Pollination and Breeding System of Lowbush Blueberries, Vaccinium angustifolium Ait. and V. myrtilloides Michx. (Ericacaeae), in the Boreal Forest

Breeding systems and pollination requirements of two wild lowbush blueberries, Vaccinium angustifolium and V. myrtilloides, in the Canadian boreal forest in the Chapleau Crown Game Preserve, Ontario, were tested. Fruit production, size and seediness were significantly higher in samples exposed to natural pollination than in those cross- or self-pollinated by hand. There were no significant differences among artificial treatments (variously hand-pollinated and bagged) except when cross-pollination (xenogamy) was done by insect pins. In V. angustifolium, the density of flowering varied with forest age (canopy closure). It was most in open areas and least in the sites with the most mature forest. Although fruit-set and seediness varied among forest habitats of different ages, there were no significant differences between sites in forests of different ages. Thus, pollination seems to be similarly effective no matter the age of the forest. In both species, fruit-set in 1992, which had severe June frosts, was markedly poorer than that in 1993 when the flowers suffered little frost damage. The combined number of complete and incomplete seeds from the fruit among the breeding and pollination systems tested were similar; however, the ratio of complete seeds to total seeds was greater from cross-pollinated than from self-pollinated flowers. Our observations indicate that there is little natural fruit-set without insect-mediated cross-pollination and that cross-pollination provides much better fruit and seed-set than does self-pollination

Polar Bear Distribution and Abundance on the Southwestern Hudson Bay Coast During Open Water Season, in Relation to Population Trends and Annual Ice Patterns

In Hudson Bay, all the ice melts in summer, and the last areas to be ice-free (around mid-to-late July) are usually off the coasts of Manitoba and Ontario. Thus, all polar bears are forced ashore to fast until freeze-up in November (ca. four months). Pregnant females remain ashore for eight months. In most years from 1963 through 1997, aerial surveys to monitor polar bear populations were conducted along all or part of the coastline between Cape Churchill, Manitoba, and Cape Henrietta Maria, Ontario, in late August and early September. Satellite data, from which breakup and ice absence times could be estimated, first became available in 1971. The numbers of animals counted were tallied in two subareas within Manitoba and three within Ontario. We evaluated the coastal counts, along with independent data on the movements of tagged bears and annual patterns of ice breakup from 1971 through 1996. We concluded that 1) the coastal survey data reliably indicated the population trends in Manitoba and Ontario; 2) little exchange occurred between the Western Hudson Bay (Manitoba) and Southern Hudson Bay (Ontario) populations; 3) between 1971 and 2001, there was a statistically significant trend toward earlier breakup of sea ice off the Manitoba coast, but not off the Ontario coast; 4) the onset of ice absence along the coast had no significant relationship to the number of bears present in each sub-sampling area within either the Manitoba or the Ontario population, but did significantly influence the distribution of bears on the coastline of each province independently of the other; 5) timing of the surveys can influence the results; and 6) adult male and female bears both showed a high degree of fidelity to specific areas during summer, independent of the pattern of ice breakup.Dans la baie d'Hudson, toute la glace fond en été, et les dernières zones à être non englacées (du milieu à la fin de juillet environ) se trouvent généralement au large des côtes du Manitoba et de l'Ontario. Ainsi, tous les ours polaires sont forcés de rester sur la terre ferme et de jeûner jusqu'à l'engel en novembre (soit environ quatre mois). Les femelles gravides, elles, restent sur la terre ferme pendant huit mois. Presque chaque année entre 1963 et 1997, à la fin août et au début de septembre, on a effectué des relevés aériens pour surveiller les populations d'ours polaires le long du littoral entre Cape Churchill, au Manitoba, et Cape Henrietta-Maria, en Ontario. Les données satellitaires, qui ont permis d'estimer la période de la débâcle et celle de l'absence de glace, sont devenues disponibles à partir de 1971. Le nombre d'animaux repérés a été inventorié comme provenant de deux sous-zones à l'intérieur du Manitoba et de trois à l'intérieur de l'Ontario. On a évalué le dénombrement des relevés côtiers ainsi que des données indépendantes sur les déplacements d'ours marqués et les schémas annuels de débâcle de 1971 à la fin de 1996. On en a conclu que: 1) les données des relevés côtiers révélaient de façon fiable les tendances démographiques au Manitoba et en Ontario; 2) il n'y avait que peu d'échanges entre les populations de la baie d'Hudson occidentale (Manitoba) et de la baie d'Hudson méridionale (Ontario); 3) entre 1971 et 2001, il y a eu une tendance statistiquement significative à une débâcle précoce au large du littoral manitobain, mais pas au large du littoral ontarien; 4) le début de l'absence de glace le long de la côte n'avait pas de lien marqué avec le nombre d'ours présents dans chaque secteur de sous-échantillonnage, au sein de la population du Manitoba ou de celle de l'Ontario, mais cette absence de glace avait une forte incidence sur la distribution des ours le long de la côte de chaque province indépendamment l'une de l'autre; 5) le choix de l'époque des relevés peut influencer les résultats; et 6), durant l'été, les ours mâles comme femelles manifestaient une grande fidélité pour des secteurs spécifiques, indépendamment de l'évolution de la débâcle

Does Predation Influence the Seasonal and Diel Timing of Moose Calving in Central Ontario, Canada?

Birth synchrony is well documented among ungulates and is hypothesised to maximize neonate survival, either by minimizing the risk of predation through predator swamping or by synchronising birthing with increased seasonal food availability. We used encapsulated vaginal implant transmitters to locate and capture neonatal moose calves and document the seasonal and diel timing of parturition in two adjacent study areas with different predation pressure in central Ontario, Canada. We tested the hypothesis that predation promotes earlier and more synchronous birth of moose calves. Across both areas, proportionately more births occurred during the afternoon and fewer than expected occurred overnight. Mean date of calving averaged 1.5 days earlier and calving was also more synchronous in the study area with heavier predation pressure, despite average green-up date and peak Normalized Difference Vegetation Index date occurring 2 days later in this study area than in the area receiving lighter predation pressure. We encourage analysis of data on timing of parturition from additional study areas experiencing varying degrees of predation pressure to better clarify the influence of predation in driving seasonal and diel timing of parturition in temperate ungulate

Temporal variation in food habits of the American Black Bear (Ursus americanus) in the boreal forest of northern Ontario

We used scat analysis to investigate temporal variation in the food habits of American Black Bears (Ursus americanus) in the boreal forest of northern Ontario. Specifically, we examined whether there was a seasonal shift in foraging over three years (1990–1992) and which foods, if any, varied in occurrence among years. American Black Bears ate foods ranging from green vegetation in the spring to ants in mid-summer and berries and nuts in late summer and fall. Late summer berry forage, especially blueberries (Vaccinium spp.), varied greatly among years. American Black Bears in northern Ontario consumed a variety of foods opportunistically. Understanding how American Black Bears in northern Ontario exploit food resources and how these food items vary among years can provide insights into demographic processes and help wildlife managers better anticipate changes in the structure of the harvest of American Black Bears and in human–bear conflict levels. In northern Ontario, forest management practices that increase the availability of early successional species would be beneficial to American Black Bear populations

Pollination and Breeding System of Lowbush Blueberries, <em>Vaccinium angustifolium</em> Ait. and <em>V. myrtilloides</em> Michx. (Ericacaeae), in the Boreal Forest

Breeding systems and pollination requirements of two wild lowbush blueberries, Vaccinium angustifolium and V. myrtilloides, in the Canadian boreal forest in the Chapleau Crown Game Preserve, Ontario, were tested. Fruit production, size and seediness were significantly higher in samples exposed to natural pollination than in those cross- or self-pollinated by hand. There were no significant differences among artificial treatments (variously hand-pollinated and bagged) except when cross-pollination (xenogamy) was done by insect pins. In V. angustifolium, the density of flowering varied with forest age (canopy closure). It was most in open areas and least in the sites with the most mature forest. Although fruit-set and seediness varied among forest habitats of different ages, there were no significant differences between sites in forests of different ages. Thus, pollination seems to be similarly effective no matter the age of the forest. In both species, fruit-set in 1992, which had severe June frosts, was markedly poorer than that in 1993 when the flowers suffered little frost damage. The combined number of complete and incomplete seeds from the fruit among the breeding and pollination systems tested were similar; however, the ratio of complete seeds to total seeds was greater from cross-pollinated than from self-pollinated flowers. Our observations indicate that there is little natural fruit-set without insect-mediated cross-pollination and that cross-pollination provides much better fruit and seed-set than does self-pollination

Traditional Ecological Knowledge of Polar Bears in the Northern Eeyou Marine Region, Québec, Canada + Supplementary Appendix 1 (See Article Tools)

Polar bears are important socio-cultural symbols in the communities of the Eeyou Marine Region (EMR) in northwestern Québec, Canada. Members of the Cree communities in this region are generally not active polar bear hunters, but they encounter polar bears when fishing, trapping, or hunting during the ice-free season. A growing body of scientific evidence suggests that reduced annual sea ice cover in Hudson Bay has led to declines in body condition of polar bears in the local Southern Hudson Bay subpopulation and to a population decline in the neighboring Western Hudson Bay subpopulation. In June 2012, we conducted 15 semi-directed interviews on the subject of polar bear biology and climate change with local elders and hunters in three communities in the northern EMR: Wemindji, Chisasibi, and Whapmagoostui. The interviews held in Whapmagoostui included informants from Kuujjuarapik, the adjacent Inuit community. The interviews addressed knowledge gaps in the Recovery Strategy for Polar Bear in Ontario. Transcripts of the interviews were coded thematically and analyzed using both qualitative and quantitative methods. The interviews revealed important insights into polar bear distribution, terrestrial habitat use, denning, and foraging patterns. Participants were unanimous in their recognition of a warming climate and prolonged ice-free season in the area in recent years. However, communities differed in their observations on other issues, with latitudinal trends evident in observations of polar bear distribution, denning activity, and foraging habits. Communities also differed in their perception of the prevalence of problem polar bears and the conservation status of the species, with one-third of participants reporting that polar bears will be unaffected by, or even benefit from, longer ice-free periods. A majority of participants indicated that the local polar bear population was stable or increasing. Interviewees also identified future research priorities pertinent to the communities, and provided comments on the methods employed by polar bear biologists. Our results demonstrate that communities in the EMR have important knowledge about polar bear ecology and illustrate the unique opportunities and challenges of combining traditional ecological knowledge with wildlife science in the context of a rapidly changing subarctic environment.L’ours blanc revêt un caractère socioculturel important pour les communautés de la Région marine d’Eeyou (RME), située dans le nord-ouest de la province de Québec, au Canada. Bien que les Cris de ces communautés ne soient pas reconnus pour chasser particulièrement l’ours blanc, ils partagent le territoire avec l’ours blanc lors de leurs déplacements et activités de chasse, de pêche et de trappe. Un nombre croissant de preuves scientifiques suggère que la réduction annuelle de la couverture de glace dans la baie d’Hudson aurait causé une dégradation de la condition physique des ours blancs de la sous-population sud de la baie d’Hudson et un déclin de la sous-population voisine, dans l’ouest de la baie d’Hudson. En juin 2012, nous avons réalisé une série de 15 entrevues semi-dirigées concernant la biologie de l’ours blanc et les changements climatiques avec des aînés et des chasseurs de trois communautés de la portion nordique de la RME : Wemindji, Chisasibi et Whapmagoostui. Les entrevues tenues à Whapmagoostui ont inclus des répondants du village inuit adjacent, Kuujjuarapik. Les entrevues abordaient des lacunes au niveau des connaissances, telles que déterminées par le Programme de rétablissement de l’ours polaire en Ontario. Les entrevues ont été transcrites et codées par thèmes afin d’être analysées suivant des méthodes qualitatives et quantitatives. Les entrevues révèlent d’importantes informations relativement aux connaissances sur la distribution, l’utilisation des habitats terrestres, les aires de mise bas et les habitudes alimentaires des ours blancs. Les participants ont unanimement constaté le réchauffement du climat et la prolongation de la période libre de glace au cours des dernières années sur leur territoire d’activités. Cependant, les points de vue des participants diffèrent pour ce qui est de certains enjeux, selon un gradient latitudinal évident, concernant la distribution, les activités de mise bas et les habitudes alimentaires de l’espèce. Les perceptions des communautés diffèrent aussi relativement à la prévalence des ours blancs problématiques et en ce qui concerne le statut de conservation de l’espèce, avec le tiers des participants jugeant que les ours blancs ne seraient pas affectés, ou pourraient même bénéficier, d’une plus longue période libre de glace. Une majorité de participants indique que la population locale d’ours blancs est stable ou en augmentation. Enfin, les répondants ont indiqué les priorités de recherches pertinentes à leur communauté et partagé des commentaires sur les méthodes employées par les biologistes. Les résultats montrent que les communautés de la RME possèdent des connaissances importantes concernant l’écologie de l’ours blanc, illustrant ainsi les opportunités et les défis afin de combiner ces données à celles des sciences biologiques, ceci dans un contexte de changement rapide de l’environnement subarctique

Polar bear depredation of a thick-billed murre fledgling in open water at Prince Leopold Island, Nunavut

Sea-ice distribution and duration are declining across the circumpolar range of the polar bear (Ursus maritimus), resulting in a reduced access to ice-obligate seals, its primary prey. Consequently, polar bears may have increased reliance on alternative food sources in the future. Foraging on land is well documented but foraging in open water is less understood. We report the successful depredation of a thick-billed murre (Uria lomvia) in open water near Prince Leopold Island, Nunavut, and discuss implications for understanding the behavioural plasticity of polar bears and their opportunistic foraging patterns. _______________________________ View the supplementary vide

Re-assessing abundance of Southern Hudson Bay polar bears by aerial survey: effects of climate change at the southern edge of the range

The Southern Hudson Bay polar bear (Ursus maritimus Phipps, 1774) subpopulation is considered stable but conflicting evidence lends uncertainty to that designation. Capture-recapture studies conducted 1984-86 and 2003-05 and an aerial survey conducted 2011/12 suggested abundance was likely unchanged since the mid-1980s. However, body condition and body size declined since then, and duration of sea ice decreased by about 30 days. Due to conflicting information on subpopulation status and ongoing changes in sea ice, we conducted another aerial survey in 2016 to determine whether abundance had changed. We collected data via mark-recapture distance sampling and double-observer protocols. Results suggest abundance declined 17% from 943 bears (95% CI 658-1350) in 2011/12 to 780 (95% CI 590â 1029) in 2016. The proportion of yearlings declined from 12% of the population in 2011 to 5% in 2016, whereas the proportion of cubs remained similar (16% in 2011 vs. 19% in 2016) suggesting low survival of the 2015 cohort. In a warming Arctic, duration of sea ice is predicted to continue to decline in Hudson Bay affecting all ice-dependent wildlife; therefore, further monitoring of this subpopulation is warranted. We recommend a conservative approach to harvest management and repeating the aerial survey in 2021.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Establishing a definition of polar bear (\u3ci\u3eUrsus maritimus\u3c/i\u3e) health: A guide to research and management activities

The meaning of health for wildlife and perspectives on how to assess and measure health, are not well characterized. For wildlife at risk, such as some polar bear (Ursus maritimus) subpopulations, establishing comprehensive monitoring programs that include health status is an emerging need. Environmental changes, especially loss of sea ice habitat, have raised concern about polar bear health. Effective and consistent monitoring of polar bear health requires an unambiguous definition of health. We used the Delphi method of soliciting and interpreting expert knowledge to propose a working definition of polar bear health and to identify current concerns regarding health, challenges in measuring health, and important metrics for monitoring health. The expert opinion elicited through the exercise agreed that polar bear health is defined by characteristics and knowledge at the individual, population, and ecosystem level. The most important threats identified were in decreasing order: climate change, increased nutritional stress, chronic physiological stress, harvest management, increased exposure to contaminants, increased frequency of human interaction, diseases and parasites, and increased exposure to competitors. Fifteen metrics were identified to monitor polar bear health. Of these, indicators of body condition, disease and parasite exposure, contaminant exposure, and reproductive success were ranked asmost important. We suggest that a cumulative effects approach to research and monitoring will improve the ability to assess the biological, ecological, and social determinants of polar bear health and provide measurable objectives for conservation goals and priorities and to evaluate progress