By Susan Milius
Dubbed “yellow crazy ants” by people, an invasive ant drives birds crazy too.
Nicknamed for their wild scurrying, the ants keep birds from eating and dispersing fruit, says ecologist Dennis O’Dowd of Monash University in Melbourne, Australia. On Christmas Island, an Australian territory in the Indian Ocean, hordes of yellow crazy ants (Anoplolepis gracilipes) pester birds landing on plants. Experiments that kept ants off plant stems in invaded zones more than doubled the chances that a fruit would be bitten by a bird, O’Dowd and his colleagues report online September 15 in Biology Letters.
O’Dowd and others have been chronicling the ants’ impact on the native creatures of Christmas Island since the 1980s, but this paper is the team’s first to test ants’ effect on fruit eating. Ant impacts “ramify through a system in such extraordinary ways,” O’Dowd says.