The Proboscis Bat (*Rhynchonycteris naso*) is a small, remarkably camouflaged insectivorous bat found across a broad range of lowland tropical habitats from southern Mexico through Central America and into much of South America, where it is most commonly encountered along the banks of rivers, streams, lakes, and other bodies of water, clinging in small, tightly clustered groups to exposed surfaces such as tree trunks, logs, rocks, and the undersides of bridges and boats in a manner that is highly unusual among bats, which more typically seek concealed roosting sites. Weighing a mere 4 to 8 grams and measuring only about 1.5 to 2 inches in body length, the Proboscis Bat is a tiny animal, but what it lacks in size it more than compensates for in the elegance of its adaptations, most notably its namesake feature — a distinctively elongated, pointed snout that is more prominent and tubular than that of most other bat species and gives the animal an immediately recognizable profile quite unlike its relatives. Its fur is a beautifully cryptic mixture of grey and brown with two wavy, pale whitish stripes running along each side of the back, a pattern that mimics with remarkable fidelity the appearance of tree bark, lichen, and weathered wood, rendering a roosting group of these bats effectively invisible against the dappled, textured surfaces they favor — an adaptation so effective that even experienced naturalists can walk directly past a roosting colony without detecting it. The bats roost in small groups of typically 5 to 30 individuals arranged in a characteristic staggered, diagonal line on their chosen surface, with each individual spaced just far enough from its neighbors to avoid touching, a precise social spacing that enhances the disruptive camouflage effect of the group as a whole by preventing the cluster from forming an obvious animal-shaped outline. Like all members of the family Emballonuridae — the sac-winged bats — male Proboscis Bats possess small glandular pouches on their wings that produce scented secretions used in courtship and territorial communication, and males perform elaborate hovering display flights in front of females while fanning these scents toward them, a sophisticated olfactory and visual courtship ritual that adds a layer of behavioral complexity to this already fascinating little animal. Foraging at dusk and through the night, Proboscis Bats hunt small insects — particularly midges, mosquitoes, and other tiny flying invertebrates — over the surface of water using echolocation, flying in fast, erratic patterns just above the water's surface and snatching prey with remarkable precision, making them important and efficient controllers of insect populations in the riparian ecosystems they call home.
