wildlife

Birds return to threatened refuges

Loss of mangroves could affect thousands of migratory birds in Panama.

barton paxton/courtesy

pit stop: Shorebirds congregate on beaches near the capital.1119627

In recent flights over the Bay of Panama, American biologists Bryan Watts and Barton Paxton were relieved to find that the number of migratory shorebirds was the same they counted in 1997, but warned that damage to mangroves in areas like Juan Díaz will eventually take their toll on bird populations if nothing is done to protect them.

Counts conducted during October and earlier this month revealed some 490,560 migratory birds, of which 86,427 had gathered in a 30 kilometer stretch of mangroves thickets east of the capital, in the community of Juan Díaz.

Based on those figures, the biologists estimated that at least 2 million birds pass through the Bay of Panama during the course of the year.

Watts, who directs the Center for Conservation Biology at the College of William & Mary in Virginia, said that the reason for the abundance of birds in the mangroves of Juan Díaz has much to do with the ample supply of food found in the mangroves’ unique ecosystem.

It may be that more of the birds’ preferred food is concentrated within that 30-kilometer area than in any other location in the world, he conjectured.

Therein lies the biologists’ main concern as well, since when they began their study of the region 11 years ago, real estate developments had not yet encroached on the south side of Juan Díaz.

“For us, anything that happens here is going to affect birds in Alaska, Mexico, Argentina and Chile, because it will interrupt the biological corridor stretching through the Bay of Panama,” said Watts.

The reasearch team’s original studies in 1997 took place in the same Juan Díaz section of mangroves that was later included in Ramsar List of Wetlands of International Importance, an index of locations chosen by migratory birds for rest, feeding and mating.

A delegation of scientists from the Ramsar Institute has made Panama the focus of a research mission aimed at assessing the status of mangroves around the world.