560 research outputs found

    Movements of Wolves at the Northern Extreme of the Species' Range, Including during Four Months of Darkness

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    Information about wolf (Canis lupus) movements anywhere near the northern extreme of the species' range in the High Arctic (>75°N latitude) are lacking. There, wolves prey primarily on muskoxen (Ovibos moschatus) and must survive 4 months of 24 hr/day winter darkness and temperatures reaching −53 C. The extent to which wolves remain active and prey on muskoxen during the dark period are unknown, for the closest area where information is available about winter wolf movements is >2,250 km south. We studied a pack of ≥20 wolves on Ellesmere Island, Nunavut, Canada (80°N latitude) from July 2009 through mid-April 2010 by collaring a lead wolf with a Global Positioning System (GPS)/Argos radio collar. The collar recorded the wolf's precise locations at 6:00 a.m. and 6:00 p.m. daily and transmitted the locations by satellite to our email. Straight-line distances between consecutive 12-hr locations varied between 0 and 76 km. Mean (SE) linear distance between consecutive locations (n = 554) was 11 (0.5) km. Total minimum distance traveled was 5,979 km, and total area covered was 6,640 km2, the largest wolf range reported. The wolf and presumably his pack once made a 263-km (straight-line distance) foray to the southeast during 19–28 January 2010, returning 29 January to 1 February at an average of 41 km/day straight-line distances between 12-hr locations. This study produced the first detailed movement information about any large mammal in the High Arctic, and the average movements during the dark period did not differ from those afterwards. Wolf movements during the dark period in the highest latitudes match those of the other seasons and generally those of wolves in lower latitudes, and, at least with the gross movements measurable by our methods, the 4-month period without direct sunlight produced little change in movements

    DO WOLVES AFFECT WHITE-TAILED BUCK HARVEST IN NORTHEASTERN MINNESOTA?

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    We used simple linear regression to analyze 8-23 years of data on a wolf (Canis lupus) population and human harvest of white-tailed deer (Odocoileus virginianus) bucks in northeastern Minnesota to determine any effects of wolves on buck harvesting. Over the long term, wolves accounted for at least 14-22% inter-year variation in buck harvest in the region, but an unknown amount of variation in hunter effort have obscured any more precise estimate. For part of the area with poorest habitat, we found strong relationships (r2 = 0.66-0.84) between annual wolf numbers and buck harvests from 1988 to 1995 when pressure was considered relatively constant. However, in better habitat, where our buck harvest sample larger, we found no evidence of wolves influencing buck harvest. Our findings tend to confirm the suitability of the Minnesota Department of Natural Resource\u27s deer harvest regulations fo

    Twenty-year home-range dynamics of a white-tailed deer matriline

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    We examined the seasonal migration and home-range dynamics of a multigeneration white-tailed deer (Odocoileus virginianus) matriline comprising six females from four generations spanning a 20-year period in northeastern Minnesota. All, from the matriarch to her great-granddaughter, migrated to the same summer and winter ranges, the longest individual record being 14.5 years. Three maternal females concurrently occupied exclusive fawning sites within their ancestral matriarch’s summer range, while two nonmaternal females explored new areas and ranged near their mothers. One great-granddaughter expanded her summer range 1 km beyond the matriarch’s summer range while essentially vacating half of her ancestors’ range and becoming nonmigratory the last 4 years of her life. These data indicate that individual movements of matriline members can potentially expand their ranges beyond the areas occupied by their ancestors through a slow process of small incremental changes. This suggests that the rapid extension of deer range in eastern North America resulted from natal dispersal by yearling deer rather than from the type of home-range expansion reported here. Nous avons étudié la migration saisonnière et la dynamique des déplacements dans les domaines au sein d’une lignée maternelle de plusieurs générations de Cerfs de Virginie (Odocoileus virginianus), lignée composée de six femelles de quatre générations recouvrant une période de 20 ans dans le nord-est du Minnesota. De l’aïeule à son arrière-petite-fille, toutes les femelles occupaient les mêmes domaines d’été et d’hiver, le record d’occupation atteignant 14,5 ans. Trois femelles mères occupaient en même temps des sites de mise-bas exclusifs à l’intérieur du domaine ancestral d’été, alors que deux femelles non mères ont exploré de nouvelles régions et occupaient des domaines voisins de ceux de leurs mères. Une arrière-petite-fille a étendu son domaine d’été de 1 km au-delà de celui de son aïeule, évacuant la moitié du domaine ancestral, et a cessé de migrer au cours des 4 dernières années de sa vie. Ces données indiquent que les déplacements des femelles d’une lignée maternelle peuvent éventuellement agrandir les domaines audelà des limites du domaine de leurs ancêtres, mais très lentement et par petites augmentations seulement. Il semble donc que l’expansion rapide de la répartition du Cerf de Virginie observée en Amérique du Nord résulte de la dispersion des jeunes de l’année à la naissance plutôt que du type d’expansion de domaine tel que décrit ici

    Wolves, \u3ci\u3eCanis lupus\u3c/i\u3e, Carry and Cache the Collars of Radio-collared White-tailed Deer, \u3ci\u3eOdocoileus virginianus\u3c/i\u3e, they Killed

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    Wolves (Canis lupus) in northeastern Minnesota cached six radio-collars (four in winter, two in spring-summer) of 202 radio-collared White-tailed Deer (Odocoileus virginianus) they killed or consumed from 1975 to 2010. A Wolf bedded on top of one collar cached in snow. We found one collar each at a Wolf den and Wolf rendezvous site, 2.5 km and 0.5 km respectively, from each deer’s previous locations

    MORTALITY OF WHITE-TAILED DEER IN NORTHEASTERN MINNESOTA

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    Abstract: Two hundred nine white-tailed deer (Odocoileus virginianus) were radiotracked in the central Superior National Forest, Minnesota, from 1973 through winter 1983-84; 85 deaths were recorded. Annual survival was 0.31 for fawns (\u3c1.0 years old), 0.80 for yearling (1.0-2.0 years old) females, 0.41 for yearling males, 0.79 for adult (≥2.0 years old) females, and 0.47 for adult males. Monthly survival rates were high from May through December (0.94-1.00), except for yearling (0.60) and adult (0.69) bucks during the November hunting season. Most mortality occurred from January through April when gray wolf (Canis lupus) predation was an important mortality source for all cohorts. Yearlings males were most vulnerable to hunting and adult males to wolf predation

    Wolves, Canis lupus, Carry and Cache the Collars of Radio-collared White-tailed Deer, Odocoileus virginianus, they Killed

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    Wolves (Canis lupus) in northeastern Minnesota cached six radio-collars (four in winter, two in spring-summer) of 202 radio-collared White-tailed Deer (Odocoileus virginianus) they killed or consumed from 1975 to 2010. A Wolf bedded on top of one collar cached in snow. We found one collar each at a Wolf den and Wolf rendezvous site, 2.5 km and 0.5 km respectively, from each deer's previous locations

    RELATIONSHIP BETWEEN SNOW DEPTH AND GRAY WOLF PREDATION ON WHITE-TAILED DEER

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    Abstract: Survival of 203 yearling and adult white-tailed deer (Odocoileus virginianus) was monitored for 23,441 deer days from January through April 1975-85 in northeastern Minnesota. Gray wolf (Canis lupus)predation was the primary mortality cause, and from year to year during this period, the mean predation rate ranged from 0.00 to 0.29. The sum of weekly snow depths/month explained 51% of the variation in annual wolf predation rate, with the highest predation during the deepest snow

    DEMOGRAPHIC EFFECTS OF CANINE PARVOVIRUS ON A FREE-RANGING WOLF POPULATION OVER 30 YEARS

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    We followed the course of canine parvovirus (CPV) antibody prevalence in a subpopulation of wolves (Canis lupus) in northeastern Minnesota from 1973, when antibodies were first detected, through 2004. Annual early pup survival was reduced by 70%, and wolf population change was related to CPV antibody prevalence. In the greater Minnesota population of 3,000 wolves, pup survival was reduced by 40–60%. This reduction limited the Minnesota wolf population rate of increase to about 4% per year compared with increases of 16–58% in other populations. Because it is young wolves that disperse, reduced pup survival may have caused reduced dispersal and reduced recolonization of new range in Minnesota

    Image sequence analysis for emerging interactive multimedia services - The European COST 211 framework

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    Cataloged from PDF version of article.Flexibility and efficiency of coding, content extraction, and content-based search are key research topics in the field of interactive multimedia. Ongoing ISO MPEG-4 and MPEG-7 activities are targeting standardization to facilitate such services. European COST Telecommunications activities provide a framework for research collaboration. COST 211bis and COST 211ter activities have been instrumental in the definition and development of the ITU-T H.261 and H.263 standards for videoconferencing over ISDN and videophony over regular phone lines, respectively. The group has also contributed significantly to the ISO MPEG-4 activities. At present a significant effort of the COST 211ter group activities is dedicated toward image and video sequence analysis and segmentation—an important technological aspect for the success of emerging object-based MPEG-4 and MPEG-7 multimedia applications. The current work of COST 211 is centered around the test model, called the Analysis Model (AM). The essential feature of the AM is its ability to fuse information from different sources to achieve a high-quality object segmentation. The current information sources are the intermediate results from frame-based (still) color segmentation, motion vector based segmentation, and changedetection-based segmentation. Motion vectors, which form the basis for the motion vector based intermediate segmentation, are estimated from consecutive frames. A recursive shortest spanning tree (RSST) algorithm is used to obtain intermediate color and motion vector based segmentation results. A rule-based region processor fuses the intermediate results; a postprocessor further refines the final segmentation output. The results of the current AM are satisfactory; it is expected that there will be further improvements of the AM within the COST 211 project

    Differential wolf-pack-size persistence and the role of risk when hunting dangerous prey

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    Risk to predators hunting dangerous prey is an emerging area of research and could account for possible persistent differences in gray wolf (Canis lupus) pack sizes. We documented significant differences in long-term wolf-pack-size averages and variation in the Superior National Forest (SNF), Denali National Park and Preserve, Yellowstone National Park, and Yukon, Canada (p \u3c 0.01). The SNF differences could be related to the wolves’ risk when hunting primary prey, for those packs (N = 3) hunting moose (Alces americanus) were significantly larger than those (N = 10) hunting white-tailed deer (Odocoileus virginianus) (F1,8 = 16.50, p = 0.004). Our data support the hypothesis that differential pack-size persistence may be perpetuated by differences in primary prey riskiness to wolves, and we highlight two important extensions of this idea: (1) the potential for wolves to provision and defend injured packmates from other wolves and (2) the importance of less-risky, buffer prey to pack-size persistence and year-to-year variation
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