NESTING CHRONOLOGY 



Initiation of egg-laying for a given species at a given colony can vary 

 by as much as 3 weeks from year to year due to environmental conditions. 

 Also, birds in the western part of the Maine coast tend to nest earlier than 

 birds in eastern Maine due to differences in climate. Therefore, the 

 estimated breeding chronology of seabirds and wading birds in Maine is shown 

 by phenophase diagrams (Figures 4-8). In general, great black-backed 

 gulls, herring gulls, common eiders, great blue herons, and double-crested 

 cormorants start nesting in late April or early May. The terns, alcids. 

 Leach's storm-petrels, and laughing gulls nest later. 



There are insufficient data from Maine to determine the breeding 

 chronology of roseate terns; however, for this report the timing is assumed 

 to be similar to that of common and Arctic terns. Breeding chronology data 

 are scant for such scarce nesters as razorbills, laughing gulls, and some of 

 the wading birds. The complete citation for each literature reference is 

 included in the REFERENCES section of this report. Diagrams without a 

 reference are based on observations made during the present study. 



POPULATION TRENDS OF WATERBIRDS IN MAINE 



Drury (1973) summarized the status of seabird populations in New 

 England (primarily Maine) prior to 1900 as follows: 



Seabirds were almost completely "eaten off" the outer islands during 

 the 18th and 19th centuries (Bent, 1919, 1921, 1922, 1925; Dutcher, 

 1901, 1902, 1903, 1904, 1905; Forbush, 1925, Norton, 1907, 1923, 

 1924a, b, 1925a, b). Double-crested Cormorants ( Phalacrocorax 

 auritus ) and Great Black-backed Gulls ( Laru s marinuF ) had dis- 

 appeared from the coast as breeding birds early in the 19th century. 

 By the 1870' s Common Eiders (Somateria mollissima ). Common Puffins 

 ( Fratercula arctica ), and Black Guillemots ( Cepphus grylle ) were 

 essentially eliminated and the remnant populations of Herring Culls 

 (Larus argentatus ) were driven to small outer islands. Only small 

 birds of relatively little food value, such as Leach's Petrels 

 (Oceanodroma leucorhoa ) and terns (Sterna sp. ) survived in large 

 numbers. Two great campaigns of shooting seabirds for the millinery 

 trade, about 1876 and 1896, nearly eliminated all seabirds except 

 petrels (Norton 1923, 1924, 1925). The low ebb of seabird popula- 

 tions in New England seems to have been between 1890 and 1906. 



Norton (unpublished) reported that in 1900 there were only 28 colonies 

 of gulls and terns along the entire coast of Maine. Seabirds were protected 

 on their breeding grounds starting in 1901 under the auspices of the 

 American Ornithologists' Union and the National Association of Audubon 

 Societies. Maine islands now support major populations of several seabird 

 species. Historical trends for individual species follow. 



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