Alligators need warm weather to settle in an area


Since 2015, alligators have occasionally been seen in Maryland and Virginia communities around the Chesapeake Bay. Does this mean that prehistoric-looking reptiles are moving into the Mid-Atlantic region?

Adult alligators can spend time in brackish waters where food resources such as blue crabs are plentiful, said alligator biologist Alicia Davis of the North Carolina Wildlife Resources Commission. “However, the Chesapeake Bay is too far north to support alligator populations. North Carolina is the northernmost stretch of alligator range.

Chris Rowe of the University of Maryland Environmental Services thinks humans are to blame for the sightings. “My gut feeling is that they’ve been freed from illegal pets,” Rowe said. Alligators have survived millions of years but need temperatures above 40 degrees to be active and cannot digest food if the temperature is below 70.

Reptiles are cold blooded (ectothermic) and depend on external heat sources to regulate their body temperature. The armor-like scales along an alligator’s back act like solar panels. As the alligators bask in the sun, the blood flowing through the scales warms the alligator’s body. To cool off, alligators hold their mouths open like a panting dog.

Alligators do not hibernate. In cold weather, they enter short periods of dormancy called “brumation”. Their heart rate slows and they become very sluggish, burrowing into dens or tunnels at the water’s edge, periodically venturing out to bask in the sun. Alligators cannot breathe underwater. They periodically surface or keep their nostrils above the ice to breathe.

While they stop eating, they continue to drink water to avoid dehydration. With large bodies and short legs, alligators cannot migrate on land. They also don’t have glands to filter out toxic levels of salt like crocodiles do. This means alligators cannot travel north across the ocean.

They live in swamps, slow-flowing freshwater lakes and rivers, and some brackish water (partly fresh, partly salty). Some alligators will go into the ocean for short periods. “The reason is a mystery,” Rowe said. Are they looking for some of their favorite foods – crabs and young sharks? Have storms or floods pushed them out to sea? Further research is needed to find out why.

As apex predators, alligators help balance smaller predators such as blue crabs, which eat snails and mussels. Research shows that long-legged wading birds such as herons and egrets sometimes build nests above where alligators are present. This is because alligators can unwittingly protect nests. They eat raccoons and possums, which like to eat bird eggs. Alligators profit by eating chicks that fall from birds’ nests.

You are most likely to see alligators in zoos and aquariums, but if you were to see one in the wild, you should keep your distance. “People should keep at least two school bus lengths away from an alligator,” Davis said.

Alligators are most active between dusk and dawn. They can run around 35 mph on land in short bursts and often hide in vegetation along the water’s edge. Their sneaky attacks on food sources, and sometimes unsuspecting people, are due to the fact that they can lie motionless underwater with only their nostrils and eyes visible above. As prey approaches, vibration sensors on an alligator’s snout prompt it into action, snapping its strong jaws quickly around a meal.

But humans are not typical prey. In most cases, alligators try to stay away from them. “They’re not monsters,” Rowe said. “Alligators rarely have anything to do with humans unless humans do something to them.”


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