scholarly journals Prevalence of Echinococcus granulosus and Taenia hydatigena in caribou in north-central Canada

Rangifer ◽  
1996 ◽  
Vol 16 (4) ◽  
pp. 331 ◽  
Author(s):  
Donald C. Thomas
Keyword(s):  
Echinococcus Granulosus ◽  
Rangifer Tarandus ◽  
Infection Intensity ◽  
Parasite Prevalence ◽  
Predation Rate ◽  
Older Individuals ◽  
Taenia Hydatigena ◽  
North Central ◽  
Central Canada ◽  
Few Data

There are few data on the prevalence and infection intensity of parasites in large samples of caribou (Rangifer tarandus). Therefore, differences related to sex, age, and season are unknown. The effect of parasites on the health and condition of caribou also is poorly known. From 1980 through 1987, 1258 barren-ground caribou (R.t. groenlandicus) were collected from the Beverly herd in north-central Canada. The prevalence in lungs of cysts of the hydatid tapeworm (Echinococcus granulosus) increased significantly with age of caribou. Prevalence in females was 2% in the 2-5 year class and 8% in older individuals. Cysts were more prevalent in young females compared with young males. Reductions in physical condition and fecundity were not statistically significant. The prevalence of Taenia hydatigena cysts in livers increased significantly with age of host but not with sex and condition of the hosts. The use of parasite prevalence as an index of predation rate is discussed.

scholarly journals Fire - caribou - winter range relationships in northern Canada

Rangifer ◽  
1996 ◽  
Vol 16 (2) ◽  
pp. 57 ◽  
Author(s):  
D.C. Thomas ◽  
S.J. Barry ◽  
G. Alaie
Keyword(s):  
Rangifer Tarandus ◽  
Fire Suppression ◽  
Age Classes ◽  
The West ◽  
North Central ◽  
Winter Range ◽  
Peak Biomass ◽  
Central Canada ◽  
Cladina Rangiferina ◽  
Terrestrial Lichen

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.

scholarly journals The late winter diets of barren-ground caribou in North-Central Canada

Rangifer ◽  
1986 ◽  
Vol 6 (2) ◽  
pp. 305 ◽  
Author(s):  
Donald C. Thomas ◽  
David P. Hervieux
Keyword(s):  
Rangifer Tarandus ◽  
Late Winter ◽  
North Central ◽  
Winter Range ◽  
Barren Ground ◽  
South Central ◽  
Conifer Needles ◽  
Central Canada ◽  
Winter Diets ◽  
Composite Samples

Rumen samples from 104 barren-ground caribou (Rangifer tarandus groenlandicus) collected in March 1980 and 1981 at 18 sites on the winter range in south-central Northwest Territories (NWT) and northern Saskatchewan were examined microscopically for relative occurrence of plant fragments. The composition of plant fragments in the rumens of calves did not differ from that in older caribou. Samples were homogeneous within sites and among them. Therefore we analyzed composite samples for each site and then pooled the data. Terricolous fruticose and foliose lichens averaged 68.5 ± 1.5% (SE) ot tallied fragments at all 18 sites, followed by conifer needles (11.9 ± 1.2%), green leaves of Vactinium spp., Ledum spp., and other shrubs and iorbs (5.6 ± 0.6%), twigs and bark (5.5 ± 0.4%), bryophytes (4.9 ± 0.6%) and 3.6% unidentified. The lichen component consisted of 8.4 ± 1.5% Stereocaulon spp., 46.9 ± 2.6% other fruticose lichens (largely Cladina spp., Cladonia spp., and Cetraria spp.), and 13.2 ± 1.5% foliose lichens (largely Peltigera spp.). A comparison of rumen contents with the average relative abundance of plants found in feeding craters at 13 sites suggests that use of plant species was not always proportionate to their occurrence.

scholarly journals A life table for female barren-ground caribou in north-central Canada

Rangifer ◽  
1990 ◽  
Vol 10 (3) ◽  
pp. 177 ◽  
Author(s):  
Donald C. Thomas ◽  
Samuel J. Barry
Keyword(s):  
Life Table ◽  
Rangifer Tarandus ◽  
Sampling Error ◽  
Sampling Period ◽  
Cohort Size ◽  
North Central ◽  
Pooled Data ◽  
Barren Ground ◽  
Average Survival ◽  
Central Canada

A survivorship curve and cohort-specific life table were developed for female barren-ground caribou (Rangifer tarandus groenlandicus) sampled from the Beverly herd from 1980 through 1987. Significant (P~< 0.05)differences among yearly samples in the age distributions of females>2.5 years old were attributed to sampling error and real cohort size fluctuations caused by variations in productivity. Pooled data overcame much of that variation and the resultant quadratic-fit curve and life table are believed to yield about average survival/mortality statistics over the 8-year sampling period. Mortality rates increased progressively from 10.6% between age 2 and 3 years to 22.4% between age 10 and 11 years and accelerated thereafter.

Kill rate by wolves on moose in the Yukon

2000 ◽  
Vol 78 (1) ◽  
pp. 49-59 ◽  
Author(s):  
R D Hayes ◽  
A M Baer ◽  
U Wotschikowsky ◽  
A S Harestad
Keyword(s):  
Canis Lupus ◽  
Snow Depth ◽  
Prey Density ◽  
Large Scale ◽  
Rangifer Tarandus ◽  
Prey Selection ◽  
Ecological Factors ◽  
Predation Rate ◽  
Wolf Predation ◽  
Kill Rate

We studied the kill rate by wolves (Canis lupus) after a large-scale wolf removal when populations of wolves, moose (Alces alces), and woodland caribou (Rangifer tarandus caribou) were all increasing. We followed a total of 21 wolf packs for 4 winters, measuring prey selection, kill rates, and ecological factors that could influence killing behavior. Wolf predation was found to be mainly additive on both moose and caribou populations. Kill rates by individual wolves were inversely related to pack size and unrelated to prey density or snow depth. Scavenging by ravens decreased the amount of prey biomass available for wolves to consume, especially for wolves in smaller packs. The kill rate by wolves on moose calves was not related to the number of calves available each winter. Wolves did not show a strong switching response away from moose as the ratio of caribou to moose increased in winter. The predation rate by wolves on moose was best modeled by the number and size of packs wolves were organized into each winter.

scholarly journals Taeniid cestodes in a wolf pack living in a highly anthropic hilly agro-ecosystem

Parasite ◽  
2021 ◽  
Vol 28 ◽  
pp. 10
Author(s):  
Fabio Macchioni ◽  
Francesca Coppola ◽  
Federica Furzi ◽  
Simona Gabrielli ◽  
Samuele Baldanti ◽  
...  
Keyword(s):  
Echinococcus Granulosus ◽  
Microscopic Examination ◽  
One Health ◽  
Toxocara Canis ◽  
Wolf Population ◽  
Cestode Species ◽  
Taenia Hydatigena ◽  
Predator Prey ◽  
Zoonotic Infections ◽  
Faecal Samples

The Italian wolf population in human-modified landscapes has increased greatly in the last few decades. Anthropisation increases the risk of transmission of many zoonotic infections and in this context, control of taeniid cestode species needs to be addressed from a One Health perspective. Predator-prey interactions are at the root of taeniid cestode transmission, and the wolf plays a key role in the maintenance and transmission of taeniids. To date, all available data on the taeniids of wolves in Italy refer to populations living in a wild habitat. Between 2018 and 2019, we investigated taeniids in a wolf pack living in a highly anthropic hilly agro-ecosystem. Thirty-eight faecal samples were collected and analysed, 4 of which were also genetically characterised for individual wolves and belonged to three different animals. Samples collected were analysed microscopically and by molecular analysis in order to identify the taeniid species. Taeniid eggs were detected in 34.2% (13/38) of samples. Within samples positive to taeniid eggs only Echinococcus granulosus s.s. and Taenia hydatigena were identified in 26.3% and 10.5% of the samples, respectively. On microscopic examination, Capillaria spp., Ancylostomatidae and Toxocara canis eggs, Crenosoma vulpis larvae, and coccidian oocysts were also found. The combination of low biodiversity of taeniid species with a high occurrence of E. granulosus s.s. recorded in this study could be the consequence of a deeper link occurring between wolves and livestock in human-modified landscapes than in wild settings.

The effect of oxfendazole on Echinococcus granulosus and Taenia hydatigena infections in dogs

1979 ◽  
Vol 26 (3) ◽  
pp. 389-390 ◽  
Author(s):  
M.A. Gemmell ◽  
P.D. Johnstone ◽  
G. Oudemans
Keyword(s):  
Echinococcus Granulosus ◽  
Taenia Hydatigena
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