Senin, 26 Oktober 2009

Opportunistic Anis

Smooth-billed ani.

Last July I was on a digiscoping trip to Trinidad & Tobago sponsored by Leica Sport Optics. On the second day of the trip, we left the friendly confines of Asa Wright Nature Centre for a bit of birding afield. We drove down out of the mountains to the Aripo Agricultural Research Station, where, after turning off the highway into the station's entrance, we encountered our first interesting birds.

A pair of tiny green-rumped parrotlets was exploring a natural cavity in a tree by the roadside and we stopped our vans to try to get photographs of them. We snapped a few shots, but needed to disembark from the van to let everyone see the birds. As happens so often, our stopping and unloading spooked the birds into flight. Even though hundreds of cars and trucks pass right by this tree each day, few of them probably stop by this tree. And our stopping was enough to encourage the birds to flee. We thought they might be nesting in the cavity, so we removed ourselves a bit and waited, hoping they would return.

Green-rumped parrotlets.

About this time a crew of workers down the road 40 yards started up their weed-whackers. The noise immediately over-rode all other sounds around us and the tall grass which they were cutting down began to fly, in pieces, in all directions. Along a fence line behind the workers a flock of smooth-billed anis began dropping down onto the ground and flutter-walking over toward the weed whacking action. I did a double-take. Conventional wisdom would have had the birds fleeing at the start of the noisy, smoky, grass-destroying trimmers. But these birds were attracted to the noise and activity.

Anis in my experience almost always look disheveled.

And then it dawned on me. The anis were after an easy meal. Just like bald eagles waiting below a dam spillway in winter, grizzly bears gorging on post-spawn salmon, or the barn swallows that follow my tractor when I mow, these anis had made the connection between weed whacking and easy-to-catch insect prey. The string trimmers (called, I once was told, "strimmers" in the United Kingdom!) cutting down the grass were disturbing and maiming lots of grasshoppers and beetles and other yummy bugs. Smart birds.]

Here's a short video of the opportunistic smooth-billed anis:




Judging from the height of the grass, the trimming had not been done here for a long time—maybe a few months. Yet the anis knew to associate the sounds and activity with an easy meal. Isn't that interesting?

Smooth-billed anis are reasonably common birds in the central part of their range: from the islands of the Caribbean, south throughout South America. But they reach the united States only in central and southern Florida, where the species seems to be declining rapidly. Where you find one smooth-billed ani, you are likely to find others since they spend their lives as a part of a noisy flock of a dozen or more birds.

Speaking of a flock of anis. I wonder what the term of venery for a flock of anis is? A showtune of anis? A yawn of anis? A Yanni of anis (for the horrible noise they make)? Your suggestions are welcome here.