Thesis (M.A.)--University of Wisconsin--Madison, 1968. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

I studied the social behaviour of the Vancouver Island marmot, Marmota vancouverensis, during the summers of 1973 and 1974. Virtually nothing was known about the behaviour of this species at the outset of this study, Barash (1973b, 1974a) suggested that the social behaviour and social organization of marmot species was determined by the severity of the environment (the vegetative growing season) and its effect on the growth rate of marmots. He predicted that marmot species living in short growing season environments would be highly social but that social tolerance would decrease as the growing season increased. The objective of this study was to test this hypothesis by observing the social behaviour of Vancouver Island marmots and comparing this to the length of the vegetative growing season. M. vancouverensis is endemic to Vancouver Island, British Columbia. The original colonizers of this species probably crossed to Vancouver Island via land connections that existed during the Illinoian glacial period, approximately 100,000 years ago, and survived subsequent glacial maxima on nunataks and coastal refugia or both. Vancouver Island marmots have been isolated from mainland forms for a length of time (10,000 to 100,000 years) sufficient to show specific evolutionary adaptations to their Vancouver Island environment. Vancouver Island marmots live in small colonies in the subalpine parkland. Social groups consisted of one adult male, one adult female, and variable numbers of two-year-olds, yearlings, and infants. Social groups were highly integrated with a large amount of communication occurring among colony members. Alarm calls were given in response to potential predators and could be heard over the whole colony. Short whistles were given in response to aerial predators (e.g. eagles) and long whistles were given in response to terrestrial predators (e.g. black bears). Both calls are narrow bandwidth sounds, a characteristic that makes them difficult to locate. The most common social behaviour that occurred among colony members was a nose touching behaviour termed greeting. All age-sex classes of Vancouver Island marmots engaged in greetings as well as other social behaviour patterns in about the same proportions. The vegetative growing season experienced by Vancouver Island marmots was approximately the same as that of M. flaviventris but the social behaviour of Vancouver Island marmots most closely resembled M. olympus, a species living where the growing season is much shorter. On this basis I rejected Barash's hypothesis that the length of the vegetative growing season is sufficient to account for the variability that Barash observed among marmot species. I suggest that vegetative growing season not be used as an index of growth rate but that the time taken to reach adult size be measured directly. The degree of social tolerance is positively correlated with the length of time required to reach maturity. / Science, Faculty of / Zoology, Department of / Graduate

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Thesis--University of Wisconsin--Madison. / Typescript. Vita. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Vancouver Island marmots (M. vancouverensis) rank among the world's most critically endangered mammals. There were probably fewer than 100 marmots in 1998, with 90% distributed south of Alberni Inlet, and the remainder on or near Mount Washington. This represents a 60–70% decline in numbers during the past 10 years, and a considerably reduced geographic range during the past several decades. I used data from marked animals, radio-telemetry and population counts to test whether population dynamics were consistent with predictions made under five hypotheses: habitat tracking, sink-connectivity, weather, predators and disease. Estimates of demographic rates from intensive mark-recapture work and population counts were generally consistent, although estimation of adult survival from counts was problematic because of the difficulty of distinguishing surviving marmots from immigrants. There was no apparent influence of mark-recapture on survival or reproduction, and intensively studied colonies showed similar dynamics to colonies that were visited infrequently. There was little evidence for habitat tracking in natural habitats. Few colonies showed chronically low reproduction or survival, which would be the predicted result of a gradually deteriorating environment. Declines were more often abrupt and catastrophic. Marmots did not colonize clearcuts in proportion to their temporal or spatial availability, and ultimately colonized only a minuscule fraction of the potential habitat. However, marmots already inhabiting clearcuts represent a special case of habitat tracking; survival rates were significantly lower at clearcuts of more advanced seral age (i.e., >11 years after harvest). Evidence for source-sink and landscape connectivity processes was relatively strong. Marmots inhabiting clearcuts had chronically lower survival rates (by 5–10%). Per female reproductive contribution in clearcuts was half that of females inhabiting natural environments. However not all clearcuts acted as sinks, or acted as sinks in all years. Colonizations of clearcuts were spatially concentrated and none occurred at distances greater that 5 km from an existing natural colony. Apparent adult survival was significantly associated with isolation but juvenile survival was not, which is consistent with the prediction that isolated colonies should receive fewer immigrants. However the spatial pattern of extinctions was unexpected. Isolated and closely-clustered colonies had similar probabilities of extinction. Weather significantly influenced marmot survival and reproduction but explained only small amounts of variation. Survival was significantly associated with rainfall, temperature and snowpack depth. Reproduction was negatively associated with snowpack and temperature. Slope aspect was significantly associated with survival, perhaps suggesting the importance of snowmelt patterns. Natural and clearcut colonies responded differently to weather. Indices of wolf and cougar abundance were inconsistent and probably do not reflect true population sizes. Deer abundance was weakly associated with marmot survival in natural habitats, which could suggest switching of predator hunting effort. Marmot survival was spatially correlated, which is consistent with the idea that a few individual predators may focus hunting efforts at adjacent colonies. Field observations and radio-telemetry corroborated the importance of predators. In natural habitats, disappearances were uniformly distributed throughout summer, as predicted. In clearcuts, disappearances, were more heavily skewed towards late summer, suggesting that winter mortality was more important. Spatial correlation of survival is also consistent with the disease hypothesis. Survival was lower in colonies with high relative density of adults, which is a predicted result given the prediction of increased risk of disease transmission. The incidence of high mortality events increased during the 1990s, and the degree of spatial correlation also increased despite a more fragmented population structure. These trends are consistent with a hypothesis of a new disease organism or increased risk of infection. Forestry appears to be the primary cause of recent population dynamics in the Nanaimo Lakes region. Logging reduced overall marmot survival, inhibited their ability to re-colonize sites, and concentrated the population, making colonies more susceptible to predators and disease. The prognosis for continued survival remains hopeful provided that current plans for captive-breeding and captive-breeding and reintroduction are pursued aggressively. / Graduate

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I used 8 years of mark-recapture data to test alternative hypotheses about the relative influence of winter climate, social structure, and life history on survival, reproduction, and population dynamics of hoary marmots (Marmota caligata) in the southwest Yukon. Climate, characterized by the mean winter Pacific Decadal Oscillation index (PDO), was strongly related to juvenile survival, more weakly linked with adult survival and fecundity, and did not appear to influence breeding probability. Group social structure had little influence on population dynamics. Variation in adult and juvenile survival affected the population growth rate more strongly than fecundity or breeding probability, but the relative influence of life history parameters changed from year to year. Comparisons between hoary marmots and other alpine mammals indicated that the average environment to which an animal is adapted, the strategies employed to survive winter, and life history constraints may all affect demographic sensitivity to winter climate. / Ecology

Population dynamics of yellow-bellied marmots (Marmota flaviventris) were studied at Watch Lake, British Columbia. I attempted to determine how population size was regulated and compared life history tactics of the Watch Lake populations with those in other areas. Ninety-three percent of adult females and eight percent of yearling females had litters. The mean litter size was 6'. 1 ± .38. The size and weight of a female's litter were negatively correlated with her reproductive effort in the previous year. The annual mortality rate of juveniles was 62%; mortality of yearlings and adults was 33%. Most yearling males and a few yearling females emigrated. . The populations were expanding at a rate of increase of approximately .27. The Watch Lake colonies were generally larger and denser than those reported from other areas. Adult males were territorial throughout the active season. Adult females defended territories during pregnancy and lactation. This is the first report of female territoriality in Marmota flaviventris. Experiments indicated that' (1) adult males caused yearling males to emmigrate and (2) adult females inhibited reproduction of yearling females. I predict that numbers will stabilize through the territorial behaviour of breeding females either reducing the breeding success of females or increasing the emigration rate of yearling females. I describe an experiment to test this hypothesis. Marmot numbers near Watch Lake have been increasing for several decades as new habitat becomes available. Life history tactics of these populations differs from those inhabiting the stable environment of subalpine Colorado. Marmots at Watch Lake suffered greater mortality. They began breeding at a younger age than those in other populations. They allocated relatively more energy to.reproduction, produced larger litters of smaller young, and grew to smaller adult size. These differences are consistent with those predicted by the theory of r- and K- selection for colonizing and stable populations. / Science, Faculty of / Zoology, Department of / Unknown