Adapting sampling plans to caribou distribution on calving grounds
Between 1984 and 1988, the size of the two caribou herds in northern Québec was derived by combining estimates of female numbers on calving grounds in June and composition counts during rut in autumn. Sampling with aerial photos was conducted on calving grounds to determine the number of animals per...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Septentrio Academic Publishing
1991-10-01
|
| Series: | Rangifer |
| Subjects: | |
| Online Access: | https://septentrio.uit.no/index.php/rangifer/article/view/1004 |
| _version_ | 1819126267025293312 |
|---|---|
| author | Michel Crête Louis-Paul Rivest Didier Le Hénaff Stuart N. Luttich |
| author_facet | Michel Crête Louis-Paul Rivest Didier Le Hénaff Stuart N. Luttich |
| author_sort | Michel Crête |
| collection | DOAJ |
| description | Between 1984 and 1988, the size of the two caribou herds in northern Québec was derived by combining estimates of female numbers on calving grounds in June and composition counts during rut in autumn. Sampling with aerial photos was conducted on calving grounds to determine the number of animals per km2, telemetry served to estimate the proportion of females in the census area at the time of photography in addition to summer survival rate, and helicopter or ground observations were used for composition counts. Observers were able to detect on black and white negatives over 95 percent of caribou counted from a helicopter flying at low altitude over the same area; photo scale varied between = 1:3 600 and 1:6 000. Sampling units covering less than 15-20 ha were the best for sampling caribou distribution on calving grounds, where density generally averaged » 10 individuals-km"2. Around 90 percent of caribou on calving grounds were females; others were mostly yearling males. During the 1-2 day photographic census, 64 to 77 percent of the females were present on the calving areas. Summer survival exceeded 95 percent in three summers. In autumn, females composed between 45 and 54 percent of each herd. The Rivière George herd was estimated at 682 000 individuals (± 36%; alpha = 0.10) in 1988. This estimate was imprecise due to insufficiens sample size for measuring animal density on the calving ground and for determining proportion of females on the calving ground at the time of the photo census. To improve precision and reduce cost, it is proposed to estimate herd size of tundra caribou in one step, using only aerial photos in early June without telemetry. |
| first_indexed | 2024-12-22T07:53:19Z |
| format | Article |
| id | doaj.art-6fea82a07ac24026bc8cccf08724e378 |
| institution | Directory Open Access Journal |
| issn | 1890-6729 |
| language | English |
| last_indexed | 2024-12-22T07:53:19Z |
| publishDate | 1991-10-01 |
| publisher | Septentrio Academic Publishing |
| record_format | Article |
| series | Rangifer |
| spelling | doaj.art-6fea82a07ac24026bc8cccf08724e3782022-12-21T18:33:25ZengSeptentrio Academic PublishingRangifer1890-67291991-10-0111410.7557/2.11.4.1004946Adapting sampling plans to caribou distribution on calving groundsMichel CrêteLouis-Paul RivestDidier Le HénaffStuart N. LuttichBetween 1984 and 1988, the size of the two caribou herds in northern Québec was derived by combining estimates of female numbers on calving grounds in June and composition counts during rut in autumn. Sampling with aerial photos was conducted on calving grounds to determine the number of animals per km2, telemetry served to estimate the proportion of females in the census area at the time of photography in addition to summer survival rate, and helicopter or ground observations were used for composition counts. Observers were able to detect on black and white negatives over 95 percent of caribou counted from a helicopter flying at low altitude over the same area; photo scale varied between = 1:3 600 and 1:6 000. Sampling units covering less than 15-20 ha were the best for sampling caribou distribution on calving grounds, where density generally averaged » 10 individuals-km"2. Around 90 percent of caribou on calving grounds were females; others were mostly yearling males. During the 1-2 day photographic census, 64 to 77 percent of the females were present on the calving areas. Summer survival exceeded 95 percent in three summers. In autumn, females composed between 45 and 54 percent of each herd. The Rivière George herd was estimated at 682 000 individuals (± 36%; alpha = 0.10) in 1988. This estimate was imprecise due to insufficiens sample size for measuring animal density on the calving ground and for determining proportion of females on the calving ground at the time of the photo census. To improve precision and reduce cost, it is proposed to estimate herd size of tundra caribou in one step, using only aerial photos in early June without telemetry.https://septentrio.uit.no/index.php/rangifer/article/view/1004cariboucensusaerial photographyGeorge River herdRivière GeorgeRiviere aux Feuilles |
| spellingShingle | Michel Crête Louis-Paul Rivest Didier Le Hénaff Stuart N. Luttich Adapting sampling plans to caribou distribution on calving grounds Rangifer caribou census aerial photography George River herd Rivière George Riviere aux Feuilles |
| title | Adapting sampling plans to caribou distribution on calving grounds |
| title_full | Adapting sampling plans to caribou distribution on calving grounds |
| title_fullStr | Adapting sampling plans to caribou distribution on calving grounds |
| title_full_unstemmed | Adapting sampling plans to caribou distribution on calving grounds |
| title_short | Adapting sampling plans to caribou distribution on calving grounds |
| title_sort | adapting sampling plans to caribou distribution on calving grounds |
| topic | caribou census aerial photography George River herd Rivière George Riviere aux Feuilles |
| url | https://septentrio.uit.no/index.php/rangifer/article/view/1004 |
| work_keys_str_mv | AT michelcrete adaptingsamplingplanstocariboudistributiononcalvinggrounds AT louispaulrivest adaptingsamplingplanstocariboudistributiononcalvinggrounds AT didierlehenaff adaptingsamplingplanstocariboudistributiononcalvinggrounds AT stuartnluttich adaptingsamplingplanstocariboudistributiononcalvinggrounds |