By: Sam Nowicki, Animal Keeper Ipublished Tue April 09, 2013
Have you been to the alligator exhibit at the zoo lately? Our male, Jacques, usually steals all the attention by sunning himself on the island and showing his full length of 13.5 feet! But you might not have noticed we have some unsuspecting and rather small visitors in the branches of the trees right above their heads that line the back fence to their exhibit.
Every year, our alligator exhibit turns into a temporary home for green herons. Just like the great blue heron which we are all familiar with, these birds look very similar with the long, narrow bills, long legs, and long necks which can stretch out and fold back. Unlike the great blue heron, however, the green herons are much smaller (about the size of a large crow) and have…you guessed it…green feathers. They also have dark brown feathers around their neck and chest with bright yellow eyes to contrast. For food, they prefer small fish living in shallow water. These birds might be one of the smartest birds around, because they actually use tools to lure fish! By picking up small crumbs of bread or little insects, they place the bait in the water and wait for hungry fish to swim by. Then with extremely quick speed, they lunge and spear the fish.
Why do they build nests over the heads of alligators? It seems like a silly decision with bad consequences, but there is a very good reason. As they build their nests in the trees and lay their eggs (up to 6 at a time), there are many predators that would love nothing more than to eat those eggs such as raccoons and opossums. But with the scent of an alligator territory around the nest, they know they might end up as a snack to the big reptile, and stay well away. This gives the baby birds a chance to hatch and grow through the summer.
So why aren’t green herons here through the winter? As soon as the fledglings (that’s what we call baby birds that aren’t quite babies and aren’t quite adults) get the hang of flying, autumn closes in and the temperature drops. Rather than stay through our cold winters, the herons fly to Mexico, Central America, and South America to enjoy more warmth for the rest of the season.
We have at least three sets of herons building their nests right now. If you drop by periodically throughout the summer and watch closely, you will be able to see the babies hatch and grow!