Piper, W. H., and R. H. Wiley.   1991.   Effects of laparotomies on wintering white-throated sparrows and the usefulness of wing chord as a criterion for sexing.   Journal of Field Ornithology 62:   40-45.


We examined (1) the effects of laparotomies on the behavior, condition, and survival of wintering White-throated Sparrows Zonotrichia albicollis; and (2) the degree to which the sexes are distinguishable on the basis of wing chord alone.   Laparotomized individuals did not differ from controls in dominance status, fat level during midwinter, range size, tendency to be trapped, or return rate to the study area in a subsequent winter.   However, laparotomized birds were significantly more likely than controls to become winter residents of the study area.   Future sexing of White-throated Sparrows by laparotomy might be unnecessary in many cases, because sex can be determined correctly for 91% of all birds solely on the basis of wing chord.

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