Date: February 1, 2017
Source: Fundação de Amparo à Pesquisa do Estado de São Paulo
The number of vampire bats, which transmit rabies and are a concern for livestock breeders, may be increasing in Brazil and the Americas along with growth in the populations of invasive feral pigs and wild boars (Sus scrofa).
A group of researchers has recently reported an alarming rise in the numbers and distribution of S. scrofa, as well as showing that the common vampire bat Desmodus rotundus is now feeding on the blood of these animals.
Results of this study have been published in the journal Frontiers in Ecology and the Environment by Mauro Galetti, a professor at São Paulo State University's Bioscience Institute in Rio Claro, Brazil (IB-UNESP/RC), his PhD supervisee Felipe Pedrosa, Alexine Keuroghlian, a biologist with the Wildlife Conservation Society (WCS Brazil), and Ivan Sazima, a collaborating professor at the University of Campinas's Zoology Museum (MZ-UNICAMP) in São Paulo State.
As numbers of invasive feral pigs increase, so does the damage to crops and native fauna, among other problems. S. scrofa is also a growing source of blood for vampire bats, so the population of D. rotundus is also likely to increase.
Only three of the approximately 1,200 known bat species feed exclusively on blood, and all three are found only in the Americas. D. rotundus is the most widely distributed, inhabiting a territory that ranges from Mexico to Argentina. This species feeds mostly on livestock and poultry, but it has also been documented to prey on mammals such as tapirs and deer.
In Brazil's Atlantic Forest biome, about 1.4% of vampire bats are infected with rabies. The proportion may be as high as 10% in the Peruvian Amazon. Transmission of rabies by vampire bats is a major concern for ranchers in Brazil, even in areas where cattle are routinely vaccinated. Wild animals, including feral pigs, are not vaccinated and may therefore pose a serious threat by spreading this disease.