Culvert Blitz

1st Annual Bridge Blitz

Rafinesque’s big eared bats roosting under a bridge in Mississippi.

The Mississippi Bat Working Group’s First Annual Bridge Blitz was held from July 12-18, 2021. Seventeen members participated, covering nine survey routes throughout the state. Four of the 71 bridges surveyed were occupied (5.6% occupancy rate). These bridges were in the Claiborne County area and contained 120 southeastern myotis (Myotis austroriparius), 15 big brown bats (Eptesicus fuscus), and one Rafinesque’s big-eared bat (Corynorhinus rafinesquii). The bridge with the largest colony of southeastern myotis was surveyed three weeks later and found to have increased to 220 Myotis. Thank you to everyone that participated in this event! For more information, please contact Alison McCartney at


2018 Culvert Blitz

Photo: Katelin Cross/MDWFP

The 2nd Annual Culvert Blitz was held the weekend of January 5-7.  Participants included biologists and volunteers from across the state who inspected culverts for the presence of roosting bats.  In stark contrast to the unseasonably warm temperatures during last year’s survey, this year’s culvert blitz was marked by cold, icy conditions.  The results of the survey were exciting, as the MBWG completed 15 routes in the three-day survey period, checking a total of  234 culverts.  Over 3,000 bats were documented using the culverts, including tricolored bats (Perimyotis subflavus), Southeastern myotis (Myotis austroriparius), big brown bats (Eptesicus fuscus), Rafinesque’s big-eared bats (Corynorhinus rafinesquii), and Brazilian free-tailed bats (Tadarida brasiliensis). (more…)