12-8 



Monthly species diversity was variable (Table 12-3). Generally, 

 fewest species were observed in spring and highest numbers observed in 

 summer and fall. The lowest number of species recorded was 4 in June 

 1977 and the highest was 54 in August 1977. The highest number of 

 waterfowl species was observed during the winter months while greatest 

 number of shorebird species occurred during spring and summer; species 

 diversity of gulls did not vary seasonally (Figure 12-3, 12-4 and 12-5). 



The seasonal distribution of species was typical of coastal 

 areas in the latitude of New Haven. The number of waterfowl species in- 

 creased during fall, remained high during winter, then decreased to low 

 numbers in summer (Figure 12-3) . The increase resulted from the influx 

 of birds from Canada and northern New England which utilize New Haven 

 Harbor either as a resting habitat before migrating further south, or as 

 a wintering habitat. The spring decrease in waterfowl species occurred 

 as the birds departed for their traditional breeding grounds in Canada 

 and the northern United States (Kortright, 1942) . 



In exact opposition to this pattern was that exhibited by 

 shorebirds. The number of species of these birds was highest in the 

 summer (Figure 12-4) . Shorebirds breed in the vicinity of New Haven as 

 well as areas farther north and, in addition, those yearling shorebirds 

 that do not breed remain on their wintering ground or along the migration 

 routes which include coastal New England. During the winter months 

 shorebirds inhabit the southern United States, the Caribbean and South 

 America (Stout, 1967) . 



The June observations of extremely low numbers of shorebirds 

 (Figure 12-4) does not correspond with what would be expected at this 

 time of year. Examination of the raw data revealed that of the five 

 census periods conducted during June (one each year from 1972 - 1976), 

 four were conducted at high tide. Shorebirds that feed on intertidal 

 flats or in shallow water would be expected to utilize the areas in New 

 Haven Harbor at low tide and to be found elsewhere at high tide. In a 

 similar situation. Burger et al., 1977 found shorebirds feeding on New 

 Jersey tidal flats to be a function of tide time rather than time of 



Continued on page 13 



