Monday, October 11, 2010


A couple of posts ago, I grumbled about having seen so little hawk migration thus far in El Salvador.

Last Saturday, Roselvy and I went to a Maya archaeological site called San Andrés, in the Valley of Zapotitán, more or less halfway between San Salvador and Santa Ana. Here, we found beauty, tranquility and, atop "Estructura 4", a 360° view of the sky.

Structure 4 is the hill on the far right in this picture, behind the little tree. The other three hills are Structures 1, 2 and 3, which are off limits. Although not as impressive as Tikal in Guatemala or Copán in Honduras, San Andrés is an interesting place to visit, with remains of human habitation dating back 3000 years. Situated in the Central American Volcanic Belt, its history is one of settlements establishing themselves, growing, flourishing, and then being wiped out by a volcanic eruption, before the whole process starts again.

Between 10 AM and 4 PM, we watched thousands of raptors, mostly hawks and vultures, stream high overhead. In the morning, the flight was dominated by Swainson's Hawks, which can be seen in the picture at the very top. A few broadwings are also visible in that photo.

Turkey Vulture and Broad-winged Hawk were the other two abundant species, both of which can be seen in this picture if you click on it. The hawk on the left is something else, and if you want to try and identify it for yourself, go right ahead. I'll tell you what it is a little further down in this post.

In the afternoon, the flight was dominated by Turkey Vultures, with thousands streaming over. Scattered among them were Broad-winged Hawks, eight of which can be seen in this picture.

Other migrant hawks we noted were Zone-tailed Hawk (2), Mississippi Kite (12), American Kestrel (1) and Sharp-shinned Hawk (1). With non-migratory, resident raptor species Northern Caracara, Short-tailed Hawk and Roadside Hawk, we got to 11 diurnal raptors, two vulture species included. The 'mystery hawk' in the third photo of course is a Zone-tailed Hawk. Only superficially similar to Turkey Vulture, the bird stands out as different from TV's in a number of ways: wingtips pointier and swept back, tail longer and thinner, head bigger. In this photo, the zone-tail looks a lot smaller than the Turkey Vultures, but that's partly because it is flying higher.

To get a sense of where we were seeing all these birds, here is a relief map of western El Salvador. Right in the middle, below a small crater, is San Salvador. The crater belongs to Volcán de San Salvador. The two yellow cards halfway between that crater and a crater lake, called Lago Coatepeque, identify two archaeological sites, one of which is San Andrés.

We saw birds flying mostly due east, which would bring them a little north of Volcán de San Salvador. I posted our sightings to the national birding listserv here in El Salvador, and this yielded a couple more descriptions from people who had seen the same thing.

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