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Journal
Publications
Johnson, C.J., M.S. Boyce, R.L. Case, H.D.
Cluff, R.J. Gau, A. Gunn, and
R. Mulders. 2005. Cumulative effects on human developments on Arctic
wildlife. Wildlife Monograph no. 160. 36 pages.
Abstract:
Recent
discoveries of diamondiferous kimberlite deposits in the Canadian central
Arctic led to unprecedented levels of mineral exploration and development.
The cumulative effects of such activities are an issue of concern for
government regulatory agencies, regional and international conservation
organizations, wildlife managers, and indigenous peoples. We investigated
the impacts of human activities and associated infrastructure on the
distribution of Arctic wildlife in 190,000 km2 of the Taiga Shield and
Southern Arctic ecozones 400 km northeast of Yellowknife, Northwest
Territories, Canada.
We used
covariates for vegetation, interspecific interactions, and human disturbance
features to develop seasonal resource-selection models for barren-ground
caribou (Rangifer tarandus groenlandicus), gray wolves (Canis
lupus), grizzly bears (Ursus arctos), and wolverines (Gulo
gulo). We used an information-theoretic approach to select 11 seasonal
models for the 4 species. Nine models were good predictors of species
occurrence and vegetation covariates were important components of all
models. Mines and other major developments had the largest negative affect
on species occurrence, followed by exploration activities, and outfitter
camps. We did not, however, record strong avoidance responses by all species
during all seasons to each disturbance type (i.e., major developments,
mineral exploration sites, outfitter camps) and for some models carnivores
selected for disturbance features (i.e., occurred closer to sites than
comparison random locations). We used a geographic information system (GIS)
to extrapolate each seasonal resource-selection model to the study area and
quantified the reduction in habitat effectiveness as a function of modeled
and hypothetical disturbance coefficients. Across all models, grizzly bears
and wolves demonstrated the strongest negative response to disturbance and
corresponding reduction in habitat effectiveness, followed by caribou and
wolverines. The largest seasonal effect was recorded for caribou during the
post-calving period, where model coefficients suggested a 37% reduction in
the area of the highest quality habitats and an 84% increase in the area of
the lowest quality habitats.
This is the
first study to demonstrate the cumulative effects of multiple sources of
human disturbance for caribou, wolves, bears, and wolverines found across
the Canadian central Arctic. Resource selection models and corresponding
maps of important habitats can be used to guide and evaluate future
development proposals and can serve as a component of a regional
environmental assessment. However, inferences from largescale modeling
efforts should be carefully evaluated when making detailed prescriptive
recommendations. Study design, sample size, reliability of GIS data, and
accuracy of model predictions are important considerations when evaluating
the strength and scale of inference of correlative resource selection
studies such as this. We recommend that regional cumulative effects analyses
serve as the coarsest framework for understanding the impacts of human
developments on wide-ranging animals. Monitoring and research should be
conducted at various behavioral scales leading to a body of knowledge that
fully describes the range and strength of impacts resulting from cumulative
effects. |
