Researching little-known species: the African bat Otomops martiensseni (Chiroptera : Molossidae)

摘要

Listed as 'vulnerable' by the International Union for the Conservation of Nature, the molossid bat Otomops martiensseni occurs widely in Africa and, according to some authorities, in Madagascar. Apart from a few known cave roosts, there are few records of O. martiensseni, although around Durban, South Africa, the species is common and roosts in buildings. Originally described as three species, populations of O. martiensseni differ significantly in size (length of forearm) between East Africa and Durban or Madagascar, but not between Durban and Madagascar. Seventeen buildings used as roosts by O. martiensseni averaged 34.5 +/- 15.8 years old. In the Durban area, bats entered roosts by landing and crawling. Roost populations ranged from 7 to 29 individuals, typically consisting of one adult male, several adult females and young (bats with unossified epiphyses), suggesting a harem social structure. The ratio of adult females to young was virtually 1:1, and among young the ratio of males:females averaged 2:1. Radio-tracking showed that individuals used several day and night roosts, and foraged widely in a landscape dominated by sugarcane and urban development. The echolocation and many social calls of O. martiensseni are readily audible to human observers, allowing a non-contact, low technology method for monitoring the local distribution and activity of these bats. Although listed as a species of special concern in KwaZulu Natal, there these bats appear to be candidates for inclusion on a 'blue' list of species, ones showing stabilized or increased abundance. We recommend that O. martiensseni be recognized as a 'flagship' species in the Durban area, r epresenting the resilience of nature.