What we have to do then is look at the biology of plants in the area to see the effects of the absence of these animals. To do this, Rodolfo works in two research locations. Los Tuxtlas in Veracruz, Mexico is a known defaunated site, where many of the native animals are no longer found in expected quantities. By looking at natural patterns in each place, Rodolfo observes what may be the results of a loss of animal diversity. Further experiments help him determine whether the patterns he sees are due to defaunation, or some other ecological process.
Animals feed on seeds and they trample plants, creating natural disturbances.
In the absence of these activities, many plant species have to compete for space on the forest floor. Dominant species, or those best equipped to survive under these changing conditions, monopolize the forest understory. Since the understory is essentially made up of babies of the big trees, what grows up there will be the forest of the future. In other words, defaunation may lead to a reduction of forest diversity in the future. When thinking about his career as an ecologist, Rodolfo speaks highly of the scientists who have served as mentors in his life.