Spring 2007 West Texas Aplomado Falcon Survey
Brian Mutch— 22 March 2007 — in Aplomado Falcon Restoration    ShareDuring The Peregrine Fund’s fall planning meetings in Boise, Idaho, we decided to organize our first intensive survey for breeding Aplomado Falcons in west Texas. Having just completed our fourth season of releasing young Aplomados to this arid desert grassland, a northern extension of the Chihuahuan Desert, we all felt there was a good chance of discovering a breeding pair. So, on 10 March 2007, four Peregrine Fund biologists, Angel Montoya, Paul Juergens, Christina Kleberg, and I, met in Marfa, Texas, where we were joined by Peregrine Fund Founding Chairman and Director, Dr. Tom Cade. In our favor, a surprising weather report for the area called for little wind (March is a very windy month in west Texas), highs in the 70s, cool nights, and the chance for a cold front with a little precipitation—all in all, perfect conditions for surveying, and conditions we felt might make this small falcon a little more conspicuous in all this huge country.

We decided to concentrate our efforts on the ranches where most of the releases have occurred and in the areas where our biologists and other bird enthusiasts have been seeing the species. This area would still encompass a vast region with many unique challenges for the crew. One such challenge was simply the lack of accessibility from the limited number of ranch roads.

Having split up into three groups, each with a four-wheel-drive vehicle, we together began to cover all of the prioritized areas, stopping every quarter mile or less to thoroughly “glass” (using binoculars) the immediate area. We closely examined distant objects with spotting scopes to determine whether they were, in fact, birds (yucca seed pods through distant heat waves have an uncanny way of looking exactly like an Aplomado Falcon). After seven to ten hours each day of driving, glassing, and scoping everything in sight, we found ourselves wanting to turn every “good looking” object into a falcon!

The first full day of the survey (11 March) revealed just two Aplomado Falcons. The first was a young female released during the prior summer and the second an adult male released just 5 km away in 2005. We gave the male extra attention as we thought he might be paired with a female, but we saw him feeding as it began to get dark, and he showed no sign of having a mate. We would check this area again to be certain.

In my field notebook next to 12 March 2007 is an excitedly penned star. Today we were to discover the first documented, reintroduced, west Texas Aplomado Falcon pair which, by all observed behavior, included an adult female appearing either to be laying a first egg or adding an egg to her clutch! Needless to say, we were very excited about our find! As we did not want to disturb this pair by getting too close during the sensitive timing, we decided to confirm in the weeks to come whether the pair was incubating. Tom Cade had spotted the male of this pair perched on the shaded downwind side of a yucca. After some intensive glassing of the nearby tall yucca trees, we noticed the female crouching low and inconspicuously in a nest. She slowly rose up out of the nest but continued to stand there until we left the area.

It is difficult to describe the satisfaction of seeing such positive results after so many people have worked so hard and towards the goal of what we witnessed here today. Tom and I felt very lucky to find this pair, and to once again look on at the very infancy of a recovery effort in progress.

As our survey efforts proceeded during the next several days, two additional adult pairs were located as well as three more, single individuals. On 14 March, Angel Montoya, Paul Juergens, and Christina Kleberg found a pair very near Highway 90 and showing all the signs of having selected a nest in a yucca tree. The trio of biologists observed the falcons making some great hunting flights at what appeared to be Vesper’s Sparrows. In fact, the pair managed three successful flights at this quarry in the hour and a half observed. Food transfers and copulations were also observed. So, we had our second breeding pair located! Angel phoned Tom and me, working far to the east that day, and informed us of the great news.

Tom and I found a third adult pair which had been frequenting the area of an airstrip on a large private ranch. The owner told us where to concentrate our search efforts and sure enough, we found them in a little over an hour. Although they did not appear to have selected a particular nest site yet, they were frequenting some beautiful habitat. We will check back with them as spring progresses.

As this first west Texas survey came to an end, we were all encouraged to have found the several pairs beginning to set up territories, showing all the signs of early spring breeding activity. As icing on the cake, one of our rancher friends found a fourth adult pair we had missed. It is big country, and so we very likely missed others as well. With some luck, maybe a couple of pairs will successfully fledge young this year and give us cause for a real celebration. At this point in time, that certainly looks encouraging!

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