records of heron colonies are sketrhy and population estimates are 

 inadequate to establish trends. 



Colonies in Maine have not been accurately inventoried due, in part, to 

 the difficulty of finding the colonies and also because heronries have been 

 reported incidental to seabird censuses. 



Norton (unpublished) found seven great blue heron colonies in eastern 

 and midcoast Maine in 1931. In 1977, 18 great blue heron colonies were 

 located with a total of 903 pairs. Colony size ranged from 1 to 150 pairs. 

 More inventories will be required in future years to establish the population 

 trend of great blue herons in Maine. 



If all major colonies of black-crowned night herons were found during 

 the 1977 inventory, there is little doubt that their population has drastically 

 declined in recent years. Colonies containing several hundred pairs have 

 been reported at various times in the last 75 years (Gross 1923, H.L. 

 Mendall, personal communication). In 1977 only eight coastal colonies were 

 found with an estimated breeding population of 117 pairs. 



Snowy egrets were first reported nesting in Maine in 1963 on Stratton 

 Island by Tyler (unpublished). In 1966 snowy egrets also were nesting on 

 Appledore Island at the New Hampshire border. By 1977 colonies were found 

 on Mark Island, Wood Island, Stratton Island, and Appledore Island with 50 

 pairs at the latter colony. Louisiana herons were found nesting for the first 

 time in Maine on Stratton Island in 1976 and also nested in 1977 (Vickery 

 1977). Eggs and young were observed. Three pairs of little blue herons 

 pioneered to Stratton Island in 1977 and nested there. They first nested on 

 Appledore Island in 1971 (Erwin, unpublished). 



Glossy ibises began nesting in southern Maine in 1972 on Stratton Island 

 and have since nested also on Wood and Appledore Islands. Seventy-five 

 pairs nested on those three islands in 1977. 



Common eider . The numbers of common eiders nesting on the Maine 

 coast have fluctuated greatly since Colonial days. Historical accounts mention 

 a gradual decline from the mid-1800's to shortly after the turn of the 20th 

 century. According to Gross (1944), the low point for eiders in Maine was 

 reached about 1907. Norton (1907) found only one breeding colony that year 

 on Old Man Island in eastern Maine. According to the early writers, egg 

 collecting for food and over-shooting at concentration points, especially on 

 breeding islands in the spring, were the major factors causing the decline. 

 Soon after 1907, protection policies were implemented. They included 

 abolition of spring shooting, complete closing of the eider hunting season for 

 several years and the protection of several seabird nesting islands by the 

 National Audubon Society. As a result, by 1915 the population of eiders 

 began to increase (Figure 9). 



At first the increase was gradual. Gross (1944) surveyed seabird colo- 

 nies in Maine and found eiders nesting on 31 islands and probably nesting on 

 14 others. He estimated the population as "probably" more than 2,000 pairs 

 in 1943. Eiders were nesting on at least 75 islands in 1967 (Mendall 1968), 

 and the population appeared to have stabilized between the mid-1960's and the 



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