Final gate at Mary Lawson Cave. - Photo Credit: U.S. Fish and Wildlife Service photo

In 2004, the Columbia, Missouri Ecological Services Field Office provided funds to the Missouri Department of Conservation to gate Mary Lawson Cave that is an important cave for the endangered gray bat (Myotis grisescens).

Gating the cave was necessary due to human disturbance prior to and even after construction of a gate. In 2008, the gate was further reinforced to eliminate human disturbance and the bats responded to additional protection.

In 2004, summer counts at the cave resulted in only 1,878 bats being observed although some bats may have departed prior to the count. Nonetheless, 40,321 gray bats were noted in 2009 and observations using thermal infrared imagery in July of 2011 yielded an outstanding count of 201,737 individuals.

This year’s count documents one of the largest gray bat maternity colonies ever recorded in Missouri. The success of this cave gate clearly highlights the excellent relationship between the Service and the Missouri Department of Conservation and demonstrates the potential recovery benefits to federally listed species through solid partnerships.