Abstract 203 – Explaining recent increases of grizzly bears in central Alberta: Habitat dynamics, demographics, and translocation

John Boulanger, Gorden Stenhouse, Scott Nielsen

DNA-based inventories of 2 bear management areas in central Alberta (east of Jasper and Banff
National Parks) conducted in 2004 and 2005 revealed low densities (<5 bears/1000 km2) of
grizzly bears. This prompted conservation actions, including a moratorium on hunting, as well
as research into demographic status and potential factors limiting these populations. DNA
inventories for these 2 areas were repeated in 2014 and 2018 revealing increases of 6-7% per
year in each area. We hypothesized that these increases were due to improvements in habitat,
reduced mortality, and recipients (immigrants) from translocations of bears. We used open
spatially explicit capture recapture models, demographic modelling, as well as modelling of
change in habitat to test which mechanisms best explain local patterns of increase. Supported
mechanisms include a net increase in ungulate habitat, higher survival rates, and transplants of
bears into one of the survey areas. We identified hotspot areas of increase relative to areas of
higher habitat value and potential mortality risk. We rank these mechanisms within the context
of management objectives. Our results provide an assessment of the most likely factors
influencing increases, as well as potential methodologies that can be used for continued
monitoring of these populations.