scholarly journals Energy-expending behaviour in frightened caribou when dispersed singly or in small bands

Rangifer ◽  
1997 ◽  
Vol 17 (1) ◽  
pp. 44
Author(s):  
Otto Blehr
Keyword(s):  
Canis Lupus ◽  
Rangifer Tarandus ◽  
Look Back ◽  
Save Energy ◽  
The One ◽  
Rangifer Tarandus Groenlandicus

The behaviour of single, and small bands of caribou (Rangifer tarandus groenlandicus) when confronted by humans was compared with the energy—saving behaviour zoologists have ascribed to caribou in encounters with non-hunting wolves (Canis lupus). When confronted by me, or upon getting my scent, caribou ran away on all occasions. Their flight was occasionally interrupted by short stops to look back in my direction, but would continue on all occasions until they were out of sight. This behaviour is inconsistent with the one ascribed to caribou by zoologists when the intruder is a wolf instead of a human. In their view, the caribou stop their flight soon after the wolf gives up the chase, and accordingly save energy owing to their ability to distinguish between hunting and non-hunting wolves. However, small bands of caribou, as well as single animals, have never been observed to behave in this manner. On the contrary, the behaviour of caribou in such encounters is known to follow the same pattern as in their encounters with humans. Energy—saving behaviour is, however, sometimes observed when caribou become inquisitive about something in their surroundings. They will then readily approach as well as try to get down-wind of the object. When the object does not induce fear, it may simply be ignored, or charged before the caribou calm down. The effect of this "confirming behaviour" is that energy which would otherwise have been spent in needless flights from non-predators is saved.

scholarly journals Predation of a Barren-ground Caribou, Rangifer tarandus groenlandicus, by a Single Gray Wolf, Canis lupus, in Northern Manitoba, Canada

2010 ◽  
Vol 124 (3) ◽  
pp. 270
Author(s):  
Brian W. Kiss ◽  
Scott K. Johnstone ◽  
Robert P. Berger
Keyword(s):  
Canis Lupus ◽  
Rangifer Tarandus ◽  
Open Water ◽  
Gray Wolf ◽  
Small Section ◽  
Barren Ground ◽  
Rangifer Tarandus Groenlandicus

A single Gray Wolf (Canis lupus) was observed successfully trapping and predating a Barren-ground Caribou (Rangifer tarandus groenlandicus) in a small section of open water.

scholarly journals Caribou calf deaths from intraspecific strife — a debatable diagnosis

Rangifer ◽  
1986 ◽  
Vol 6 (2) ◽  
pp. 203
Author(s):  
Frank L. Miller ◽  
Anne Gunn
Keyword(s):  
Canis Lupus ◽  
Aggressive Behaviour ◽  
Small Area ◽  
Rangifer Tarandus ◽  
Alternative Explanation ◽  
Physical Contact ◽  
Short Period ◽  
Newborn Calves ◽  
Calf Mortality ◽  
Rangifer Tarandus Groenlandicus

led to the deaths of several newborn barren-ground caribou (Rangifer tarandus groenlandicus) calves within a short period of time and on a small area. This event took place during calving in June 1958 on the calving ground of the Beverly caribou herd in the Northwest Territories. The lack of other examples of multiple deaths of newborn caribou calves from intraspecific strife and our findings on the same calving ground during a study of calf mortality in June 1981, 1982, and 1983 and a study of cow-calf behaviour in June 1981 and 1982 cause us to question the published explanation. As we rarely saw aggressive behaviour among cows and newborn calves that involved actual physical contact and none that resulted in injury or death and because we found instances of multiple killings of calves by wolves {Canis lupus) we suggest that a probable alternative explanation of the 1958 findings is surplus killing by wolves. Most importantly, only direct observation of an event allows separation of a death caused by injuries due to intraspecific strife from a death caused by accidental injuries.

Surplus killing as exemplified by wolf predation on newborn caribou

1985 ◽  
Vol 63 (2) ◽  
pp. 295-300 ◽  
Author(s):  
Frank L. Miller ◽  
Anne Gunn ◽  
Eric Broughton
Keyword(s):  
Northwest Territories ◽  
Canis Lupus ◽  
Rangifer Tarandus ◽  
The Other ◽  
Wolf Predation ◽  
Barren Ground ◽  
Rangifer Tarandus Groenlandicus

We searched for newborn calf carcasses of migratory barren-ground caribou (Rangifer tarandus groenlandicus) in June 1982 in the Northwest Territories. On 17 June, we found 34 calves killed by wolves (Canis lupus), clumped in a 3-km2 area. The calves had been killed apparently within minutes of each other and about 24 h before being found. Wolves had not fed on 17 of the carcasses and had only partially eaten the other 17. Ground observations illustrate the speed of and efficiency with which wolves can kill calves: a single wolf killed three calves on one occasion and three and possibly four calves on a second occasion at average kill rates of 1 calf/min, and 1 calf/8 min or 1 calf/6 min between the first and last deaths. We attributed the surplus killing of newborn caribou calves to their high densities and their vulnerability on the calving grounds. We recommend that a distinction be made between "surplus killing" and "excessive killing" by predators.

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.

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 Age-specific fecundity of the Beverly herd of barren-ground caribou

Rangifer ◽  
1990 ◽  
Vol 10 (3) ◽  
pp. 257 ◽  
Author(s):  
Donald C. Thomas ◽  
Samuel J. Barry
Keyword(s):  
Rangifer Tarandus ◽  
Barren Ground ◽  
Rangifer Tarandus Groenlandicus

The age-specific fecundity of the Beverly herd of barren-ground caribou (Rangifer tarandus groenlandicus) was monitored each winter from 1979-80 through 1986-87. Fecundity in 840 females increased with age from 12% in yearlings to 86% at age 5 years and it did not decline in old (> 11 yr) females. Significant variations occurred among winters and even between two subherds in one winter. Reproductive abnormalities were detected in 2 of 840 females and a probable resorption in 1 of 420 females collected in March. Only about 5% of the fetuses were conceived late, possibly by repeat ovulators. Combining survival and fecundity data yielded age-specific calf production, which indicated that, for example, 54% of calves were born to females 3-6 years old.

Apollon Musagète

2018 ◽  
Author(s):  
Nancy Reynolds
Keyword(s):  
Twentieth Century ◽  
Turning Point ◽  
Igor Stravinsky ◽  
String Orchestra ◽  
George Balanchine ◽  
Clear Cut ◽  
Ballets Russes ◽  
Look Back ◽  
The One ◽  
New Phase

Apollon Musagète, premiered by Serge Diaghilev’s Ballets Russes in 1928, and most widely known since the 1950s as Apollo, is the oldest work by choreographer George Balanchine still in active repertoire. For its age alone the ballet is significant, but it also marked a new phase in the development of Balanchine’s artistic philosophy. In 1945 he wrote, "Apollo I look back on as a turning point. In its discipline and restraint … the score was a revelation. It seemed to tell me that I could dare not to use everything, that I too could eliminate. I began to see how I could clarify … by reducing what seemed to be multiple possibilities to the one which is inevitable" (Balanchine qtd in Lederman 1975: 81). Such was Balanchine’s influence that what was a turning point for him was also a turning point for ballet in the twentieth century. The score that so influenced Balanchine was composed, by Igor Stravinsky, for a small string orchestra. Diaghilev described it as "an amazing work, extraordinarily calm, and with greater clarity than anything he has so far done, [with] filigree counterpoint [a]round transparent, clear-cut themes, all in the major key; [it is] somehow music not of this world, but from somewhere above" (Diaghilev qtd in White 1979: 342).

scholarly journals Diet of Grey Wolves (Canis lupus) During Calving in a Moose– Caribou System in Northern Ontario

2018 ◽  
Vol 131 (3) ◽  
pp. 215-220
Author(s):  
Rob Found ◽  
Ashley A. D. McLaren ◽  
Arthur R. Rodgers ◽  
Brent R. Patterson
Keyword(s):  
Canis Lupus ◽  
Rangifer Tarandus ◽  
Castor Canadensis ◽  
Northern Ontario ◽  
Southern Limit ◽  
Proximate Cause ◽  
Declining Populations ◽  
Dietary Component ◽  
A Minor ◽  
The Impact

Grey Wolves (Canis lupus) are a leading proximate cause of declining populations of Woodland Caribou (Rangifer tarandus), a threatened species. Although predation on adult caribou has been well documented, less is known about predation on neonatal calves. We used scat analysis to examine the diet of wolves in an area of Ontario overlapping the receding southern limit of caribou occurrence. Wolves consumed mostly Moose (Alces americanus; 82.7%), followed by American Beaver (Castor canadensis; 10.9%), caribou (3.1%), and Snowshoe Hare (Lepus americanus; 1.5%). This low use of caribou is consistent with other evidence suggesting that caribou are a minor dietary component of wolves in this system; however, because most caribou consumption consists of calves, the impact on this slowly reproducing species may still be significant.

Morphology of the barren-ground caribou ovary

1978 ◽  
Vol 56 (8) ◽  
pp. 1684-1696 ◽  
Author(s):  
T. Charles Dauphiné Jr.
Keyword(s):  
Connective Tissue ◽  
Rangifer Tarandus ◽  
Corpora Lutea ◽  
Seasonal Incidence ◽  
Histological Techniques ◽  
Northern Canada ◽  
Ovary Weight ◽  
Barren Ground ◽  
Ovarian Stroma ◽  
Rangifer Tarandus Groenlandicus

Reproductive tracts were collected from 532 female caribou (Rangifer tarandus groenlandicus) in northern Canada over a [Formula: see text]-year period. Ovaries were weighed and scrutinized by gross and histological techniques. Ovaries of nulliparous and nongravid, parous cows responded to follicular fluctuations by increasing in weight in summer and declining in winter. Weights of ovaries from calves, yearlings, and 2 year olds overlapped extensively. Formation of corpora lutea of pregnancy more than doubled ovary weight. During gestation ovary weight declined and then partially recovered; it increased with age in pregnant cows. The number and size of follicles [Formula: see text] diameter increased with age until puberty, reaching greatest development just before the autumn rut. After puberty the seasonal incidence of such follicles remained stable except during gestation, when it declined. Corpora lutea of pregnancy regressed to form apparently permanent scars composed of vascular and connective tissue remnants. Secondary corpora lutea developed in 35% of the cows at or before conception and upon regression produced scars which were not permanent. Regressing corpora lutea of estrus also disappeared into the ovarian stroma, apparently within 1 year. In individual cows one ovary, selected at random, dominated in the production of ova and corpora lutea.

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