Local groups, ranging between 25 and 52 eagles, were noted historically in 

 coastal Maine at a large fish kill in Casco Bay (region 1; Josselyn 1672), as 

 well as at Damariscotta Lake (region 3; Bent 1937), Penobscot Bay (region 4), 

 and the Narraguagus River (region 5) during migration. Wintering eagles in 

 Maine formerly were characterized as common to occasionally numerous in some 

 coastal regions (Palmer 1949). 



Breeding population . Nesting inventories from 1962 to 1979 identified 76 

 bald eagle breeding sites in the characterization area. Their distribution 

 and recent occupancy status are shown in figure 16-5. Fifty-two of these 

 sites have been occupied at one time or another since 1975. Eighty-three 

 percent of the State's breeding sites are in eastern Maine between the 

 Penobscot River and St. Croix River drainages, primarily in regions 5 and 6 

 and the interior portion of Washington County. Breeding sites for bald eagles 

 in coastal Maine are included in atlas map 4. 



Surveys of bald eagles nesting in the characterization area since 1962 are 

 summarized in table 16-11. These data provide the best estimates of the 

 annual breeding population and production of young. The apparent population 

 trends are not actual but are the product of variations in sampling 

 methodology. The data suggest coastal Maine's breeding eagle population is 

 increasing and the number of occupied breeding sites nearly tripled from 15 to 

 40 between 1967 and 1978. Such apparent growth is primarily an artifact of 

 improved survey coverage. The largest apparent advancement occurred during 

 intensive search efforts of a recent study (Todd 1979; and Todd and Owen 

 1979). A 43% increase in the number of occupied sites between 1976 and 1978 

 paralleled 23% and 36% increases in the respective numbers of breeding sites 

 and intact nests monitored in the characterization area. Discovery rates of 

 new sites suggest the present survey efficiency does not exceed 80% of the 

 total population. The apparent decrease from 1978 to 1979 reflects a loss of 

 breeding pairs and/or the effects of a delayed survey in 1979. The latter 

 probably underestimated the population size because some unsuccessful breeding 

 pairs abandon their nests early. 



The known production of fledgling eaglets in coastal Maine increased more than 

 ten-fold from a low of 2 in 1967 and 1972 to a high of 26 in 1979. The 

 increase is less dramatic on a production rate basis but average recruitment 

 since 1976 is significantly higher than it was in previous years. Both 

 nesting success (the number of occupied sites where eaglets fledge) and 

 fledgling brood size (the number of eaglets fledging from a successful nest) 

 increased significantly. 



The recruiting of eagles in coastal Maine between 1977 and 1979 was 0.63 

 fledglings for each occupied site and 0.73 fledglings for each apparent 

 nesting attempt (excluding nonbreeding pairs), both of which remain below 

 minimal numbers required for population stability. Eagles nesting on Cape 

 Breton Island, Nova Scotia, Canada (the other major breeding area in the 

 Northeast) averaged 1.35 fledglings for each apparent nesting attempt during 

 1978 to 1979 (Smith, unpublished ) . The productivity of relatively healthy 

 eagle populations in Michigan (Postupalsky , unpublished ) , Minnesota (Mathisen 

 1979), and Kodiak Island, Alaska (Delaney, unpublished ) during 1977 to 1979 

 ranged between 0.95 to 1.09 fledglings per occupied site and 0.97 to 1.22 

 fledglings per apparent nesting attempt. The decline in fledgling recruitment 

 of Maine eagles indicates its population is declining. 



16-35 



10-80 



