Green herons (Butorides virescens) are cool birds. Small, subtle little guys, they tend to be pretty shy in these parts and not pose for photos all that eagerly – the shot above (and here) was taken at Wakodahatchee Wetlands in Florida, a manmade preserve smack in the heart of suburbia at Delray Beach that has to be seen to be believed. Cross the boardwalk bridge from the parking area into the wetland proper, and the cacophony of bird sounds is likely to hit you almost physically, sounding like an overdone jungle movie. And like many such areas in Florida, the normally shy birds are acclimated to people and allow much closer approaches. Yeah, you thought nature photography was all about careful stalking skill and sitting for days in blinds? It’s also about finding the places where you can get closer with less effort ;-)
Over at Why Evolution Is True, Jerry Coyne has a post about green herons and their usage of tools, a very rare thing among birds. It seems some of them, without this being universal among the species, have taken to bait fishing by placing bread fragments on the surface of the water and waiting for it to be visited by fish, which is of course what green herons eat. Check it out, because he’s got video of this going on.
As I remarked upon over there, I’ve never seen this behavior myself, but I have seen white ibis, the birds also seen in the beginning of the video, performing this dunking maneuver, only to soften the bread it would seem. And I’ve cheated a little (just destroying all of your cherished beliefs about nature photographers, aren’t I?) and tossed bread into a pond in front of my camera to get egrets to chase the fish it attracted. Learning this behavior is an interesting bit of cognition for birds.
It’s hard for me to say how this compares to other species and behaviors. Great blue herons (Ardea herodias) have apparently learned that, in Florida, five-gallon buckets often contain easy meals, since live-bait fishing is popular in that state and such buckets are used to house and carry fish like finger mullet. Fisherfolk learn to keep a lid on their buckets, because the herons can get pretty brazen about landing on fishing docks and helping themselves. I’ve also watched brown pelicans (Pelecanus occidentalis), who’ve learned that casting nets can suddenly come ashore bulging with effortless meals, mobbing the poor angler who was collecting bait for a subsequent fishing trip. Many years ago when milk in England was delivered to doorstops daily, I remember reading about songbirds who would pierce the foil seals on the tops of the bottle to obtain a drink (which was bizarre in itself – milk?) None of these are tools, of course, but they all show a certain level of learning behavior, not very far removed from tossing bread into the water.
Alternately, while this isn’t directly related, I’ll include a link to show just how large a fish a great blue heron can manage to swallow whole.