Reindeer Activity on Hardangervidda

Gaare, E.; Thomson, Brian R.; Kjos‐Hanssen, Odd

doi:10.1007/978-3-642-66276-8_27

Cited by 18 publications

(22 citation statements)

References 3 publications

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“…The day length in early and mid winter in Norway is 25% and 38%, respectively, compared to 15%) and 25% in central Yukon. It is not surprising, therefore, that Gaare et al (1975) presented an early winter cycle similar to our mid winter cycle (one very distinct lying peak) and a mid winter cycle similar to our late winter cycle (two distinct lying peaks). Furthermore, Gaare et al (1975) indicated that their observation period in mid winter was only from 1.5 hours after sunrise to 1.5 hours before sunset, thus yielding an overestimate of percent lying compared to our estimates.…”

Section: Discussionsupporting

confidence: 81%

“…In particular, the latitude, date, and time of daily observations are important when comparing winter activity among different herds. For example, comparing our results in early and mid winter to data presented by Gaare et al (1975) could be misleading. They observed Norwegian herds at approximately 60°N compared to 65°N for our study.…”

Section: Discussioncontrasting

confidence: 57%

“…2). Herds in Norway (Gaare et al, 1975), which exhibited the least variation in percent lying, were located at the most southerly latitudes. Our data (65°N latitude) generally exhibit a lower early winter minimum in lying and a higher late winter maximum.…”

Section: Discussionmentioning

confidence: 96%

“…One factor that complicates a direct comparison of percent lying among studies is the observation that Rangifer cue their activity to sunrise (Gaare et al, 1975;Thomson, 1977;Roby, 1978;Erriksson etui, 1981), and that day length (percent of a day occurring between sunrise and sunset) affects activity pattern (Erriksson et ai, 1981). Thus, since winter ranges are located at different latitudes and winter studies have occurred at different times, our objective in this paper is to define the relationship between day length and percent lying and compare studies based on this relationship.…”

Section: Introductionmentioning

confidence: 99%

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Winter ecology of the Porcupine caribou herd, Yukon: Part III, Role of day length in determining activity pattern and estimating percent lying

Russell¹,

Martell²

1986

Ran

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Data on the activity pattern, proportion of time spent lying and the length of active and lying periods in winter are presented from a 3 year study on the Porcupine caribou herd. Animals were most active at sunrise and sunset resulting in from one (late fall, early and mid winter) to two (early fall and late winter) to three (spring) intervening lying periods. Mean active/lying cycle length decreased from late fall (298 mm) to early winter (238 min), increased to a peak in mid winter (340 min) then declined in late winter (305 min) and again in spring (240 min). Mean length of the lying period increased throughout the 3 winter months from 56 min m early winter to 114 min in mid winter and 153 min in late winter. The percent of the day animals spent lying decreased from fall to early winter, increased throughout the winter and declined in spring. This pattern was related, in part, to day length and was used to compare percent lying among herds. The relationship is suggested to be a means of comparing quality of winter ranges.

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Section: Discussionsupporting

confidence: 81%

Section: Discussioncontrasting

confidence: 57%

Section: Discussionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

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Winter ecology of the Porcupine caribou herd, Yukon: Part III, Role of day length in determining activity pattern and estimating percent lying

Russell¹,

Martell²

1986

Ran

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“…Several authors have emphasized the usefulness of activity studies in judging the relative nutritional status of Rangifer and/or range condition of a herd (Segal 1962, Gaare et al 1975, Reimers 1980, Roby 1980. From June 1978 through April 1980, the Denali caribou herd was studied to assess the role of energetics/nutrition in the decline of the herd from approximately 20.000 -30.000 animals during 1942 (Murie 1944) to the low of 1.000 -1.500 animals during this study.…”

Section: Introductionmentioning

confidence: 99%

Seasonal activity of the Denali caribou herd, Alaska

Boertje¹

1985

Ran

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Summary: Activity of female and young caribou in the Denali herd was studied from June 1978 through April 1980 to help assess the food availability/nutritional status of this reduced population. No nutritional stress was evident as inferred by the greater activity of Denali caribou in late winter compared with starving caribou in West Greenland and by the low proportion of time spent grazing in spring compared with reindeer on overgrazed ranges in Norway. Also, low proportions of time were spent running from insects due to relatively few insects and a high availability of insect-relief sites. A low proportion of time was spent cratering due to windswept conditions. Activity budgets calculated from complete active-rest cycles and accompanied by the duration of active and rest periods may be useful indicators of relative food availability/nutritional status, particularly in late winter/early spring. Duration of active periods is presumably most strongly related to rumen fill, and, thus, food availability. Duration of rest periods was not significantly different among seasons (P<0.05), except when insects, rutting bulls, and, presumably, mushroom-searching altered active-rest cycles.

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Diversity of Biomass and Nitrogen Distribution Among Plant Species in Arctic and Alpine Tundra Ecosystems

Pastor

1995

Ecological Studies

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Reindeer Activity on Hardangervidda

Cited by 18 publications

References 3 publications

Winter ecology of the Porcupine caribou herd, Yukon: Part III, Role of day length in determining activity pattern and estimating percent lying

Winter ecology of the Porcupine caribou herd, Yukon: Part III, Role of day length in determining activity pattern and estimating percent lying

Seasonal activity of the Denali caribou herd, Alaska

Diversity of Biomass and Nitrogen Distribution Among Plant Species in Arctic and Alpine Tundra Ecosystems

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