Familiar nest sites beat better lakes

摘要

When common loons (Gavia immer, pictured) settle down to breed, they pick sites similar to the ones they hatched in, even if better sites are available. As part of a 20-year study, researchers led by Walter Piper at Chapman University in Orange, California, tagged and observed birds across glacial lakes in the north-central United States. Loons that were reared on small, acidic lakes tended to settle on similar sites, even though large, less-acidic lakes can support more and healthier chicks. The researchers suggest that adult loons might survive best on lakes that offer the types offish and other prey that the birds are most familiar with. A trade-off between reproductive success and survival rate could help to explain the apparently maladaptive habitat choices seen in loons and other species, the authors say.