12-16 



Waterfowl 



Scaup were the most abundant and black ducks the second most 

 abundant waterfowl species in all six years surveyed (1972-1977) . 

 Common goldeneyes were the third most abundant during four of the years, 

 being replaced in this position by canvasbacks in 1972 and 1977 (Appendix 

 Table 12-2) . 



The species of scaup observed in New Haven Harbor include both 

 the greater scaup (Aythya marila) and the lesser scaup (Aythya affinis) . 

 It is difficult to differentiate these two species; when observed in 

 large rafts offshore it is nearly impossible. It is likely that most of 

 the scaup observed were greater scaup. Lesser scaup prefer freshwater 

 areas and smaller salt water areas while greater scaup are more apt to 

 be found on large bodies of salt water (Kortright, 1942; Collins, 1959). 

 In addition, Benson reported that the proportion of greater to lesser 

 scaup ranged from 6:1 near New York City to 10:1 off the coasts of 

 Massachusetts, Connecticut and Rhode Island (Bellrose, 1968). 



Greater scaup come to New Haven from breeding grounds in 

 northwestern Canada and Alaska via one corridor stretching from Manitoba 

 to Lake Superior, Lake Ontario and Long Island Sound. Another corridor 

 brings the birds from Alaska to James Bay, Lake Champlain and Long Is- 

 land Sound (Bellrose, 1968) . Lesser scaup breed in the prairie pro- 

 vinces of Canada and arrive at Long Island Sound via Lake Erie and the 

 central lakes region of New York. 



The largest number of scaup observed in New Haven Harbor at 

 one time was 10,500. Records from the Connecticut State Board of Fish- 

 eries and Game show as many as 25,000 in Long Island Sound from Pond 

 Point to Sachem Head, Connecticut (Normandeau Associates, Inc., 1971). 

 Furthermore, winter inventory estimates (Bellrose, 1968) for 1960-1966 

 showed that 225,000 scaup winter between Boston and Delaware Bay. 

 Larger numbers of both species winter farther south. 



