Historical, biogeographical and ecological factors explain the success of some native dung beetles after the introduction of Cattle in Mexico

Resumen

The introduction of different types of livestock following the Spanish conquest of Mexico generated notable changes in the landscape of the Mexican High Plateau and tropical regions of the country, replacing the mostly agricultural activities of indigenous populations with European-style livestock production. While the effects on native vegetation were significant, the dung produced by the livestock— mainly cattle, horses and goats—did not create the same degree of environmental problems that later occurred in Australia and New Zealand. This is explained because the dung beetles of Mexico— and that of the Americas in general—were capable of exploiting this exotic resource and

incorporate it into the nutrient cycles of the tropical and temperate soils of the American continent. This ability to utilize an exotic resource can be explained by the evolutionary, biogeographic and ecological history of the species of beetles native to the American continent. Biogeographically, Mexican dung beetle species come from phyletic lines that originated in the Palearctic, Nearctic and Neotropical regions, arriving in Mexico in different waves during the Miocene and Pleistocene. During these epochs, the megafauna of Mexico included mammoths, mastodons, gomphotheres, horses, camels, glyptodonts, bison and antelope, among others. These animals produced dung that was similar to that of the livestock from Spain, especially that of cattle and horses. This made it possible for the native dung beetles to easily exploit the resource provided by the livestock introduced by the Europeans. In an anthropized landscape such as Mexico, we must focus not only on the conservation of the dung beetles that inhabit our temperate and tropical forests, but also on the species found in man-made pastures, both of which provide valuable

ecosystem services such as incorporating dung into the soil nutrient cycle.