Dwindling numbers of a single mammal species involved in seed
dispersal could change the nature of Brazilian Atlantic forests
in far-reaching ways. A recent study in PLOS ONE examined the
role of two fruit-eating species, tapirs and woolly spider
monkeys, in dispersing seeds across tropical forests in
southeastern Brazil. Together, the two species are responsible
for spreading the seeds of over 300 plant species, and are thus
important contributors to plant biodiversity. The study found
significant differences in the frequency and patterns with which
the two species dispersed seeds. Woolly spider monkeys, or
muriquis, dispersed 5 times more plant species and 13 times more
seeds than tapirs living in the same area did. Tapirs dispersed
fewer seeds and spread fewer numbers of plant species across the
forest than the muriquis did. However, they also dispersed
larger seeds than muriquis and moved the plants into sites not
reached by the monkeys, such as large gaps in the forest and
fragmented open areas nearby. T