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

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.

Parasitology ◽  
2008 ◽  
Vol 136 (2) ◽  
pp. 253-265 ◽  
Author(s):  
J. HUGHES ◽  
S. D. ALBON ◽  
R. J. IRVINE ◽  
S. WOODIN

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.


Rangifer ◽  
1996 ◽  
Vol 16 (2) ◽  
pp. 57 ◽  
Author(s):  
D.C. Thomas ◽  
S.J. Barry ◽  
G. Alaie

We needed data on temporal changes in caribou forages after fire and relative use of age-classes of forests by caribou to help devise a fire suppression priority strategy for caribou winter range in north-central Canada. Consequently, from 1983 through 1986, we estimated the abundance of vegetation and relative use by caribou at 197 sites in western and eastern study areas on the winter range of the Beverly herd of caribou {Rangifer tarandus). Species of lichens attained peak biomass at different periods after fire - as early as 40-60 years for Cladonia spp. to > 150 years for Cladina rangiferina and Cetraria nivalis. Biomass of the primary "caribou lichen", Cladina mitis, increased rapidly from 21-30 years after fire to 41-50 years and attained maximum biomass at 81-90 yeats in the west and 41-60 years in the east. However, total lichen biomass increased with age of forest to 100-150 years because biomass of Stereocaulon spp. did not peak until after 100 years. The biomass of "caribou lichens" {Cladina spp. and Cetraria nivalis) stabilized after 61-80 years in the west and 41-60 years in the east. The biomass of terrestrial lichen species can be predicted from their cover. Caribou lichen abundance apparently was only one of several factors that caused caribou to use stands 151-250 years after fire more than othet age classes.


2007 ◽  
Vol 85 (11) ◽  
pp. 1143-1156 ◽  
Author(s):  
Susan J. Kutz ◽  
Ingrid Asmundsson ◽  
Eric P. Hoberg ◽  
Greg D. Appleyard ◽  
Emily J. Jenkins ◽  
...  

Fecal samples are often the only feasible means to assess diversity of parasites in wildlife; however, definitive identification of egg or larval stages in feces by morphology is rarely possible. We determined partial sequences from the second internal transcribed spacer region (ITS-2) of nuclear ribosomal DNA for first-stage, dorsal-spined larvae (DSL) in feces from caribou ( Rangifer tarandus tarandus (L., 1758), Rangifer tarandus caribou (Gmelin, 1788), Rangifer tarandus grantii (Allen, 1902)), muskoxen ( Ovibos moschatus moschatus (Zimmermann, 1780), Ovibos moschatus wardi Lydekker, 1900), moose ( Alces alces gigas Miller, 1899 and Alces alces andersoni Peterson, 1952), and from the tissue of one slug ( Deroceras laeve (Müller, 1774)) in Arctic–Subarctic North America. A previously uncharacterized, genetically distinct species was recognized based on sequences of 37 DSL from 19 ungulate hosts and the slug. Sequence similarity among individuals of this novel species was 91%–100%. For many individual DSL, paralogues of ITS-2 were detected. ITS-2 sequences from the novel species were 72%–77% similar to those of Varestrongylus alpenae (Dikmans, 1935) and 51%–61% similar to those of other protostrongylids known in North American and some Eurasian ungulates. Results indicate a discrete lineage of an undescribed protostrongylid infecting muskoxen, caribou, and moose from Alaska to Labrador. Sympatric infections with Parelaphostrongylus andersoni Prestwood, 1972 were found in three caribou herds.


Rangifer ◽  
2005 ◽  
Vol 25 (4) ◽  
pp. 37 ◽  
Author(s):  
Jim Dau

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.


Author(s):  
I. Zolnikov ◽  
◽  
A. Vybornov ◽  
A. Anoikin ◽  
A. Postnov ◽  
...  

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.


2021 ◽  
Vol 4 ◽  
Author(s):  
Sara Atienza Casas ◽  
Markus Majaneva ◽  
Thomas Jensen ◽  
Marie Davey ◽  
Frode Fossøy ◽  
...  

Biodiversity assessments using molecular identification of organisms through high-throughput sequencing techniques have been a game changer in ecosystem monitoring, providing increased taxonomic resolution, more objective identifications, potential cost reductions, and reduced processing times. The use of DNA metabarcoding of bulk samples and environmental DNA (eDNA) is now widespread but is not yet universally implemented in national monitoring programs. While bulk sample metabarcoding involves extraction of DNA from organisms in a sample, eDNA analysis involves obtaining DNA directly from environmental samples, which can include microorganisms, meiofauna-size taxa and macrofauna traces such as larval stages, skin and hair cells, gametes, faeces and free DNA bound to particles. In Norway, freshwater biomonitoring in compliance with the EU Water Framework Directive (WFD) is conducted on several administrative levels, including national monitoring programs for running water, small and large lakes. These programs typically focus on a fraction of the actual biodiversity present in the monitored habitats (Weigand 2019). DNA metabarcoding of both bulk samples and eDNA samples are relevant tools for future freshwater biomonitoring in Norway. The aim of this PhD project is to develop assessment protocols based on DNA-metabarcoding and eDNA of benthic invertebrates, microcrustaceans and fish that can be used as standard biomonitoring tools to assess the ecological condition of lakes. The main topics addressed will be: - Development of protocols throughout the eDNA-metabarcoding workflow (i.e. sampling, filtration, preservation, extraction, amplification and sequencing) suitable to execute biodiversity assessments and determine the ecological status of lakes. - Comparison of the results obtained using molecular tools and traditional morphology-based approaches in order to assess the feasibility of such techniques to be incorporated as standard biomonitoring tools, such as the ones implemented under the provisions of the WFD. - Evaluate the effect of improved taxonomic resolution from molecular techniques on determining the ecological status of lakes, both by broadening the number of taxa analyzed and by identifying more taxa to species level. - Assess the feasibility of using eDNA extracted from water samples, taken at different depths and fish densities, to measure fish abundance/biomass as a proxy to calculate the ecological quality indices regulated in the WFD. - Analyze the coverage and resolution provided by reference libraries for certain taxa, such as crustacea, in order to assess the reliability and precision of taxonomic assignments.


1992 ◽  
Vol 281 (3) ◽  
pp. 725-728 ◽  
Author(s):  
B Giardina ◽  
S G Condò ◽  
O Brix

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.


2016 ◽  
Vol 52 (1) ◽  
pp. 96-99 ◽  
Author(s):  
Ingebjørg Helena Nymo ◽  
Kimberlee Beckmen ◽  
Jacques Godfroid

Sign in / Sign up

Export Citation Format

Share Document