Generating Timed Pregnancies in Fruit Bats (Carollia perspicillata)

INTRODUCTION

When female short-tailed fruit bats (Carollia perspicillata) are bred, they are first kept sexually segregated for some months to adapt to captivity (in the case of recently captured animals) and to ensure that none are already pregnant. In the case of captive-reared females that had previously been housed with males, 4 mo should be sufficient. In the case of wild-caught females, 7 or 8 mo may not be too long, because introduction into captivity can substantially prolong existing early pregnancies (i.e., at or earlier than the primitive streak stage). Wild-caught females are also much more prone than captive-reared females to take pregnancies into delay after captive breeding. It is important to note that females should not be housed in sexual isolation for prolonged periods, because this can eventually lead to the development of markedly hyperplastic uteri and reduced fertility. Although this is a very serious problem for zoos maintaining all-female colonies of Carollia, it is not the case with our captive colony because the adult females are regularly bred, both to replenish the colony and to inhibit the development of hyperplastic uteri. The generation of timed pregnancies is described in this protocol. For breeding purposes, a stud male with prominent testes is introduced into each cage of females. Vaginal aspirates are then checked each morning thereafter for the presence of spermatozoa.