Grant: Discovery Grants Program - Individual

Individual differences affect population growth, the evolution of reproductive strategies and the ecological consequences of environmental change and human exploitation. My research on wild mammals quantifies variation in individual reproductive success, survival and physical characteristics, identifies the sources of that variation and explores its effects on population dynamics. My research group combines theories and methods from ecology and evolution to understand how animals react to changing environments, including changes due to human activities and exploitation. Our primary technique is lifetime monitoring of marked individuals, with detailed information on sex, age, pedigree, genotype, size, growth, reproductive success, social behavior and survival. Study species include bighorn sheep, mountain goats, eastern grey kangaroos, caribou, chamois and brown bears. Bighorn sheep at Ram Mountain have been affected by trophy hunting, and loss of genetic variability may have depressed population growth. Sheep from another population were recently introduced to attempt a genetic rescue. This experiment, combined with more restrictive hunting regulations, will explore if changes in the genetic make-up of the population will influence its dynamics. I will examine how age, size, heterozygosity and social behavior affect the reproductive success of male bighorn sheep and kangaroos. Students will analyze decades of records of annual horn growth for thousands of harvested Stone's sheep from BC and chamois from Italy to determine how hunter selectivity, weather and other variables affect age- and sex-specific horn growth and survival. I will experimentally study the costs of reproduction in female kangaroos in collaboration with an ongoing program of artificial contraception, and examine the ecological causes and consequences of variation in litter size in brown bears. My research has important implications for conservation. It provides clues to changes in population size and structure, and long-term data to assess the impacts of global change and of management decisions on the ecology and evolution of animal populations.