Predatory falcon makes Pacific dunlin lose weight

Washington, January 21 (ANI): A new research 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.

The research, by a team of ecologists led by Ronald Ydenberg from Simon Fraser University, drew on a pool of data spanning four decades to find that the dunlins have had to adapt their behavior - and their diets - in order to survive.

According to Ydenberg, "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".

Starving during the winter is still a very real possibility for Pacific dunlins, but they can no longer rest easy now that peregrine falcons are around.

Some dunlins will fly long distances to find safer roosts, but many now choose to take to the air en masse during peak peregrine feeding times instead.

"Over-ocean flocking is energetically expensive, but the risk from predators is now greater than the threat of starvation," said team member Dick Dekker.

Due to the risk of predation, the average weight of a Pacific dunlin has decreased by 2 - 4 g over the past 40 years.

These adaptations, along with spending more time flying out at sea, help the dunlin to escape predators so that they can safely make it through the winter. (ANI)