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Response of moose hunters to predation following wolf return in Sweden.

Wikenros C, Sand H, Bergström R, Liberg O, Chapron G - PLoS ONE (2015)

Bottom Line: However, the reduction in hunter harvest was stronger within wolf territories compared to control areas without wolves.The reduction in harvest was larger in small (500-800 km2) compared to large (1,200-1,800 km2) wolf territories.We show that the re-colonization of wolves may result in an almost instant functional response by another large predator-humans-that reduced the potential for a direct numerical effect on the density of wolves' main prey, the moose.

View Article: PubMed Central - PubMed

Affiliation: Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, Riddarhyttan, Sweden.

ABSTRACT

Background: Predation and hunter harvest constitute the main mortality factors affecting the size and dynamics of many exploited populations. The re-colonization by wolves (Canis lupus) of the Scandinavian Peninsula may therefore substantially reduce hunter harvest of moose (Alces alces), the main prey of wolves.

Methodology/principal findings: We examined possible effects of wolf presence on hunter harvest in areas where we had data before and after wolf establishment (n = 25), and in additional areas that had been continuously exposed to wolf predation during at least ten years (n = 43). There was a general reduction in the total number of moose harvested (n = 31,827) during the ten year study period in all areas irrespective of presence of wolves or not. However, the reduction in hunter harvest was stronger within wolf territories compared to control areas without wolves. The reduction in harvest was larger in small (500-800 km2) compared to large (1,200-1,800 km2) wolf territories. In areas with newly established wolf territories moose management appeared to be adaptive with regard to both managers (hunting quotas) and to hunters (actual harvest). In these areas an instant reduction in moose harvest over-compensated the estimated number of moose killed annually by wolves and the composition of the hunted animals changed towards a lower proportion of adult females.

Conclusions/significance: We show that the re-colonization of wolves may result in an almost instant functional response by another large predator-humans-that reduced the potential for a direct numerical effect on the density of wolves' main prey, the moose. Because most of the worlds' habitat that will be available for future colonization by large predators are likely to be strongly influenced by humans, human behavioural responses may constitute a key trait that govern the impact of large predators on their prey.

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Related in: MedlinePlus

Harvest of moose within wolf territories compared to control areas.Total harvest of moose (males, females and calves pooled) during a) five years prior to wolf establishment and five years with wolf presence (n = 25) compared to control areas, and b) ten years with presence of wolves (n = 43) compared to control areas. The vertical line in a) indicates the first year with wolf presence.
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pone.0119957.g001: Harvest of moose within wolf territories compared to control areas.Total harvest of moose (males, females and calves pooled) during a) five years prior to wolf establishment and five years with wolf presence (n = 25) compared to control areas, and b) ten years with presence of wolves (n = 43) compared to control areas. The vertical line in a) indicates the first year with wolf presence.

Mentions: The total number of harvested moose did not differ between wolf territories (mean ± 95% CI = 3.70 ± 0.26) and control areas (3.68 ± 0.22), but decreased with time (meanyear 1 = 4.49 ± 0.64, meanyear 10 = 2.82 ± 0.41, B = -0.24 ± 0.055, Table 1, Fig. 1a). This pattern was also evident for all single categories of moose (Table 1). A statistically significant interaction effect between time and type of area (wolf territories and control areas, Table 1) for the total number of harvested moose and for females separately showed that the reduction in harvest was larger within wolf territories compared to control areas (Fig. 1a). As the reduction in harvest within wolf territories compared to control areas was mainly a result of a decreased number of females harvested, the composition of the hunted animals changed after wolf establishment. The largest effect between consecutive years occurred between year five and year six (the first year with presence of wolves) for both the total number of harvested moose (F1, 48 = 14.05, p < 0.001, ηp2 = 0.23, Fig. 1a) and for females separately (F1, 48 = 6.71, p = 0.013, ηp2 = 0.12).


Response of moose hunters to predation following wolf return in Sweden.

Wikenros C, Sand H, Bergström R, Liberg O, Chapron G - PLoS ONE (2015)

Harvest of moose within wolf territories compared to control areas.Total harvest of moose (males, females and calves pooled) during a) five years prior to wolf establishment and five years with wolf presence (n = 25) compared to control areas, and b) ten years with presence of wolves (n = 43) compared to control areas. The vertical line in a) indicates the first year with wolf presence.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4390345&req=5

pone.0119957.g001: Harvest of moose within wolf territories compared to control areas.Total harvest of moose (males, females and calves pooled) during a) five years prior to wolf establishment and five years with wolf presence (n = 25) compared to control areas, and b) ten years with presence of wolves (n = 43) compared to control areas. The vertical line in a) indicates the first year with wolf presence.
Mentions: The total number of harvested moose did not differ between wolf territories (mean ± 95% CI = 3.70 ± 0.26) and control areas (3.68 ± 0.22), but decreased with time (meanyear 1 = 4.49 ± 0.64, meanyear 10 = 2.82 ± 0.41, B = -0.24 ± 0.055, Table 1, Fig. 1a). This pattern was also evident for all single categories of moose (Table 1). A statistically significant interaction effect between time and type of area (wolf territories and control areas, Table 1) for the total number of harvested moose and for females separately showed that the reduction in harvest was larger within wolf territories compared to control areas (Fig. 1a). As the reduction in harvest within wolf territories compared to control areas was mainly a result of a decreased number of females harvested, the composition of the hunted animals changed after wolf establishment. The largest effect between consecutive years occurred between year five and year six (the first year with presence of wolves) for both the total number of harvested moose (F1, 48 = 14.05, p < 0.001, ηp2 = 0.23, Fig. 1a) and for females separately (F1, 48 = 6.71, p = 0.013, ηp2 = 0.12).

Bottom Line: However, the reduction in hunter harvest was stronger within wolf territories compared to control areas without wolves.The reduction in harvest was larger in small (500-800 km2) compared to large (1,200-1,800 km2) wolf territories.We show that the re-colonization of wolves may result in an almost instant functional response by another large predator-humans-that reduced the potential for a direct numerical effect on the density of wolves' main prey, the moose.

View Article: PubMed Central - PubMed

Affiliation: Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, Riddarhyttan, Sweden.

ABSTRACT

Background: Predation and hunter harvest constitute the main mortality factors affecting the size and dynamics of many exploited populations. The re-colonization by wolves (Canis lupus) of the Scandinavian Peninsula may therefore substantially reduce hunter harvest of moose (Alces alces), the main prey of wolves.

Methodology/principal findings: We examined possible effects of wolf presence on hunter harvest in areas where we had data before and after wolf establishment (n = 25), and in additional areas that had been continuously exposed to wolf predation during at least ten years (n = 43). There was a general reduction in the total number of moose harvested (n = 31,827) during the ten year study period in all areas irrespective of presence of wolves or not. However, the reduction in hunter harvest was stronger within wolf territories compared to control areas without wolves. The reduction in harvest was larger in small (500-800 km2) compared to large (1,200-1,800 km2) wolf territories. In areas with newly established wolf territories moose management appeared to be adaptive with regard to both managers (hunting quotas) and to hunters (actual harvest). In these areas an instant reduction in moose harvest over-compensated the estimated number of moose killed annually by wolves and the composition of the hunted animals changed towards a lower proportion of adult females.

Conclusions/significance: We show that the re-colonization of wolves may result in an almost instant functional response by another large predator-humans-that reduced the potential for a direct numerical effect on the density of wolves' main prey, the moose. Because most of the worlds' habitat that will be available for future colonization by large predators are likely to be strongly influenced by humans, human behavioural responses may constitute a key trait that govern the impact of large predators on their prey.

Show MeSH
Related in: MedlinePlus