scholarly journals Wolf predation in the Burwash caribou herd, southwest Yukon

Rangifer ◽  
1986 ◽  
Vol 6 (2) ◽  
pp. 137 ◽  
Author(s):  
David A. Gauthier ◽  
John B. Theberge
Keyword(s):  
Rangifer Tarandus ◽  
Climatic Factors ◽  
Mortality Factor ◽  
Rangifer Tarandus Caribou ◽  
Limited Data ◽  
Mortality Factors ◽  
Wolf Predation ◽  
Calf Mortality ◽  
Annual Mortality

The role of wolf predation as a proximate mortality factor influencing caribou herd growth was assessed in the Burwash herd (400 animals) in the southwest Yukon between 1980 - 1982. Ten to 14 wolves in two packs preyed primarily on caribou (Rangifer tarandus caribou) and moose (Alces alces) with disproportionate consumption of caribou (relative to available biomass) in the rut and winter periods. Wolf predation was responsible for 72% of total annual mortality in 1980 - 1981 and 46% in 1981 - 1982. Losses due to human harvest varied between 7 to 13%. Additional limited data on climatic factors and winter forage indicated forage-climate were not major proximate mortality factors in 1980 - 1981, but that early-calving climate may have been a factor in increased calf mortality in 1982.

REGULAR ARTICLES / ARTICLES RÉGULIERSFactors affecting the distribution and transmission of Elaphostrongylus rangiferi (Protostrongylidae) in caribou (Rangifer tarandus caribou) of Newfoundland, Canada

2001 ◽  
Vol 79 (7) ◽  
pp. 1265-1277 ◽  
Author(s):  
Mark C Ball ◽  
Murray W Lankester ◽  
Shane P Mahoney
Keyword(s):  
Rangifer Tarandus ◽  
Climatic Factors ◽  
Rangifer Tarandus Caribou ◽  
Intermediate Hosts ◽  
Parasite Abundance ◽  
Annual Minimum Temperature ◽  
Transmission Period ◽  
Summer Temperatures ◽  
Elaphostrongylus Rangiferi ◽  
Dual Infections

Elaphostrongylus rangiferi was introduced to caribou (Rangifer tarandus caribou) of Newfoundland by infected reindeer (R. t. tarandus) from Norway and has caused at least two epizootics of cerebrospinal elaphostrongylosis (CSE), a debilitating neurologic disease. In an attempt to understand the conditions necessary for such outbreaks, we examined the effects of herd density and climatic factors on parasite abundance. The abundance of E. rangiferi was represented by counts of first-stage larvae in feces collected from young caribou (calves and yearlings) in 7 distinct caribou herds in Newfoundland. Abundance of E. rangiferi was highest in February and in the Avalon (632 ± 14 (mean ± SE)) and St. Anthony (526 ± 145) herds, the 2 herds in which CSE was most frequently reported. Mean abundance in February samples from young animals correlated positively with mean annual minimum temperature (rS = 0.829, df = 6, P = 0.04) and the number of days per year above 0°C (rS = 0.812, df = 6, P = 0.05) and negatively with mean summer temperatures (rS = –0.830, df = 6, P = 0.04). Results suggest that abundance of E. rangiferi and the likelihood of cases of CSE are increased by moderate summer temperatures suitable for the activity and infection of gastropod intermediate hosts and by mild winters with little snow that extend the transmission period. Abundance of larvae was not correlated with herd density. Animals in all 7 herds also had the muscle worm Parelaphostrongylus andersoni, a related nematode with similar dorsal-spined larvae. In 2 additional herds (Cape Shore and Bay de Verde), P. andersoni occurred alone and larvae were passed only by young caribou. In herds with dual infections, numbers of P. andersoni larvae were depressed, declined more quickly in young animals, and were considered to be present in only low numbers in February samples used for E. rangiferi analysis. Upon initial infection, young caribou develop a resistance to E. rangiferi that prevents or reduces reinfection later in life. This was demonstrated by examining the brains of caribou for recently acquired worms, which must develop there for up to 90 days before continuing their tissue migration into the skeletal muscles. Recent infections were detected in only calves and yearlings in all herds with E. rangiferi except the Avalon herd, where developing worms were also found on the brains of older caribou. The infection of older animals in the Avalon herd may reflect a lower immunocompetence of a naive herd that has only recently been exposed to E. rangiferi.

scholarly journals Pack Size of Wolves, Canis lupus, on Caribou, Rangifer tarandus, Winter Ranges in Westcentral Alberta

2006 ◽  
Vol 120 (3) ◽  
pp. 313 ◽  
Author(s):  
Gerald W. Kuzyk ◽  
Jeff Kneteman ◽  
Fiona K. A. Schmiegelow
Keyword(s):  
Canis Lupus ◽  
Landscape Change ◽  
Rangifer Tarandus ◽  
Prey Size ◽  
Rocky Mountain ◽  
Predation Pressure ◽  
Resource Extraction ◽  
Rangifer Tarandus Caribou ◽  
Pack Size ◽  
Wolf Predation

We studied pack size of Wolves (Canis lupus) on Woodland Caribou (Rangifer tarandus caribou) winter ranges in westcentral Alberta. These Caribou winter ranges are experiencing increasing pressure from resource extraction industries (forestry, energy sector) and concerns have been raised regarding increased Wolf predation pressure on Caribou in conjunction with landscape change. Thirty-one Wolves, from eight Wolf packs, were fitted with radiocollars on two Caribou winter ranges in the Rocky Mountain foothills, near Grande Cache, Alberta (2000-2001). There was a mean of 8.2 Wolves/pack and between 30 and 39 Wolves on each of the RedRock/Prairie Creek and Little Smoky Caribou ranges. The average pack size of Wolves in this region does not appear to have increased over that recorded historically, but the range (5-18) in the number of Wolves per pack varied considerably over our study area. Wolves preyed predominately on Moose (Alces alces), averaging one Moose kill every three to five days. There was some indication that pack size was related to prey size, with the smallest pack preying on Deer (Odocoileus spp.). It was clear that Caribou could not be the primary prey for Wolves, due to their low numbers, and relative to the pack size and Wolf kills we observed.

Woodland caribou: Facts for forest managers

1992 ◽  
Vol 68 (4) ◽  
pp. 481-491 ◽  
Author(s):  
H. G. Cumming
Keyword(s):  
Forest Management ◽  
Rangifer Tarandus ◽  
Population Decline ◽  
Habitat Destruction ◽  
Rangifer Tarandus Caribou ◽  
Woodland Caribou ◽  
Mortality Factors ◽  
Resource Managers ◽  
Ultimate Cause ◽  
Multiple Resource

A literature review points to predation as the proximate factor controlling woodland caribou (Rangifer tarandus caribou) populations in most cases, but that finding does not obviate the need for caribou to be included in forest management. Managers must consider the indirect effects of forest operations on caribou through their impacts on caribou mortality factors, such as prédation. Lichens remain important. Habitat destruction may in some cases be the ultimate cause of population decline. Reactions of caribou to disturbance vary, and remain controversial; more research is needed. Multiple resource managers of boreal commercial forests should identify sensitive components of caribou range – calving grounds, rutting locations, wintering areas, and travel routes among them – and prescribe for these areas in forest management plans. Ways of accommodating caribou in commercial forests are not well established, but some examples suggest how this might be done. Most importantly, areas that have been proven by their continued use to contain all necessary requirements for caribou survival should not be physically altered until their essential qualities and functions are better understood. Key words: Rangifer tarandus caribou, woodland caribou, predation, forest management.

scholarly journals Examining the role of terrestrial lichen transplants in restoring woodland caribou winter habitat

2017 ◽  
Vol 93 (03) ◽  
pp. 204-212 ◽  
Author(s):  
Sean B. Rapai ◽  
Duncan McColl ◽  
Richard Troy McMullin
Keyword(s):  
Habitat Restoration ◽  
Rangifer Tarandus ◽  
Rangifer Tarandus Caribou ◽  
Woodland Caribou ◽  
Winter Habitat ◽  
Transplant Program ◽  
Restoration Techniques ◽  
Terrestrial Lichen

The development of habitat restoration techniques for restoring critical woodland caribou (Rangifer tarandus caribou) winter habitat will play an important role in meeting the management thresholds in woodland caribou recovery plans. The goal is to restore disturbed environments within critical winter habitat for the declining woodland caribou. Woodland caribou are diet specialists, utilizing lichen-rich habitat for forage during winter months. Cladonia sub-genus Cladina is the most frequently eaten species during this time. Herein, we provide: 1) A review of previously used methods for transplanting Cladonia sub-genus Cladina and their feasibility in restoring woodland caribou winter habitat; 2) A stepby- step protocol on how to carry out a terrestrial lichen transplant program (using Cladonia sub-genus Cladina and C. uncialis); and, 3) An evaluation of our protocol through the establishment of a case study in northern British Columbia. Our results indicate that transplanting C. sub-genus Cladina fragments is the most efficient technique for transplanting terrestrial lichen communities, but transplanting lichen ‘patches’ or ‘mats’ may also be effective.

scholarly journals Calf mortality of semi-domesticated reindeer (Rangifer tarandus tarandus) in the Finnish reindeer-herding area

Rangifer ◽  
2013 ◽  
pp. 79-90 ◽  
Author(s):  
Mauri Nieminen ◽  
Harri Norberg ◽  
Veikko Maijala
Keyword(s):  
Birth Weight ◽  
Rangifer Tarandus ◽  
Total Mortality ◽  
Reindeer Herding ◽  
Brown Bears ◽  
Rangifer Tarandus Tarandus ◽  
Golden Eagles ◽  
Calf Mortality ◽  
Annual Mortality

During 1999-2008 calf mortality was studied in six reindeer-herding cooperatives in Northern Finland, where 3942 semi-domesticated reindeer (Rangifer tarandus tarandus) calves were equipped with radio mortality collars. The calves were weighed and earmarked mostly at 2-5 days of age, or at 2-8 weeks of age. Altogether 460 dead radio-collared calves were found from calving in May until winter round-ups in October-January. In northern mountain herding cooperatives, the average mortality of calves varied between 7-12%. On average, 39-54% of calves found dead were attributed to predation. Golden eagles killed 0-3.5% of calves in different years and areas in Ivalo and Käsivarsi cooperatives. Golden eagles were responsible for 33-43% of the cases and 84-93% of all identified predation. Most calves killed by golden eagles were found in July-August and in open areas. Calves killed by golden eagles were significantly (P<0.01) lighter than those not predated. No predation occurred in the Poikajärvi cooperative, but the annual mortality of calves varied between 0-35% in cooperatives near the Russian border. In Oivanki cooperative brown bears killed on average 2% of the radio-collared calves. Most predation (87%) occurred at the end of May and in early June. In the Kallioluoma cooperative, predator-killed calves found comprised 53% and wolf-killed 45%. Predation was 70% of total mortality in the Halla cooperative, and predation by wolf, bear, lynx and wolverine comprised on average 38%, 20%, 9% and 2.3%, respectively. The sex and pelt color did not significantly affect survival of calves. Birth weight of calves killed by bears was significantly (P<0.01) lighter than those not killed, but those calves killed by lynxes were significantly (P<0.05) heavier than that survived. Bears killed calves mainly in May-July, wolves in July-October and lynx in August-December.

scholarly journals Natality and calf mortality of the Northern Alaska Peninsula and Southern Alaska Peninsula caribou herds

Rangifer ◽  
2003 ◽  
Vol 23 (5) ◽  
pp. 161 ◽  
Author(s):  
Richard A. Sellers ◽  
Patrick Valkenburg ◽  
Ronald C. Squibb ◽  
Bruce W. Dale ◽  
Randall L. Zarnke
Keyword(s):  
Rangifer Tarandus ◽  
Ursus Arctos ◽  
Haliaeetus Leucocephalus ◽  
Bald Eagles ◽  
Alaska Peninsula ◽  
Golden Eagles ◽  
Calf Mortality ◽  
Northern Alaska ◽  
Old Females ◽  
Annual Mortality

We studied natality in the Northern Alaska Peninsula (NAP) and Southern Alaska Peninsula (SAP) caribou (Rangifer tarandus granti) herds during 1996-1999, and mortality and weights of calves during 1998 and 1999- Natality was lower in the NAP than the SAP primarily because most 3-year-old females did not produce calves in the NAP Patterns of calf mortality in the NAP and SAP differed from those in Interior Alaska primarily because neonatal (i.e., during the first 2 weeks of life) mortality was relatively low, but mortality continued to be significant through August in both herds, and aggregate annual mortality was extreme (86%) in the NAP Predators probably killed more neonatal calves in the SAP, primarily because a wolf den (Canis lupus) was located on the calving area. Despite the relatively high density of brown bears (Ursus arctos) and bald eagles (Haliaeetus leucocephalus), these predators killed surprisingly few calves. Golden eagles (Aquila chrysaetos) were uncommon on the Alaska Peninsula. At least 2 calves apparently died from pneu&not;monia in the range of the NAP but none were suspected to have died from disease in the range of the SAP. Heavy scav&not;enging by bald eagles complicated determining cause of death of calves in both the NAP and SAP.

Spatial relationships of sympatric wolves (Canis lupus) and coyotes (C. latrans) with woodland caribou (Rangifer tarandus caribou) during the calving season in a human-modified boreal landscape

2013 ◽  
Vol 40 (3) ◽  
pp. 250 ◽  
Author(s):  
A. David M. Latham ◽  
M. Cecilia Latham ◽  
Mark S. Boyce ◽  
Stan Boutin
Keyword(s):  
Canis Lupus ◽  
Food Habits ◽  
Rangifer Tarandus ◽  
Mortality Factor ◽  
Rangifer Tarandus Caribou ◽  
Population Declines ◽  
Woodland Caribou ◽  
Very High Frequency ◽  
Important Prey ◽  
Calving Season

Context Woodland caribou (Rangifer tarandus caribou) populations have declined across most of North America. Wolf (Canis lupus) predation on adults is partially responsible for declines; however, caribou declines also can be attributed to low calf survival. Wolves and invading coyotes (C. latrans) may contribute to mortality of calves. Aim We assessed wolf and coyote food habits and population and individual level selection for caribou-preferred habitats (bogs and fens) during the caribou calving season (15 April to 30 June) in north-eastern Alberta, Canada, to determine what role these predators might play as a mortality factor for caribou calves. Methods We deployed global positioning system and very high-frequency (VHF) radio-collars on 32 wolves and nine coyotes in January 2006 – January 2008, and VHF collars on 42 adult female caribou individuals in 2003–08. We assessed wolf and coyote habitat selection using used-available resource-selection functions, and spatial overlap of wolves and coyotes with caribou using logistic regression to estimate coefficients for latent selection-difference functions. We collected and analysed scats to assess wolf and coyote food habits. Key results Wolves generally avoided caribou-preferred habitats, particularly bogs. Most coyotes selected caribou-preferred habitats (bogs and/or fens); however, relative to caribou, they were found closer to upland forests. Hair from adult and calf caribou was uncommon in wolf and coyote diet and caribou is likely to be an uncommon alternative prey for these predators. Conclusions We found that >25% of wolf packs and most coyotes selected caribou-preferred habitats during the calving season. Although caribou was not an important prey, limited secondary predation, by these predators and black bears (Ursus americanus), on adult and calf caribou is likely to be contributing to caribou population declines. Implications We caution that predation on caribou is likely to escalate as coyotes expand into this region and increasing human disturbance continues to create habitat for white-tailed deer (Odocoileus virginianus), which is an important prey for both wolves and coyotes.

Comment on “Widespread declines in woodland caribou (Rangifer tarandus caribou) continue in Alberta”

2015 ◽  
Vol 93 (2) ◽  
pp. 149-150 ◽  
Author(s):  
Donald Harron
Keyword(s):  
Statistical Analysis ◽  
Predictive Model ◽  
Mortality Risk ◽  
Field Data ◽  
Rangifer Tarandus ◽  
Population Trends ◽  
Rangifer Tarandus Caribou ◽  
Woodland Caribou ◽  
Selection For ◽  
Annual Mortality

The 2013 study by Hervieux et al. outlining population trends of Boreal woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) in Alberta, Canada, utilizes statistical analysis in nonconformance with this analytical method’s limitations and applied data manipulations that biases the result toward a finding of decreasing population trends. The analysis is also based on orders-of-magnitude exaggerations in the precision of field data and failed to take into account the potential for bias toward elevated annual mortality risk associated with the nonrandomized method of selection for collaring female Boreal woodland caribou, and the potential for elevated mortality as a result of the collars themselves. Due to its numerous limitations, it is unlikely that the predictive model outlined in the study is representative of actual trends in populations and is not an approach that can produce reliable population trend estimates.

scholarly journals Status of endangered and threatened caribou on Canada's arctic islands

Rangifer ◽  
2000 ◽  
Vol 20 (5) ◽  
pp. 39 ◽  
Author(s):  
Anne Gunn ◽  
Frank L. Miller ◽  
John Nishi
Keyword(s):  
Rangifer Tarandus ◽  
Canadian Arctic ◽  
High Arctic ◽  
Aerial Survey ◽  
Wolf Predation ◽  
Climatic Regions ◽  
Current Trends ◽  
Ice Conditions ◽  
Victoria Island

Caribou (Rangifer tarandus) on the Canadian Arctic Islands occur as several populations which are nationally classified as either endangered or threatened. On the western High Arctic (Queen Elizabeth) Islands, Peary caribou (R. t. pearyi) declined to an estimated 1100 caribou in 1997. This is the lowest recorded abundance since the first aerial survey in 1961 when a high of ca. 24 363 caribou was estimated on those islands. Peary caribou abundance on the eastern Queen Elizabeth Islands is almost unknown. On the southern Arctic Islands, three caribou populations declined by 95-98% between 1973 and 1994 but our information is unclear about the numerical trends for the two other populations. Diagnosis of factors driving the declines is complicated by incomplete information but also because the agents driving the declines vary among the Arctic's different climatic regions. The available evidence indicates that severe winters caused Peary caribou die-offs on the western Queen Elizabeth Islands. On Banks Island, harvesting together with unfavourable snow/ice conditions in some years accelerated the decline. On northwestern Victoria Island, harvesting apparently explains the decline. The role of wolf predation is unknown on Banks and notthwest Victoria islands, although wolf sightings increased during the catibou declines. Reasons for the virtual disappearance of arctic-island caribou on Prince of Wales and Somerset islands are uncertain. Recovery actions have started with Inuit and Inuvialuit reducing their harvesting but it is too soon to evaluate the effect of those changes. Recovery of Peary caribou on the western Queen Elizabeth Islands is uncertain if the current trends toward warmer temperatures and higher snowfall persist.

Von Willebrand disease and Weibel-Palade bodies

2010 ◽  
Vol 30 (03) ◽  
pp. 150-155 ◽  
Author(s):  
J. W. Wang ◽  
J. Eikenboom
Keyword(s):  
Platelet Adhesion ◽  
Coagulation Factor ◽  
Von Willebrand Disease ◽  
Inflammatory Factors ◽  
Limited Data ◽  
Storage Organelle ◽  
And Function ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryVon Willebrand factor (VWF) is a pivotal haemostatic protein mediating platelet adhesion to injured endothelium and carrying coagulation factor VIII (FVIII) in the circulation to protect it from premature clearance. Apart from the roles in haemostasis, VWF drives the formation of the endothelial cell specific Weibel-Palade bodies (WPBs), which serve as a regulated storage of VWF and other thrombotic and inflammatory factors. Defects in VWF could lead to the bleeding disorder von Willebrand disease (VWD).Extensive studies have shown that several mutations identified in VWD patients cause an intracellular retention of VWF. However, the effects of such mutations on the formation and function of its storage organelle are largely unknown. This review gives an overview on the role of VWF in WPB biogenesis and summarizes the limited data on the WPBs formed by VWD-causing mutant VWF.

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