Join BirdNote tomorrow, November 30th!
Illustrator David Sibley and actor H. Jon Benjamin will face off in the bird illustration battle of the century during BirdNote's Year-end Celebration and Auction!
Do Alligators Protect Herons?
Heron home security…. At what cost?
© Phil Hauck
Raccoons sometimes invade nesting colonies of herons, spoonbills, and other wading birds to eat their eggs and chicks. But some of these birds have found ways to deter the masked bandits. Researchers in the Everglades found wading birds including Great Blue Herons and Roseate Spoonbills, among others, more often chose to nest on islands where alligators swam in the surrounding water than on islands where alligators were absent. There’s some give-and-take, for sure, but alligators seem to be a better bet than raccoons.
BirdNote®
Do Alligators Protect Herons?
Written by Bob Sundstrom
This is BirdNote.
[Roseate Spoonbill sounds, https://www.xeno-canto.org/397346; good for background sound through story]
Raccoons sometimes invade nesting colonies of herons, spoonbills, and other wading birds to eat their eggs and chicks. The birds simply don’t have what it takes to drive raccoons away. But some of these birds have found ways to deter the masked bandits.
[Great Blue Heron colony sounds]
In the Southeast, herons build nests in trees on small islands. Researchers in the Everglades found wading birds more often chose nesting islands where alligators swam in the surrounding water than islands where alligators were absent. Alligators readily eat raccoons. So raccoons become the prey if they swim in ‘gator-infested waters to reach heron nests.
[American Alligator growl, https://www.youtube.com/watch?v=39pxYm1HEpg, 0.02 and 0.14]
If a heron chick falls from the nest into the water, an alligator may grab it. But still, an alligator swimming below the nest is a safer bet than a raccoon climbing in.
[Sounds of Great Blue Heron colony]
Scientists don’t think birds and ‘gators intentionally cooperate: Alligators don’t consciously guard heron nests, nor do herons surrender chicks to hungry ‘gators.
So while a moat teeming with ‘gators might be overkill home security for us humans, it works nicely for herons.
For BirdNote, I’m Michael Stein.
###
Producer: John Kessler
Executive Producer: Sallie Bodie
Editor: Ashley Ahearn
Associate Producer: Ellen Blackstone
Producer: Mark Bramhill
Roseate Spoonbill sounds courtesy of xeno-canto; recorded by Bruce Lagerquist.
Sounds of Great Blue Heron colony recorded by John Kessler.
Alligator growl recorded by skyenimals, courtesy of YouTube.
BirdNote’s theme was composed and played by Nancy Rumbel and John Kessler.
© 2020 BirdNote May 2020 Narrator: Michael Stein
ID# alligator-01-2020-05-18 alligator-01
References: https://www.livescience.com/amp/54121-birds-use-alligators-as-bodyguard…
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.01495…
Sights & Sounds
