128 MEMOIRS OF THE NUTTALL ORNITHOLOGICAL CLUB 



This roost was on the southerly side of Castle Hill and I estimated it contained 

 at times 12,000 birds. A large number of pellets collected from this roost and 

 exammed by the Biological Survey at Washington proved especially interesting 

 and the results are tabulated in the article referred to. 



In January, 1919, the great Crow roost on Castle Hill dwindled and appar- 

 ently ceased to be. Crows were to be seen flying toward the Essex Woods as 

 previously and a moderate-sized roost was found on a pine island in the marshes 

 near Labor-in-vain Creek and the Ipswich River. The cause of this break-up 

 of the roost was, I believe, a Great Horned Owl as explained in the annotations 

 under that bird. Early in April the Crows were again to be seen flying to the 

 roost on Castle Hill. The owl had undoubtedly departed to its breeding-ground 

 inland. 



All passerine birds hold their feet up in front as they fly, and this point can 

 best be observed in the Crow, our largest passerine bird.^ 



203 [494] Dolichonyx oryzivorus (Linn.). 



Bobolink. 

 Abundant summer resident. April 30 to September 30. 

 Eggs: June 3 to 14. 



The courtship song of this bird bubbles over with joy and merriment. Not 

 only from the air but from the tops of trees and from the ground the song is 

 given, but its ardor almost always carries the bird through the air. Especially is 

 this the case when the courting season is in full sway. When the birds first come, 

 before the arrival of the females, they often sing in trees, sometimes as many as 

 a dozen together, making a splendid chorus. One may see a male courting a 

 female on the ground. He spreads his tail and forcibly drags it like a Pigeon. 

 He erects his buff nape feathers, points his bill downward and partly opens his 

 wings, gurgling meanwhile a few of his song notes. The female indifferently 

 walks away. 



On the wing his song is at the best. He rises in irregular circles or progresses 

 in a horizontal plane on rapidly vibrated down-curved wings. His flight often 

 concludes by a descent with wings pointing obliquely upward. 



ijownsend, C. W. Auk, vol. 26, p. 115, 1909. 



