Building Nests Near Alligators Isn’t Such a Bird-Brained Idea After All

While it seems like a really dangerous and not-too-bright thing to do, many birds in Florida’s Everglades intentionally build their nests on trees above alligators.

“We have known for some time that ibises, storks, spoonbills and herons seem to always have alligators underneath their nests,” Peter Frederick, a University of Florida wildlife ecology and conservation professor, said in a news release. “Alligators are serving as nest protectors – keeping raccoons out of the colony, which are otherwise devastating nest predators.”

Having alligators around to chase away raccoons, possums and other predators is obviously beneficial for the birds, but what’s in it for the alligators?

According to a new study by Frederick and other University of Florida scientists, alligators in the Everglades that were found in close proximity to bird nesting colonies weighed about six pounds more and were overall in much better body condition than alligators found in similar habitats without nesting birds.

An alligator goes after a raccoon in the Everglades. Photo credit: Florida Fish and Wildlife Conservation Commission

An alligator goes after a raccoon in the Everglades. Photo credit: Florida Fish and Wildlife Conservation Commission

The reason for the gators’ good health is a little tragic: As payment for their “bodyguards,” the birds must sacrifice some chicks. When a bird lays more eggs than it can raise, the weaker chicks often fall or are pushed out of the nests.

“Many of the dead chicks end up in the water, and their potential contribution as alligator food is substantial,” Dr. Lucas Nell, another of the study’s authors, said in the news release. “In fact, we estimate that in years with especially high bird nesting, most of the breeding female alligators in the Everglades could be supported during the four-month dry season by dropped chicks alone.”

Another benefit for the alligators is that their breeding season is just a few weeks after the bird breeding season. Healthy female alligators in good body condition tend to lay more eggs.

“So, associating with birds may help the gator population to persist in this otherwise harsh habitat,” Nell said. Because of that harsh habitat, alligators in the Everglades are smaller than those elsewhere in the United States. Instead of a typical alligator diet of fish, turtles and mammals, Everglades gators must subsist on snakes, salamanders and other small creatures.

As Nell told the Los Angeles Times, “They don’t get an opportunity for big meals.”

A Wildlife Quid Pro Quo

Odd but mutually beneficial relationships like those between the birds and alligators, referred to as “facilitation,” provide a “positive ecological exchange in which one species enhances habitat for another nearby species,” according to the study.

“Ecological facilitation is an important force in shaping both community composition and distribution of species,” Frederick said. “The birds are protected from raccoons and other predators, and the alligators get food. Both partners appear to derive significant benefits from the relationship, which might enable them to exist in places they otherwise might not.”

Birds and alligators also cohabitate in areas beyond Florida.

“Colonial birds and alligators occur together throughout the subtropical and tropical biomes of the world, and it seems likely that this relationship is important worldwide,” Frederick said.

“For this reason, we believe that the relationship itself should be a focus of international conservation efforts.”

Photo credit: Rachel Kramer

98 comments

Siyus Copetallus
Siyus Copetallus2 years ago

Thank you for sharing.

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Marie W.
Marie W2 years ago

All interconnected.

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Maria C.
Maria C2 years ago

Let's leave things the way God made them!

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Jennifer H.
Jennifer H2 years ago

Which came first the alligator or the nest?! It always surprises me when "we" discover something new about the animals. They have been balancing the environment for eons and we are always amazed. But then, there we go and screw it all up.

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Ronald Walker
RONALD Walker2 years ago

It not a big surprise to me. I have read about other animals doing the same thing. As small birds build their nest just below the Hawks nest. Basically doing the samething . Protect small birds from animals that would eat there young..

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Gilbert A.
Gilbert A2 years ago

Mother Nature works in mysterious ways!

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Peggy B.
Peggy B2 years ago

Mother nature takes care of her own.

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Shirley Plowman
Shirley Plowman2 years ago

Gotta love ole mother nature and the natural world.

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Roberta Z.
Roberta Z2 years ago

Good article and well written.

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Linda W.
Linda Wallace2 years ago

Such a hard life for some but it works in a difficult place.

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