Thursday, October 28, 2010

Where is the Atascosa Highlands CBC Circle?

This is a very common question. I'll post a map of the circle below to make it easy.

Bill Harrison created this circle with apparent much thought and planning in 1960 – a circle in this region could not have been placed in a better position. And unlike almost all nearby circles it hasn't been moved by any of the subsequent compilers.

It's best features are:
• maximum coverage of public lands, minimal private lands
• nearly bisected by a single good road with access roads off of it
• minimal overlap into Mexico
• just barely including three important bodies of water – Arivaca Lake in the NW, Bear Grass Tank in the N, and Peña Blanca Lake in the SE.
• completely encompassing all of the Sycamore Canyon-California Gulch southward-flowing drainages
• and, completely unbeknownst to Bill, incorporating the entire US range of Five-striped Sparrow (the species wasn't discovered here until a few years later)

And Bill did this all without Google Earth. (He may have even used a slide rule...)

The coordinates of the center are N31.47006°, W111.17278°

Click on the image for a larger version.

Wednesday, October 27, 2010

Date Set for Friday December 31, 2010

I've already started recruiting for AZAH, the Atasoscosa Highlands Christmas Bird Count, set for Friday, December 31, 2010. I assign area leaders and their teams well in advance, so please contact me as soon as you know you can commit.

Here's a view from near the unassuming center of the circle – with almost countless canyons and rocky ridges for 7 1/2 miles in all directions. Click on the image to open a window with a larger size.

Leading the Nation in National Highs for 110th CBC!

I just received my issue of American Birds summarizing the 110th Christmas Bird Count and was surprised to find that Atascosa Highlands led the nation with highest tallies for 17 species on our January 3, 2010 count. In my last blog post I listed the 15 that I found, but Brent Ortego in his article found a couple more – Elegant Trogon (we had one, tying with three other AZ counts) and Rufous-crowned Sparrow, a silly oversight on my part – AZAH always has the high count for that one. The next closest count was Weslaco, TX, which had 15 highs.

Brent also compiled the all-time highs for all 110 years of the BC, and AZAH ranks 13th nationally with 10. Our neighbor, the Nogales CBC (which actually illegally overlaps the older AZAH circle, something that should be addressed at some point) ranks 9th, and AZAH stands a good chance of eventually topping most of those, with the exception of the exotic Elegant Quail and the 1997 Nutting's Flycatcher counted in their total.

At top: The Atascosa Highlands CBC tallied 4 Elegant Trogons in 2008, setting a new all-time high for this species. A 5th was found a few weeks late in remote Ramanote Canyon, which hadn't been covered on the CBC.