winfer feeding

BY RUDY STOCEK

Feeding birds during the winter is a beneficial activity pursued by many nature enthusiasts in the Maritimes. It is only re— cently though that providing winter food for

m. Bald Eagles has attracted at- tention.

New Brunswick has a small population of wintering eagles, about two dozen, that spend

most of that season at the southern reaches of the pro- _A Vince, along the coast and . .river estuaries. Distribution of ‘”'the birds depends upon their food A supply which is influenced by ice conditions and hence, the weather. “’ Eagles are typically opportunistic feeders and can be drawn to an area by w? : « ‘ I v a steady supply of food. They survive the winter on dead or live animal matter be it fish, fowl or flesh. Farm offal, such as livestock carcasses, readily attract these birds who us- ually continue to return to a feeding site.

Bald eagles take about five years to attain adult plumage although they can be sexually mature before that time. Prior to this they are con- sidered immatures or sub-adults. It is at this stage of their life cycle that they are most vulnerable to winter mortality. Starvation and malnu— trition during the cold, snowy winter months create major hazards for the young birds since they generally are not as adept at foraging as the adults because of their lack of experience. Additionally, more aggressive adults may supplant immatures at foraging sites. It has been suggested by studies on the northern eagle populations that only one out of every 10 immatures (10%) survives to reach adulthood. Computer modelling has demon- strated that the survival of the immatures is even more important in in- creasing eagle abundance than is the annual production of a large number of eaglets. Whatever can be done to increase the survival of the immature birds will be beneficial in maintaining a healthy and expanding Bald Eagle population.

Winter feeding for eagles has been occurring on a small scale in the Maritimes, especially in Nova Scotia for a number of years and more re- cently in Maine. This has not always been by design, however. Farmers throughout the region who normally disposed of carcasses in their fields during the winter months found that not only were ravens and crows inter- ested in the food source, but so were Bald Eagles. Certain areas in Nova Scotia have been used as eagle winter feeding areas by biologists study— ing eagle behavior and age characteristics. Those areas have attracted considerable numbers of birds, especially immatures.

Maine's winter feeding program started in 1981 at three sites: at