Who removes seeds in a heavily urbanized area?

In urban landscapes, granivores play a key ecosystem service: they contribute to the establishment of plants and thereby increase the probability of vegetal community recovery. It is therefore a priority to determine how and by whom seeds are removed, which seeds are removed and where they are removed. Our objective here was to determine the removal patterns in three core zones of an urban reserve, three urban parks, and three peri-urban parks, all in and around Mexico City. We performed a selective exclusion experiment with treatments for each type of seed consumer (ants, birds, and rodents) and seeds of nine plant species. Ants were the most important granivores in terms of seed removal (especially small seeds), followed by rodents and birds. Seeds of the native plants Passiflora subpeltata, Pittocaulon praecox and Opuntia joconostle had higher removal rates than other exotic and cosmopolitan species. The urban reserve had higher rates of seed predation compared to the urban and peri-urban parks. Thus, ants are pivotal in keeping seed removal and vegetation communities. We propose a series of measures to promote the ecosystem function of seed removal and increase plant diversity in these different urban patches.