Regional differences in number of breeding sites and eagle production are 

 manifest among Maine's breeding eagles (table 16-12). Nearly two-thirds of 

 the State's known breeding population and eagle production is in coastal 

 Maine. More than 50% of these state totals are in regions 5 and 6. Highest 

 nesting densities occur in the Frenchman Bay (region 5) and Cobscook Bay 

 (region 6) vicinities, although recruitment is significantly greater in the 

 latter where 1977 to 1979 means were 0.44 and 0.88 fledglings per occupied 

 site, respectively. Recruitment rates in all regions are below population 

 maintenance levels. 



A striking decline in bald eagle breeding numbers in this century is apparent 

 along the southwestern coast, especially in region 2. Fifteen occupied nests 

 on the lower Kennebec River estuary dwindled to 3 by 1908 (Palmer 1949). 

 Slightly upriver, the Merrymeeting Bay area was once characterized as having a 

 "colony" of nesting eagles. These two areas were inhabited by only 1 and 2 

 breeding pairs respectively in 1979. 



No occupied breeding sites have been found in region 1 since State nesting 

 surveys began in 1962. A maximum of seven breeding pairs have been recorded 

 in regions 2, 3, and 4 since 1977. Eagles nested successfully at only four of 

 these sites. Early nesting surveys in Maine observed greater nesting activity 

 in these western coastal and midcoastal areas. The contrast between past and 

 present distribution patterns reveals a slight decline and/or shift of the 

 State's resident breeding population. 



Wintering population . Aerial inventories of wintering eagles in the 

 characterization area totaled 98 eagles in 1977; 88 in 1978; and 88 in 1979. 

 Midwinter populations in coastal Maine averaged 82% of the Statewide totals. 

 Previous estimates of wintering eagle numbers in Maine were based on limited 

 ground counts and are considerably lower. Long term indices of the State's 

 winter eagle population are limited to results of Christmas bird counts 

 sponsored by the National Audubon Society, and midwinter waterfowl and eagle 

 inventories by Maine Department of Inland Fisheries and Wildlife. Extreme 

 annual fluctuations in these data indicate the inappropriateness of Christmas 

 counts as a measure of abundance. 



The midwinter distribution of bald eagles in coastal Maine is summarized in 

 table 16-13. Sixty-seven percent were found from the Penobscot River estuary 

 eastward, almost evenly divided between regions 4, 5, and 6. Regions 1 and 3 

 receive light, variable use by wintering eagles. 



Despite dispersion in the winter population, four areas of coastal Maine are 

 significant wintering grounds. They are Cobscook Bay (region 6), Frenchman 

 Bay (region 5), the Penobscot River estuary (region 4), and the Kennebec River 

 estuary (region 2) . Combined midwinter counts in these areas averaged 42% of 

 1977 to 1979 statewide populations. 



Cobscook Bay, Frenchman Bay, and the Kennebec River estuary once supported 

 comparable numbers of wintering and nesting adult eagles. The consistently 

 high year-round population levels in the two former coastal areas reaffirm 

 their crucial importance to Maine's bald eagles. 



16-38 



