Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
55
result(s) for
"Arctic hare."
Sort by:
Complete mitochondrial genome of the Arctic hare, Lepus arcticus
In this study, we report on the complete mitochondrial genome of the Arctic hare, Lepus arcticus (Leporidae; Lagomorpha) a large lagomorph endemic to the northernmost regions of Greenland. The complete mitogenome of L. arcticus was 16,972 bp long and was typical of genus Lepus mitogenomes in genomic content and structure, as the entire mitogenome contained 13 protein-coding genes (PCGs), two ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, and one control region. The phylogenetic analysis of the Arctic hare within Leporidae confirmed the sister relationship among Lepus species. This mitogenome sequence will provide a useful resource for investigations of biogeography, phylogenetic distance, and evolutionary history in lagomorphs.
Journal Article
Enhancement of local species richness in tundra by seed dispersal through guts of muskox and barnacle goose
The potential contribution of vertebrate-mediated seed rain to the maintenance of plant community richness in a High Arctic ecosystem was investigated. We analyzed viable seed content in dung of the four numerically most important terrestrial vertebrates in Northeast Greenland - muskox (Ovibos moschatus), barnacle goose (Branta leucopsis), Arctic fox (Alopex lagopus) and Arctic hare (Lepus arcticus). High numbers of plant propagules were found in the dung of muskox and barnacle goose. Seeds of many plant species were found in the faeces of one vertebrate species only. Propagule composition in barnacle goose droppings was relatively uniform over samples, with a high abundance of the nutritious bulbils of Polygonum viviparum (Bistorta vivipara), suggesting that geese have a narrow habitat preference and feed selectively. Propagule composition in muskox dung was diverse and heterogeneous among samples, suggesting a generalist approach in terms of food selection and the haphazard ingestion of plant propagules with foliage. The species composition of plant propagules in dung samples was different from that of the receiving plant communities (in terms of the Sørensen and Czekanowski dissimilarity indices), and dung deposition, especially by muskox, often brought new species to the receiving community. The results suggest that endozoochorous propagule dispersal in the Arctic has a great potential in the generation and maintenance of local species richness, albeit being little specialized. It is further suggested that endozoochory is an important means of long-distance dispersal and, thereby, of plant migration in response to climate change.
Journal Article
Revised distribution of an Alaskan endemic, the Alaska Hare ( Lepus othus ), with implications for taxonomy, biogeography, and climate change
The Alaska Hare (Lepus othus Merriam 1900) is the largest lagomorph in North America but remains one of the most poorly studied terrestrial mammals on the continent. Its current distribution is restricted to western Alaska south of the Brooks Range, but historical accounts from north of the Brooks Range (the North Slope) have led to confusion over its past, present, and predicted future distributions. To determine if L. othus occurs or historically occurred on the North Slope, we surveyed museum collections, vetted observational accounts, and produced a spatial distribution model based on the resulting georeferenced records. We located a historic specimen long presumed lost that suggests the occurrence of L. othus on the North Slope as recently as the late 1800s. We also uncovered evidence of L. othus and (or) Mountain Hare (Lepus timidus Linnaeus 1758) on several islands in the Bering Sea, raising the possibility of recurring gene flow between these closely related species across seasonal ice connecting Asia and North America. While our results paint a more complete picture of the current distribution of L. othus, persistent uncertainties surrounding its taxonomic status and potential northward range shift onto lands reserved for oil and gas development call for additional study.
Journal Article
Annual Arctic Wolf Pack Size Related to Arctic Hare Numbers
During the summers of 2000 through 2006,1 counted arctic wolf (Canis lupus arctos) pups and adults in a pack, arctic hares (Lepus arcticus) along a 9 km index route in the area, and muskoxen (Ovibos moschatus) in a 250 km 2 part of the area near Eureka (80 ° N, 86 ° W), Ellesmere Island, Nunavut, Canada. Adult wolf numbers did not correlate with muskox numbers, but they were positively related (r = 0.89;p < 0.01 ) to an arctic hare index. This is the first report relating wolf numbers to non-ungulate prey. /// Pendant les étés 2000 à 2006, j'ai compté les jeunes loups arctiques et les adultes (Canis lupus arctos) d'une bande, les lièvres arctiques (Lepus arcticus) le long d'une route indexée de 9 km dans la région, et les boeufs musqués (Ovibos moschatus) dans une zone de 250 km 2 près d'Eureka (80 ° N, 86 ° O), sur l'île d'Ellesmere, au Nunavut, Canada. Le nombre de loups adultes ne corrélait pas avec le nombre de boeufs musqués, mais il était relié de manière positive (r = 0,89; p < 0,01) à un index de lièvres arctiques. Il s'agit du premier rapport établissant un lien entre le nombre de loups et des proies non ongulées.
Journal Article
Decline and Recovery of a High Arctic Wolf-Prey System
A long-existing system of wolves (Canis lupus), muskoxen (Ovibos moschatus), and arctic hares (Lepus arcticus) in a 2600 km² area of Canada's High Arctic (80°N latitude) began collapsing in 1997 because of unusual adverse summer weather but recovered to a level at which all three species were reproducing by 2004. Recovery of wolf presence and reproduction appeared to be more dependent on muskox increase than on hare increase. /// Un vieux système biologique composé de loups (Canis lupus), de boeufs musqués (Ovibos moschatus) et de lièvres arctiques (Lepus arcticus), occupant 2600 km² de l' Extrême-Arctique canadien (80° de latit. N.), a commencé à s'effondrer en 1997 en raison d'intempéries estivales anormales, mais il s'est rétabli à un niveau qui permettait aux trois espèces de se reproduire en 2004. Le rétablissement de la présence et de la reproduction du loup semble plus dépendre de l'augmentation du boeuf musqué que de celle du lièvre.
Journal Article
Resource Partitioning by Mammalian Herbivores in the High Arctic
Willow (Salix arctica) and sedges (Carex stans and Eriophorum triste) were the dominant plants available as forage for herbivores in the high Arctic of Greenland. Willow leaves were of high quality as forage in early stages, of phenology, but crude protein and digestibility declined markedly by late stages whereas sedges, remained high in forage quality throughout the growing season. Densities of fecal pellets indicated that muskoxen (Ovibos moschatus) made heaviest use of sedge-dominated vegetation types in both winter and summer, although increased use of willow communities was observed in early summer. Hares (Lepus arcticus) favored willow-dominated communities in both winter and summer. Evidence of collared lemming (Dicrostonyx groenlandicus) winter use was mainly in willow-dominated communities where snow had accumulated, whereas in summer they were present in drier habitats dominated by willows, but with greater plant diversity. Analyses of plant tissues in feces indicated that graminoids composed over 60% of the diet of muskoxen in winter and over 40% in summer. Willows were of nearly equal importance in the muskox diet in summer, and forbs, Dryas integrifolia, and moss collectively composed over 20% of the diet in both summer and winter. Grass accounted for nearly 50% of the diet of hares in both summer and winter, with willows, forbs, and moss accounting for most of the remainder. Willows and graminoids dominated the diet of lemmings, with willows being somewhat more important in summer and graminoids in winter. Moss was a noteworthy dietary component of lemmings. Differences in body and digestive-tract morphology among the three mammalian herbivores account for differences in locomotive efficiency, predator avoidance, and foraging efficiency which interact with vegetation quality, density, and patchiness. The resulting patterns of use of the landscape result in minimal overlap in use of forage resources and help to explain the distribution and co-existence of high Arctic herbivores.
Journal Article
Lack of Reproduction in Muskoxen and Arctic Hares Caused by Early Winter?
A lack of young muskoxen (Ovibos moschatus) and arctic hares (Lepus arcticus) in the Eureka area of Ellesmere Island, Northwest Territories (now Nunavut), Canada, was observed during summer 1998, in contrast to most other years since 1986. Evidence of malnourished muskoxen was also found. Early winter weather and a consequent 50% reduction of the 1997 summer replenishment period appeared to be the most likely cause, giving rise to a new hypothesis about conditions that might cause adverse demographic effects in arctic herbivores. /// Durant l'été 1998, et ce, à la différence de la plupart des années depuis 1986, on a relevé un manque déjeunes boeufs musqués (Ovibos moschatus) et de lièvres arctiques (Lepus arcticus) dans la région d'Eureka de l'île d'Ellesmere (Territoires du Nord-Ouest [maintenant Nunavut], au Canada). On a aussi découvert des preuves de malnutrition chez le boeuf musqué. La cause la plus probable semble être un hiver hâtif et la baisse résultante de 50 p. cent de la période de restauration estivale en 1997, ce qui donne lieu à une nouvelle hypothèse sur les conditions qui pourraient avoir des répercussions démographiques nuisibles chez les herbivores de l'Arctique.
Journal Article
Comparative Winter Habitat Use and Associations among Herbivores in the High Arctic
We studied winter habitat use and interspecific associations among large-and medium-sized herbivores on southeastern Victoria Island, Arctic Canada, by documenting the deposition of feces in relation to vegetation. Associations between ptarmigan (Lagopus spp.), arctic hares (Lepus arcticus), caribou (Rangifertarandus), and muskoxen (Ovibos moschatus) were assessed using the Jaccard Index (JI) and X² at two scales, i. e., with 1 m² and 1 ha as sampling units. JI values for species pairs were greater at the larger scale, but X² revealed significant (positive) associations only at the smaller scale and only between arctic hares and caribou and between arctic hares and ptarmigan. Comparative use of habitats was described with respect to vegetation by canonical correspondence analysis (CCA). Ptarmigan and muskoxen were most strongly correlated with lowland vegetation and caribou with upland vegetation; arctic hares were intermediate. CCA also indicated rather wide separation in the multi variate space, further suggesting distinct patterns of habitat use. The results imply that these species were segregated in their use of resources in this High Arctic environment. /// On a étudié l'utilisation de l'habitat hivernal et les associations biotiques parmi les grands et moyens herbivores du sud-est de l'île Victoria située dans l'Arctique canadien, en étudiant l'emplacement des crottes par rapport à la végétation. À l'aide de l'index Jaccard (IJ) et de X² à deux échelles (c.-à-d. en prenant 1 m² et 1 ha comme unités d'échantillonnage), on a évalué les associations entre le lagopède (Lagopus spp), le lièvre arctique (Lepus arcticus), le caribou (Rangifer tarandus) et le boeuf musqué (Ovibos moschatus). Les valeurs de IJ pour les paires d'espèces étaient plus élevées à grande échelle, mais X² ne montrait des associations notables (positives) qu'à petite échelle et seulement entre le lièvre arctique et le caribou ainsi qu'entre le lièvre arctique et le lagopède. On a décrit l'utilisation comparative des habitats en rapport avec la végétation par analyse de correspondance canonique (ACC). Le lagopède et le boeuf musqué étaient córreles le plus fortement avec la végétation des bassesterres et le caribou avec celle des hautes-terres; le lièvre arctique se situait au milieu. L'ACC montrait aussi une séparation relativement importante dans l'espace à plusieurs variables, ce qui laisse suggérer des modèles distincts d'utilisation de l'habitat. Les résultats indiqueraient qu'il existait pour ces espèces une ségrégation dans l'utilisation des ressources au sein de cet environnement extrême-arctique.
Journal Article