rainforest
floor on Christmas Island (Indian Ocean), the introduced
yellow crazy ant (Anoplolepis gracilipes) attacks
and kills the dominant native omnivore, the red land crab
(Gecarcoidea natalis) (O’Dowd et al. 2003). In the forest
canopy the ant forms new associations with herbivorous,
honeydew-secreting Hemiptera (Abbott & Green
2007), that result in reciprocal increases in their population
sizes. These multidirectional, direct, and indirect
effects change the network and strength of interactions
among producers, herbivores, and detritivores to deregulate
seedling recruitment, increase tree mortality, and
reduce litter decomposition. This ant invasion rapidly resulted
in distinctive forest states, with altered resource
levels and habitat structure (O’Dowd et al. 2003), that
we hypothesize affects the broader vertebrate community.
We compared ant-invaded and uninvaded sites to
infer direct and indirect effects of yellow crazy ants on
the relative abundances, behaviors, and reproductive success
of endemic forest birds.