Action: Set hunting quotas based on target species population trends
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- Three studies evaluated the effects of setting hunting quotas for mammals based on target species population trends. One study each was in Canada, Spain and Norway.
COMMUNITY RESPONSE (0 STUDIES)
POPULATION RESPONSE (3 STUDIES)
- Abundance (2 studies): Two studies, in Spain and Norway, found that restricting hunting and basing quotas on population targets enabled population increases for Pyrenean chamois and Eurasian lynx.
- Survival (1 study): A before-and-after study in Canada found that setting harvest quotas based on population trends, and lengthening the hunting season, did not decrease the number of cougars killed by hunters.
BEHAVIOUR (0 STUDIES)
Management of wildlife species that are regarded as game animals may involve setting hunting quotas that are designed to enable the population to reach or remain at a particular level. Whilst many hunting systems use quotas, the studies included here are those based on mammal species with particular local conservation concerns rather than where quotas are based purely on maximising the harvest.
Supporting evidence from individual studies
A before-and-after study in 1990–1991 in boreal forest in Alberta, Canada (Ross et al. 1996) found that setting harvest quotas based on the population trends of the target species, and increasing the length of the hunting season, did not decrease the number of cougars Puma concolor killed by hunters. After setting harvest quotas, the number of cougars killed was higher (54 animals) than before setting of harvest quotas (33 animals). In 1981–1989 radio collars were attached to 44 cougars and data collected used to estimate the population size. The area was divided into 11 Cougar Management Areas and quotas were set at 10% of the estimated population for each area. A further quota of 50% of the total harvest quota was set for female cougars. When either quota was reached, the hunting season within a specific area was closed.
A study in 1995–2007 in mixed forest, cliffs and meadows across three mountain massifs in Navarre and Aragon, Spain (Herrero et al. 2010) found that, following imposition of hunting restrictions, populations of Pyrenean chamois Rupicapra pyrenaica pyrenaica increased. Results were not tested for statistical significance. The population at one massif rose from at least 33 in 1995 to at least 136 (an average growth rate of 15%/year) in 2007 and, at another massif, from at least 144 in 1996 to at least 455 (11%/year) in 2007. A third massif was occupied by eight chamois from at least 2002, with 11 there in 2007. The first two massifs cross regional jurisdictions. Hunting did not occur in one region, but was allowed in the other up to 1993, when it was temporarily banned. Limited hunting resumed in this region in 2006, based on 5% annual harvest. Hunting was not carried out in the third massif. Chamois were surveyed from dawn until midday in June and November each year, in 1995–2007.
A study in 1996–2008 in primarily forested areas in Norway (Linnell et al. 2010) found that adaptive management, including basing hunting quotas on population trends, enabled Eurasian lynx Lynx lynx populations to recover after a population decline. Three years after modification of hunting quotas, the population of Lynx was higher (453 animals) than prior to modifications (259 animals). Before modifications of quotas, lynx populations had dropped from 411–486 to 259 over an eight-year period. Lynx harvests were uncapped up to 1992. From 1994, responsibility for setting hunting quotas was devolved to 18 counties and then transferred to eight regional units in 2005. The number of lynx family groups was estimated by collating records of lynx tracks along with records of young animals found dead or killed by vehicles or hunters. These data were extrapolated to form overall population estimates for 1996–2008.
- Ross P.I., Jalkotzy M.G. & Gunson J.R. (1996) The quota system of cougar harvest management in Alberta. Wildlife Society Bulletin, 24, 490-494
- Herrero J., Garin I., Prada C. & Garcia-Serrano A. (2010) Inter-agency coordination fosters the recovery of the Pyrenean chamois Rupicapra pyrenaica pyrenaica at its western limit. Oryx, 44, 529-532
- Linnell J.D.C., Broseth H., Odden J. & Nilsen E.B. (2010) Sustainably harvesting a large carnivore? Development of Eurasian lynx populations in Norway during 160 years of shifting policy. Environmental Management, 45, 1142-1154