Predation rate by wolves on the Porcupine caribou herd
Large migratory catibou {Rangifer tarandus) herds in the Arctic tend to be cyclic, and population trends are mainly driven by changes in forage or weather events, not by predation. We estimated daily kill rate by wolves on adult caribou in winter, then constructed a time and space dependent model to...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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Septentrio Academic Publishing
2000-04-01
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| Series: | Rangifer |
| Subjects: | |
| Online Access: | https://septentrio.uit.no/index.php/rangifer/article/view/1624 |
| _version_ | 1818056361276080128 |
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| author | Robert D. Hayes Donald E. Russell |
| author_facet | Robert D. Hayes Donald E. Russell |
| author_sort | Robert D. Hayes |
| collection | DOAJ |
| description | Large migratory catibou {Rangifer tarandus) herds in the Arctic tend to be cyclic, and population trends are mainly driven by changes in forage or weather events, not by predation. We estimated daily kill rate by wolves on adult caribou in winter, then constructed a time and space dependent model to estimate annual wolf (Canis lupus) predation rate (P annual) on adult Porcupine caribou. Our model adjusts predation seasonally depending on caribou distribution: Pannual = SIGMAdaily* W *Ap(2)*Dp. In our model we assumed that wolves killed adult caribou at a constant rate (Kdaily, 0.08 caribou wolf1 day1) based on our studies and elsewhere; that wolf density (W) doubled to 6 wolves 1000 km2-1 on all seasonal ranges; and that the average area occupied by the Porcupine caribou herd (PCH) in eight seasonal life cycle periods (Dp ) was two times gteater than the area described by the outer boundaries of telemetry data (Ap /1000 km2). Results from our model projected that wolves kill about 7600 adult caribou each year, regardless of herd size. The model estimated that wolves removed 5.8 to 7.4% of adult caribou as the herd declined in the 1990s. Our predation rate model supports the hypothesis of Bergerud that spacing away by caribou is an effective anti-predatory strategy that greatly reduces wolf predation on adult caribou in the spring and summer. |
| first_indexed | 2024-12-10T12:27:37Z |
| format | Article |
| id | doaj.art-37d8b77c2f95433c947272beee826014 |
| institution | Directory Open Access Journal |
| issn | 1890-6729 |
| language | English |
| last_indexed | 2024-12-10T12:27:37Z |
| publishDate | 2000-04-01 |
| publisher | Septentrio Academic Publishing |
| record_format | Article |
| series | Rangifer |
| spelling | doaj.art-37d8b77c2f95433c947272beee8260142022-12-22T01:48:55ZengSeptentrio Academic PublishingRangifer1890-67292000-04-0120510.7557/2.20.5.16241520Predation rate by wolves on the Porcupine caribou herdRobert D. HayesDonald E. RussellLarge migratory catibou {Rangifer tarandus) herds in the Arctic tend to be cyclic, and population trends are mainly driven by changes in forage or weather events, not by predation. We estimated daily kill rate by wolves on adult caribou in winter, then constructed a time and space dependent model to estimate annual wolf (Canis lupus) predation rate (P annual) on adult Porcupine caribou. Our model adjusts predation seasonally depending on caribou distribution: Pannual = SIGMAdaily* W *Ap(2)*Dp. In our model we assumed that wolves killed adult caribou at a constant rate (Kdaily, 0.08 caribou wolf1 day1) based on our studies and elsewhere; that wolf density (W) doubled to 6 wolves 1000 km2-1 on all seasonal ranges; and that the average area occupied by the Porcupine caribou herd (PCH) in eight seasonal life cycle periods (Dp ) was two times gteater than the area described by the outer boundaries of telemetry data (Ap /1000 km2). Results from our model projected that wolves kill about 7600 adult caribou each year, regardless of herd size. The model estimated that wolves removed 5.8 to 7.4% of adult caribou as the herd declined in the 1990s. Our predation rate model supports the hypothesis of Bergerud that spacing away by caribou is an effective anti-predatory strategy that greatly reduces wolf predation on adult caribou in the spring and summer.https://septentrio.uit.no/index.php/rangifer/article/view/1624wolfcaribouPorcupine herdpredation rateCanis lupuskill rate |
| spellingShingle | Robert D. Hayes Donald E. Russell Predation rate by wolves on the Porcupine caribou herd Rangifer wolf caribou Porcupine herd predation rate Canis lupus kill rate |
| title | Predation rate by wolves on the Porcupine caribou herd |
| title_full | Predation rate by wolves on the Porcupine caribou herd |
| title_fullStr | Predation rate by wolves on the Porcupine caribou herd |
| title_full_unstemmed | Predation rate by wolves on the Porcupine caribou herd |
| title_short | Predation rate by wolves on the Porcupine caribou herd |
| title_sort | predation rate by wolves on the porcupine caribou herd |
| topic | wolf caribou Porcupine herd predation rate Canis lupus kill rate |
| url | https://septentrio.uit.no/index.php/rangifer/article/view/1624 |
| work_keys_str_mv | AT robertdhayes predationratebywolvesontheporcupinecaribouherd AT donalderussell predationratebywolvesontheporcupinecaribouherd |