Projecting Climate Effects on Birds and Reptiles of the Southwestern United States

Top Left: AZ black rattlesnake by A Madara, USFS;
Bottom Left: Plateau striped whiptail by Dennis Garrison, USFS;
Right: Black-throated sparrow by Dennis Garrison, USFS.
Project Type:  Research
Project Status:  Completed

Climate change models predict a warmer and drier southwestern United States, and land managers want to know how plants and animals may be affected by these changes. Scientists from the U.S. Geological Survey collaborated with university scientists in Arizona and New Mexico to model the effects of a changing climate on 12 southwestern bird and reptile species as a project of the National Climate Change and Wildlife Science Center.

The modelling process involved several steps, beginning with developing conceptual models describing the ecology of each species. Based on these conceptual models, variables were identified to statistically model how each species’ range is predicted to change over time in response to different climate change scenarios. These variables included the effect of landscape conditions (topography and exposure to sunlight), plant species distributions, and climate (temperature and precipitation). 

Project results (see Project Report in the right-hand menu) predict both range losses and gains, depending on species. While two of the bird species, the black-throated sparrow and the gray vireo, are predicted to expand their ranges, the remaining five face predicted range losses. These losses may be enough to move two species close to extinction within the next century: the Williamson’s sapsucker and the pygmy nuthatch. Of the five reptile species analyzed, three species—relatively common at present—are predicted to lose over 40 percent of their ranges: plateau striped whiptail, Arizona black rattlesnake, and the common lesser earless lizard. 

To share these results with land managers and others, the researchers are developing an innovative, interactive website application for viewing how ranges of the selected species are predicted to change in response to different model scenarios. The goal is for scientists, concerned citizens and wildlife managers to use the information proactively in addressing potential impacts of climate change on selected species. 

See news coverage on the release of this report under “References & Links” on the right-hand menu.

Project Contact(s):

Southwest Biological Science Center

2255 N. Gemini Drive
Flagstaff, AZ 86001