276 BULLETIN 16 2, UNITED STATES NATIONAL MUSEUM 



The first nuptial plumage is acquired by a partial prenuptial 

 molt, which does not involve the wings and tail and body plumage 

 but is restricted to the head region. The nuptial plumage was usually 

 completed by April. The second or adult winter plumage is ac- 

 quired by a complete postnuptial molt during August and Septem- 

 ber. Specimens collected in October and November had the adult 

 winter plumage completed. From the adult winter plumage onward 

 the plumages are repetitions of the nuptial and winter phases. 



Food. — The heath hen in its feeding habits was similar to other 

 gallinaceous birds, such as the ruffed grouse, in being very adapt- 

 able to the changing food supply throughout the seasons of the year. 

 It was not dependent on any particular item but subsisted on what 

 was most abundant and most easily procured. 



During the spring months the heath hen congregated in the open 

 fields and meadows of the farms to feed upon the tender shoots of 

 grasses, sorrel, and other plants, but when these became hardened and 

 less palatable with the approach of summer the birds changed their 

 diet to fruits and insects. In fall, berries and insects, such as grass- 

 hoppers, were freely eaten, and in the winter months, acorns, seeds, 

 and certain berries found throughout the range of the heath hen on 

 Marthas Vineyard provided the birds with a livelihood. Com- 

 paratively little snow falls on the island, and hence it was an excep- 

 tional winter when the birds were not able to obtain sufficient food 

 from native plants. Even at times when the ground was covered 

 with snow the scrub oaks held out an exhaustless supply of food in 

 the form of adorns. 



Our chief knowledge of the food of the heath hen is based upon 

 the meager notes of food included in the data with birds collected 

 and preserved as skins in various museums, upon field notes, and 

 upon studies of birds kept in captivity. The following comprise the 

 principal foods: 



The crops of three heath hens collected by C. E. Hoyle on January 

 10, 1891, and two on December 28, 1895, contained bayberries 

 {MyHca carolinensis) . A specimen of a heath hen killed by a snowy 

 owl was reported by Allan Keniston to have had its crop gorged 

 with bayberries. Birds kept in captivity at the reservation in 1915 

 ate very freely of bayberries. During the winter of 1923-24 a 

 flock of 15 birds frequented a large bayberry thicket near the south 

 shore where they subsisted chiefly on these berries. 



The bearberry (Arctostaphylos uva-ursi), sometimes wrongly 

 named mountain cranberry or cranberry, is extremely abundant 

 throughout the central portion of the island and was freely eaten 

 by the heath hen during the winter months when the trailing plants 

 were not covered with snow. 



