Loss of breeding grounds hits a sad note for common songbird

Date:  November 29, 2017

Source:  Tulane University

A Tulane University researcher who studies bird migration has found that a decline in the number of wood thrushes is probably due to deforestation in Central America, not to the loss and degrading of forest in the United States where the songbird breeds.

The study by Caz Taylor, an associate professor in the Tulane Department of Ecology and Evolutionary Biology, was published Nov. 6 in the open-access journal Scientific Reports.

Wood thrushes breed in the forests of the eastern United States and migrate in the winter to the forests of Central America. Although they remain a relatively common bird, the species has been declining rapidly since the early 1970's and several researchers have suggested that fragmentation of forests in breeding grounds are playing a major role.

In the new study, Taylor examines how breeding forest fragmentation relates to the shape and strength of density-dependence or how dwindling resources limit bird population. She was surprised to find that declines were more severe in regions where the forest was the least fragmented.

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