters, snakes, large bass or even large alligators may eat 80 % of the hatchlings
American Crocodile • Scientific Name and Range • Crocodylusactus Found in coastal wetlands along the Pacific Ocean from Western Mexico south to Ecuador and along the Atlantic Ocean from Guatemala north to the extreme tip of Florida
Similarities • Belong to same order Crocodilia • Predators • Poikilothermic • Carnivores
Differences • Alligators do not have a tooth that shows outside of the mouth when it is closed, while crocodiles DO have such a tooth • Snout of an alligator is very short and wide. Snout of a crocodile tends to be longer and more pointed • Crocodiles are generally much larger than alligators and much more ferocious
