Birding Oaxaca 2004 - Wrapup

Valles Centrale
Carribean Slope
Pacific Slope
Bird List

10 Feb 04 - Hotel Victoria, Oaxaca City, Oaxaca
Sometimes, not often, money can buy happiness. Specifically, it can buy a 30 minute airplane ride from Puerto Escondido to Oaxaca City, instead of the 6 - 10 hour car ride through those wretched, twisting roads. We flew in a Cessna Caravan II operated by Aerotucan. The flight was smooth, and quick, the scenery was spectacular and the $100 air fare an exceptionally good investment.

The geology of this area is fascinating. The mountains seem to be mostly limestone and sea floor, partially metamorphosed and in many areas seriously distorted. There were layers of ash visible, especially in the northern mountains, but the only basalt seemed to be ocean bottom. I assume the ash is from the stratovolcanoes to the north and west. There is a lot more limestone, and a lot higher up, in the southerly mountains, and the Valle Centrale seems to incorporate a strike-slip fault. It's hard to imagine that much seafloor being scraped off and pushed to 3,200 meters or more when the Cocos Plate has subducted under the North American Plate, but at a rough guess that's at least one of the mechanisms. Puerto Escondido itself seems to sit on a granite or diorite pluton, but that's the only extensive igneous rock I saw in Oaxaca. Of course, I saw only a fraction of the state.

The deep valley of the Rio Grande in the middle of the Sierra Madre Occidental is almost certainly an active strike-slip fault, uncannily like stretches of the San Andreas fault. I'd love to know more, but there isn't a lot available in English.

The birding was very good, a total of 230 species in 9 days, 81 of them lifers. Essentially all of my east coast warblers are now birds I saw first in Mexico. Here's a complete list with the location where the birds were first seen.

Mammals were scare: Mexican Fox Squirrel, Rock Squirrel and two unditenfied bat species. Everything else was domesticated.

We want again to send special thanks to our friends and guides in Oaxaca, Roque Antonio Santiago and Ramiro Aragon Perez. For more information about them try the Resources link.

Copyright 2004
Jim & Nancy DeWitt
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