Physical and reproductive characteristics of an expanding woodland caribou population (Rangifer tarandus caribou) in northern Labrador

1981 ◽  
Vol 59 (10) ◽  
pp. 1929-1940 ◽  
Author(s):  
G. R. Parker
Keyword(s):  
Rangifer Tarandus ◽  
Adult Mortality ◽  
Lean Body Weight ◽  
High Survival ◽  
Rangifer Tarandus Caribou ◽  
River Population ◽  
Female Ratio ◽  
Reproductive Maturity ◽  
Fat Reserves ◽  
George River

One hundred and fifty-nine caribou (Rangifer tarandus caribou) were collected from the area of precalving distribution of the George River population in northern Labrador between April 3 and 15, 1980. The sample revealed that caribou of northern Labrador reach physical and reproductive maturity earlier than most other free-ranging caribou populations in North America. Females attained mature values for lean body weight and shoulder height by 34 months and for total body length, heart girth, and mandible length by 46 months. Pregnancy rates for females 22, 34, and 46 months and older were 43, 90, and 95%, respectively. Measurements of fat reserves showed George River females to be in superior physical condition during spring migration than caribou on mainland Northwest Territories. Fat reserves, however, were substantially less than comparable values for females collected from the same population in March, 1976. The calf: pregnant female ratio was 42:100, suggesting a 1st year rate of mortality of approximately 58%. The most common internal parasites were Cysticercus tenuicollis and Fascioloides magna. It is concluded that the recent growth of the George River population has resulted from early female physical and reproductive maturity, low adult mortality, and high survival of calves.

Fascioloides magna (Trematoda) in woodland caribou (Rangifer tarandus caribou) of the George River herd, Labrador

1988 ◽  
Vol 66 (2) ◽  
pp. 475-479 ◽  
Author(s):  
Murray W. Lankester ◽  
Stu Luttich
Keyword(s):  
Rangifer Tarandus ◽  
Age Groups ◽  
Liver Weight ◽  
Rangifer Tarandus Caribou ◽  
Woodland Caribou ◽  
Intensity Of Infection ◽  
Fascioloides Magna ◽  
The Mean ◽  
George River ◽  
Liver Flukes

Fifty-eight percent of woodland caribou (Rangifer tarandus caribou) of the George River herd, Labrador, were infected with up to 110 giant American liver flukes (Fascioloides magna). The prevalence and intensity of infection did not differ between 2 sampling years or between sexes. Prevalence tended to increase with age while intensity did not differ among age groups. Liver weight increased with intensity of infection but condition, as measured by the mean depth of back fat, did not differ between infected and uninfected animals. Caribou must be considered a suitable host of F. magna since the growth and maturation of the parasite and lesions produced in Rangifer resemble those in deer and wapiti.

Survival of radio-collared caribou (Rangifer tarandus caribou) from the George River herd, Nouveau-Québec – Labrador

1990 ◽  
Vol 68 (2) ◽  
pp. 276-283 ◽  
Author(s):  
Brian J. Hearn ◽  
Stuart N. Luttich ◽  
Michel Crête ◽  
Maria B. Berger
Keyword(s):  
Cause Of Death ◽  
Rangifer Tarandus ◽  
Survival Rates ◽  
Rangifer Tarandus Caribou ◽  
Annual Survival ◽  
Lower Survival ◽  
Fecundity Rate ◽  
Rate Of Increase ◽  
George River ◽  
Age And Sex

Between September 1983 and June 1987, 175 caribou (Rangifer tarandus caribou) from the George River caribou herd were captured and radio-collared. By October 1987, 42 of those had died: 15 were apparently killed by predators, 8 were legally shot, 4 appeared to have died proximally from malnutrition, 1 died from an accident, and cause of death could not be determined for 14 others. Seasonal and annual survival rates were estimated most precisely for adult (≥ 24 months) females, but a consistent trend towards lower survival at the end of the study period was evident in all age and sex groups. Decreasing summer survival was responsible for the lowering of annual survival rates, as winter survival was relatively constant over the study period. Using our calculated age-specific survival rates, and estimates of age-specific fecundity, the survival–fecundity rate of increase (rs) for the female segment of the herd was 0.12 for 1983–1984 and −0.01 for 1986–1987. Decreasing summer survival thus appears to have been of greatest importance in reducing rs to zero and halting the growth of the herd. Density-dependent mechanisms acting on the George River caribou herd appear different from those described for caribou herds regulated by winter forage.

Wolf predation in a multiple-ungulate system in northern British Columbia

1998 ◽  
Vol 76 (8) ◽  
pp. 1551-1569 ◽  
Author(s):  
A T Bergerud ◽  
J P Elliott
Keyword(s):  
British Columbia ◽  
Canis Lupus ◽  
Birth Rate ◽  
Rangifer Tarandus ◽  
Adult Mortality ◽  
Recruitment Rate ◽  
Wolf Predation ◽  
Rate Of Increase ◽  
Ovis Dalli ◽  
Hunting Statistics

Caribou (Rangifer tarandus), elk (Cervus canadensis), moose (Alces alces), and Stone's sheep (Ovis dalli stonei) were either decreasing or stable in numbers in two areas in northeastern British Columbia in 1981-1982, prior to reductions in wolf (Canis lupus) numbers. Following the reduction of wolf numbers, recruitment improved 2-5 times for all four species, and all populations increased, based on either hunting statistics, census results, and (or) recruitments greater than 24 offspring at 9 months of age per 100 females. Recruitment of offspring at 9 months of age, when regressed against wolf numbers, declined with decelerating slopes for all four species. This inverse functional response is hypothesized to result from the preparturient spacing of females to reduce predation risk, and in this regard moose seem the least secure and sheep the most effectively spaced. For the four species, mean recruitment at 9 months of age that balanced adult mortality and provided a finite rate of increase of 1.00 was 24.16 ± 0.91 offspring/100 females (n = 11, coefficient of variation = 12.5%). The predicted recruitment rate for all four species in the absence of wolves was 53-57 offspring/100 females. But the birth rate of moose was much higher than those of the other species, indicating greater loss to other factors of which bear predation may be the greatest. Following wolf reductions of 60-86% of entire travelling packs, the wolves quickly recolonized the removal zones, with rates of increase ranging from 1.5 to 5.6.

Pleistocene ungulates from the Bow River gravels at Cochrane, Alberta

1968 ◽  
Vol 5 (6) ◽  
pp. 1467-1488 ◽  
Author(s):  
C. S. Churcher
Keyword(s):  
United States ◽  
Late Pleistocene ◽  
Rangifer Tarandus ◽  
Ovis Canadensis ◽  
Southern United States ◽  
Rangifer Tarandus Caribou ◽  
Cervus Canadensis ◽  
North Bank ◽  
Middle And Late Pleistocene

Five ungulates are reported from gravels comprising the second major terrace above the Bow River's north bank at Cochrane, Alberta. These ungulates are Cervus canadensis (wapiti), Rangifer tarandus (caribou), Ovis canadensis (mountain sheep), Bison occidentalis (extinct western bison), and Equus conversidens (extinct Mexican ass). E. conversidens was previously known from middle and late Pleistocene beds of the southern United States and Mexico and is here reported from the post-Wisconsin Pleistocene of Alberta and possibly Saskatchewan. Radiocarbon analysis of Bison bones from the gravels yielded two dates that averaged 11 065 B.P.

scholarly journals A synthesis of scale-dependent ecology of the endangered mountain caribou in British Columbia, Canada

Rangifer ◽  
2008 ◽  
Vol 28 (1) ◽  
pp. 33
Author(s):  
Robert Serrouya ◽  
Bruce N. McLellan ◽  
Clayton D. Apps ◽  
Heiko U. Wittmer
Keyword(s):  
British Columbia ◽  
Rangifer Tarandus ◽  
Spatial Scales ◽  
Management Strategies ◽  
Population Level ◽  
Limiting Factors ◽  
Conservation Strategies ◽  
Integrative Approach ◽  
Rangifer Tarandus Caribou ◽  
Multi Scale

Mountain caribou are an endangered ecotype of woodland caribou (Rangifer tarandus caribou) that live in highprecipitation, mountainous ecosystems of southeastern British Columbia and northern Idaho. The distribution and abundance of these caribou have declined dramatically from historical figures. Results from many studies have indicated that mountain caribou rely on old conifer forests for several life-history requirements including an abundance of their primary winter food, arboreal lichen, and a scarcity of other ungulates and their predators. These old forests often have high timber value, and understanding mountain caribou ecology at a variety of spatial scales is thus required to develop effective conservation strategies. Here we summarize results of studies conducted at three different spatial scales ranging from broad limiting factors at the population level to studies describing the selection of feeding sites within seasonal home ranges of individuals. The goal of this multi-scale review is to provide a more complete picture of caribou ecology and to determine possible shifts in limiting factors across scales. Our review produced two important results. First, mountain caribou select old forests and old trees at all spatial scales, signifying their importance for foraging opportunities as well as conditions required to avoid alternate ungulates and their predators. Second, relationships differ across scales. For example, landscapes dominated by roads and edges negatively affect caribou survival, but appear to attract caribou during certain times of the year. This juxtaposition of fine-scale behaviour with broad-scale vulnerability to predation could only be identified through integrated multi-scale analyses of resource selection. Consequently we suggest that effective management strategies for endangered species require an integrative approach across multiple spatial scales to avoid a focus that may be too narrow to maintain viable populations. Abstract in Norwegian / Sammendrag:Skala-avhengig økologi og truet fjellvillrein i Britisk ColumbiaFjellvillreinen i de nedbørsrike fjellområdene i sørøstre Britisk Columbia og nordlige Idaho som er en truet økotype av skogsreinen (Rangifer tarandus caribou), har blitt kraftig redusert både i utbredelse og antall. Mange studier har vist at denne økotypen er avhengig av vinterføden hengelav i gammel barskog hvor det også er få andre klovdyr og dermed få predatorer. Slik skog er også viktige hogstområder, og å forstå økologien til fjellvillreinen i forskjellige skaleringer er derfor nødvendig for å utvikle forvaltningsstrategier som kan berge og ta vare på denne reinen. Artikkelen gir en oversikt over slike arbeider: fra studier av begrensende faktorer på populasjonsnivå til studier av sesongmessige beiteplasser på individnivå. Hensikten er å få frem et mer helhetlig perspektiv på fjellvillreinen og finne hvordan de begrensende faktorene varierer etter skaleringen som er benyttet i studiet. Oversikten vår frembragte to viktige resultater; 1) Uansett skalering så velger dyrene gammel skog og gamle trær. 2) Dyrenes bruk av et område kan variere med benyttet skalering, for eksempel vil landskap utbygd med veier og hogstflater være ufordelaktig for overlevelsen, men synes likevel å kunne tiltrekke fjellvillreinen til visse tider av året. Forholdet mellom atferd ut fra fin-skalering og stor-skalering sårbarhet hva gjelder predasjon, ville kun blitt avdekket ved flere-skaleringsanalyse av hvordan ressursene benyttes. Ut fra dette foreslår vi at forvaltningsstrategier for truete bestander som eksempelvis fjellvillreinen, må baseres på tilnærminger ut fra ulike skaleringer for å hindre at et for snevert perspektiv kan begrense muligheten for vedvarende levedyktighet.

scholarly journals Biochemical indicators of condition, nutrition and nitrogen excretion in caribou

Rangifer ◽  
1996 ◽  
Vol 16 (4) ◽  
pp. 201 ◽  
Author(s):  
Ray Case
Keyword(s):  
Body Composition ◽  
Adult Female ◽  
Rangifer Tarandus ◽  
Nitrogen Excretion ◽  
Late Winter ◽  
Marrow Fat ◽  
Urea Nitrogen ◽  
Biochemical Indicators ◽  
Fat Reserves ◽  
Nitrogen Concentrations

Urinary urea nitrogen to creatinine ratios, urinary Nt-methylhistidine to creatinine ratios, serum urea nitrogen concentrations (SUN mg/dl), and serum Nt-methylhistidine concentrations were compared with physical measures of body composition in adult female barren-ground caribou (Rangifer tarandus groenlandicus) from the Bathurst and Southampton Island herds during late winter. Body weight and UUC were used to estimate urinary urea nitrogen (urea-N) excretion in free ranging caribou. Only mean UUC reflected differences in fat reserves between populations. None of the biochemical indicators were directly related to body composition. However, elevated UUC were only observed in caribou with depleted fat reserves as demonstrated by low kidney fat index (KFK40) and/or reduced femur marrow fat (FMF<80). UUC greater than 0.25 were indicative of undernourished animals with depleted fat reserves. SUN and UN -MHC showed no clear relationship with fat reserves. The mean estimated daily urea-N excretion for adult female caribou in late winter was extremely low (0.11+0.01SE g urea-N/day, n=76, range=0.011-0.510). The results of my study suggest that UUC can be used to detect nutritionally stressed caribou with depleted fat reserves on lichen winter ranges.

scholarly journals Caribou Conservation: Restoring Trees on Seismic Lines in Alberta, Canada

Forests ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 185 ◽  
Author(s):  
Angelo Filicetti ◽  
Michael Cody ◽  
Scott Nielsen
Keyword(s):  
Boreal Forest ◽  
Rangifer Tarandus ◽  
Site Preparation ◽  
Tree Regeneration ◽  
Tree Density ◽  
Petroleum Exploration ◽  
Rangifer Tarandus Caribou ◽  
Mechanical Site Preparation ◽  
Undisturbed Forest ◽  
Seismic Lines

Seismic lines are narrow linear (~3–8 m wide) forest clearings that are used for petroleum exploration in Alberta’s boreal forest. Many seismic lines have experienced poor tree regeneration since initial disturbance, with most failures occurring in treed peatlands that are used by the threatened woodland caribou (Rangifer tarandus caribou). Extensive networks of seismic lines, which often reach densities of 40 km/km2, are thought to have contributed to declines in caribou. The reforestation of seismic lines is therefore a focus of conservation. Methods to reforest seismic lines are expensive (averaging $12,500 per km) with uncertainty of which seismic lines need which treatments, if any, resulting in inefficiencies in restoration actions. Here, we monitored the effectiveness of treatments on seismic lines as compared to untreated seismic lines and adjacent undisturbed reference stands for treed peatlands in northeast Alberta, Canada. Mechanical site preparation (mounding and ripping) increased tree density when compared to untreated lines, despite averaging 3.8-years since treatment (vs. 22 years since disturbance for untreated). Specifically, treated lines had, on average, 12,290 regenerating tree stems/ha, which is 1.6-times more than untreated lines (7680 stems/ha) and 1.5-times more than the adjacent undisturbed forest (8240 stems/ha). Using only mechanical site preparation, treated seismic lines consistently have more regenerating trees across all four ecosites, although the higher amounts of stems that were observed on treated poor fens are not significant when compared to untreated or adjacent undisturbed reference stands.

Sign in / Sign up

Export Citation Format

Share Document