Date of this Version
Migratory raptor populations at McConnell Air Force Base in Kansas, increased dramatically in the 2008-2009 winter season, with more than a 200% increase in the number of large hawks observed on the airfield, compared to equivalent seasons in the past 3 years. This increase resulted in frequent interruptions and/or cessations of flying operations.
The primary cause was determined to be a local explosion of both Hispid Cotton Rats (Sigmodon hispidus) and Prairie Voles (Microtus ochrogaster). The cotton rat explosion was a result of record-breaking rainfall in 2008, while the explosion of voles followed the natural 3-5 year cycle. This overabundance of prey coupled with an unusually warm winter provided an ideal wintering habitat for the raptors.
Because harassment proved futile, the solution seemed to be to address the rodent populations, through the use of rodenticides. However the selection and application of a viable rodenticide, for a military airfield, presented a new set of problems. The final solution for non-lethal control of the raptors was to attempt relocations. Because of the migratory nature of the hawks, short distance relocations (70-120 miles) were preformed. This paper covers the problems, solutions, and results of our efforts to control the migratory raptor populations.