Western Arctic Caribou Herd Monitoring in the National Petroleum Reserve, Alaska

Since 1970 the size of the WAH has been monitored using the aerial photo-direct count extrapolation technique (Davis et al. 1979). A census has been conducted an average of every 3 years, and all censuses have been conducted during peak insect harassment in early July. In 1970 the WAH numbered 243,000 caribou. By 1976, when the next census was completed, the herd had declined to about 75,000 caribou - an 18% average annual rate of decline. Although many people living within the range of this herd agreed that it had declined, they felt the magnitude of the decline was much less than indicated by this census. If the 1976 census estimate was reasonably accurate, the herd then grew 13% annually until about 1990 when 416,000 caribou were counted. From 1990 to 2003, the herd continued to grow at 1-3% annually peaking at 490,000 caribou around 2003. Between 2003 and 2007 the WAH declined to 377,000 caribou - a 6% average annual rate of decline (Dau 2007). Although the WAH clearly declined from 2003 to 2007, we don't know if it declined during each of those years, perhaps in response to density dependent factors, or if it experienced 1 or 2 years of high, density-independent mortality and is still capable of stability or even slow growth. Both types of limitation could now be affecting the status of this herd. The population estimate based on the July 2009 photo-census was 348,000 which indicates a steady 4-6% decline since 2003.

Identifier
Source https://www.polardata.ca/pdcsearch/PDCSearchDOI.jsp?doi_id=12407
Metadata Access http://www.polardata.ca/oai/provider?verb=GetRecord&metadataPrefix=fgdc&identifier=12407_fgdc
Provenance
Creator Dau, Jim
Publisher Canadian Cryospheric Information Network
Contributor Polar Data Catalogue
Publication Year 2015
Rights Research programs, CCIN, or ArcticNet take no liability for the use or transmission of this data
OpenAccess true
Contact cbmp_terrestrial(at)caff.is; pdc(at)uwaterloo.ca
Representation
Language English
Format Computer file
Discipline Environmental Research
Spatial Coverage (-163.000W, 68.000S, -151.000E, 71.250N)
Temporal Coverage Begin 2000-01-01T00:00:00Z
Temporal Coverage End 9999-12-31T00:00:00Z