Straw-Coloured Fruit Bat

Eidolon helvum
African straw-colored fruit bat
Straw-colored fruit bats are native African animals, called so due to the bright orange, yellow or brownish fur, surrounding their throat, stretching onto the back of the neck and covering the special glands, which produce a specific musky-smelling fluid. This substance is usually brighter in color and more noticeable in males. Additionally, male individuals are bigger and exhibit darker overall coloration. Young individuals, on the other hand, are distinguished by the absent of a collar around their neck as well as darker coat, compared to mature bats. Straw-colored fruit bat is the second largest bat species, found in Africa.
Unknown

population size

15-22 yrs

Life span

230-340 g

Weight

14-23 cm

Length

Disrtibution

Straw-colored fruit bats are native to Africa, occurring in equatorial and sub-Saharan regions of the continent. The natural range of this species stretches from the southern tip of the Arabian Peninsula to offshore islands such as Zanzibar and Pemba. In addition, they are known to migrate to southern Africa, reaching Zambia, Malawi and Mozambique. These bats are highly adaptable creatures, capable of living in different types of habitat, from moist and dry savanna to urban areas. Overall, straw-colored fruit bats generally inhabit moist and dry tropical rainforests such as riverine and coastal forests and mangroves.

Habits and lifestyle

The Straw-colored fruit bats are a highly social species, forming extremely large groups known as colonies. A single colony of these bats may contain from thousands to as much as millions of individuals. Meanwhile, each such colony consists of small units (clusters) of up to 100 bats. Although they are nocturnal feeders, most activity occurs during the daylight hours. Most of their active hours are spent resting and moving around their roosting site. During the night, the colony splits into smaller groups, which leave to forage in nearby forests and plantations. These animals maintain the same diet throughout the year. However, they may occasionally migrate, when the usual types of food are not available or scarce. During these periods, they remain in these large colonies rather than splitting into smaller groups. Communication patterns of this species are unknown, but they evidently make a loud noise in their large colonies. Additionally, these animals are likely to vocalize when eating and roosting.

group name

cloud, colony, flock

Diet and nutrition

As the common name suggests, the Straw-colored fruit bats maintain frugivorous diet, particularly favoring dates, baobab flowers, mangoes, papaws, avocado pears, figs, passion fruit, custard apples and loquats. They may also consume other types of food such as flowers, buds and young leaves.

Diet

Mating habits

The reproductive system of this species is currently unknown. However, as mating occurs in colonies, it may mean that they exhibit polygynous mating system. Breeding occurs during late spring, from April to June. Although implantation is sometimes delayed, it generally takes place during October. In December-January, females yield a single, altricial baby in so-called ‘maternity colonies’, formed by clusters of females. In populations, where young are born undeveloped, gestation period lasts for 9 months, after which the babies continue to grow for additional 4 months. Meanwhile, populations without delayed implantation exhibit shorter gestation of only 4 months. The newborn bat cannot fly and totally depends on its mother. Nursing period lasts for around 4 months, after which the young bat has learnt to forage independently. The baby is weaned during the period of abundant food, which coincides with the peak of the wet season. The age of reproductive maturity is 2 years old.

Reproduction season

April-June

Pregnancy duration

4 months

Independent age

4 months
female

female name

male

male name

pup

baby name

1 pup

baby carrying

Population

Population Trend

Population status

ne
dd
lc
nt
vu
en
cr
ew
ex

Population threats

Although Straw-colored fruit bats are abundant and commonly found throughout their range, populations in some areas are affected by adverse factors. Thus, Straw-colored fruit bats in West and Central Africa face large-scale hunting for food. In other areas, these animals are hunted for medical use. Localized threats also include persecution and hunting as pests.

Population number

The IUCN Red List and other sources don’t provide the number of the Straw-colored fruit bats’ total population. As reported on the IUCN Red List, these bats are quite common across their range, found in very large colonies, varying from thousands to millions of individuals. Nevertheless, a colony in Kampala (Uganda) has undergone a sharp population decline, decreasing from 250,000 to 40,000 bats during the last 40 years. Overall, this species’ numbers are decreasing today, and the animal is currently classified as Near Threatened (NT) on the IUCN Red List.

Ecological niche

Straw-colored fruit bats are vital pollinators of certain flowers throughout their range. Due to their diet, these bats also act as seed dispersers, which they do through their feces. Overall, these animals are irreplaceable in sustaining their rainforest habitat, which would simply disappear without these bats.

Fun facts for kids

  1. According to satellite tracking studies, Straw-colored fruit bats exhibit the furthest migration of all mammals in Africa, travelling thousands of kilometers annually.
  2. The long, pointed and powerful wings make these bats excellent fliers.
  3. Along with other species of their sub-order, Straw-colored fruit bats don't use sonar to perceive their environment.
  4. They are able to detect fruits due to the highly-developed sense of smell and color vision.
  5. As a matter of fact, fruit bats don't eat fruits completely: they just swallow the pulp and juice, throwing away other parts.
  6. The majority of their active time is spent washing and grooming at their roosting sites. In addition, they are often seen hung by one foot while combing their body with the other foot.
  7. These animals usually roost in the characteristic upside down position, hung from a tall tree, although there have been recorded colonies, roosting in caves.
  8. Each individual of this species has its own unique scent and call. This allows mothers to find their young in large colonies of millions of individuals.
  9. These fruit bats get moisture from soft wood by puncturing it.