Airport Expansion and Endangered Bats: Development and Mitigation Actions Near the Indianapolis International Airport

Economic prosperity and globalization are major drivers for development of international airports, but aviation-oriented businesses and residential developments are a by-product of airport business models. Among the multitude of planning and development considerations is the habitat needs of endangered wildlife species. Foraging data were analyzed from 57 bats during three time periods (1998–1999: pre-mitigation; 2005–2006: during mitigation, and 2014–2016: post-mitigation) of a long-term study of Indiana bats ( Myotis sodalis) near the Indianapolis International Airport. At this site, both developed land cover and forested land cover increased between 1998 and 2016 (34.1% and 3.3%, respectively). Mitigation actions included converting 323 ha of residential lots back to forest, and creation of a 56 ha wetland and an 85 ha multi-use park. Bat use of landscape cover types was related to changes in land cover during each period and competing hypotheses were compared to explain changes in bat foraging space use. With the addition of a major highway interchange where the colony foraged, bats increased foraging ranges, presumable in search of new habitat. In all periods, bats selected for forested habitat; as trees in replanted forest and designated parks aged, bats reduced their foraging ranges. Restoring hardwood forest and setting aside parklands were effective proactive mitigation measures for the colony of Indiana bats near the Indianapolis International Airport, and similar actions should benefit other wildlife where human development and habitat needs intersect.