Sherwick Min, PhD

A study on sexual selection and behavioral ecology in a natural population of pronghorn antelope in Colorado.
Several sexually dimorphic morphological, behavioural, and territory characteristics of male pronghorn, Antilocapra americana, are highly variable. To test the hypothesis that females respond to variation among males for mate choice, I examined the relationship between these male characteristics and female congregation size and variability. Increased movement up to and during rut… Show more

A study on sexual selection and behavioral ecology in a natural population of pronghorn antelope in Colorado.
Several sexually dimorphic morphological, behavioural, and territory characteristics of male pronghorn, Antilocapra americana, are highly variable. To test the hypothesis that females respond to variation among males for mate choice, I examined the relationship between these male characteristics and female congregation size and variability. Increased movement up to and during rut and differential female congregation on the territories of males with favoured characteristics were detected as predicted. Individual females increased their home ranges nearly fourfold from summer to rut and visited 88% of the territories in the study area. Female congregation size was related to male phenotype but not to territory characteristics. A canonical correlation analysis revealed that not only were several male traits simultaneously related to female congregation size and variability, but the importance of these traits varied across years. However, male courtship, cheek-patch size, and scent marking behaviours were consistently correlated to female congregation patterns across years. Female congregation was significantly related to male courtship, but there was no correlation between former territory owner's and newcomer's attraction of females. This finding is consistent with the hypothesis that females were primarily assessing males instead of territories. Show less

A study on sexual selection and behavioral ecology in a natural population of pronghorn antelope in Colorado.
Sexually dimorphic characters in males are expected to display substantial variation if they are to be used as cues for choice of mates by females. This study examined the informative value of morphological and behavioral traits of males that were sexually dimorphic, and characteristics of their territories through an examination of the variance exhibited in male pronghorns… Show more

A study on sexual selection and behavioral ecology in a natural population of pronghorn antelope in Colorado.
Sexually dimorphic characters in males are expected to display substantial variation if they are to be used as cues for choice of mates by females. This study examined the informative value of morphological and behavioral traits of males that were sexually dimorphic, and characteristics of their territories through an examination of the variance exhibited in male pronghorns (Antilocapra americana). Cheek-patch areas and lengths of horns displayed higher levels of variation than other morphological characters. Although cheek-patch areas were more variable, asymmetry in lengths of horns may provide reliable information on quality of males. Cheek-patch areas, lengths of horns, and frequency of social behaviors differed among males, whereas their territories differed in size and vegetative cover. Individual males displayed variation between their right and left cheek patches, and their frequencies of courtship changed during rut. Both timing and bout-lengths of social behaviors were negatively associated with those of maintenance behaviors, suggesting that these two classes of activities are mutually exclusive. Sizes of territories of individual males tended to be greater during summer and cover of grasses varied over years. The expression of territoriality in pronghorns is variable both among and within populations, and may represent a frequency-dependent mating strategy of males. Further study on whether variation in traits of males is correlated with variation in reproductive success of males is necessary before questions of choice of mates by females can be addressed. Show less