Eidolon helvum (Kerr, 1792)

Etymology and common name origin

The straw-coloured fruit bat, scientifically named Eidolon helvum (Kerr, 1792), gets its common name from the silky yellowish or straw-colored fur across its body.

Wing and dorsal fur coloration

Its wings are black, while the fur on its back is pale and tawny.

Sexual dimorphism in fur color

In general, males have bright orange fur and females have yellowish fur.

Facial morphology

This species has large cheeks, large eyes, and large ears, with cheeks that are also notably large and pouch-like.

Adult body size and weight range

Adults weigh an average of 230 to 340 g (8 to 12 oz), grow 14 to 23 cm (5.7 to 9 in) in body length, and can have a wingspan reaching up to 76 cm (30 in).

Sexual dimorphism in body size

Males are typically larger than females.

Internal and wing morphology

The species has a very large heart, and its wings are long with tapered tips.

Distribution scale

This fruit bat is the most widely distributed fruit bat in Africa, and possibly the most widespread in the world.

Geographic range

It occurs primarily across sub-Saharan Africa, in many forest and savanna zones, as well as around the southwestern Arabian Peninsula.

Habitat and roosting preferences

It can also live in urban areas, at altitudes up to 2,000 m (6,600 ft), and prefers to roost in tall trees.

Social structure

The straw-coloured fruit bat is a highly social species.

Colony size

Colonies usually number over 100,000 individuals, and can sometimes reach almost one million bats.

Foraging behavior

At night, bats leave the roost in smaller groups to locate food using their vision and sense of smell.

Moisture acquisition behavior

They have been observed chewing soft wood to obtain moisture.

Ecological role

This species contributes to pollinating flowers and dispersing seeds through forests, and is the main seed dispersal agent for Milicia excelsa, an increasingly rare and economically important African teak tree.

Activity patterns

Although they feed at night, straw-coloured fruit bats are not strictly nocturnal; they rest and move within their colony during the day.

Feeding site fidelity

They return to the same feeding sites each year and each season, returning to locations they used previously.

Mating season timing

Their mating season runs from April to June, and mating is not synchronized across the population.

Delayed implantation

Implantation is delayed until October, and all females undergo implantation during this synchronized window.

Implantation timing alignment

The delay aligns with one of the two dry seasons that occur in the species' range.

Birthing period

Births take place in February and March.