Monday, May 23, 2011

Dogged Serpent

The Boa is back! It was here last month, too, but the incident was a bit sad and I decided not to dedicate an entire post to it. Briefly, though, here is what happened: Early on the morning of April 28th, I was alerted to the nearby presence of one of the two Boa Constrictors who haunt the pine trees in our yard. A good-sized flock of little feeder birds, along with the Chief Sentinel and Town Crier (both titles earned and owned by the local male Hepatic Tanager), were clustered around a pine branch, scolding and chattering. I quickly spotted a Boa, the smaller of the two regulars, coiled around a bird. All I could see of the bird was a tail, part of the yellow underparts, and pinkish-orange feet, but these details were enough for me to suspect that the prey this time was a Rufous-capped Warbler.

I had been observing the scene for about 5 minutes when the snake executed a "loosen and recoil" maneuver, during which the snake usually repositions the prey and tightens the grip on it, and/or moves it into a position where he can begin to swallow it. This time, however, the Boa dropped the bird! If I had made a dedicated blog post about the incident, the title would have been "Butterfingered Boa", which is what our friend Jorge called the snake when I told him about it that day.

The bird fell to the ground in a spot where I could easily retrieve it, which I did, and sure enough - it was a Rufous-capped Warbler, a young of the year. I was sad because it seemed like a waste of a perfectly good warbler, although I realize the invertebrates would have done their work on it. I left the bird on the terrace so Marco could see it; he was out picking up Gonzalo for some gardening. Then we left the bird on the terrace railing for several days until finally something ate it, leaving only the rectrices and a few fluffy flank feathers scattered on the ramp.

The Boa remained on the same branch, in almost the same position, through May 5th. It never did appear to be lumpy during that time, so we don't think it caught anything.

Our friend Dennis helped Marco put up a clothesline about two months ago, not for clothes, but for another Cerro Azul Bird Feeding System®. They strung it from a pine tree near the terrace to a pine well down the hill toward the creek. It has pulleys so we can reel it in and out, with three feeders hanging from it: a small hummer feeder, a standard suet feeder stocked with bananas, and a shallow plastic basket also stocked with bananas.

Our hope is that by placing the feeders way out there, some of the more wary species (who don't like coming to the feeders near the house) will be brave enough to make an appearance at them.

This month's incident began before breakfast on May 16th. We heard the birds being all excited, and saw them gathered on the clothesline. We both gave the birds and the area a quick glance , but didn't detect the cause for their alarm. A few minutes later, while we were enjoying breakfast on the terrace, Marco noticed that the smaller Boa was toward the far end of the clothesline, stretched lengthwise along it, within inches of the suet feeder. We interrupted the meal while Marco spent a few minutes maneuvering the clothesline back and forth, shaking it, removing and replacing feeders. Eventually, the Boa gave up its grip and fell to the ground. All was then calm, and we and the birds had our breakfasts.

The next morning when we opened the kitchen door we saw that the Boa had returned - not to the clothesline this time, but to a small stub branch that comes off the trunk a couple feet below the pulley. It would be interesting to know how long it took him to climb up that pine trunk and settle on the new perch.

The Boa stayed in position all day - the birds knew he was there, and they would occasionally remember or rediscover him, flitting around the branch to investigate. The young Bananaquits make us especially nervous - their curiosity is so extreme that they get waaaay too close to the snake for our comfort.

Marco has assembled some footage of the day, a time-lapse series that shows a few of the birds as they keep a watch on the Boa:

To be continued . . . . . . .

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