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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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Quota and harvest of adult moose within wolf territories compared to control areas.Quota and hunter harvest of adult moose (males and females pooled) within a) wolf territories (n = 22) and b) control areas during five years prior to wolf establishment and five years with wolf presence. The vertical line in a) indicates the first year with wolf presence.
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pone.0119957.g003: Quota and harvest of adult moose within wolf territories compared to control areas.Quota and hunter harvest of adult moose (males and females pooled) within a) wolf territories (n = 22) and b) control areas during five years prior to wolf establishment and five years with wolf presence. The vertical line in a) indicates the first year with wolf presence.

Mentions: Quotas allocated for adult moose (2.75 ± 0.18) were higher than the actual harvest (2.10 ± 0.16). There was no statistically significant interaction with time (Table 3, Fig. 3a) indicating that the actual harvest followed the same trend as the quotas allocated over the study period. The largest difference between quotas and harvest during the 10-year period occurred between year five and year six (the difference increased by 110%, F1, 42 = 6.23, p = 0.017, ηp2 = 0.13). Similarly, for control areas the quotas allocated were higher (2.65 ± 0.14) than actual hunter harvest (2.08 ± 0.13), and showed no interaction with time (Table 3, Fig. 3b), but with the largest difference between years occurring between year eight and year nine (the difference decreased by 54%, F1, 42 = 4.81, p = 0.034, ηp2 = 0.10). Comparing quotas between wolf territories and control areas showed that there were no difference (Table 4) but that quotas decreased with time (meanyear 1 = 3.09 ± 0.37, meanyear 10 = 2.01 ± 0.27, Table 4, Fig. 3a-b). There was a tendency of a statistically significant interaction with time (p = 0.055, Table 4) indicating that quotas decreased with time in wolf territories but remained similar in control areas. A comparison of quota development with time between wolf territories and control areas showed that the largest difference between consecutive years occurred between year five and year six where quotas remained similar in control areas but was reduced in wolf territories (F1, 42 = 5.39, p = 0.025, ηp2 = 0.11).


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

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

Quota and harvest of adult moose within wolf territories compared to control areas.Quota and hunter harvest of adult moose (males and females pooled) within a) wolf territories (n = 22) and b) control areas during five years prior to wolf establishment and five years with wolf presence. 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.g003: Quota and harvest of adult moose within wolf territories compared to control areas.Quota and hunter harvest of adult moose (males and females pooled) within a) wolf territories (n = 22) and b) control areas during five years prior to wolf establishment and five years with wolf presence. The vertical line in a) indicates the first year with wolf presence.
Mentions: Quotas allocated for adult moose (2.75 ± 0.18) were higher than the actual harvest (2.10 ± 0.16). There was no statistically significant interaction with time (Table 3, Fig. 3a) indicating that the actual harvest followed the same trend as the quotas allocated over the study period. The largest difference between quotas and harvest during the 10-year period occurred between year five and year six (the difference increased by 110%, F1, 42 = 6.23, p = 0.017, ηp2 = 0.13). Similarly, for control areas the quotas allocated were higher (2.65 ± 0.14) than actual hunter harvest (2.08 ± 0.13), and showed no interaction with time (Table 3, Fig. 3b), but with the largest difference between years occurring between year eight and year nine (the difference decreased by 54%, F1, 42 = 4.81, p = 0.034, ηp2 = 0.10). Comparing quotas between wolf territories and control areas showed that there were no difference (Table 4) but that quotas decreased with time (meanyear 1 = 3.09 ± 0.37, meanyear 10 = 2.01 ± 0.27, Table 4, Fig. 3a-b). There was a tendency of a statistically significant interaction with time (p = 0.055, Table 4) indicating that quotas decreased with time in wolf territories but remained similar in control areas. A comparison of quota development with time between wolf territories and control areas showed that the largest difference between consecutive years occurred between year five and year six where quotas remained similar in control areas but was reduced in wolf territories (F1, 42 = 5.39, p = 0.025, ηp2 = 0.11).

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