Infectious diseases and extinction risk in wild mammals

Abstract

Infectious diseases can be a major threat to wildlife populations, and parasites have been identified as a cause of population decline in many mammal species. This study assessed how mammal clades differ in their vulnerability to infectious disease threats to better understand the role of parasites in contemporary mammal extinctions. The researchers identified 54 mammal species recognized as threatened by parasites on the IUCN Red List and found that the majority of these species were either carnivores or artiodactyls, two clades that include the majority of domesticated animals. The parasites affecting these species were predominantly viruses and bacteria that infect a wide range of host species, including domesticated animals. Close-contact parasites were more likely to cause extinction risk than parasites transmitted by other routes, counter to the researchers’ expectations. Species threatened by parasites were not better studied for infectious diseases than other threatened mammals and did not have more parasites or differ in key traits that affect parasite species richness. These findings underscore the need for better information concerning the distribution and impacts of infectious diseases in populations of endangered mammals. This study also suggests that the similarity to domesticated animals could be a key factor associated with parasite-mediated declines, and that efforts to limit contact between domesticated hosts and wildlife could reduce extinction risk. – AI-generated abstract.