In Florida, I frequently see water birds in close proximity to alligators. We can define ‘close proximity’ as less than one alligator body length away. I find this curious, as alligators do occasionally eat birds. So why aren’t birds more wary of alligators? I know I am not the only one who finds this situation somewhat puzzling. While observing alligators at a popular local trail, one of the most common things I hear both children and adults say is something along the lines of: “that alligator is about to get that bird.” But it never transpires. Despite observing this situation hundreds of times (various water birds going about their business next to a resting alligator) I have never seen an alligator lunge toward a bird or attempt to capture it. In fact, I have only seen an alligator with an already dead bird in its mouth two times (despite hundreds of hours of observation).
Herons and Egrets in close proximity to Alligators. Click photo to enlarge and open gallery view.
Various other water birds in close proximity to Alligators. Click photo to enlarge and open gallery view.
While thinking about this situation, I came up with what I think is a reasonable explanation based on the context in which it occurs and the biology of both species. There is a well-known phrase: “the most dangerous alligator is the one you don’t see.” I think this may hold the key to what is going on between birds and alligators. The situation I am describing occurs when the alligator is making no attempt to conceal its presence (i.e. it is resting on the bank or in shallow water). The bird clearly sees the alligator and is aware of its presence. The element of surprise is gone. Because of this fact alone, the alligator may pose little threat to the bird. Specifically, alligators may instinctively realize that without the element of surprise the probability of successfully capturing a vigilant bird is so low so as to not even be worth attempting. Conversely, birds also may instinctively know that without the element of surprise alligators do not pose a significant threat, and therefore they are comfortable approaching to relatively close proximity (also note, birds are not going extremely close to the alligator’s mouth). So, a temporary truce is reached where each species essentially ignores each other.
Although I have never seen an alligator capture a bird, I have twice seen an alligator with a dead bird in its mouth, and stomach content analysis indicates birds are eaten by alligators. I would imagine that birds are most likely to be captured when a juvenile falls from its nest into the water, or when the alligator is concealed underwater and launches a sneak attack upon an unsuspecting bird either floating on the water’s surface or resting at the water’s edge.
Finally, I once saw a White-tailed deer closely approach a group of basking alligators. Alligators eat deer, so this was somewhat surprising. Rather than lunging toward the deer, the alligators suddenly became spooked and dashed into the water. Similar to the situation with alligators and birds, I suspect that without the element of surprise the deer instinctively knew that the alligators posed little threat and therefore was comfortable coming in for a closer look.
Reason and Nature 