Female Choice for Male Morphological Traits in House Sparrows, Passer domesticus

Abstract

AbstractFemale mate choice for male morphological traits was examined in captive house sparrows in New Mexico, USA. A study of house sparrows in Denmark indicated that male bib size is important in female choice (Moller 1988, 1989). To examine this issue further, and to compare the selective pressures on male morphological traits between the two populations, bibs of males were manipulated to one of four standard sizes and females were allowed to choose from four males, one of each bib size. The amount of time the female spent with each male was recorded for 40 trials. Males were then ranked in each trial, with a rank of 4 given to the male the female spent the most time with. The ranks a male obtained were then averaged to provide an indication of a male's attractiveness to females. Data from 23 different males indicated that bib size was not correlated with a male's average rank, even when the effects of other traits were controlled statistically. In addition, the size of the original (unaltered) bib was not correlated with male average rank. Bill depth was the only trait significantly correlated with a male's average rank. Differences in the populations studied or the methodologies used may have led to differences between the results obtained in this study and that of Moller (1988).