Data from: Down by the riverside: Riparian edge effects on three monkey species in a fragmented Costa Rican forest

Rivers represent natural edges in forests, serving as transition zones
between landscapes. Natural edge effects are important to study to
understand how intrinsic habitat variations affect wildlife as well as the
impact of human-induced forest fragmentation. We examined the influence of
riparian and anthropogenic edge on mantled howler, white-faced capuchin,
Central American spider monkeys, and vegetation structure at La Suerte
Biological Research Station (abbreviated as LSBRS), Costa Rica. We
predicted lower monkey encounter rate, tree species richness, and median
DBH at both edge types compared to interior, and that monkeys would show
species-specific responses to edge based on size and diet. We expected
large, folivorous-frugivorous howler monkeys and small, generalist
capuchins would be found at increased density in the forest edge, while
large, frugivorous spider monkeys would be found at decreased density in
the forest edge. We conducted population and vegetation surveys along
interior, riparian, and anthropogenic edge transects at LSBRS and used
GLMM to compare vegetation and monkey encounter rate. Tree species
richness and median DBH were higher in the forest interior than in the
anthropogenic edge zones. Although spider monkey encounter rate did not
vary between forest edges and interior, howler monkeys were encountered at
highest density in riparian edge, while capuchins were encountered at
highest density in anthropogenic edge. Our results indicate that diverse
forest edges have varying effects on biota. Vegetation was negatively
affected by forest edges, while monkey species showed species-specific
edge preferences. Our findings suggest that riparian zones should be
prioritized for conservation in Neotropical forests.