Survival of radio-collared caribou (<i>Rangifer tarandus caribou</i>) from the George River herd, Nouveau-Québec – Labrador

Hearn, Brian J.; Luttich, Stuart N.; Crête, Michel; Berger, Maria B.

doi:10.1139/z90-041

Cited by 32 publications

(45 citation statements)

References 37 publications

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“…We inferred a death to have occurred when the satellite data indicated that a caribou had not moved for several days (Schaefer et al, 1999). Although evidence such as disarticulated carcasses, crushed long bones, or, if only the collar was retrieved, tooth marks or blood on the collar, indicated predation in some cases (Hearn et al, 1990;Schaefer et al, 1999), the long time interval between caribou death and collar retrieval precluded definitive identification of cause of death in several cases. Therefore, we consider here only deaths owing to harvest by humans and deaths assumed to be from natural causes (i.e., occurring far from human settlements and not associated with known hunting activities).…”

Section: Survivalmentioning

confidence: 99%

Sea Ice and Migration of the Dolphin and Union Caribou Herd in the Canadian Arctic: An Uncertain Future

Poole¹,

Gunn²,

Patterson³

et al. 2010

ARCTIC

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ABSTRACT. Caribou (Rangifer tarandus groenlandicus × pearyi) of the Dolphin and Union herd migrate across the sea ice between Victoria Island and the adjacent Canadian Arctic mainland twice each year, southward in fall-early winter and northward in late winter-spring. As a result of warmer temperatures, sea ice between Victoria Island and the mainland now forms 8 -10 days later than it did in 1982, raising questions about the impact of delayed ice formation on the ecology of the herd. We examined movements of female Dolphin and Union caribou as they relate to sea-ice crossings using four satellite collar datasets (46 caribou) obtained between 1987 and 2006. Since the late 1980s, Dolphin and Union caribou have been moving by early October to the southern coast of Victoria Island, where they stage until sea-ice formation allows migration across the sea ice to winter range on the mainland. Caribou spending the summer farther north on Victoria Island arrive later at the coast, which shortens their time spent on the staging area. During the study period, the collared caribou began crossings as soon as sea-ice formation allowed. Most caribou departed from just a few areas and tended to use the same departure areas each year. Highest mortality occurred during the fall-early winter ice crossing and in mid to late winter. Our research raises the question of how the Dolphin and Union caribou will persist in supporting harvesting if the crossing becomes riskier for them or if the seasonal migrations between Victoria Island and the mainland are interrupted.Key words: caribou, Rangifer, Dolphin and Union herd, migration, sea ice, climate, satellite collar, Canada, Nunavut RÉSUMÉ. Les caribous (Rangifer tarandus groenlandicus × pearyi) du troupeau Dolphin-et-Union migrent en passant sur la glace de mer entre l'île Victoria et la partie continentale adjacente de l'Arctique canadien deux fois par année, se dirigeant vers le sud à l'automne et au début de l'hiver, et vers le nord à la fin de l'hiver et au printemps. En raison des températures plus chaudes, la glace de mer entre l'île Victoria et la partie continentale se forme maintenant de huit à dix jours plus tard qu'en 1982, ce qui a pour effet de soulever des questions sur les incidences de la formation tardive de la glace sur l'écologie du troupeau. Nous avons examiné les mouvements des caribous femelles de Dolphin-et-Union pendant qu'elles traversaient la glace de mer à l'aide de quatre ensembles de données obtenus par colliers-satellites (46 caribous) entre 1987 et 2006. Depuis la fin des années 1980, les caribous de Dolphin-et-Union se déplacent vers le début d'octobre vers la côte sud de l'île Victoria, où ils transitent jusqu'à ce que la formation de la glace permette la migration pour passer l'hiver sur la partie continentale. Les caribous qui passent l'été plus au nord sur l'île Victoria arrivent à la côte plus tard, ce qui a pour effet de raccourcir le temps qu'ils passent en halte migratoire. Au cours de la période visée par l'étude, les caribous dotés d'un collie...

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Section: Survivalmentioning

confidence: 99%

Sea Ice and Migration of the Dolphin and Union Caribou Herd in the Canadian Arctic: An Uncertain Future

Poole¹,

Gunn²,

Patterson³

et al. 2010

ARCTIC

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“…Caribou from the Riviere George herd have been equipped with radio collars since the autumn 1983 and monitored animals appear representative of the entire herd (Hearn et al 1990). Their location was determined a few days before photography.…”

Section: Proportion Of Females On Calving Grounds and Summer Survivalmentioning

confidence: 99%

PART B: 5th American Caribou Workshop, 19-21 March 1991, Yellowknife, Northwest Territories, Canada.

Skjenneberg¹

1991

Ran

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The secondary effects of these habitat changes, (i.e. increased roads leading to increased hunting and poaching, and increased early succession habitat leading to increased alternate prey/predator densities) has led in some cases to the total loss or decreased size of local herds. Three ecotypes of woodland caribou are described and their relative distribution delineated. These ecotypes live under different environmental conditions and require different inventory and management approaches. Woodland caribou herds in northern B.C., Yukon and N.W.T. generally are of good numbers and viable (stable or increasing), and management primarily is directed at regulating human harvest and natural predation to prevent, herd declines. Land use activities such as logging or energy development are not extensive. Managers in southern caribou ranges stress the need for a better understanding of caribou population stability within mixed prey/predator regimes; how habitat changes (eg. through logging) affect these regimes; and how to develop effective land use guidelines for resource extraction that can sustian caribou populations and maintain resource industries. Caribou managers have suggested that herds may be priorized for research and management efforts. Unstable, remnant populations may be left to their own fate. The limited research dollars available and difficult management decisions should be applied to caribou herds that are apparently sustainable and provide the greatest potential for long-term viability.

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“…The Rivière George caribou herd in northern Québec and Labrador increased at an annual rate of more than 10% in the period from 1954 to 1986, and seems to have stabilized at more than 680 000 individuals thereafter (Messier et al, 1988;Hearn et al, 1990;Couturier et al, 1996; situated on the tundra plateaus of the Rivière George (Messier et al, 1988;Crête et al, 1990a). For most North American ungulate species, winter habitats are normally more critical, in terms of forage availability and quality, than summer habitats (Messier et al, 1988).…”

Section: Introductionmentioning

confidence: 99%

In Vitro Digestibilities of Summer Forages Utilized by the Rivière George Caribou Herd

Côté¹

1998

ARCTIC

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ABSTRACT. The Rivière George caribou herd (northern Québec-Labrador, Canada) is thought to be regulated by forage limitations in its summer range. In such a situation, digestibilities of plants may strongly affect the diet choice and physical condition of animals. In vitro dry matter disappearance (IVDMD) of the most important summer forages of the Rivière George caribou herd was determined during fermentation periods of 12, 24, and 48 h using rumen fluid collected from a Holstein cow. IVDMD values for Cyperaceae (Eriophorum angustifolium and Carex rariflora), and shrubs (Betula glandulosa and Vaccinium uliginosum) collected in July and August were higher for long fermentation periods (48 h) than for shorter ones (12 and 24 h). Plants collected in early summer were also more digestible than those collected in late summer. Contrary to my prediction, both Cyperaceae were more digestible than the two shrubs in mid-July. However, no difference occurred in early August. The fermentation period did not affect the IVDMD of lichens; maximum digestibility was attained after 12 h. Alectoria ochroleuca and Cetraria spp. were more digestible than Cladina rangiferina, Cladina stellaris, and Stereocaulon paschale, likely because of their lower fibre content. These results suggest that the preference of caribou for Cladina spp. is not based on digestibility, but probably on the fact that these species are abundant in the Rivière George area. Variations in IVDMD seem to be explained by plant phenology, because longer fermentation periods were necessary to attain a high level of digestibility as summer progressed. Plant digestibility alone cannot explain caribou summer diet. Other variables such as plant constituents (e.g., protein) and relative abundance must also be considered.Key words: caribou, Cyperaceae, digestibility, fermentation, foraging ecology, in vitro, lichens, nutrition, Québec, Rangifer tarandus RÉSUMÉ. Il a été suggéré que l'abondance du troupeau de caribous de la rivière George (Québec nordique-Labrador, au Canada) était régulée par la disponibilité de nourriture dans les habitats d'été. Dans un tel système, la digestibilité des plantes peut affecter de façon importante le régime alimentaire et la condition physique des animaux. La disparition in vitro de la matière sèche (DIVMS) des principales espèces végétales composant la nourriture estivale des caribous de la rivière George a été déterminée durant des périodes de fermentation de 12, 24 et 48 heures, à l'aide de jus de rumen provenant d'une vache Holstein. Les valeurs de DIVMS des cypéracées (Eriophorum angustifolium et Carex rariflora) et des arbustes (Betula glandulosa et Vaccinium uliginosum) récoltés en juillet et août étaient plus élevées pour de longues périodes de fermentation (48 heures) que pour de courtes périodes (12 et 24 heures). Les plantes récoltées tôt durant l'été étaient aussi plus digestes que celles récoltées tard. Contrairement aux prédictions, les deux espèces de cypéracées étaient plus digestes que les deux espèces d'arbustes à la mi-...

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Survival of radio-collared caribou (Rangifer tarandus caribou) from the George River herd, Nouveau-Québec – Labrador

Cited by 32 publications

References 37 publications

Sea Ice and Migration of the Dolphin and Union Caribou Herd in the Canadian Arctic: An Uncertain Future

Sea Ice and Migration of the Dolphin and Union Caribou Herd in the Canadian Arctic: An Uncertain Future

PART B: 5th American Caribou Workshop, 19-21 March 1991, Yellowknife, Northwest Territories, Canada.

In Vitro Digestibilities of Summer Forages Utilized by the Rivière George Caribou Herd

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