Ecology of Boreal Caribou of the Dehcho Region, NWT

Nicholas C. Larter & Danny G. Allaire

© John Nagy

Presented at the NWT Environmental Research & Monitoring Results Workshop: Dehcho Region, Fort Simpson, 19-20 January, 2016.

Discuss openly wildlife research and monitoring programs in the Dehcho that are important to decision makers.

State of boreal caribou population a concern of local First Nations and decision makers.

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Dehcho Boreal Caribou Study

Initiated in 2004 an ongoing study into ecology of boreal caribou in Dehcho. First Nation Partners include: Sambaa K’e DB, Jean Marie River FN, Denendeh Harvesters Committee of Líídlįį Kue FN, Fort Simpson Métis, Pehdzeh Ki FN, Nahanni Butte DB, and Acho Dene Koe Band. ENR contracted various laboratories for the analysis of biological samples.

Approximately 80,000km2

NWT Western Biophysical (GNWT), Environment Canada, ENR, CIMP.

Where do they go when we do not see them? What are they doing?

Where and when do they calve?

The need to know more about the elusive boreal caribou. Sambaa K’e Dene Band

Critical need for baseline information on boreal caribou population prior to resource development.

The combination of SK with TK would provide the best information so someone could look out for boreal

caribou.

Extensive consultation between Sambaa K’e DB and ENR resulted in designing a monitoring program that would rely heavily on information provided by collared boreal caribou females. First collars deployed in March 2004; annually since except 2011. Subsequent years other First Nations saw the value of the program in their traditional areas and the program expanded. At community meetings/regional workshops technological advances in collars and changes to handling procedures have been evaluated and implemented; capture/collar left to professionals.

All communities in the Dehcho were and continue to be involved in the design of the program that adapts to landscape changes, technological advances, and changes in local questions. All communities decide where they would like animals to be collared in their traditional areas and areas where not to collar. Sambaa K’e DB used location data from this program to do a community-based study on boreal caribou. ENR provided location data and technical expertise for their study.

Community Involvement

Calving Female caribou show a distinctive movement pattern when calving. Can determine where, when and if a calf was born based solely on location data; no need do air surveys. Less animal harassment and get better data on calf production/survival. Can better address site fidelity. Indicates close to 100% conception; 251 calves born out of 264 possible calving events. Indicates individuals bear young at almost the same date annually.

Where They Go In April female caribou move a great deal as they disperse across the range to have calves (in small groups) in May. Calving occurs on islands. Wrigley TK said some calve in the mountains of the McConnell Range which collared females did even when there was snow cover. Caribou remain in small groups, generally not moving far from where they calved all summer unless they lose their calf. Daily movement is reduced and caribou use more denser forested areas in mid-winter. TK indicated little movement of caribou across the Mackenzie River; no collared animals have done so.

Group Size

During the mid-winter capture operations snow depth is measured at each capture site throughout the Dehcho. Annual aerial surveys conducted within 3 weeks of the capture. Collared animals are relocated, group size is recorded and caribou are classified by sex and age. Ten years of data shows a positive relationship between snow depth and group size, consistent with TK.

Unexpected Findings

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Female caribou can live to 17 years old, and can rear calves at 16 years of age. Some caribou in the Dehcho have been exposed to the pathogenic bacterium Erysipelothrix rhusiopathiae. Female caribou are fatter in the Dehcho than their counterparts in NEBC during mid-winter.

Variability in adult female survival and recruitment and population impacts.

Knowledge Contributions and Significance

Results are currently being used in: The development of boreal caribou range plans as part of the National Recovery strategy. National population demographic modeling by Environment Canada. The development of Forest Management Agreements by GNWT. and have contributed to an enhanced analytical tool for determining when and where caribou calve based solely on location data. Much more accurate parameters available for population modeling.

Creative duty cycle programming to allow collars to have a life span that covers five calving periods. Reduces the number of collars and collared individuals required while providing better knowledge on fidelity. Provided new information on the ecology of boreal caribou in the Dehcho, unique to boreal caribou populations studied elsewhere. Living to 17 years and calving at 16 years. Almost 100% pregnancy and successful calving, offsetting low calf survival.

Knowledge Contributions and Significance

Key Outputs

http://www.enr.gov.nt.ca/sites/default/files/progrep11_dehcho_boreal_caribou_study_2015.pdf

Annual Progress Report

Written with our First Nations partners in mind (limited scientific jargon). Documents calving timing and location and sex and age classification survey results. Provides estimates of calf production, adult female and calf survival, recruitment and annual rate of population increase. Lab results on pregnancy, disease, parasites, animal fatness, age at death. Provides summary information on each individual caribou collared in the study.

Hard copies are distributed to all FN partners, readily available on ENR website.

Range Use Maps

Provided to First Nations partners on a quarterly basis. Important to note they do not show real time locations which are considered highly sensitive data by ENR and First Nation partners. Show areas used over a 3 month period by individual female caribou. Maintains a connection with the study and the seasonal changes in use of the landscape and different traditional use areas by caribou.

Program Presentations and Updates

Regional Wildlife Workshops every 2 years • Delegates from all First Nations partners in attendance. • A sharing of results and open critique of the program by delegates. • Program modifications discussed/incorporated as action items.

North American Caribou Workshops every 2 years • National audience for sharing knowledge about region. • Often accompanied by community members. • Promote the combination of scientific/traditional knowledge.

Community Meetings as and when requested • Intimate sharing of results and knowledge at the local level.

Key Messages Some questions can only be answered by

having collared animals – collar only as many individuals as needed and respect those individual caribou for providing knowledge.

Baseline information over uninterrupted time series is critical.

For wide ranging species baseline information must be collected at the landscape level.