Hildegarde's tomb bat (Taphozous hildegardeae)

KingdomAnimalia
PhylumChordata
ClassMammalia
OrderChiroptera
FamilyEmballonuridae
GenusTaphozous (1)
SizeMale body length: 10.4 - 11 cm (2)
Female body length: 10.5 - 10.9 mm (2)
Male weight: 24 - 36 g (2) (3)
Female weight: 20 - 27 g (2)

Hildegarde’s tomb bat is classified as Vulnerable (VU) on the IUCN Red List (1).

Hildegarde’s tomb bat (Taphozous hildegardeae) is a medium-sized bat with fine, pale brown fur and a characteristic white furry stomach. It has a hairy rump, and wings which fade from brown to white nearer the wing tip. Unlike other species in theTaphozous genus, Hildegarde’s tomb bat lacks a bare patch of skin on its throat, known as the gular sac (2).

The male and the female Hildegarde’s tomb bats are similar in size, but the male has a black, furry throat, or beard, larger ears and a distinctly larger skull (2).

A characteristic high-pitched “tcheek tcheeck” sound is often made by Hildegarde’s tomb bat during territorial behaviour, or in response to danger (2).

Hildegarde’s tomb bat is found mainly on the south-eastern coast of Kenya and the north-eastern coastal areas and islands of the United Republic of Tanzania (1). So far, this species has been found in just ten coastal regions, the latest being the Three Sisters Caves on the Kenyan coast (4) (5).

Hildegarde’s tomb bat is restricted to coastal areas, and can be found roosting in caves associated with tropical dry forests (1).

Hildegarde’s tomb bat is insectivorous, primarily feeding on grasshoppers, moths and butterflies (1) (3). Not much is known about its hunting methods, but, as with other bat species, echolocation is considered to play a vital role (2). 

Large colonies of Hildegarde’s tomb bats roost in open areas of caves. This species often co-habits with other bat species, such as the African sheath-tailed bat (Coleura afra) and the Persian trident bat (Triaenops persicus) (2). Colonies are not thought to migrate, but local cave to cave movements may occur (2) (4). 

Hildegarde’s tomb bat has a polygamous mating system, with dominant males maintaining year-round territories within the roosting site. Harems of females and young may be maintained by a single dominant male, or a group of males (2). The reproductive cycle of Hildegarde’s tomb bats coincides with the seasonal fluctuations in food supply. Mating usually occurs during the rainy season between April and June. A second period of sexual activity occurs during the short rains between November and December. In this second period, mating does not usually occur, and the behaviour is thought to help maintain male territories and group dynamics (2) (3). The female usually gives birth in December (2).

The male Hildegarde’s tomb bat exhibits a seasonal weight fluctuation. With a larger available food supply during the rainy season, extra fat is deposited in order to sustain the male during competitive mating and the dry season. Females show less fluctuation, exhibiting weight change only during pregnancy (2). This weight change distinguishes Hildegarde’s tomb bat from other members of the same order (3).

The population of Hildegarde’stomb bat is thought to be in decline (6). It faces a number of threats, from encroaching deforestation to the disturbance of its roosting caves (1). In Kenya, deforestation is caused by a variety of activities, from illegal logging and charcoal burning to the unlawful encroachment of farmland upon forested areas (7).

There are no known conservation measures specifically in place to protect Hildegarde’s tomb bat. This species may, however, occur in some protected areas (1). Stricter protection of roosting and nesting sites is recommended (1). Local actions and religious beliefs are thought to help in the conservation of certain site, such as the Three Sisters Cave, Kenya, which has been identified as a point of cultural and religious significance (5).  

Find out more about Hildegarde’s tomb bat:

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

  1. IUCN (August, 2011)
    http://www.iucnredlist.org
  2. Colket, E. and Wilson, D.E. (1998) Mammalian species: Taphozous hildegardeaeAmerican Society of Mammalogists, 597: 1-3. Available at:
    http://www.science.smith.edu/msi/pdf/i0076-3519-597-01-0001.pdf
  3. McWilliam, A.N. (1988) The reproductive cycle of male tomb bats, Taphozous hildegardeae (Chiroptera: Emballonuridae), in a seasonal environment of the African tropics. Journal of Zoology, 215: 433-442.
  4. Marshall, J. (2010) Sacred sites act as wildlife sanctuaries. Discovery News, 14 January. Available at:
    http://news.discovery.com/earth/sacred-sites-wildlife-sanctuary-biodiversity.html
  5. Metcalfe, K., French-Constant, R. F. and Gordon, I. (2010) Sacred sites as hotspots for biodiversity: the Three Sisters Cave complex in coastal Kenya. Oryx, 44: 118-123.
  6. Nowak, R.M. (1999) Walkers Mammals of the World. Volume 1. Sixth edition. Johns Hopkins University Press, Baltimore.
  7. Kenya Forests Working Group (November, 2011)
    http://www.kenyaforests.org/index.php