• 2002  Executive Summary and Final Report
• 2005  Executive Summary and Final Report

• Falcon Project Deliverables -- GIS data

2002 Model         2005 Model

In the United States (U.S.), aplomado falcons (Falco femoralis) historically occurred in southern Texas, southern New Mexico, and southeastern Arizona. Although aplomado falcons were once considered fairly common throughout their U.S. range, populations apparently declined rapidly after the 1930s. When the aplomado falcon was federally listed as endangered in 1986, concern for recovery of the species increased. Starting in the early 1990s, increases in reliable falcon sightings prompted additional interest in recovery of the species in New Mexico.

In 1998, we started this research in the northern Chihuahuan Desert to provide a better understanding of aplomado falcon natural history, and to predict areas of potential habitat in southern New Mexico, western Texas, and northern Chihuahua.

We surveyed for aplomado falcons and other raptorial birds in northern Chihuahua during 1998-1999. From 1999-2000, we characterized falcon habitats at 3 spatial scales:  community, microhabitat, and nest.  Data was collected at falcon nest and detection sites, and random sites in northern Chihuahua. 

From 2000-2002, we developed a spectrally-driven predictive habitat model for the northern Chihuahuan Desert.   This model was based on the spatial configuration (how land cover types were arranged) and composition (which land cover types were present) of the landscape around falcon use sites in northern Chihuahua.  A variety of statistical analyses of remotely sensed data around falcon sites were conducted. Five statistical significant input layers were chosen for the predictive model. Each input layer was converted to a binary layer that was summed to produce a predictive habitat model that ranges in suitability values from 0-5. The final model indicated areas of similar spectral characteristics in the northern Chihuahuan Desert as observed at falcon sites in northern Chihuahua.

Starting in 2003, we conducted research to evaluate the components of the predictive habitat model.  Our approach was to dissect the predictive model into the 32 model input layer combinations and investigate how the model components might interact to describe falcon habitat. 

Results from this research have been summarized in 2 final reports:

• 2002  Final Report (Characterizing and predicting suitable aplomado falcon habitat for conservation planning in the northern Chihuahuan Desert).

• 2005 Final Report (Assessment of predictive values from the aplomado falcon habitat suitability model:  Validation information for conservation planning in the northern Chihuahuan Desert).

To view Executive Summaries of each report, and to download pdf's of the reports, click on the link above.

Manuscripts produced from this research:

• Desmond, M.J., K.E. Young, B.C. Thompson, R.Valdez, and A. Lafon Terrazas. 2005. Habitat associations and conservation of grassland birds in the Chihuahuan Desert Region: two case studies in Chihuahua, Mexico. In J.L.E. Cartron, G. Ceballos, and R.S. Felger, eds. Biodiversity, ecosystems, and conservation in northern Mexico. Oxford University Press, New York, New York

• Young, K. E., B. C. Thompson, A. Lafón Terrazas, A. B. Montoya, and R. Valdez. 2004. Aplomado falcon abundance and distribution in the northern Chihuahuan Desert of Mexico. Journal of Raptor Research 38:107-117.