Seed dispersal networks
During the fruiting season (January–April) we identified all
fleshy-fruited plant species in each site. To quantify seed dispersal by
birds, we observed one hour per plant and recorded the number of fruits
consumed by birds. We discarded the records of seed predators and pulp
pickers. Censuses were performed from 6:30 to 10:30 h. In addition, to
evaluate seed dispersal by the endemic marsupial, we collected and
analyzed their feces. The feces were collected with a mesh on the floor
of Tomahawk traps (10 cm × 10 cm × 30 cm). We placed 17 Tomahawk traps
at a height of 1-2 m above the ground on shrubs or trees. Traps were
arranged in a star grid and separated from each other by 15 m to cover
an effective area of one hectare. We controlled the traps daily at dawn
during four consecutive days in February and March. To determine the
number of fruits dispersed by D. gliroides , we divided the number
of seeds of each plant species found in the sample (feces) by the
average number of seeds per fruit of the same species. Moreover, to
accumulate more observation hours per plant species we used two infrared
camera traps (Bushnell trophy cam) per site, programmed to record during
day and night. Cameras were placed focusing branches bearing fruits of
different plant species and relocated periodically to obtain records of
all species present in the site. From the videos, we documented the same
variables recorded with direct observations, considering a dispersal
event when we visually recorded the consumption of fruit by the seed
disperser. Overall, 132 observation periods were conducted for all sites
and plant species in 2017–2018, and 158 observation periods in
2018–2019. These numbers varied across species and sites because
species differed in their abundance, duration of fruiting period and
fruit production (Table S2).