scholarly journals Traditional behaviour and fidelity to caribou calving grounds by barren-ground caribou

Rangifer ◽  
1986 ◽  
Vol 6 (2) ◽  
pp. 151 ◽  
Author(s):  
Anne Gunn ◽  
Frank L. Miller

Evidence for the fidelity of female barren-ground caribou (Rangifer tarandus spp.) of each herd to specific calving grounds is convincing. Involvement of learned behaviour in the annual return of those cows to the same calving grounds implies such actions are a form of «traditional» behaviour. Even wide variations in population size have not yet knowingly led to marked changes in size or location of calving grounds or prolonged abandonment of established ones. Rarely is the adoption of new calving grounds reported and emigration to another herd's calving ground or interchange between calving grounds has not yet been unequivocally documented. The calving experience of individual caribou and environmental pressures may modify the cow's use patterns of her calving grounds. The current definition of herds based on traditional calving grounds may require modification, if increasing caribou numbers result in changes in traditions. However, current data do not contradict either the fidelity to traditional calving grounds or the concept of herd identity based on that fidelity.

2003 ◽  
Vol 117 (3) ◽  
pp. 399 ◽  
Author(s):  
Rehaume Courtois ◽  
Jean-Pierre Ouellet ◽  
André Gingras ◽  
Claude Dussault ◽  
Laurier Breton ◽  
...  

We examined published historical information, reports on aerial surveys conducted since 1953, and harvest data collected since 1971 to describe changes in the distribution and abundance of Caribou (Rangifer tarandus) in Québec. The southern limit of the Caribou distribution diminished considerably in the late 19th century, and the decline in numbers probably continued until the 1960s and 1970s east of the 62nd meridian. South of the 49th parallel, only four small populations still persist. Despite the fact that all Caribou of the province were assigned to the same sub-species (R. t. caribou), three ecotypes with specific habitats and behaviour are found. The Barren-Ground ecotype, the only migratory form, is found north of the 52nd parallel. This ecotype currently occupies ≈ 255 000 km2 in fall and winter, mainly in the ecological subzones of the forest tundra and the taiga. The Barren-Ground Caribou was characterized by a very low abundance from the end of the 19th century until the mid-1950s, but increased markedly thereafter reaching over a million individuals at the beginning of the 1990s. Populations of the Mountain ecotype have been identified in the southeastern and, possibly, in the northeastern parts of the province. The latter Mountain population is virtually unknown. The southeastern population is sedentary and uses mainly the boreal forest. This population has decreased over the last century and currently numbers only ≈ 140 individuals. Finally, the Forest-Dwelling ecotype is found discontinuously, mainly between the 49th and 55th parallels. Its current distribution covers ≈ 235 000 km2, mainly east of the 72nd meridian. This sedentary ecotype is found almost exclusively in the boreal forest, principally in areas with long forest fire cycles. Its abundance has also decreased over the years. Large Forest-Dwelling populations still persisted during the 1950s and 1960s, but they apparently disappeared. The current abundance is not known precisely, but based on density estimates and considering the current distribution, it probably does not exceed 3000 individuals. Current data are insufficient to identify precisely the causes of the population decline, although hunting seems to be an important proximal cause.Nous avons utilisé les données historiques publiées, les rapports d’inventaires aériens réalisés depuis 1953 et les statistiques de récolte sportive colligées depuis 1971 pour décrire les changements dans la répartition et l’abondance du Caribou (Rangifer tarandus) au Québec. La limite méridionale de l’aire de répartition a beaucoup diminué à la fin du 19e siècle et la régression s’est probablement poursuivie durant les années 1960 et 1970 à l’est du 62e méridien. Au sud du 49e parallèle, on ne retrouve plus que quatre petites populations. Bien que tous les caribous du Québec soient considérés appartenir à la même sous-espèce (R. t. caribou), on distingue trois écotypes fréquentant des milieux différents et arborant des comportements spécifiques. Au nord du 52e parallèle, on retrouve l’écotype Toundrique, lequel est migrateur. Ces Caribous se répartissent sur ≈ 255 000 km2 durant l’automne et l’hiver, principalement dans les sous-zones écologiques de la toundra forestière et de la taïga. Cet écotype était peu abondant entre la fin du 19e siècle et le milieu des années 1950, mais il s’est accru considérablement pour atteindre plus d’un million d’individus au début des années 1990. Une population de l’écotype Montagnard est présente au sud-est de la province et une autre existe possiblement au nord-est. Cette dernière n’est pas bien connue. Celle du sud-est utilise principalement la forêt boréale. Cette population sédentaire a diminué considérablement depuis une centaine d’années et elle ne compte plus qu’environ 140 individus. Finalement, l’écotype Forestier est présent de façon discontinue, principalement entre les 49e et 55e parallèles. Ces Caribous sont également sédentaires. On les retrouve presque exclusivement en forêt boréale, principalement là où le cycle des feux de forêt est long. Leur répartition actuelle couvre ≈ 234 000 km2, principalement à l’est du 72e méridien. D’importantes populations forestières existaient encore durant les années 1950 et 1960, mais elles semblent avoir disparu. L’abondance actuelle n’est pas connue mais elle pourrait difficilement dépasser 3000 individus si l’on se base sur les estimations de la densité et de l’aire de répartition. Les données disponibles sont insuffisantes pour identifier les causes exactes des diminutions d’effectifs bien que la chasse semble une cause proximale importante.


2013 ◽  
Vol 2013 ◽  
pp. 1-9
Author(s):  
Song Luo ◽  
Ning Hu

Anonymity of identity-based encryption (IBE) means that given a ciphertext, one cannot distinguish the target identity from a random identity. In this paper, we thoroughly discuss the anonymity of IBE systems. We found that the current definition of anonymity is obscure to describe some IBE systems, such as Gentry IBE system. Furthermore, current definition cannot express the degree of anonymity. So we divide the degree of anonymity into weak anonymity and strong anonymity based on indistinguishability between different games. For weakly anonymous IBE systems, the target identity in a ciphertext cannot be distinguished from a random identity. For strongly anonymous IBE systems, the whole ciphertext cannot be distinguished from a random tuple. We also discuss the type of anonymity and divide it into two types. Type 1 means that a random tuple can be seen as a valid ciphertext, while type 2 cannot. Based on our new definitions, we show that three famous IBE systems, Gentry IBE system, Boyen-Waters IBE system, and Lewko IBE system, have strong but different types of anonymity.


2019 ◽  
Vol 105 (8) ◽  
pp. 794-796
Author(s):  
David Wands ◽  
Rachel Tayler ◽  
Deirdre Kelly ◽  
Fernando Pinto ◽  
Judith Helen Simpson ◽  
...  

BackgroundOur current understanding regarding the aetiology of infantile acute liver failure largely derives from studies conducted by regional liver units. This may introduce selection bias and therefore not provide a true reflection of the wider population.MethodsEvery coagulation screen with a prothrombin time ≥18 s in our centre was examined over one calendar year. All patients less than 1 year of age were included and their electronic records retrospectively reviewed.Results24 patients were identified, from 9989 coagulation screens, that fit the current definition of acute liver failure. Hypoxic birth injury and ischaemic events were the most common aetiologies. Survival was 75%.ConclusionThe ‘catch-all’ methodology employed demonstrated that acute liver failure is more common than previously reported and suggests that current data may exclude large numbers who either have more minor self-resolving disease or conversely have severe disease leading to death prior to transfer.


Rangifer ◽  
1986 ◽  
Vol 6 (2) ◽  
pp. 103 ◽  
Author(s):  
James L. Davis ◽  
Patrick Valkenburg ◽  
Rodney D. Boertje

The Delta and Yanert caribou (Rangifer tarandus granti) herds apparently maintained discrete calving areas from 1979 through 1983 (as determined by radio telemetry studies), even though substantial intermixing occurred during other seasons. Also, the Delta herd apparently used a single traditional calving area from the 1950's through 1983, based on results of aerial surveys and 1979-83 telemetry studies. Calving distribution in 1984 changed dramatically; 5 of 25 radio-collared Delta herd cows ^3 years old and 5 of 24 radio-collared Delta herd cows <3 years old were located in the calving area of the Yanert herd, 72 km west-southwest of the traditional Delta herd calving area. Use of traditional, separate calving areas resumed for the two herds in 1985. One implication of these data is that the current definition of a caribou herd may not always apply. A second implication is that current models of caribou socioecology, based largely on the concepts of traditional use of calving grounds, herd identity/fidelity, and dispersal, inadequately predict or explain all empirical observations. An evolving model of optimal and dynamic use of space can help refine current models of caribou socioecology.


2017 ◽  
Vol 1 (1) ◽  
pp. 15-31
Author(s):  
Francisco Xavier Morales

The problem of identity is an issue of contemporary society that is not only expressed in daily life concerns but also in discourses of politics and social movements. Nevertheless, the I and the needs of self-fulfillment usually are taken for granted. This paper offers thoughts regarding individual identity based on Niklas Luhmann’s systems theory. From this perspective, identity is not observed as a thing or as a subject, but rather as a “selfillusion” of a system of consciousness, which differentiates itself from the world, event after event, in a contingent way. As concerns the definition  of contents of self-identity, the structures of social systems define who is a person, how he or she should act, and how much esteem he or she should receive. These structures are adopted by consciousness as its own identity structures; however, some social contexts are more relevant for self-identity construction than others. Moral communication increases the probability that structure appropriation takes place, since the emotional element of identity is linked to the esteem/misesteem received by the individual from the interactions in which he or she participates.


Entropy ◽  
2018 ◽  
Vol 20 (8) ◽  
pp. 572
Author(s):  
Pier Bissiri ◽  
Stephen Walker

The current definition of a conditional probability enables one to update probabilities only on the basis of stochastic information. This paper provides a definition for conditional probability with non-stochastic information. The definition is derived by a set of axioms, where the information is connected to the outcome of interest via a loss function. An illustration is presented.


Rangifer ◽  
1990 ◽  
Vol 10 (3) ◽  
pp. 257 ◽  
Author(s):  
Donald C. Thomas ◽  
Samuel J. Barry

The age-specific fecundity of the Beverly herd of barren-ground caribou (Rangifer tarandus groenlandicus) was monitored each winter from 1979-80 through 1986-87. Fecundity in 840 females increased with age from 12% in yearlings to 86% at age 5 years and it did not decline in old (> 11 yr) females. Significant variations occurred among winters and even between two subherds in one winter. Reproductive abnormalities were detected in 2 of 840 females and a probable resorption in 1 of 420 females collected in March. Only about 5% of the fetuses were conceived late, possibly by repeat ovulators. Combining survival and fecundity data yielded age-specific calf production, which indicated that, for example, 54% of calves were born to females 3-6 years old.


Rangifer ◽  
1989 ◽  
Vol 9 (1) ◽  
pp. 9 ◽  
Author(s):  
Katherine L. Parker

<p>Body weights, leg lengths, and surface area were monitored for bottle-raised barren-ground caribou calves (Rangifer tarandus granti) from the Porcupine herd up to 1 year of age. Body weights were compared with maternally-raised calves from the same cohort in the wild and from the Delta herd. A successful feeding regime for bottle-raising caribou calves is presented.</p><p>Veksthastigheter og morfologiske m&aring;l hos Porcupine karibu-kalver.</p><p>Abstract in Norwegian / Sammendrag: Kroppsvekter, visse knokkel-lengder og kropps-overflate areal ble m&aring;lt hos flaske-oppf&oslash;dde kalver av barren-ground karibu (Rangifer tarandus granti) fra Porcupine-stammen opp til 1 &aring;rs alder. Kroppsvekter ble sammelignet med normalt oppf&oslash;dde kalver av samme type i det fri og fra Delta-stam-men. Det presenteres et vellykket system for flaske-oppforing av karibu-kalver.</p><p>Porcupine-lauman karibuvasojen kasvunopeus ja morfologiset mitat.</p><p>Abstract in Finnish / Yhteenveto: Porcupine -lauman pulloruokinnalla olleiden tundrakaribuvasojen ruumiinpainot, jalanpituu-det ja ruumiin pinta-alat mitattiin 1 vuoden ik&auml;&auml;&auml;n saakka. Ruumiinpainoja verrattiin vastaaviin luonnon-oloissa kasvaneisiin saman lauman ja Delta -lauman vasoihin. Tutkimus kuvaa toimivan vasojen pulloruo-kintamenetelm&auml;n.</p>


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