Biological invasions can alter direct and indirect
interactions between species, generating farreaching
changes in ecological networks that
affect key ecological functions. We used model
and real fruit assays to show that the invasion
and formation of high-density supercolonies by
the yellow crazy ant (YCA), Anoplolepis
gracilipes, disrupt frugivory by endemic birds
on Christmas Island, Indian Ocean. The overall
handling rates of model fruits by birds were
2.2–2.4-fold lower in ant-invaded than in uninvaded
rainforest, and pecking rates by two bird
species declined by 2.6- and 4.5-fold, respectively.
YCAs directly interfered with frugivory;