Anthropogenic water sources and the effects on Sonoran Desert small mammal communities.

Aaron B Switalski,Heather L Bateman

doi:10.7717/peerj.4003

Aaron B Switalski, Heather L Bateman

Open Access

https://doi.org/10.7717/peerj.4003

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Abstract

Anthropogenic water sources (AWS) are developed water sources used as a management tool for desert wildlife species. Studies documenting the effects of AWS are often focused on game species; whereas, the effects on non-target wildlife are less understood. We used live trapping techniques to investigate rodent abundance, biomass, and diversity metrics near AWS and paired control sites; we sampled vegetation to determine rodent-habitat associations in the Sauceda Mountains of the Sonoran Desert in Arizona. A total of 370 individual mammals representing three genera and eight species were captured in 4,800 trap nights from winter 2011 to spring 2012. A multi-response permutation procedure was used to identify differences in small mammal community abundance and biomass by season and treatment. Rodent abundance, biomass, and richness were greater at AWS compared to control sites. Patterns of abundance and biomass were driven by the desert pocket mouse (Chaetodipus penicillatus) which was the most common capture and two times more numerous at AWS compared to controls. Vegetation characteristics, explored using principal components analysis, were similar between AWS and controls. Two species that prefer vegetation structure, Bailey’s pocket mouse (C. baileyi) and white-throated woodrat (Neotoma albigula), had greater abundances and biomass near AWS and were associated with habitat having high cactus density. Although small mammals do not drink free-water, perhaps higher abundances of some species of desert rodents at AWS could be related to artificial structure associated with construction or other resources. Compared to the 30-year average of precipitation for the area, the period of our study occurred during a dry winter. During dry periods, perhaps AWS provide resources to rodents related to moisture.

Highlights

Water is seen as a limiting resource for the distribution of many animal species in arid environments (Roberts, 1977; Broyles, 1997; Rosenstock, Ballard & Devos, 1999)
Rodent community abundance and biomass differed between treatments (MRPP, P < 0.001 for both metrics); with abundance almost twice as high at Anthropogenic water sources (AWS) compared to CS (Table 1)
Rodent diversity was similar between treatments with Simpson diversity indices of AWS and CS equal to 2.859 and 2.971, respectively

Summary

Introduction

Water is seen as a limiting resource for the distribution of many animal species in arid environments (Roberts, 1977; Broyles, 1997; Rosenstock, Ballard & Devos, 1999). Within western North America, supplemental water has been used as a management tool for game species and livestock (Broyles, 1997) and for mitigating the loss of natural water sources from increased aridity, human use, and urbanization (Dolan, 2006; How to cite this article Switalski and Bateman (2017), Anthropogenic water sources and the effects on Sonoran Desert small mammal communities. Natural resource managers commonly use anthropogenic water sources (AWS, e.g., guzzlers, stock tanks, earthen ponds, and other constructed water sources) to supplement or enhance existing natural sources of water in arid environments (Krausman, Rosenstock & Cain, 2006). The effects of AWS on non-game species (Simpson, Stewart & Bleich, 2011) are understudied

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