No. 123.] DIVISION OF ORNITHOLOGY. 53 



On one farm where formerly these birds were common several 

 cats were acquired and naturally there the Heath Hens disap- 

 peared. Althou<jh roaming vagrant cats are continually de- 

 stroyed by the superintendent on the reservation, they are 

 abundant in many parts of the island, and are without doubt 

 the worst single menace to the welfare of the Heath Hen. If 

 general diminution continues, the Heath Hen will soon be 

 extinct. 



Condition of the Gulls and Terns on the Massachusetts 



Coast. 



The larger colonies of mingled Common, Roseate and Arctic 

 Terns in Massachusetts no longer show an annual increase in 

 the number of individuals. On the other hand, gulls continue 

 to multiply. The increasing gulls seem to be inimical to the 

 terns. On Skiffs Island, where many Common Terns formerly 

 bred, this species has been much reduced in numbers since the 

 Herring Gulls began to breed there. Similar conditions have 

 been reported from Maine islands formerly occupied by terns 

 which have disappeared following the invasion and nesting of 

 Herring Gulls. The great multiplication of Laughing Gulls on 

 Muskeget Island has been accompanied by more or less diminu- 

 tion in the numbers of the terns which have always summered 

 on the island. Herring Gulls also are now nesting on Muskeget. 

 Owing to the excessive increase of Herring Gulls on Maine 

 islands, and because of the complaints regarding their depreda- 

 tions, the National Association of Audubon Societies has dis- 

 continued its warden service on several of the larger breeding 

 places of the species. The protection of these gulls became 

 necessary at a time when their extinction was threatened by 

 the millinery trade, but it seems that now they have recovered 

 their normal numbers. These gulls are useful as scavengers. 

 If they become too numerous, however, they may attack grain 

 in the fields, as they did in the British Islands, where they 

 increased unduly under protection. 



During the past summer the terns breeding at Chatham suf- 

 fered much from heavy rains at hatching time, and later, when 

 the young were nearly fledged, many died from lack of sufficient 

 food. This greatly restricted the annual increase. At Mono- 

 moy the birds seemed to find an adequate supply of food, 



