Tracking Cluster Migration Across the Hibernation Period

Myotis sodalis clusters relocate across chambers from October to April as microclimate preferences shift with fat reserves and ambient VPD. EchoQuilt tracks the full migration from warm autumn back chambers to cold late-winter entrance zones using passive wing-beat and cluster-body echo returns.

A Pennsylvania hibernaculum logged 4,800 Myotis sodalis in November clusters along the warm back-chamber ceiling. The April exit survey logged 4,600 bats — but they were no longer on that ceiling. The clusters had migrated somewhere across 300 meters of cave passage during hibernation, and the surveyors had no spatial record of the movement. They learned there had been a shift only because they saw fresh guano piles in a side passage where none existed in November.