Carnivore Re-Colonisation: Reality, Possibility and a Non-Equilibrium Century for Grizzly Bears in the Southern Yellowstone Ecosystem
Entry ID:
NRMSC_carnivorerecolonisation
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Summary
Most large native carnivores have experienced range contractions due to
conflicts with humans, although neither rates of spatial collapse nor expansion
have been well characterized. In North America, the grizzly bear (Ursus
arctos) once ranged from Mexico northward to Alaska, however its range in the
continental United States has been reduced by 95-98%. Under the ... U.S.
Endangered Species Act, the Yellowstone grizzly bear population has
re-colonized habitats outside Yellowstone National Park. We analyzed
historical and current records, including data on radio-collared bears, (i) to
evaluate changes in grizzly bear distribution in the southern Greater
Yellowstone Ecosystem over a 100-year period, (ii) to utilise historical rates
of recolonization to project future expansion trends and (iii) to evaluate the
reality of future expansion based on human limitations and land use. Analysis
of distribution in 20-year increments reflects range reduction from south to
north (1900-1940) and expansion to the south (1940-2000). Expansion was
exponential and the area occupied by grizzly bears doubled approximately every
20 years. A complementary analysis of bear occurrence in Grand Teton National
Park also suggests an unprecedented period of rapid expansion during the last
20-30 years. The grizzly bear population currently has re-occupied about 50%
of the southern GYE. Based on assumptions of continued protection and
ecological stasis, our model suggests total occupancy in 25 years.
Alternatively, extrapolation of linear expansion rates from the period prior to
protection suggests total occupancy could take > 100 years. Analyses of
historical trends can be useful as a restoration tool because they enable a
framework and timeline to be constructed to pre-emptively address the social
challenges affecting future carnivore recovery.
One of the purposes of the dataset is to predict when grizzly bear occupation
of Southern Yellowstone Ecosystem will be total.
We focused on a 24,000 square kilometer mosaic of mostly public land that is
managed by various federal and state agencies. Our analysis of changes in
grizzly bear distribution during 1900-2000 was divided into 20-year periods.
For each, we used various data sources for grizzly bear occurrence to create
digital maps of bear distribution using ArcView GIS 32. (ESRI, Redlands, CA)
We digitized reports, interviews, conflicts, mortalities and observations as
points. We created a polygon for the 1920 source data, a hand-drawn
distribution map by Merriam (1922). More methodology given in Pyare, 2004
paper.
Geographic Coverage
Spatial coordinates
| N: 45.0 |
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S: 44.0 |
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E: -110.0 |
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W: -111.0 |
Data Set Citation
Dataset Creator:
Sanjay Pyare, Steve Cain, Dave Moody, Chuck Schwartz and Joel Berger
Dataset Title:
Carnivore Re-Colonisation: Reality, Possibility and a Non-Equilibrium Century for Grizzly Bears in the Southern Yellowstone Ecosystem
Dataset Release Date:
2003
Dataset Release Place:
Bozeman, Montana
Dataset Publisher:
U.S. Geological Survey, Northern Rocky Mountain Science Center
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Temporal Coverage
Start Date:
1900-01-01
Stop Date:
2000-12-31
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Location Keywords
Science Keywords
ISO Topic Category
Quality
Analyzed data from 1900 to 2000.
Access Constraints
None
Use Constraints
None
Ancillary Keywords
Data Set Progress
Data Center
Personnel
CHARLES
SCHWARTZ
Role:
TECHNICAL CONTACT
Phone:
406 994-5043
Fax:
406 994-6416
Contact Address:
U.S. Geological Survey
City:
Bozeman
Province or State:
Montana
Postal Code:
59717
TYLER
B.
STEVENS
Role:
DIF AUTHOR
Phone:
(301) 614-6898
Fax:
301-614-5268
Email:
Tyler.B.Stevens at nasa.gov
Contact Address:
NASA Goddard Space Flight Center
Global Change Master Directory
City:
Greenbelt
Province or State:
MD
Postal Code:
20771
Country:
USA
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Related URL
Publications/References
Sanjay Pyare, Steven Cain, Dave Moody, Chuck Schwartz and Joel Berger, 2004
Carnivore re-colonisation: reality, possibility and a non-equilibrium century
for grizzly bears in the Southern Yellowstone Ecosystem Geospatial Data
Presentation Form: Journal article Animal Conservation; 7, 1-7 London, United
Kingdom. The Zoological Society of London.
http://www.nrmsc.usgs.gov/
Creation and Review Dates
DIF Creation Date:
2005-12-30
Last DIF Revision Date:
2008-05-27
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Links
