Proboscis Bat

Identification

The proboscis bat is one of the world's tiniest bats, measuring only around 6 centimetres in length and weighing just 4 grams—roughly the mass of a penny. Males average 56 millimetres long, while females are slightly larger at 59 millimetres, with a short tail of about 16 millimetres. As the sole species in its genus Rhynchonycteris, it belongs to the family Emballonuridae, the sac-winged or sheath-tailed bats, and is distinguished by its characteristically elongated nose that gives the species its common name.

Range & Habitat

The proboscis bat is found across a wide swathe of the neotropics, from southern Mexico and Belize through Central America and into South America, including Venezuela, Ecuador, Peru, Bolivia, Brazil, and the island of Trinidad. The species is strictly a lowland dweller, seldom occurring above 300 metres in elevation. It shows a strong affinity for aquatic environments, typically inhabiting riparian forests, wetlands, swamps, and pastures—always remaining close to water sources that are essential to its ecology.

Behaviour & Diet

Proboscis bats are highly social and nocturnal, living in small, tight-knit colonies typically numbering between five and ten individuals, though rarely exceeding forty. They are famous for their distinctive daytime sleeping posture: lined up nose to tail in a perfectly straight row along a branch or wooden beam, creating an unusual and arresting sight. Each colony maintains a regular feeding territory centred on a small patch of water, where they hunt insects using echolocation, targeting midges, mosquitoes, beetles, and caddisflies. The species has no defined breeding season and instead maintains stable year-round harems, with each female producing a single young that is weaned at two to four months old, after which both sexes disperse.

Best Time & Places to See It

Proboscis bats are nocturnal and active year-round, so they may be encountered on any night, though observation requires patience and knowledge of their roosting sites. The best strategy is to locate their daytime roosts along branches overhanging water in riparian zones and wetlands. Look for their distinctive linear formations on wooden structures near water in lowland areas of Central America and northern South America. Local guides familiar with regional wetlands and river systems will greatly increase your chances of finding them.

Photography Tips

Photographing proboscis bats presents considerable challenges due to their tiny size, nocturnal habits, and preference for roosting in linear formations. Daytime photography of their roosting formations offers the best opportunity, requiring macro or telephoto lenses with excellent focusing capability and high shutter speeds to freeze any movement. Night photography demands specialized equipment including infrared illumination or high-sensitivity sensors, combined with fast lenses. A tripod is essential, and working with a local guide to locate active colonies will be crucial to successful photography.