S. Bouchard et al., Autumn mating and likely resorption of an embryo by a hoary bat, Lasiurus cinereus (Chiroptera : Vespertilionidae), AM MIDL NAT, 145(1), 2001, pp. 210-212
In December 1999 a female hoary bat (Lasiurus cinereus) was found in Ontari
o. The bat, which was kept in captivity from then on, showed signs of distr
ess resembling abortion in late April 2000. Autopsy revealed the presence o
f two foetuses in the uterus, a male at the latest stage of development and
a smaller dead one. The latter stopped development at an earlier stage and
was most likely being resorbed, probably due to deficiencies in the female
's diet. Mating leading to this pregnancy must have occurred in autumn, lik
ely before the onset of migration.