RESULTS 



SPECIES ABUNDANCE AND DISTRIBUTION 



The 1976 breeding season was considered an experimental period to develop 



inventory techniques, train observers, and refine the logistics of visiting 



the colonies by boat. Data collected during the 1977 season are presented as 



baseline information. Nearly every colony was visited by boat during the 1977 



field season whereas many colonies, especially in eastern Maine, were not 

 visited in 1976. Estimates of nesting populations were made between 23 May 

 and 19 July 1977. 



Cooperators located 353 waterbird colony sites along the Atlantic coast 

 of Maine. Colonies west of Cape Elizabeth (Figure 1) were inventoried by 

 R. M. Bollengier and A. C. Borror in conjunction with the waterbird inventory 

 conducted by the Massachusetts Cooperative Wildlife Research Unit. Informa- 

 tion on those colonies in western Maine are included in this report to bring 

 all of the Maine data together. The numbers of colonies and estimated popula- 

 tions for each species are summarized in Table 2. The number of nesting pairs 

 of each species in each colony is shown in Table 3. An atlas (Erwin and 

 Korschgen 1979), based on this and the companion study by the Massachusetts 

 Unit shows colony location, description, species composition, and population 

 estimates. An alphabetical list of colony site names (APPENDIX B) and a 

 cross reference to Maine Coastal Island Registry numbers (APPENDIX C) are 

 included. 



Most of the colony sites contained more than one waterbird species. 

 The Matinicus Rock site with nine species had the greatest diversity of 

 birds. Black guillemots, herring gulls, great black-backed gulls, double- 

 crested cormorants, and common eiders commonly nested at the same site. 

 Birds nesting at the northern edge (laughing gull, roseate tern, least 

 tern, snowy egret, little blue heron, Louisiana heron, and glossy ibis) 

 or southern edge (common puffin and razorbill) of their breeding ranges 

 occurred in relatively few colonies and in low numbers. 



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