ABSTRACT
Vampire bats represent the pinnacle of specialization and adaptation in the bat world. Fossil vampires taken from Pleistocene deposits are clearly identifiable with present-day desmodontids. The introduction of livestock and poultry into the Western Hemisphere has provided vampire bats with a new, more readily accessible source of blood than indigenous wildlife provided. The original equilibrium in nature for vampire bats exists only in those areas where domestic animals have not been introduced and the bats still feed upon wildlife. In Mexico, Greenhall analyzed about 500 blood meal samples, and determined that Desmodus fed primarily upon cattle, varied with a few other domestic animals. In Brazil Sazima and Uieda reported on the feeding behavior of Diaemus on free-ranging poultry. Uieda has compared the feeding postures of Desmodus, Diaemus, and Diphylla also in Brazil. There have been very few direct observations of Desmodus feeding upon wild animals.
