scholarly journals Two caribou mortality events in Northwest Alaska: possible causes and management implications

Rangifer ◽  
2005 ◽  
Vol 25 (4) ◽  
pp. 37 ◽  
Author(s):  
Jim Dau
Keyword(s):  
High Mortality ◽  
Rangifer Tarandus ◽  
Ambient Air ◽  
Management Implications ◽  
Severe Storms ◽  
Ovibos Moschatus ◽  
Winter Range ◽  
Local Residents ◽  
Western Arctic ◽  
Snow Conditions

During fall and winter 1994—1995 and winter 1999—2000, caribou (Rangifer tarandus granti) from the Western Arctic Herd experienced high, localized mortality in northwest Alaska near Cape Thompson. Substantial numbers of caribou wintered in this area during 1986—1987, 2001—2002, and 2002—2003 without suffering high mortality. During the 1994—1995 event, 2000 to 3000 caribou died out of roughly 10 000 that wintered in this area. About 4000 caribou perished out of approximately 20 000 that wintered here during 1999—2000. During both mortality events, gross characteristics and tissue analyses indicated caribou in this area were malnourished. Weather near Cape Thompson during winter 1994—1995 was colder, windier, and had more snow than other years when caribou wintered in this area; in contrast, conditions during 1999—2000 were not unusually severe. Additionally, Cape Thompson experienced 2—5 occurrences of severe conditions during winter 1994—1995 while 1999—2000 experienced only 1 such occurrence at most. Several indicators suggested severe storms killed some caribou before starvation was fatal. Cape Thompson consistently experienced higher wind, lower ambient air temperature, and shallower snow cover than other portions of winter range used by this herd. Unlike years when caribou wintered in this area without experiencing high mortality, caribou were in relatively poor body condition during the autumn that preceded each die-off. Although these mortality events were inconsequential to size of this caribou herd, they raised local residents' concerns that contaminants had poisoned caribou and possibly jeopardized human health. Muskoxen (Ovibos moschatus) in this area were not affected by weather or snow conditions during either caribou mortality event.

Is there a cost of parasites to caribou?

Parasitology ◽  
2008 ◽  
Vol 136 (2) ◽  
pp. 253-265 ◽  
Author(s):  
J. HUGHES ◽  
S. D. ALBON ◽  
R. J. IRVINE ◽  
S. WOODIN
Keyword(s):  
Rangifer Tarandus ◽  
Parasite Species ◽  
Negative Relationship ◽  
Apparent Competition ◽  
Range Shift ◽  
The Arctic ◽  
Contributory Factor ◽  
Ovibos Moschatus ◽  
Winter Range ◽  
Nematode Parasites

SUMMARYMacroparasites potentially play a significant but often ignored role in the ecology and dynamics of wild ruminant populations. In the Arctic, parasites may impact on host populations by exacerbating the effects of seasonal and limited forage availability on the condition, fecundity and survival of individuals. We studied the effects of abomasal nematode parasites and warble flies, Hypoderma tarandi, on condition and pregnancy of caribou Rangifer tarandus in the Dolphin-Union herd, Nunavut, Canada. By the end of winter, female caribou over 2 years old showed a significant decrease in body weight with increasing nematode burden, and a decrease in back fat depth with increasing warble abundance. These effects were exaggerated in the non-pregnant fraction of the population. High warble larvae burdens were also associated with significantly reduced probability of being pregnant. Our research demonstrates a negative relationship between parasites and caribou condition that may have consequences for their fitness. Additionally, we discuss the possibility that muskox Ovibos moschatus share some parasite species with the caribou and could lead to elevated burdens in the sympatric host. Parasites may have been a contributory factor in a previous winter range-shift of the caribou herd and this may reflect a form of apparent competition between the two ungulate species.

scholarly journals Population ecology of two woodland caribou herds in the southern Yukon

Rangifer ◽  
1996 ◽  
Vol 16 (4) ◽  
pp. 63 ◽  
Author(s):  
Richard Farnell ◽  
Norman Barichello ◽  
Katherina Egli ◽  
Gerry Kuzyk
Keyword(s):  
Population Ecology ◽  
Rangifer Tarandus ◽  
Distribution Patterns ◽  
Late Winter ◽  
Woodland Caribou ◽  
Winter Range ◽  
Pup Survival ◽  
Moose Population ◽  
Snow Conditions ◽  
The Impact

Since the mid 1980's, the Aishihik herd of woodland caribou (Rangifer tarandus caribou) declined from approximately 1500 to 583 animals. During the same period a nearby herd, the Wolf Lake Herd increased from approximately 664 to 1249 animals. This paper compares aspects of the ecology of these two herds to determine how these relationships conform to a general model of caribou population ecology described by Seip (1992). Comparisons include caribou demographic characteristics and distribution patterns, predator densities, abundance of alternate prey, human hunting and snow depth on caribou winter range. Ecological differences between herds were apparent in the ratio of prime bulls to cows, the abundance of moose (Alces alces), the occurrence of coyotes (Canis latrans), late winter snow conditions, and access to hunting. We hypothesize that the Wolf Lake herd was able to grow because wolves {Canis lupus) preyed mainly on the relatively abundant moose population. A highly clumped winter caribou distribution may have further reduced the impact of wolf predation on the Wolf Lake herd. In contrast, the decline of the Aishihik herd was accompanied by a relative scarcity of moose, few prime aged caribou bulls probably due to a more liberal trophy harvest, and wider late-winter dispersion that offered wolves greater access to caribou. The decline may have been exaggerated by the peak in the snowshoe hare (Lepus americanus) cycle which may have temporarily improved wolf pup survival. We suspect that moose are normally the primary prey of wolves in the Yukon and that a decline in moose eventually results in their being too scarce to offer an economical prey choice, prompting a prey switch to caribou. Results of our analyses conform incompletely to Seip's (1992) model for woodland caribou population ecology, particularly because the Wolf Lake herd prospered where moose were relatively abundant.

scholarly journals Changes in vegetative cover on Western Arctic Herd winter range from 1981 to 2005: potential effects of grazing and climate change

Rangifer ◽  
2007 ◽  
Vol 27 (4) ◽  
pp. 199 ◽  
Author(s):  
Kyle Joly ◽  
Randi R. Jandt ◽  
Cynthia R. Meyers ◽  
Martha J. Cole
Keyword(s):  
Climate Change ◽  
Rangifer Tarandus ◽  
Global Climate ◽  
Shrub Cover ◽  
Population Declines ◽  
Vegetative Cover ◽  
Habitat Condition ◽  
Winter Range ◽  
Lichen Cover ◽  
Western Arctic

The population of the Western Arctic Herd, estimated at 490 000 caribou (Rangifer tarandus granti) in 2003, is at its highest level in 30 years. Twenty permanent range transects were established in the winter range of the Western Arctic Herd in 1981 to assess the impacts of grazing. These transects were revisited in 1995 and 1996 (1995/96). Only 18 of the transects were re-located, so an additional 7 transects were established in 1996. In 2005, all 25 remaining transects were revisited. Lichen coverage dropped by a relative 45.1% between 1981 and 1995/96 and by an additional relative 25.6% between 1995/96 and 2005. There was a significant decline in primary forage lichens between 1995/96 and 2005. Caribou use was greater in areas with high lichen abundance. Graminoid cover increased by a relative 118.4% from 1981 to 1995/96 and again by a relative 26.1% from 1995/96 to 2005. Shrub cover increased during the study whereas forb cover declined. The decline in lichen abundance on the winter range of the Western Arctic Herd over 24 years is an index of caribou habitat condition. The observed changes in vegetation cover can be attributed to caribou grazing, fire, and possibly global climate change. Continued declines in lichen cover could lead to population declines within the herd, range shifts, or both.

scholarly journals Assessment of Alaska reindeer populations and range conditions

Rangifer ◽  
1992 ◽  
Vol 12 (1) ◽  
pp. 33 ◽  
Author(s):  
J. D. Swanson ◽  
M. H. W. Barker
Keyword(s):  
Bering Sea ◽  
Rangifer Tarandus ◽  
Alces Alces ◽  
Ecological Condition ◽  
Sea Islands ◽  
Ovibos Moschatus ◽  
Winter Range ◽  
Monitoring Programs ◽  
Cladina Rangiferina

Populations of reindeer (Rangifer tarandus) have fluctated greatly since their introduction to Alaska in 1891. In the 1930s, reported numbers exceeded 600 000. Presently, 38 000 reindeer graze 6.2 million ha of rangeland and woodland in Western Alaska (from 66°54'N to 52°07'N latitude). Condition of winter range producing fruticose lichens (Cladina rangiferina, Cladina arbuscula, Cladina stellaris, Cetraria cucullata, Cetraria islandica) is of major concern. Monitoring programs have been established for vegetation, fire, reindeer and wildlife. Reindeer have overgrazed lichen resources on some Bering Sea Islands. Wildfires have had the greatest impact on lichen range depletion on the mainland. Overgrazing has been a problem in localized areas. Moose (Alces alces) and muskox (Ovibos moschatus) rarely contribute to major lichen depletion. 60-80% of the mainland and 5-30% of most island winter lichen ranges are presently estimated to be in good to excellent ecological condition. Procedures for assessing condition of the lichen ranges are being further refined.

РАДИОУГЛЕРОДНЫЕ ДАТИРОВКИ ПАЛЕОНТОЛОГИЧЕСКИХ ОБРАЗЦОВ ВЕРХНЕГО ПЛЕЙСТОЦЕНА НИЖНЕЙ ОБИ

2020 ◽  
Author(s):  
I. Zolnikov ◽  
◽  
A. Vybornov ◽  
A. Anoikin ◽  
A. Postnov ◽  
...  
Keyword(s):  
Mass Spectrometer ◽  
Rangifer Tarandus ◽  
Western Siberia ◽  
Budker Institute ◽  
Mammuthus Primigenius ◽  
Upper Pleistocene ◽  
Ovibos Moschatus ◽  
The North

In the course of studies conducted by IAET SB RAS in the Lower Ob in 2016–2019, the understanding of the conditions for settlement of the Paleolithic population in the north of Western Siberia was significantly supplemented. Dating of a series of paleontological finds was carried out at the "Accelerated mass spectrometer of the Budker Institute of Nucle- ar Physics of SB RAS". The dates obtained show the distribution of the main representatives of the Upper Pleistocene fauna of Subarctica: Mammuthus primigenius – 50,000–15,000 BP, Coelodonta antiquitatis – 43,000–38,000 BP and 27,000–25,000 BP, Rangifer tarandus, Equus ferus – 40,000–10,000 BP, Bison sp. – 50,000–40,000 BP, Ovibos moschatus – 41,000–32,000 BP.

scholarly journals Aerial survey and telemetry data analysis of a peripheral caribou calving area in northwestern Alaska

Rangifer ◽  
2019 ◽  
Vol 39 (1) ◽  
pp. 43-58
Author(s):  
Alexander K. Prichard ◽  
Ryan L. Klimstra ◽  
Brian T. Person ◽  
Lincoln S. Parrett
Keyword(s):  
Industrial Development ◽  
Rangifer Tarandus ◽  
Aerial Survey ◽  
The Arctic ◽  
Primary Data ◽  
Data Sets ◽  
Telemetry Data ◽  
Western Arctic ◽  
Data Source

With industrial development expanding in the Arctic, there is increasing interest in quantifying the impacts of development projects on barren ground caribou (Rangifer tarandus granti). The primary data source to assess caribou distribution and predict impacts in remote areas of Alaska has shifted in recent decades from aerial survey data to telemetry data, but these techniques have different strengths and weaknesses. The ranges of two caribou herds, the Western Arctic Herd and the Teshekpuk Herd, overlap in northwest Alaska between Wainwright and Atqasuk, Alaska. Based on long-term telemetry data sets, this region was thought to be outside of the core calving ranges of both herds. Calving has long been reported to occur in this general area, but early reports assumed caribou were from the Western Arctic Herd and only one systematic aerial survey of caribou density and distribution during calving has been conducted in this area in recent decades. Following interest in industrial development in this area, we conducted aerial strip-transect surveys during early to mid-June 2013–2015 to directly assess the density and distribution of caribou in the area and we used existing telemetry data to compare our results to the seasonal distribution of both herds. Total caribou densities varied between 0.36 and 1.06 caribou/km² among years, and calf densities varied 0.04 and 0.25 calves/km² among years. Contrary to assumptions by early researchers in the area, telemetry data indicated that caribou in this area during early to mid-June were from the Teshekpuk Herd. The use of telemetry data alone underestimated the importance of this area for calving, but the combination of aerial surveys and telemetry data provided complementary information on caribou use of this area showing the importance of collecting the appropriate types of data for assessing potential impacts of development on caribou.

scholarly journals Caribou of the Central Arctic Region of Alaska in relation to adjacent caribou herds

Rangifer ◽  
1986 ◽  
Vol 6 (2) ◽  
pp. 65
Author(s):  
D. R. Carruthers ◽  
R. D. Jakimchuk
Keyword(s):  
Rangifer Tarandus ◽  
Arctic Region ◽  
Early Spring ◽  
Summer Period ◽  
Western Arctic ◽  
Unusual Increase

There was an unusual increase in numbers of caribou (Rangifer tarandus granti) in the Central Arctic region of Alaska from 1981 to 1985. In fall and winter numbers were up to five times greater than at the onset of calving in June. Numbers appeared to double during the month of June each year, then remain relatively stable over the summer period with a further increase in the fall. Ingress of caribou from outside the region in fall was observed in all years and egress in the early spring is postulated. We conclude that a small resident herd inhabits the region year round with numbers increasing through ingress of caribou from the Western Arctic herd possibly beginning as early as June. Increases or decreases in the size of adjacent herds probably will affect the numbers of caribou occupying the Central Arctic region.

Habitat selection and home-range dynamics of the Gaspé caribou: a hierarchical analysis

2003 ◽  
Vol 81 (7) ◽  
pp. 1174-1184 ◽  
Author(s):  
Arnaud Mosnier ◽  
Jean-Pierre Ouellet ◽  
Luc Sirois ◽  
Nelson Fournier
Keyword(s):  
Home Range ◽  
Habitat Use ◽  
Rangifer Tarandus ◽  
Large Diameter ◽  
Habitat Type ◽  
Spatial And Temporal Scales ◽  
Management Plans ◽  
Forested Areas ◽  
Range Dynamics ◽  
Snow Conditions

We used several spatial and temporal scales to determine space and habitat use of the caribou (Rangifer tarandus caribou) of the Gaspé Peninsula. Thirty-five radio-collared caribou were followed from November 1998 to April 2001. Habitat use was studied by superimposing radiolocations on ecoforestry maps using five predefined habitat types (deciduous, immature, mature spruce, mature fir, and barren). At a finer scale, we tracked caribou in forested areas during winter 2000 and 2001 in order to describe physical and biological characteristics of foraging tracks and used stands. Our results indicated that the distribution of caribou extended beyond the limits of Gaspé Conservation Park. Patterns of space use showed the existence of three groups, which formed a metapopulation. These groups consisted of spatially distinct units that used space and habitat differently. At the home-range level, caribou preferred barren areas found in alpine and subalpine zones at all times of the year. The most frequently used forested habitat type was the mature fir. At the finer scale of foraging tracks, caribou selected fir stands characterized by dense snow conditions and large diameter trees bearing greater quantities of lichen. Our results demonstrated the importance of protecting areas outside the park that are likely to become used or reused by caribou, and of managing these areas to increase settlement by caribou. Lastly, management plans must be adapted to each of the three groups forming this metapopulation.

scholarly journals The interplay of temperature and protons in the modulation of oxygen binding by squid blood

1992 ◽  
Vol 281 (3) ◽  
pp. 725-728 ◽  
Author(s):  
B Giardina ◽  
S G Condò ◽  
O Brix
Keyword(s):  
Rangifer Tarandus ◽  
Effect Of Temperature ◽  
Strong Temperature Dependence ◽  
Oxygen Binding ◽  
Experimental Conditions ◽  
Ovibos Moschatus ◽  
High Affinity ◽  
Loading And Unloading ◽  
Musk Ox ◽  
Oxygen Equilibrium Curve

An extensive set of data relating to the binding of oxygen by haemocyanin from the squid Todarodes sagittatus has been collected under various experimental conditions. The results obtained show that, within the range of physiological pH, the concentration of protons affects mainly the high-affinity state of the molecule without significantly affecting the low-affinity state. As far as the effect of temperature is concerned, the data show a characteristic feature which is very similar to that previously described in the case of haemoglobins from Arctic mammals such as reindeer (Rangifer tarandus) and musk ox. (Ovibos moschatus). The shape of the oxygen equilibrium curve shows strong temperature-dependence, since the overall heat of the binding of oxygen to the low-affinity state of the molecule is strongly exothermic and that to the high-affinity state is very close to zero. The results provide an outline of the intramolecular compromise that, through the interplay of temperature and protons, optimizes the loading and unloading of oxygen under the various environmental conditions experienced by this species of squid.

scholarly journals Antler possession by west Greenland female caribou in relation to population characteristics

Rangifer ◽  
1986 ◽  
Vol 6 (2) ◽  
pp. 297 ◽  
Author(s):  
Henning Thing ◽  
Carsten Riis Olesen ◽  
Peter Aastrup
Keyword(s):  
Rangifer Tarandus ◽  
Reproductive Rate ◽  
Population Characteristics ◽  
Relative Importance ◽  
West Greenland ◽  
Winter Range ◽  
Factors Influencing ◽  
Summer Mortality ◽  
Close Relationship ◽  
Antler Development

The frequency of antlerless adult female caribou (Rangifer tarandus groenlandicus) was studied in four separate populations in west Greenland. Between the herds antlerlessness varied from 21% to 79%. An inverse relationship between winter range quality and percentage of unantlered cows is demonstrated. Relationship between calf percentage and maternal antler status was studied in one population and antlerless cows showed higher reproductive rate than antlered ones. In another population antlerless cows were almost absent outside the calving area. Calves of antlerless mothers were more susceptible to diseases and had significantly higher summer mortality than other calves, 42% and 27% respectively. The relative importance of factors influencing antler development under various environmental conditons are assessed and a close relationship between antlerlessness, physical condition, lactation, and length of period between calving and midsummer is discussed.

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