Biology ETDs

Publication Date

5-1-2015

Abstract

Avian communities of arid ecosystems may be particularly vulnerable to global climate change due to the magnitude of model projected change for desert regions and the inherent challenges for species of resource limited ecosystems. How arid zone birds will be affected by rapid increases in air temperature and increased drought frequency and severity is poorly understood. To date, avian responses to climate change have primarily been studied in northern temperate regions in relatively mesic habitats. We studied the effects of increasing air temperature and aridity on a Burrowing Owl (Athene cunicularia) population in the southwestern USA from 1998-2013. Over 16 years, the breeding population declined 98.1%, from 52 pairs to 1 pair, and nest success and fledgling output also declined significantly. These trends were strongly associated with the combined effects of decreased precipitation and increased air temperature. Arrival on the breeding grounds, pair formation, nest initiation, and hatch dates all showed significant delays ranging from 9.4 - 25.1 days over 9 years, which have negative effects on reproduction. Adult and juvenile body mass decreased significantly over time, with a loss of 10.9% mass in adult males and 7.9% mass in adult females over 16 years, and a loss of 20.0% mass in nestlings over 8 years. These population and reproductive trends have serious implications for population persistence. The southwestern USA has been identified as a climate change hotspot, with projections of warmer temperatures, less winter precipitation, and an increase in frequency and severity of extreme events including drought and heat waves. An increasingly warm and dry climate may contribute to this species decline, and may already be a driving force of their apparent decline in the desert southwest.

Language

English

Keywords

Athene cunicularia, body condition, Burrowing Owl, delayed breeding, nest success, population declines, precipitation, prey abundance

Document Type

Thesis

Degree Name

Biology

Level of Degree

Masters

Department Name

UNM Biology Department

First Committee Member (Chair)

Witt, Christopher

Second Committee Member

Gutzler, David

Third Committee Member

N/A

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