Sudan dye for tagging birds. — A physiological 

 tagging technique for identifying birds that feed 

 on candidate chemosterilants has been developed 

 by i he Massachusetts Wildlife Unit. .Sudan 

 Black B dye, when ingested by adult birds just 

 before or during the egg-laying period, is depos- 

 ited in the yolk in discreet layers. The position 

 and color intensity of the layer in the yolk indi- 

 cates the quantity consumed and the date of in- 

 gestion. The most important application of the 

 tagging technique is its use as an experimental 

 control in field testing candidate chemosterilants 

 with large numbers of birds without capture and 

 with a minimum of disturbance in the breeding 

 colonies. 



(hill populations in southeastern New Eng- 

 land. — A recent winter gull census by the Massa- 

 chusetts Audubon Society, under contract with 

 the Bureau, showed that feeding sites around 



met ropolitan Boston and Xew York City harbored 

 about 80,000 of approximately 110,01)1) gulls be- 

 tween Grand Manan, New Brunswick, and central 

 New Jersey. About 20,000 of the remaining 

 30,000 birds were at dumps near smaller towns. 

 Only about lO,ooo gulls were found along the 

 shore in what might he considered the "natural" 

 habitat for herring gulls. 



A comprehensive report on this contract showed 

 that in 1900 the breeding population of herring 

 gulls in Xew England numbered about 8,150 pairs, 

 all nesting on islands east of Penobscot Bay, 

 Maine. In 1961, the population was estimated at 

 58,000 pairs, more than half of which nested in 

 Massachusetts. Continued increase in numbers 

 has been associated with the founding of new 

 colonies. 



Observations of gull concentrations at feeding 

 areas such as dumps and fish piers indicated the 



Decoy traps liberally baited with waste grain and set adjacent to cornfields may take large numbers of depredating 

 blackbirds. This farmer-built model, costing a few dollars, proved effective in Arkansas. (Photo by Brooke Meanlev 



59 



