NESTING CHRONOLOGY 



The sequence of reproductive activities from spring arrival until depar- 

 ture from the breeding grounds is described in this section. The information 

 was extracted from 33 major sources of both published and unpublished reports. 

 Data from the 1976-1977 survey were incorporated also. For most of the 28 

 species, a figure was prepared showing the peaks of adults arriving in the 

 spring (A), the major egg-laying period (E), the hatching peak (H), and the 

 average departure dates (D). Where references in the literature included 

 exceptionally "early" or "late" dates of arrival, departure, etc., they were 

 omitted in an attempt to document the modal periods of arrival, egg-laying, 

 hatching, and departure. Inclusion of extreme dates would have greatly 

 extended the primary nesting period for many species. Since references from 

 the early 19C0's to the present were included, a number of changes in breeding 

 status and nesting periods were found. Some species which were formerly only 

 breeding populations are now year-round residents. Also, because of Federal 

 protection laws in 1918, almost all of the seabird and wading bird species 

 made a major recovery from near extirpation, expanding their breeding ranges. 

 Their status, then, in many States has changed from visitor or wintering to 

 breeding or permanent resident. 



To present the chronology in a concise fashion, each species is treated 

 separately in three geographic areas along the coast: southern New England, 

 New York-New Jersey, and the Delaware-Maryland-Virginia (hereafter "DelflarVa") 

 coast and Chesapeake Bay region. There were only \jery slight differences 

 among States within regions. For many species, no data were available from 

 certain States. The bar graphs show the major activity, relative to periods 

 early (week 1), in the middle (weeks 2-3), and at the end (week 4) of the 

 month (at the top of the figure). If a species did not breed in a given 

 region, that section on the figure was left blank. Source code numbers are 

 shown on the upper right of each bar and are referenced in Table 39. A brief 

 summary for each species follows: 



SEABIRDS 



Leach's Storm-Petrel 



Nesting chronology data are unknown for the single colony at Penikese 

 Island, Massachusetts. 



Double-crested Comiorant 



This species shares many of its colonies with herring and great black- 

 backed gulls and is fairly synchronous in egg-laying and hatching with them 

 (Fig. 15). Narrow bands reflect few data points. 



Common Eider 



Since only introduced birds nested at Penikese Island, eiders are not 

 included in this section. 



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