Excerpts from Jim Conrad's
Naturalist Newsletter

from the June 2, 2007 Newsletter issued from Sierra Gorda Biosphere Reserve, QUERÉTARO, MÉXICO

Last weekend I camped beyond the far end of the reservoir, a bit up the main arroyo feeding the lake. Early Sunday morning when just enough light filtered into the narrow valley for birds to start flying up and down the intermittent stream I sat cross-legged in my tent's door gazing across a green pool of water. I'd pegged the tent beneath a big Mexican Sycamore where I had a good view up and down the stream, which was strewn with white, rounded, hippopotamus-size limestone boulders.

I'd chosen the spot hoping to see wildlife visiting the pool to drink. During the night I'd heard lots of frogs and something knocking rocks about, but that was about it -- except for the sharp, excited-sounding whistles near my tent at dusk the previous day and first thing that morning. The whistles had reminded me of Woodchuck warning calls, so I'd figured it was some kind of mammal with a den in the rocky ledge behind my tent annoyed by my presence.

At the corner of my vision suddenly there was quick movement, a splash, and by the time I'd focused on the action I saw about 30 feet away a large, black hawk carrying something heavy in his talons. Apparently the thing being carried weighed too much to fly far with, for the hawk landed with it at the water's edge. The binoculars told the story: A Common Black Hawk had just plucked something looking like a Giant Toad from the stream.

What a view I had, the tent serving perfectly as a wildlife blind. The hawk was all black except for two conspicuous white bands on his tail, a brightly yellow, curved beak, and exceptionally long, yellow legs. You can see what a Common Black Hawk looks like and hear a version of its sharp whistles at http://identify.whatbird.com/obj/441/overview/Common_Black-Hawk.aspx.

The whistles at the above site sound perfectly hawky, but the ones I heard were just short, agitated-sounding outbursts.

That poor toad! The hawk perched atop it apparently puncturing and repuncturing its body with his talons. Several times a minute, with a brief fluttering of wings, the hawk would jump straight up, raising the toad six inches or so, and I interpreted this as the hawk trying to gain better purchase on his prey, thus probably making new holes in him. After every three to five jumps the hawk would bend forward and cut at the toad with his big, curved beak, sometimes seeming to carve out chunks which he'd swallow. This went on a good 15 minutes.

Up until this time I wasn't 100% sure that the prey was actually a Giant Toad, so now I emerged from the tent and began inching closer. The hawk would have none of this. He flew off, dropping the toad with a heavy plop onto the limestone bed. Reaching the toad and confirming my identification, I was amazed to find him still capable of righting himself and gamely trying to make it to water. When I drew close he took in air, bloating his body considerably. I've read that Giant Toads do this to make themselves too large for certain predators' mouths, but now I wondered whether another advantage might not be to separate the skin from vulnerable organs inside, by lots of air.

The hawk was perched nearby casually with one yellow leg drawn up into his black chest feathers, glaring at me, so I left the scene, hoping I'd not irretrievably disrupted an important moment in the local ecosystem's workings.