Reproduction in two species of equatorial free-tailed bats (Molossidae)

Abstract

(1) The insectivorous bat T. pumila living at Entebbe latitude 0o6'N breeds throughout the year. However, it exhibits peaks in its breeding cycle which appear to coincide with the two rainfall peaks which occur at Entebbe and in Uganda generally; a low one in October-November and a higher one in April-May.

(2) The other insectivorous bat T. condylura living at Bukalasa latitude 0o43'N exhibits a bimodal breeding rhythm also closely correlated with the rainfall pattern at Bukalasa which is similar to that at Entebbe.

(3) Rain may therefore be an important proximate factor in the breeding of these bats while food (insects) may play an important ultimate role.

(4) One young per bat is the rule and implantation which always takes place in the right horn of the bicornuate uterus of both species is unilateral.

(5) The gestation period in T. condylura is about 2 months and in T. pumila, it may be shorter than this.

(6) Both species develop and mature rapidly and as they are often found living together, the difference in their breeding patterns is advantageous in that it helps to reduce competition between them.