January 21, 2010
Shorebirds Shape Up And Ship Out
Some Canadian shorebirds have had to get fit or die trying. Research published in the open access journal BMC Ecology has found that the average Pacific dunlin has lost weight and spends more time in flight as a response to the increased threat of predation from their arch-enemy, the peregrine falcon.
Fortunately for the falcon, the outlawing of the highly toxic chemical fertilizer DDT in the 1970s has led to an increase in their population. Bad luck though for Pacific dunlins, which once enjoyed lazy winter afternoons roosting in relative safety on the shore of the Fraser River estuary in British Columbia. Drawing on a pool of data spanning four decades, a team of ecologists led by Ronald Ydenberg from Simon Fraser University has found that the dunlins have had to adapt their behavior "“ and their diets "“ in order to survive. Ydenberg says, "In the past, dunlins stored up fat reserves in the autumn months so that they could survive the harsh Canadian winters when food is short. What we're seeing now, however, with the increase in numbers of peregrine falcons, is that the dunlins have to consider the energy trade-off between preparing for starvation and being able to escape quickly".
On the Net: