Preliminary Assessment of Burrowing Owl Population Status in Wyoming

Currently, little is known about Burrowing Owl (Athene cunicularia) abundance in Wyoming. The Wyoming Game and Fish Department (WCFD) classifies the Burrowing Owl as a Species of Special Concern. We identified available data sources to assess Burrowing Owl distribution and population trends in Wyoming and conducted a population survey in eastern Wyoming. The WGFD's Wildlife Observation System (WOS), initiated in 1974, shows a decline in Burrowing Owl records, particularly during the 12-yr period 1986-97. However, trends in WOS records over time likely reflect changing interest in the database, rather than real population trends. Likewise, Breeding Bird Survey data since 1971 suggest a negative trend, but low numbers warrant caution in interpreting these data. Additional monitoring efforts are required to assess Burrowing Owl population trend more accurately within the state. To evaluate Burrowing Owl abundance at historical nesting locations, we surveyed 103 previously reported sites. A total of 18% of these historical sites was reoccupied in 1999. We also surveyed 85 plots selected at random from northern mixed- and short-grass prairie types to obtain an unbiased picture of Burrowing Owl distribution in eastern Wyoming. Only one owl was found on these random survey plots, emphasizing the importance of historical nesting sites to Wyoming Burrowing Owls.