Data from: Bird responses to lowland rainforest conversion in Sumatran smallholder landscapes, Indonesia

Rapid land-use change in the tropics causes dramatic losses in
biodiversity and associated functions. In Sumatra, Indonesia, lowland
rainforest has mainly been transformed by smallholders into oil palm
(Elaeis guineensis) and rubber (Hevea brasiliensis) monocultures,
interspersed with jungle rubber (rubber agroforests) and a few forest
remnants. In two regions of the Jambi province, we conducted point counts
in 32 plots of four different land-use types (lowland rainforest, jungle
rubber, rubber plantation and oil palm plantation) as well as in 16 nearby
homegardens, representing a small-scale, traditional agricultural system.
We analysed total bird abundance and bird abundance in feeding guilds, as
well as species richness per point count visit, per plot, and per land-use
system, to unveil the conservation importance and functional responses of
birds in the different land-use types. In total, we identified 71 species
from 24 families. Across the different land-use types, abundance did not
significantly differ, but both species richness per visit and per plot
were reduced in plantations. Feeding guild abundances between land-use
types were variable, but homegardens were dominated by omnivores and
granivores, and frugivorous birds were absent from monoculture rubber and
oil palm. Jungle rubber played an important role in harbouring forest bird
species and frugivores. Homegardens turned out to be of minor importance
for conserving birds due to their low sizes, although collectively, they
are used by many bird species. Changes in functional composition with
land-use conversion may affect important ecosystem functions such as
biological pest control, pollination, and seed dispersal. In conclusion,
maintaining forest cover, including degraded forest and jungle rubber, is
of utmost importance to the conservation of functional and taxonomic bird
diversity.