Overview
Rafinesque’s Big-eared Bat (Corynorhinus rafinesquii), affectionately known across the American South as the ‘southeastern big-eared bat,’ is a charismatic vespertilionid bat renowned for its monumental, rabbit-like ears that measure more than one-third of its total body length. Inhabiting the historic bald cypress-water tupelo swamps and bottomland hardwood floodplains of the southeastern United States, this agile nocturnal aeronaut functions as a premier agricultural insect predator and an acute biological indicator of old-growth riparian wetlands.
Biology and Physical Characteristics
The defining anatomical feature of Corynorhinus rafinesquii is its immense pinnae ears, which reach up to 1.5 inches (3.8 cm) in length. When resting or in torpor, the bat curls its ears backward across its shoulders in tight spirals that resemble ram horns to conserve body heat and moisture. Its dorsal pelage is a soft, velvety grayish-brown, contrasted sharply by a white-tipped belly. On its snout sit two prominent glandular lumps. Its large, broad wings provide exceptional low-speed maneuverability, allowing it to hover stationary inside dense forest understories.
Behavior and Ecology
Unlike bats that forage in open skies above the forest canopy, Rafinesque’s big-eared bat is an elite ‘whispering’ gleaning predator. It emits ultra-quiet echolocation calls that nocturnal moths—such as noctuid and tent-caterpillar moths—cannot detect, allowing the bat to approach silently and pluck resting insects directly from leaves, tree bark, and spiderwebs. For roosting, the species exhibits an obligate dependency on large hollow tree trunks, specifically ancient water tupelo (Nyssa aquatica) and bald cypress (Taxodium distichum) trees featuring hollow basal chimneys.
Conservation and Human Impact
While categorized as Least Concern globally by the IUCN, Corynorhinus rafinesquii is designated as a Species of Special Concern in nearly every state across its range due to historic logging of mature swamp forests. The drainage of bottomland hardwood ecosystems and the commercial harvesting of ancient cypress trees have eliminated critical nursery cavities. Conservation partnerships focus on preserving old-growth riparian buffers, installing artificial roost towers in regenerating floodplains, and protecting winter hibernation caves.
Interesting Factoid
When sleeping, Rafinesque’s big-eared bat curls its enormous ears backward into tight spiral coils that look just like miniature bighorn ram horns; when it wakes, it unrolls them like party noisemakers using blood pressure.
Last updated: October 2026