l?Iar., 1911 57 NOTES ON THE NESTING OF THE FORSTER AND BLACK TERNS IN COLORADO By R()BF, RT B. l.?()CKVglt, l,l,
VITH SEVEN PHOTOS
FORSTER TERN THE most beautiful and graceful bird with which our studies of bird life in the [ Barr Lake region brought us in contact, was the Forster Tern (?S7er?a forster/). Their clear pearl-gray backs, snowy breasts, black crowns and brilliant orange feet and bills, coupled with the slender wings, deeply forked tail, Fig. 23. FOUR "FLOATING" NESTS OF TI-IE FORSTER TERN IN THE BARR LAKE REGION OF COLORADO and graceful easy flight, all set off by a back-ground of deep-blue sky made a never-to-be-forgotten picture. Furthermore the striking contrast between their charming manners when unmolested aud their screaming freuzy when excited, made them especially interesting examples of bird temperament. Their peculiar modes of nesting, and the many problems arising from their erratic habits lent fur- ther interest to our field work among them; and on the whole these charming birds furnished us with some of our most delightful days afield.* That these birds nested in Colorado was recogufized as early as 1873 by Ridg- way (Bull. Essex Institute V, Nov. 1873, 174) who stated that "a few breed in the state, but most of them are merely migrants," and Prof. W. ?,V. Cooke in his "Birds of Colorado" (March 1897) classes them a? "Summer Resident, rare." Both of these statements were no doubt true at the time they were written, which was before the day of extensive irrigation projects in Colorado. But through the
- All of the notes on which this paper is based were taken in company with Mr. I,. J. Hersey.
