Changes in the Community Composition and Distribution of Bats in the Delaware Water Gap National Recreation Area Following the Emergence of White-nose Syndrome

Hauer, Christopher

The author used mist netting surveys to assess the potential impacts of white-nose syndrome on the community composition of bats in the Delaware Water Gap National Recreation Area by comparing capture data from 2013-14 with capture data from the park’s last comprehensive bat survey in 1997-98. The author also used AnaBat SD2 and AR125 acoustic detectors to record bat echolocation calls along a 109 km transect route in the DWGNRA and conducted emergence counts to monitor active summer bat maternity roosts to assess current reproductive rates and possible declines as the result of WNS. Since the discovery of white-nose syndrome (WNS) in February 2006, populations of hibernating bats have experienced severe declines throughout eastern North America. I used mist netting surveys to assess the potential impacts of white-nose syndrome on the community composition of bats in the Delaware Water Gap National Recreation Area (DWGNRA) by comparing capture data from 2013-14 with capture data from the park’s last comprehensive bat survey in 1997-98. Mist netting at 19 sites in 2013-14 captured 85 bats and 6 species, with 71 captures (83.5%) of big brown bats (Eptesius fuscus). There was a significant decline in capture rates of little brown myotis (Myotis lucifugus) and northern long-eared myotis (M. septentrionalis) from 1997-98 to 2013-14, whereas capture rates of big brown bats increased significantly between WNS periods. I used AnaBat SD2 and AR125 acoustic detectors to record bat echolocation calls along a 109 km transect route in the DWGNRA. The majority of recorded bat passes were identified as big brown and eastern red bats (Lasiurus borealis), and these species now appear to be widely distributed in the DWGNRA. I also conducted emergence counts to monitor active summer bat maternity roosts to assess current reproductive rates and possible declines as the result of WNS. A maximum of 295 little brown myotis were observed during the emergence counts at Bushkill Outreach (PA), representing a 90% decline from the 2,500-3,000 individuals that were present in 1997-1998. Both big brown bats and little brown myotis were identified emerging from the Birchenough barn, suggesting that big brown bats may have partially displaced the former colony of an estimated 400 little brown myotis. The information gathered in this study will be used to provide the National Park Service with survey guidelines and management recommendations for future monitoring and management of bat maternity roosts and foraging/roosting habitats in the DWGNRA.

Changes in the Community Composition and Distribution of Bats in the Delaware Water Gap National Recreation Area Following the Emergence of White-nose Syndrome

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