Desert amphibian selection of arid land breeding habitat undermines reproductive effort

Abstract

Understanding how animals select habitat is important for understanding how to better conserve those species. As droughts become more frequent and water availability declines in many systems, understanding selection of water sources becomes even more important for conservation. Tinajas and anthropogenic catchments are critical ephemeral breeding sites for Sonoran Desert anurans. Tadpoles have been documented in both water types even though anthropogenic catchments can contain very high concentrations of ammonia. We currently do not know how amphibians are selecting breeding habitat. We tested three hypotheses of habitat selection based on resource quality, resource quality and territoriality, and proximity of water site to other water sites. Male Anaxyrus punctatus called from all sites regardless of habitat quality or male quality; however, they were found more often at sites within 2 km of other sites. This suggests that male desert anurans are selecting close breeding habitat regardless of quality for breeding, indicating ammoniated sites are likely either population sinks or ecological traps. Consequently, adding anthropogenic water sites, without managing to reduce ammonia, will provide low quality habitat that could cause long-term declines in desert anuran populations.