As South American rain forests are cleared away to make room for livestock pastures, vampire bats in the area are increasingly attacking cattle. The bovines are easier prey than the bats' traditional forest meals–tapirs and peccaries whose habitat is being destroyed. Researchers from the Leibniz Institute for Zoo and Wildlife Research noticed this shift in diet by analyzing the breath of bats in Costa Rica. From National Geographic:
Cattle and rain forest mammals feed on different plants that can be distinguished by their carbon isotopes. Since these chemical clues are present in prey's blood, the signature in the bats' breath varies with their meals.The study clearly indicated that the vampires' most recent victims were almost always cattle, the team said.
