Foraging at the wildland–urban interface decouples weather as a driver of recruitment for desert bighorn sheep

Wildlife Society Bulletin
By: , and 

Links

Abstract

A growing number of ungulate populations are living within or near the wildland–urban interface. When resources at the interface are of greater quality than that of adjacent natural habitat, wildlife can be attracted to these developed areas. Little is known about how use of the wildland–urban interface by wildlife may affect vital rates. Under natural conditions, recruitment by desert bighorn sheep (Ovis canadensis nelsoni) correlates with variation in the timing and amount of rainfall that initiates and enhances growth of annual plant species. However, for populations that forage in developed areas, this relationship may become decoupled. In the River Mountains of Nevada, USA, desert bighorn sheep have been feeding in a municipal park at the wildland–urban interface since its establishment in 1985. Approximately one-third of the population now uses the park during summer months when nutritional content of natural forage is low. We hypothesized that use of this municipal area, with its abundant vegetation and water resources, may have decoupled the previous relationship between precipitation and lamb recruitment. We assessed variables known to affect lamb recruitment before (1971–1986) and after (1987–2006) establishment of the park using linear regression models. Our top candidate model for the pre-park period indicated that total November precipitation was the greatest driver of lamb recruitment in this population. After park establishment, this relationship became decoupled because lamb recruitment was no longer driven by weather variables. These results raise questions about the effects of decoupling drivers of population growth and maintaining natural populations near urban areas.

Study Area

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Foraging at the wildland–urban interface decouples weather as a driver of recruitment for desert bighorn sheep
Series title Wildlife Society Bulletin
DOI 10.1002/wsb.679
Volume 40
Issue 3
Year Published 2016
Language English
Publisher Wildlife Society
Publisher location Washington, D.C.
Contributing office(s) Western Ecological Research Center
Description 6 p.
First page 494
Last page 499
Country United States
State Nevada
Other Geospatial Lake Mead National Recreation Area