Can There Be Too Many Eagles?
A conservation icon in Europe, the white-tailed eagle has made an astounding comeback—and that’s not entirely good news.
There can never be too many eagles, right? The comeback of northern Europe’s largest bird of prey could challenge that notion.
Some scientists are worried that the white-tailed, or sea, eagle (Haliaeetus albicilla), which has recovered from near-extinction in the 1980s, poses a new threat to other at-risk birds.
There are now as many as 24,500 adult white-tailed eagles in Europe, which bounced back after countries banned the pesticide DDT and industrial chemicals known as PCBs.
These pollutants, which dry out eggshells and affect embryo production, cut the birds' reproductive success by 80 percent, according to the Swedish Museum of Natural History’s Björn Helander, who led Sweden's white-tailed eagle recovery program for 40 years.
Now, the Baltic Sea coastline is home to well over 2,000 eagles, and numbers are rising fast—almost 8 percent a year in Sweden, for example, according to the Baltic Marine Environment Protection Commission in Helsinki, Finland.
With eight-foot (2.4-meter) wingspans, these apex predators require around a pound (0.5 kilogram) of food a day—and their diet includes other vulnerable birds.
Multiply that by the Baltic population, and