โ Scribed by F. E. Wasserman; J. A. Cigliano
No coin nor oath required. For personal study only.
We investigated the importance of song length and singing rate in stimulating female white-throated sparrows, Zonotrichia albicollis. In November 1988 ten female and one male white-throated sparrow were captured during the fall migration. To enhance the expression of sexual receptivity, the females were implanted with 17-beta-estradiol silastic pellets. Using the visual stimulus of a non-singing male to further enhance the expression of sexual receptivity in the females, we found that females gave a greater response, in the form of copulation displays, to a five-note versus a two-note version of a typical male white-throated sparrow song. Each version was played back at four songs per minute. In May 1990 birds were captured and treated as before, except that the two-note song was played at ten songs per minute and the five-note song at four songs per minute. Therefore, each female heard twenty notes per minute. In the second experiment, the females did not show a statistical difference in response to the two-and five-note song playbacks. We interpret the results of the second experiment as indicating the song rate as well as song length is important in stimulating female whitethroated sparrows because increasing the rate of the twonote song brought the response up to the level of response we obtained to the five-note song played at the slower rate. We conclude that in white-throated sparrows, song output is important for female stimulation.
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