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