Re-estimating the Size of the Polar Bear Population in Western Hudson Bay

Lunn, Nicholas J.; Stirling, Ian; Andriashek, Dennis; Kolenosky, George B.

doi:10.14430/arctic1105

Cited by 26 publications

(12 citation statements)

References 16 publications

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“…The low densities at which polar bears occur and their relative invisibility against a background of white snow and ice have made capture-recapture the most common procedure used to estimate population size (Lunn et al, 1997;Stirling et al, 1999;Amstrup et al, 2001b;McDonald and Amstrup, 2001). Just as the Agreement was based upon the assumption that hunters share one population throughout the SBS, early population estimates were based upon the same assumption.…”

Section: Discussionmentioning

confidence: 99%

Allocating Harvests among Polar Bear Stocks in the Beaufort Sea

Amstrup¹,

Durner²,

Stirling³

et al. 2010

ARCTIC

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ABSTRACT. Recognition that polar bears are shared by hunters in Canada and Alaska prompted development of the "Polar Bear Management Agreement for the Southern Beaufort Sea." Under this Agreement, the harvest of polar bears from the southern Beaufort Sea (SBS) is shared between Inupiat hunters of Alaska and Inuvialuit hunters of Canada. Quotas for each jurisdiction are to be reviewed annually in light of the best available scientific information. Ideal implementation of the Agreement has been hampered by the inability to quantify geographic overlap among bears from adjacent populations. We applied new analytical procedures to a more extensive radiotelemetry data set than has previously been available to quantify that overlap and thereby improve the efficacy of the Agreement. We constructed a grid over the eastern Chukchi Sea and Beaufort Sea and used twodimensional kernel smoothing to assign probabilities to the distributions of all instrumented bears. A cluster analysis of radio relocation data identified three relatively discrete groups or "populations" of polar bears: the SBS, Chukchi Sea (CS), and northern Beaufort Sea (NBS) populations. With kernel smoothing, we calculated relative probabilities of occurrence for individual members of each population in each cell of our grid. We estimated the uncertainty in probabilities by bootstrapping. Availability of polar bears from each population varied geographically. Near Barrow, Alaska, 50% of harvested bears are from the CS population and 50% from the SBS population. Nearly 99% of the bears taken by Kaktovik hunters are from the SBS. At Tuktoyaktuk, Northwest Territories, Canada, 50% are from the SBS and 50% from the NBS population. We displayed the occurrence of bears from each population as probabilities for each cell in our grid and as maps with contour lines delineating changes in relative probability. This new analytical approach will greatly improve the accuracy of allocating harvest quotas among hunting communities and jurisdictions while assuring that harvests remain within the bounds of sustainable yield.Key words: Arctic, Beaufort Sea, boundaries, clustering, harvest allocation, kernel, management, polar bears, Ursus maritimus, population delineation, radiotelemetry, smoothing RÉSUMÉ. La reconnaissance du fait que l'ours polaire est chassé tant au Canada qu'en Alaska a initié la création de l'«Accord de gestion de l'ours polaire dans le sud de la mer de Beaufort». En vertu de cet accord, le prélèvement de l'ours polaire du sud de la mer de Beaufort est partagé entre les chasseurs inupiat de l'Alaska et les chasseurs inuvialuit du Canada. Les quotas pour chaque territoire de compétence doivent être révisés sur une base annuelle à la lumière de la meilleure information scientifique disponible. Une parfaite mise en oeuvre de l'accord a été rendue difficile en raison de l'impossibilité de quantifier le chevauchement géographique des populations d'ours voisines. En vue de quantifier ce chevauchement et d'améliorer ainsi l'efficacité de l'accord, on a appliqu...

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Section: Discussionmentioning

confidence: 99%

Allocating Harvests among Polar Bear Stocks in the Beaufort Sea

Amstrup¹,

Durner²,

Stirling³

et al. 2010

ARCTIC

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“…This was an increase from 1997 scientific population estimates and from the previous target number of 1200 animals (Lunn et al, 1997). The population estimate was raised in the 2005 agreement because community consultations revealed that Inuit harvesters felt there were more bears than the surveys indicated, and they estimated nine more bears could be harvested per year.…”

Section: Introductionmentioning

confidence: 97%

"The Time of the Most Polar Bears": A Co-management Conflict in Nunavut

Dowsley¹,

Wenzel²

2009

ARCTIC

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ABSTRACT. Since the 1990s, Inuit traditional knowledge (Inuit Qaujimajatuqangit) has taken on a substantial role in polar bear management in the Canadian territory of Nunavut through its direct use in quota-setting procedures. A co-management conflict has arisen from an increase of hunting quotas in January 2005 for Inuit living in the Baffin Bay and Western Hudson Bay polar bear population areas. The quotas were based on Inuit observations and their conclusion that these polar bear populations had increased. Scientific information suggests that climate change has concentrated polar bears in areas where humans are more likely to encounter them, but that the populations are in decline as a result of overhunting and climate-change effects on demographic rates. During consultations with wildlife managers and through other interviews in 2005, Inuit indicated their lack of support for quota reductions. Discussions with Inuit reveal two categories of problems that, though couched in the polar bear management issue, involve the co-management system and the integration of Inuit and scientific knowledge more generally. The first relates to direct observations of the environment by both Inuit and scientists and the synthesis of such information. The second relates to Inuit conceptualizations of human-animal relationships and the incorporation of scientific studies and management into that relationship. These problems reveal that differences between Inuit Qaujimajatuqangit and scientific knowledge are not fully understood and accounted for within the co-management system and that the system does not effectively integrate Inuit cultural views into management.Key words: Inuit, polar bears, Ursus maritimus, co-management, Inuit Qaujimajatuqangit, traditional ecological knowledge, climate change, Baffin Bay, western Hudson Bay RÉSUMÉ. Depuis les années 1990, les connaissances traditionnelles des Inuits (Inuit Qaujimajatuqangit) jouent un grand rôle dans la gestion des ours polaires du territoire canadien du Nunavut et ce, grâce au recours direct aux quotas. Un conflit de co-gestion s'est déclaré en raison de l'augmentation des quotas de chasse en janvier 2005 chez les Inuits vivant dans les régions peuplées d'ours polaires de la baie de Baffin et de l'ouest de la baie d'Hudson. Les quotas avaient été établis en fonction des observations faites par les Inuits et de leur conclusion selon laquelle les populations d'ours polaires étaient à la hausse. Pour leur part, les données scientifiques laissent entendre que le changement climatique a fait en sorte que les ours polaires se concentrent dans des régions où les humains sont plus susceptibles de les rencontrer, mais que les populations connaissent une diminution en raison de la chasse abusive et des effets du changement climatique sur les taux démographiques. Dans le cadre de consultations avec des gestionnaires de la faune et d'entrevues réalisées en 2005, les Inuits ont mentionné qu'ils n'appuyaient pas la réduction des quotas. D'après les discussions entretenues avec les Inuit...

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“…During the summer and early autumn, our study area is frequented by a large proportion of the Western Hudson Bay population of polar bears which come ashore during the months when Hudson Bay is ice free (Stirling et al 1977;Derocher and Stirling 1990;Stirling et al 2004;Stapleton et al 2014a). Population dynamics and habitat use of this population has been extensively studied (e.g., Derocher and Stirling 1995;Lunn et al 1997;Regehr et al 2007;Cherry et al 2013), yet virtually nothing is known about polar bearhuman interactions outside communities in this region. In late summer and autumn, bears (primarily adult males) congregate at Cape Churchill in the north-eastern corner of the Park (Latour 1981).…”

Section: Study Sitementioning

confidence: 99%

Temporal aspects of polar bear (Ursus maritimus) occurrences at field camps in Wapusk National Park, Canada

et al. 2017

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Interaction between polar bears (Ursus maritimus) and people is a growing concern for both bear conservation and human safety in a warming Arctic climate. Consequently, the importance of monitoring temporal trends in the proximity of polar bears to people has become critical in managing human-polar bear conflicts. Such concerns are acute in Wapusk National Park in Manitoba, Canada on the Western Hudson Bay coast, where we deployed 18 camera traps at three remote field camps from 2010-2014 (~22,100 camera-days) to monitor the frequency and timing of bears' visits to those facilities. Following seasonal breakup of Hudson Bay's sea ice polar bear occurrences at these camps increased throughout the summer and into fall (low in May-July and increasing sharply through August-November and then approaching zero in December when Hudson Bay freezes). We quantified age and sex class and estimated body condition of bears visiting the camps: adult males were most prevalent at Nester One camp close to where adult males congregate at Cape Churchill, whereas the two camps farther south were visited more frequently by females with dependent young, likely traveling to and from a known maternal denning area. Few subadults were observed. As expected, body condition scores declined throughout the on-shore season. Our method of monitoring polar bear occurrence on shore is robust, cost-effective, and non-invasive, and so may provide an economical complement to data gathered through more conventional techniques.Keywords: Climate change, Hudson Bay, human-wildlife conflict, non-invasive, polar bears, Ursus maritimus, Wapusk National Park Cite this article as: Laforge, M.P., Clark, D.A., Schmidt, A.L. et al. Polar Biol (2017) 40: 1661. The final publication is available at https://link.springer.com/article/10.1007/s00300-017-2091-6 2 Introduction Current scientific knowledge of the causes and dynamics of conflicts between people and polar bears is insufficient for managing such conflicts; a problem that has become increasingly urgent as changes in the Arctic climate accelerate (Osvyanikov 1996;Clark 2003;Clark et al. 2012;Boisen 2014). Polar bears (Ursus maritimus) depend on sea ice in order to catch seals, which constitute the majority of their total annual diet. Where sea ice melts entirely in the summer, bears move onto shore and feed only opportunistically (Ramsay and Hobson 1991). As such, polar bears are particularly vulnerable to further reductions in the total number of days in which sea ice is present, which ultimately affects reproductive success, survival, and long-term population sustainability (Stirling et al. 1999;Derocher et al. 2004). Climate change driven alteration of sea ice dynamics have resulted in changes in polar bear habitat use (Ferguson et al. 2000;Pilfold et al. 2015). Earlier ice break-up has also been associated with increased mortality in juvenile, sub-adult and senescent polar bears (Regehr et al. 2007). Although it is well established that reduced sea ice is detrimental to polar bear populations (...

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Re-estimating the Size of the Polar Bear Population in Western Hudson Bay

Cited by 26 publications

References 16 publications

Allocating Harvests among Polar Bear Stocks in the Beaufort Sea

Allocating Harvests among Polar Bear Stocks in the Beaufort Sea

"The Time of the Most Polar Bears": A Co-management Conflict in Nunavut

Temporal aspects of polar bear (Ursus maritimus) occurrences at field camps in Wapusk National Park, Canada

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