| Summary: | The objectives of the study were to describe the agonistic interactions of the snowshoe hare, Lepus americanus, to describe the social structure of the hares, and by experiments to determine if these interactions might affect hare population dynamics. I built two 30 x 30 metre enclosures to gather initial descriptions of agonistic interactions, and to perform experiments in a controlled situation. I observed wild hares and performed some experiments in the field to confirm the results of pen observations.
Agonistic interactions were stereotyped and occurred in both penned and wild hares. Interactions occurred over access to food, water, resting spots, and right-of-way. The hares formed dominance hierarchies in the pens and in the wild, with males being most dominant in the winter and females being most dominant during the spring and summer. Hares were aggressive with up to 23 interactions per hour observed at a feeding station in the wild.
A mating experiment in an enclosure showed the dominant male to be responsible for most copulations. Subordinate males were behaviourally prevented from copulating by the dominant males. The courtship itself involved fast chases by several males after an oestrous female, with high levels of aggression occurring between the males (94 interactions per hour). At the end of each female's oestrous she became extremely aggresssive to further approaches by males. Similar, but less complete, courtship sequences were seen in the wild which suggests that the captive animals provided a reasonable description of mating events. At high population densities the extreme male competition for oestrous females may have some effect on mortality.
Wild juveniles were introduced into enclosures containing resident juveniles and adults to mimic a situation in which juveniles disperse into a new area. All 30 introduced juveniles were harrassed by the residents, both adults and juveniles. I observed similar interactions between adults and juveniles in the wild, but was unaware of their residential status. This experiment suggests there is a behavioural mechanism for preventing the recruitment of non-resident juveniles into a population. === Science, Faculty of === Zoology, Department of === Graduate
|
|---|
