12-19 



Shorebirds 



The four most abundant shorebird species observed in New Haven 

 Harbor were the semipalmated sandpiper, sanderling, dunlin and black- 

 bellied plover. Rankings varied somewhat, with sanderlings being most 

 abundant during the 1972-1974 period and semipalmated sandpipers most 

 abundant during the 1975-1977 period. This change in number of sand- 

 erlings was most apparent in 1975 when numbers dropped appreciably from 

 approximately 1000 in each of 1972, 1973 and 1974 to 50 in 1975. Their 

 numbers then increased in 1976 and 1977. This change in rankings is 

 most likely a function of the study design. Because of a limited number 

 of sampling periods , coincidence plays a large role in this type of 

 sampling program. Sanderlings which may have been present in larger 

 numbers could have been missed on the day observations were conducted or 

 could have been in areas of the harbor at times not coinciding with 

 those of the observer. In addition, sightings of large flocks sometimes 

 distort yearly averages : for example , 600 semipalmated sandpipers were 

 observed at a single observational location in August 1975. Thus, these 

 changes in shorebird rankings are not considered to be indicative of 

 changes in relative abundance. 



Black-bellied plovers, sanderlings, semipalmated sandpipers 

 and sanderlings all breed in the Arctic and pass through New Haven on 

 migration to the wintering grounds in the southern United States, the 

 Caribbean and South America. Dunlins migrate from the Arctic to Hudson 

 Bay and then southeast to the eastern United States , wintering farther 

 north than many shorebird species. Black-bellied plovers pass through 

 New Haven on their way to the West Indies and South America while the 

 semipalmated sandpipers follow part of the large migration corridor 

 stretching from the Rocky Mountains to the east coast (Stout, 1967) . 



