Patterns of frugivory in the columnar cactus Pilosocereus leucocephalus

In the frugivory networks of many arid and semi-arid Mesoamerican ecosystems, columnar cacti act as keystone species that produce fruits with a high content of water and nutrients attractive to numerous vertebrates. The aim of this investigation was to assess the fruit removal patterns of two guilds of frugivores on the fruits of the woolly torch Pilosocereus leucocephalus. We assessed fruit pulp removal in two ways: by estimating the consumption of seeds given the amount of pulp removed per visit and by estimating the percentage of pulp removal over time. We put exclosures on unripe, intact fruits to keep frugivores from removing material. Once ripe, we removed the exclosures and tracked animal visitation of 69 fruits using camera traps. We obtained a total of 2162 h of footage (14:47 h of them with effective pulp removal). The highest number of visitors is that of diurnal species (n=12, all birds) vs. only four nocturnal (three bats, one rodent). The most effective species in pulp rem...