COS 10-8
The response of an insectivorous bat community to solar development

Monday, August 11, 2014: 4:00 PM
Regency Blrm E, Hyatt Regency Hotel
Dave S. Johnston, H. T. Harvey & Associates, San Jose, CA
Meredith K. Jantzen, H.T. Harvey & Associates, San Luis Obispo, CA
Kim M. Briones, H.T. Harvey & Associates, San Luis Obispo, CA
Gabriel A. Reyes, H.T. Harvey & Associates, San Jose, CA

Solar energy installations are on the rise in the United States and around the world, but their effects on wildlife are poorly understood. We investigated the impact that solar arrays had on a community of insectivorous bats at a 250-megawatt photovoltaic solar farm in California. Previous studies have shown that many bat species benefit from the addition of a strong linear element such as a hedgerow or a forest edge with high contrast. Therefore, we predicted that because solar panels were stored at an angle at night, the majority of bat species would increase their activity in array areas, due to the edge structure provided. Secondly, we predicted that bat species specializing in low flight and gleaning ground dwelling insects would decrease their activity inside array areas, due to fencing surrounding the arrays. To investigate the effects of solar arrays on the activity of different bat species, we deployed 26 passive acoustic bat detectors and recorded echolocation calls of bats from sunset to sunrise from July 2012-December 2013. We manually identified the calls to species using AnaLook and callviewer v.18. We used general linear models to analyze the effects of arrays on the activity of each bat species.


When controlling for month, individual detector location, and year, we rejected the null hypothesis that the solar arrays of panels had no effects on bats and that there were no differences among species. Mexican free tailed bats (Tadarida brasiliensis) and canyon bats (Parastrellus hesperus) had significantly higher activity within arrays, compared to conservation lands, but Pacific pallid bats (Antrozous pallidus pacificus), which specialize in foraging at low heights significantly decreased their activity in array areas. Our results suggest that fencing around arrays may create barriers for some bat species such as ground gleaning insectivorous bats, while the additional structure in an otherwise open habitat may create favorable foraging situations for other species.