Biology ETDs

Publication Date



The deserts of the Southwestern United States are experiencing rapid warming and climate models predict declining winter precipitation. The combined effects of higher air temperatures and drought are a reduction in productivity, which may importantly impact reproduction in consumers. Here, we investigate the effects of warming and drought on the reproductive timing and output in loggerhead shrikes (Lanius ludovicianus) in central New Mexico from 2007 to 2012. We found increases in air temperature of 3°C during the breeding season (March—July) and highly variable winter and annual precipitation. With increasing spring temperatures, shrikes advanced nesting phenology by 20 days over 6 years, a much higher rate than is reported for any other bird species. During this period, the number of breeding pairs also increased from 25 to 37, and clutch size and the number offspring produced per successful nest did not vary. Nest success, however, was often very low and ranged from 11% to 44%. Although our models indicated that low nest success was driven by precipitation and temperature, it was mediated indirectly through increased predation rates during the hot and dry periods.




Loggerhead Shrike, nest phenology, nest survival, climate change, predation

Document Type


Degree Name


Level of Degree


Department Name

UNM Biology Department

First Advisor

Wolf, Blair O.

First Committee Member (Chair)

Newsome, Seth D.

Second Committee Member

Collins, Scott L.

Third Committee Member


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Biology Commons