Poleward movement seen in many species
By Summit Voice
FRISCO — Researchers in Finland say they’ve documented bird populations trends that are at least partly linked with global warming. Comparing data from extensive bird counts conducted between 1981 to 1999, and 2000 to 2009, the biologists said that, in general, northern species have decreased and southern species increased.
Mean temperatures in Finland rose between the two periods, with April to June mean temperatures climbing by 0.7 degrees Celsius.
According to the study, population densities of common forest habitat generalists remained the same between the two periods, while densities of species of conservation concern showed contrasting trends. Species preferring old-growth or mature forests increased, but those living on mires and wetlands, and species of Arctic mountains decreased. (more…)