A swallow's nest appears on the interior wall of a low bridge near the Vance Air Force Base airfield Tuesday, April 29, 2014. Aaron Betts, the wildlife biologist from the United States Department of Agriculture assigned to the base, with the help of the Vance Safety Office maintains the wildlife and habitat management near the flight area each day as part of BASH, the bird aircraft strike management program. (Staff Photo by BONNIE VCULEK)

Swallow NestVance Air Force BaseAaron BettsWildlife BiologistUnited States Department of AgricultureVance Safety OfficeBASHWildlife ManagementBonnie VculekEnid