Tennessee Warblers in Marin County, California
Tennegaee Warblers in Marin County, California.-An unusually heavy migration of warblers occurred during the fall of 1944 through Marin County, California, and the water traps nearest our warbler aviary at Manor produced a number of surprises, not the least of which were four examples of the Tennessee Warbler (Vermivora peuegrina). The first bird was taken on the morning of September 16, 1944. Not being familiar with this eastern species, it was banded and placed in a holding cage pending identification, which was subsequently accomplished without difficulty. Other Tennessee Warblers were seen in shrubbery adjacent to the aviaries on the same and subsequent days, and another individual was trapped on September 19. A third Tennessee Warbler was taken on September 24, and although others were occasionally seen on the grounds in the following fortnight, the fourth individual was not caught until October 15.
Because of the rarity of the species in California, it was determined to keep all four birds for aviary purposes. Much to our surprise, we found this species to be among the easiest of the whole warbler group to “break off,” a term used for the technique of weaning captive birds from a natural to an artificial diet.
These warblers were carried over the winter in a separate aviary compartment in the large heated shelter and were not released into the warbler aviary‘proper until late April of this year. At the date of thii writing they are showing signs of an early summer molt, not an unusual occurrence with adult migrants trapped in the preceding fall and wintered over in heated quarters. They are very much like our Orange-crowned Warblers (Vermivora celata) both in action and behavior, and this is particularly noticeable under the conditions imposed by the aviary. Upon death, they will be made irito skins to complete the record.-ERIC CAMPBELL KINSEY,, Manor, Marin County, California, June 6,1945.
