African sheath-tailed bat
Coleura afra
— Where the name comes from
Coleura is “tail in a sheath”, from the Greek koleós, the scabbard of a sword — the same word behind “Coleoptera”, the insects with sheathed wings — and ourá. The tail pierces the interfemoral membrane and emerges above it, sliding within like a blade in its scabbard as the animal stretches or gathers its legs. Afra is the Latin “African”.
— Facts
- Group
- Mammals · Mammalia
- Order
- Bats
- Habitat
- Coastal caves and limestone caverns; hunting over bush and cropland
- Range
- Eastern and western Africa, the southern Arabian peninsula
- Size
- 5–7 cm of body, 30 cm wingspan, 8–12 g
- Diet
- Insectivore — small insects in fast flight
- Lifespan
- Little known
— Characteristics
- 01
The tail slides inside the membrane like a blade in a scabbard.
- 02
Colonies in the coastal caves of Kenya number tens of thousands.
- 03
It flies very fast, on the narrow wings of an open-air species.
— What sets it apart
Its tail solves an engineering problem that faces all bats: the membrane between the legs is needed for manoeuvring in flight and for scooping up prey, and a stiff tail running through it would lock it. In this family the tail pierces the membrane and slides through it like a blade in a scabbard, so the animal can stretch its legs to widen the surface and draw them in to narrow it, with the tail no impediment. It is a sliding joint, invented by a mammal.
