BIRDS OF ESSEX COUNTY. 8l 



Their larger size distinguishes them from the Red-throated Diver, but on 

 the ocean, size is often deceptive. In the adult plumage, however, there is no 

 difficulty in distinguishing the birds, and generally the larger body and head in 

 proportion to the neck make it easy to recognize them. In the immature and 

 winter plumage, the absence of white spots on the back serves to distinguish the 

 Loon from the smaller Diver. Moulting takes place and the white spots begin 

 to appear as early as the middle of February. 



[9] Gavia arcticus (Linn.). Black-throated Diver. An arctic bird rare or casual in 

 winter in the northerly parts of the United States. Given by Putnam 1 as "Adult, rare." It is 

 probable that young of G. lumme were mistaken for it, although its occurrence on the coast is 

 not impossible. I can, however, find no specimens for Essex County to confirm this supposi- 

 tion, and the bird is excluded from Howe and Allen's List. 2 



5 [11] Gavia lumme (Gunn.). 

 Red-throated Diver; "Cape Race"; "Cape Racer"; "Scape-grace." 



Abundant transient visitor in the autumn, uncommon in late winter and 

 spring ; August 27 to April 8. 



The Red-throated Diver is a lover of salt water, very rarely, in Essex 

 County, entering the fresh-water ponds and rivers. In the autumn, flocks of 

 from three or four up to a dozen, all in immature and winter plumage, are com- 

 monly to be found feeding off the beaches. 



In habits and call notes they closely resemble their larger cousin. I have 

 sometimes amused myself, as also with the Loon, by calling or "tolling" in a 

 flock of these birds by sitting still on the shore and waving a hat or handker- 

 chief on a stick. When the birds see the handkerchief they huddle together, 

 appear to look at each other enquiringly, utter in low and conversational tones 

 their laughing cry, and begin to swim slowly in towards the curious object, fre- 

 quently pausing to talk it over. About one hundred and fifty yards is the 

 nearest point to which I can entice them. 



Like all waterfowl, the Red-throated Diver devotes much time to preening 

 his feathers and hunting for concealed enemies. One may often be seen turn- 

 ing over nearly on his back with one leg waving frantically in the air, the other 

 in the water keeping the balance, while the bird vigorously preens the feathers 

 of the breast and abdomen. The sudden change in appearance, owing to their 



1 F. W. Putnam : Proc. Essex Inst., vol. 1, p. 223, 1856. 



2 R. H. Howe, Jr., and G. M. Allen : The Birds of Massachusetts, p. 21, 1901. 



