BUREAU OF BIOLOGICAL SURVEY. 557 



tain the exact limits of the range of this bird in the United States, 

 the rate at which it is spreading, and its economic status, an orni- 

 thologist was detailed during June to conduct a special investigation. 

 Stomachs have been secured, field notes of abundance and haljits 

 made, and other features of the question have been investigated. A 

 full report of the results will be rendered during the coming year. 



NATIONAL BIRD RESERVATIONS. 



No change has been made during the year in either the number or 

 the boundaries of the national bird reservations. The total number 

 of reservations remains 51, but one of these has been transferred to 

 the Department of Commerce and Labor. Under the act to protect 

 the seal fisheries of Alaska, approved April 21, 1910, the Pribilof 

 Islands in Bering Sea were placed in one reservation in charge of the 

 Secretary of Commerce and Labor. This group includes Walrus and 

 Otter islands, and while the bird reservation on these islands is still 

 maintained it is no longer under the jurisdiction of this Department. 



As an aid to administration the various reservations have been 

 divided into six districts, as follows: (1) The Gulf district, including 

 15 reservations in Florida, Louisiana, and Porto Rico; (2) the Lake 

 district, including 4 reservations in ^Michigan and North Dakota ; (3) 

 the Mountain district, including 11 reservations in the Rocky Moun- 

 tain States; (4) the Pacific district, including 14 reservations in Cali- 

 fornia, Oregon, and Washington; (5) the Alaska district, including 

 C reservations; and (6) the Haw^aiian district, including 1 res- 

 ervation. 



Some of the reservations on reservoir sites of the reclamation 

 projects are not yet ready for occupancy, as construction work is still 

 under way. These and several of the other reservations have not 

 yet been provided with wardens. Under the appropriation for main- 

 tenance of reservations, which became available July 1, 1909, wardens 

 have been appointed for varying periods of time at fifteen reserva- 

 tions, as follows: Seven in the Gulf district, two in the Lake district, 

 five in the Pacific district, and one in the Mountain district. Several 

 of th(>se wardens are maintained in cooperation with the National 

 Association of Audubon Societies, and on some of the reservations 

 protection has been afforded the birds through light keepers and em- 

 ployees of the Reclamation Service. 



As a means of coordinating the work of the w^ardens and exercising 

 closer supervision, inspection of some of the reservations in the first 

 and second districts was made by members of the Office, and examina- 

 tions of other reservations in the first and some in the third and 

 fourth districts were made by special inspectors. Experiments in 

 marking birds with bands to determine the course of migration were 

 initiated on the Stump Lake (N. Dak.) and Klamath Lake (Oreg.) 

 reservations, and investigations to determine the homing instinct and 

 the power of birds to find their way back to the breeding grounds, 

 begun by Prof. J. B. Watson in 1907 on the Tortugas (Fla.) reserva- 

 tion, under the direction of the Carnegie Institution, were continued in 

 the spring of 1910. The food liabits of birds on this reservation and 

 on Pelican Island also are being investigated. 



The protection of birds on reservations has resulted rather unex- 

 pectedly in extending protection to certain mammals. On the 



