Butte College is situated on a 376-ha wildlife refuge that has over three km of riparian habitat, 130 ha of blue oak woodlands, 90 ha of grassland and over 70 ha of developed structures as part of the campus. This project focuses on local bat populations within these habitats and how abiotic factors affect population size. Diversity of the bats at five locations per habitat type was determined using an ultrasonic recorder over a period of two years. Data suggests up to 12 species are present in the refuge, with distinct habitat preferences. Tadarida brasiliensis was most common in the Oak and Campus areas, where significant activity of Lasiurus noctivagans and Lasiurus cinereus were also observed. Myotis californicus/yumanensis dominate the Riparian habitat. In addition, guano estimates from 20 bat boxes on campus indicate highest occupation during June and July. Occupancy increases with temperature from May to July and decreases during peak temperatures, with the highest number of bats at around 31°C. We intend to place data loggers inside bat boxes to compare with ambient temperatures and continue data collection for several years to further elucidate seasonal patterns.