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Frank van Manen is an emeritus ecologist with the USGS who blends his research interest in large carnivores with landscape ecology. Frank was team lead of the Interagency Grizzly Bear Study Team from 2012-2025 and he is continuing to work with the team.
Frank's research focus is on 1) grizzly bear and black bear ecology and management, 2) demographic models to inform large carnivore management, 3) resource selection and energy landscapes, 4) wildlife genetics, and 5) international bear conservation.
Formerly, Frank spent 12 years with the USGS Leetown Science Center specializing in responses of mammals to landscape changes, management of large carnivores, and habitat models to support protection and restoration of plants and trees.
For available articles, click on the Publications tab.
Sequential estimates of occupied ranges for grizzly bears in the Greater Yellowstone Ecosystem during 1990–2022 (Dellinger et al. 2023). Range extents are based on methods described in Bjornlie et al. (2014).
Sequential estimates of occupied ranges for grizzly bears in the Greater Yellowstone Ecosystem during 1990–2022 (Dellinger et al. 2023). Range extents are based on methods described in Bjornlie et al. (2014).
Sequential estimates of occupied ranges for grizzly bears in the Greater Yellowstone Ecosystem during 1990–2018. Range extents are based on methods described in Bjornlie et al. (2014).
Sequential estimates of occupied ranges for grizzly bears in the Greater Yellowstone Ecosystem during 1990–2018. Range extents are based on methods described in Bjornlie et al. (2014).
Grand Teton National Park in autumn.
When looking for a place to set up a capture location, biologists look for existing bear sign such as scratches on trees and bear scat. Sometimes traps are set in areas that have no obvious bear sign to determine if indeed bears are present.
When looking for a place to set up a capture location, biologists look for existing bear sign such as scratches on trees and bear scat. Sometimes traps are set in areas that have no obvious bear sign to determine if indeed bears are present.
USGS biologists collecting biological information from a grizzly bear they have captured. Biologists collect hair samples for genetic analysis, weigh the bear, and gather numerous measurements of the body, such as the head, paws, claws, teeth, etc. Overall condition of the bear is assessed as well, including a body fat measurement.
USGS biologists collecting biological information from a grizzly bear they have captured. Biologists collect hair samples for genetic analysis, weigh the bear, and gather numerous measurements of the body, such as the head, paws, claws, teeth, etc. Overall condition of the bear is assessed as well, including a body fat measurement.
Sequential estimates of occupied ranges for grizzly bears in the Greater Yellowstone Ecosystem during 1990–2022 (Dellinger et al. 2023). Range extents are based on methods described in Bjornlie et al. (2014).
Sequential estimates of occupied ranges for grizzly bears in the Greater Yellowstone Ecosystem during 1990–2022 (Dellinger et al. 2023). Range extents are based on methods described in Bjornlie et al. (2014).
Sequential estimates of occupied ranges for grizzly bears in the Greater Yellowstone Ecosystem during 1990–2018. Range extents are based on methods described in Bjornlie et al. (2014).
Sequential estimates of occupied ranges for grizzly bears in the Greater Yellowstone Ecosystem during 1990–2018. Range extents are based on methods described in Bjornlie et al. (2014).
Grand Teton National Park in autumn.
When looking for a place to set up a capture location, biologists look for existing bear sign such as scratches on trees and bear scat. Sometimes traps are set in areas that have no obvious bear sign to determine if indeed bears are present.
When looking for a place to set up a capture location, biologists look for existing bear sign such as scratches on trees and bear scat. Sometimes traps are set in areas that have no obvious bear sign to determine if indeed bears are present.
USGS biologists collecting biological information from a grizzly bear they have captured. Biologists collect hair samples for genetic analysis, weigh the bear, and gather numerous measurements of the body, such as the head, paws, claws, teeth, etc. Overall condition of the bear is assessed as well, including a body fat measurement.
USGS biologists collecting biological information from a grizzly bear they have captured. Biologists collect hair samples for genetic analysis, weigh the bear, and gather numerous measurements of the body, such as the head, paws, claws, teeth, etc. Overall condition of the bear is assessed as well, including a body fat measurement.