Bears

Harry V. Reynolds, James A. Curatolo, Roland Quimby, Denning Ecology of Grizzly Bears in Northeastern Alaska, Bears: Their Biology and Management, Vol. 3, A Selection of Papers from the Third International Conference on Bear Research and Management, Binghamton, New York, USA, and Moscow, U.S.S.R., June 1974. IUCN Publications New Series no. 40 (1976), pp. 403-409

@article{doi1023073872790,
    author = "Reynolds, Harry V. and Curatolo, James A. and Quimby, Roland",
    title = "Denning Ecology of Grizzly Bears in Northeastern Alaska",
    year = "1976",
    journal = "Bears Their Biology and Management",
    abstract = "Harry V. Reynolds, James A. Curatolo, Roland Quimby, Denning Ecology of Grizzly Bears in Northeastern Alaska, Bears: Their Biology and Management, Vol. 3, A Selection of Papers from the Third International Conference on Bear Research and Management, Binghamton, New York, USA, and Moscow, U.S.S.R., June 1974. IUCN Publications New Series no. 40 (1976), pp. 403-409",
    url = "https://doi.org/10.2307/3872790",
    doi = "10.2307/3872790",
    openalex = "W2799894783"
}

@book{kurten1976the2,
    author = "Kurten, B",
    title = "The Cave Bear Story",
    year = "1976",
    publisher = "New York, Columbia University Press",
    note = "talkorigins\_source = {true}; raw\_reference = {Kurten, B., 1976, The Cave Bear Story: New York, Columbia University Press.}"
}

@misc{craighead1979track1,
    author = "Craighead, F. C",
    title = "Track of the Grizzly",
    year = "1979",
    howpublished = "San Francisco, Sierra Club Books",
    note = "talkorigins\_source = {true}; raw\_reference = {Craighead, F. C., 1979, Track of the Grizzly: San Francisco, Sierra Club Books.}"
}

G. William Vroom, Stephen Herrero, R. T. Ogilvie, The Ecology of Winter Den Sites of Grizzly Bears in Banff National Park, Alberta, Bears: Their Biology and Management, Vol. 4, A Selection of Papers from the Fourth International Conference on Bear Research and Management, Kalispell, Montana, USA, February 1977 (1980), pp. 321-330

@article{doi1023073872887,
    author = "Vroom, G. William and Herrero, Stephen and Ogilvie, R. T.",
    title = "The Ecology of Winter Den Sites of Grizzly Bears in Banff National Park, Alberta",
    year = "1980",
    journal = "Bears Their Biology and Management",
    abstract = "G. William Vroom, Stephen Herrero, R. T. Ogilvie, The Ecology of Winter Den Sites of Grizzly Bears in Banff National Park, Alberta, Bears: Their Biology and Management, Vol. 4, A Selection of Papers from the Fourth International Conference on Bear Research and Management, Kalispell, Montana, USA, February 1977 (1980), pp. 321-330",
    url = "https://doi.org/10.2307/3872887",
    doi = "10.2307/3872887",
    openalex = "W2801674195"
}

Black bears (Ursus americanus) were studied in northeastern Minnesota from 1969 through 1985 to determine (1) the annual cycle of foraging and social behavior, (2) changes in mother-offspring relationships from birth through maturity, (3) the influence of food availability on social behavior, movements, and population growth, and (4) important habitat components. Studies were most intensive during 1971-76 when 28 males and 55 females were radio-tracked. The study area had relatively few fruit and mast species and a frost-free growing season of only 118 days. Crop failures were common and reduced the reproductive rate to less than half the biological potential. Females first reproduced at 4-8 years of age (average 6.3 years), depending upon food supply, and produced subsequent litters at 2-4-year intervals (average 2.28 years). Litters averaged 2.38 cubs. Cub survival was 59-88%, depending on food supply in the year of conception and the year of birth. Bears that supplemented their diets with garbage reproduced nearly twice as fast as the above. Density was 1 bear/4.1−6.3 k⁢m2, including cubs. The annual cycle of behavior was closely tied to the annual cycle of plant growth and fruiting. Bears emerged from dens in late March or April, depending in part on weather, but females and subadults remained lethargic until late April or early May when aspen (Populus spp.) catkins and young green vegetation became available. Mature females then re-established territories averaging 9.6 k⁢m2, and mature males used overlapping mating ranges averaging 75 k⁢m2. Mating began about 10 June and was essentially completed by 9 July when fruit began to ripen in abundance. Foraging then became the main activity until fruit and nuts disappeared in late summer. Sixty-seven percent of the males and 40% of the females foraged >7 km outside their territories or mating ranges in late summer or early fall, moving up to 200 km away before returning for denning. Adult males that remained in their mating ranges after the mating season spent a disproportionate amount of time in the buffer zones between female territories rather than inside them. Despite generally solitary habits, bears behaved in accordance with kinship theory within a social order governed mainly by the distribution and abundance of food. Mothers recognized their independent offspring and tolerated them in their territories. Mothers avoided areas where their yearlings concentrated their activities, thereby allowing them to have nearly exclusive feeding areas. Young males voluntarily dispersed as subadults and settled 13-219 km away (average 61 km). Young females usually expanded their yearling ranges into adult territories. Mothers shifted away as their daughters expanded their ranges, thereby aiding daughters in obtaining territories. Adults of both sexes deterred immigration. The bears behaved as described above where food was dispersed, but formed hierarchies where food was clumped as at garbage dumps. There, female territories overlapped slightly, and males commonly tolerated individual distances of <2 m. Play was common among bears up to 4.7 years old around garbage dumps but was not seen elsewhere except among cubs. Adult females used garbage dumps in their territories but avoided other dumps where unfamiliar adult males congregated. The denning period was 5-7 months. Very fat bears abandoned food and entered dens in late September. Less fat bears that found food continued to feed as late as early November. Bears in northeastern Minnesota achieved a deeper hibernation than has been reported from regions with shorter denning periods. Hibernating bears commonly did not awaken in midwinter until after several minutes of prodding. Overwinter mortality was <1% regardless of den type, but lightweight yearlings starved after emergence in spring. Starvation was the main cause of death among cubs and yearlings, and gunshot was the main cause of death among older bears. Bears commonly roamed farther in northeastern Minnesota than has been reported from other regions. A larger area of unbroken habitat may be needed to maintain this population than would be needed where food is more reliable and abundant. Habitat management practices beneficial to bears in northeastern Minnesota are identified.

@article{openalexw1498603190,
    author = "Rogers, Lynn L.",
    title = "Effects of Food Supply and Kinship on Social Behavior Movements and Population Growth of Black Bears in Northeastern Minnesota USA",
    year = "1987",
    journal = "Digital Commons - USU (Utah State University)",
    abstract = "Black bears (Ursus americanus) were studied in northeastern Minnesota from 1969 through 1985 to determine (1) the annual cycle of foraging and social behavior, (2) changes in mother-offspring relationships from birth through maturity, (3) the influence of food availability on social behavior, movements, and population growth, and (4) important habitat components. Studies were most intensive during 1971-76 when 28 males and 55 females were radio-tracked. The study area had relatively few fruit and mast species and a frost-free growing season of only 118 days. Crop failures were common and reduced the reproductive rate to less than half the biological potential. Females first reproduced at 4-8 years of age (average 6.3 years), depending upon food supply, and produced subsequent litters at 2-4-year intervals (average 2.28 years). Litters averaged 2.38 cubs. Cub survival was 59-88\%, depending on food supply in the year of conception and the year of birth. Bears that supplemented their diets with garbage reproduced nearly twice as fast as the above. Density was 1 bear/4.1−6.3 k⁢m2, including cubs. The annual cycle of behavior was closely tied to the annual cycle of plant growth and fruiting. Bears emerged from dens in late March or April, depending in part on weather, but females and subadults remained lethargic until late April or early May when aspen (Populus spp.) catkins and young green vegetation became available. Mature females then re-established territories averaging 9.6 k⁢m2, and mature males used overlapping mating ranges averaging 75 k⁢m2. Mating began about 10 June and was essentially completed by 9 July when fruit began to ripen in abundance. Foraging then became the main activity until fruit and nuts disappeared in late summer. Sixty-seven percent of the males and 40\% of the females foraged >7 km outside their territories or mating ranges in late summer or early fall, moving up to 200 km away before returning for denning. Adult males that remained in their mating ranges after the mating season spent a disproportionate amount of time in the buffer zones between female territories rather than inside them. Despite generally solitary habits, bears behaved in accordance with kinship theory within a social order governed mainly by the distribution and abundance of food. Mothers recognized their independent offspring and tolerated them in their territories. Mothers avoided areas where their yearlings concentrated their activities, thereby allowing them to have nearly exclusive feeding areas. Young males voluntarily dispersed as subadults and settled 13-219 km away (average 61 km). Young females usually expanded their yearling ranges into adult territories. Mothers shifted away as their daughters expanded their ranges, thereby aiding daughters in obtaining territories. Adults of both sexes deterred immigration. The bears behaved as described above where food was dispersed, but formed hierarchies where food was clumped as at garbage dumps. There, female territories overlapped slightly, and males commonly tolerated individual distances of <2 m. Play was common among bears up to 4.7 years old around garbage dumps but was not seen elsewhere except among cubs. Adult females used garbage dumps in their territories but avoided other dumps where unfamiliar adult males congregated. The denning period was 5-7 months. Very fat bears abandoned food and entered dens in late September. Less fat bears that found food continued to feed as late as early November. Bears in northeastern Minnesota achieved a deeper hibernation than has been reported from regions with shorter denning periods. Hibernating bears commonly did not awaken in midwinter until after several minutes of prodding. Overwinter mortality was <1\% regardless of den type, but lightweight yearlings starved after emergence in spring. Starvation was the main cause of death among cubs and yearlings, and gunshot was the main cause of death among older bears. Bears commonly roamed farther in northeastern Minnesota than has been reported from other regions. A larger area of unbroken habitat may be needed to maintain this population than would be needed where food is more reliable and abundant. Habitat management practices beneficial to bears in northeastern Minnesota are identified.",
    openalex = "W1498603190"
}

@article{ross1988late,
    author = "Ross, P. I. and Hornbeck, G. E. and Horejsi, B. L.",
    title = "Late Denning Black Bears Killed by Grizzly Bear",
    year = "1988",
    journal = "Journal of Mammalogy",
    url = "https://doi.org/10.2307/1381638",
    doi = "10.2307/1381638",
    number = "4",
    openalex = "W2325076646",
    pages = "818-820",
    volume = "69"
}

@article{doi101016000632079190044a,
    author = "Blanchard, Bonnie M. and Knight, Richard R.",
    title = "Movements of yellowstone grizzly bears",
    year = "1991",
    journal = "Biological Conservation",
    url = "https://doi.org/10.1016/0006-3207(91)90044-a",
    doi = "10.1016/0006-3207(91)90044-a",
    openalex = "W1968230941"
}

We documented one instance of an adult male grizzly bear preying upon a black bear and four instances where circumstantial evidence suggested that grizzly bears (two cubs-of-the-year, one yearling female that was injured, and one adult male) had been preyed upon by conspecifics. We also examined feces of grizzly bears for bear remains. Remains of bears tended to be more common in spring feces and did not differ in frequency between early and late years of the study. Our observations generally support existing hypotheses concerning cannibalism among bears.

@article{doi1023071382078,
    author = "Mattson, David J. and Knight, Richard R. and Blanchard, Bonnie M.",
    title = "Cannibalism and Predation on Black Bears by Grizzly Bears in the Yellowstone Ecosystem, 1975-1990",
    year = "1992",
    journal = "Journal of Mammalogy",
    abstract = "We documented one instance of an adult male grizzly bear preying upon a black bear and four instances where circumstantial evidence suggested that grizzly bears (two cubs-of-the-year, one yearling female that was injured, and one adult male) had been preyed upon by conspecifics. We also examined feces of grizzly bears for bear remains. Remains of bears tended to be more common in spring feces and did not differ in frequency between early and late years of the study. Our observations generally support existing hypotheses concerning cannibalism among bears.",
    url = "https://doi.org/10.2307/1382078",
    doi = "10.2307/1382078",
    openalex = "W2089074342",
    references = "ross1988late"
}

@inproceedings{frank1995grizzly,
    author = "Frank, Martin R.",
    title = "Grizzly Bear",
    year = "1995",
    booktitle = "Proceedings of the 8th annual ACM symposium on User interface and software technology",
    url = "https://doi.org/10.1145/215585.215663",
    doi = "10.1145/215585.215663",
    openalex = "W1964098262",
    pages = "75-76",
    references = "doi101111146786591130093, doi101145169059169225, doi101145192426192466, doi101145225434225453"
}

This article addresses the taphonomic issues surrounding artifact-bear associations in Yarimburgaz Cave, northwestern Turkey. Our purpose is to evaluate the circumstances of bone assemblage formation in the Middle Pleistocene deposits of the cave, identifying the agencies responsible for the accumulations and the causes of bone damage before and following deposition. Pleistocene species representation, bone damage, body part representation, and mortality data indicate that cave bear remains in Yarimburgaz are unrelated to hominid use of the same site. None of the observations on the cave bear remains contradicts the expectations developed from modern wildlife accounts of modern bear behavior; these accumulations resulted from mortality normally associated with hibernation over many generations of den use. Nonursid carnivores also played roles in bone collection and/or modification. We conclude that at least three distinct biological processes contributed to the formation of the Middle Pleistocene faunas: hibernating bears, bone-collecting carnivores such as wolves, and hominids in descending order of importance. The Yarimburgaz faunas represent palimpsests or overlays of many short-term depositional events, the close spatial associations of which are explained by slow or uneven sedimentation rates inside the cave. Although occupations by hominids appear to have been ephemeral in nature, hominids ultimately discarded nearly 1700 stone artifacts in Yarimburgaz Cave. The hominids did not discard many ungulate bones in the same circumstances. These observations suggest that hominid foraging efforts focused on resources other than large game while at the cave. © 1996 John Wiley & Sons, Inc.

@article{doi101002sici15206548199607114279aidgea130co2z,
    author = "Stiner, Mary C. and Arsebük, Güven and Howell, F. Clark",
    title = "Cave bears and paleolithic artifacts in Yarimburgaz Cave, Turkey: Dissecting a palimpsest",
    year = "1996",
    journal = "Geoarchaeology",
    abstract = "This article addresses the taphonomic issues surrounding artifact-bear associations in Yarimburgaz Cave, northwestern Turkey. Our purpose is to evaluate the circumstances of bone assemblage formation in the Middle Pleistocene deposits of the cave, identifying the agencies responsible for the accumulations and the causes of bone damage before and following deposition. Pleistocene species representation, bone damage, body part representation, and mortality data indicate that cave bear remains in Yarimburgaz are unrelated to hominid use of the same site. None of the observations on the cave bear remains contradicts the expectations developed from modern wildlife accounts of modern bear behavior; these accumulations resulted from mortality normally associated with hibernation over many generations of den use. Nonursid carnivores also played roles in bone collection and/or modification. We conclude that at least three distinct biological processes contributed to the formation of the Middle Pleistocene faunas: hibernating bears, bone-collecting carnivores such as wolves, and hominids in descending order of importance. The Yarimburgaz faunas represent palimpsests or overlays of many short-term depositional events, the close spatial associations of which are explained by slow or uneven sedimentation rates inside the cave. Although occupations by hominids appear to have been ephemeral in nature, hominids ultimately discarded nearly 1700 stone artifacts in Yarimburgaz Cave. The hominids did not discard many ungulate bones in the same circumstances. These observations suggest that hominid foraging efforts focused on resources other than large game while at the cave. © 1996 John Wiley \& Sons, Inc.",
    url = "https://doi.org/10.1002/(sici)1520-6548(199607)11:4<279::aid-gea1>3.0.co;2-z",
    doi = "10.1002/(sici)1520-6548(199607)11:4<279::aid-gea1>3.0.co;2-z",
    openalex = "W2017251765",
    references = "ross1988late"
}

During June 1993 and 1994, 11 radiocollared and 7 unmarked grizzly bears (Ursus arctos) were monitored visually (observation) from fixed-wing aircraft to document predation on calves of the Porcupine Caribou (Rangifer tarandus) Herd (PCH) in northeastern Alaska. Twenty-six (72%) grizzly bear observations were completed (≥60 min) successfully (median duration = 180 min; ±95% CI = 136-181 min; range = 67-189 min) and 10 were discontinued (duration ≤24 min) due to disturbance to the bear, or unfavorable weather conditions. Of the 26 successfully completed observations, 15 (58%) included predatory activity (encounter) directed at caribou calves and 8 (31%) included kills. Of 32 encounters, 9 resulted in kills, for a success rate of 28%. The median duration of encounters was 1 minute (±95% CI = 1-2 min; range = 1-6 min; n = 32;), and the median time spent at a kill was 14 minutes (±95% CI = 9-23 min; range = 6-56 min; n = 9). Sows with young (n = 4) killed more frequently (75%; P = 0.0178) than barren sows, boars, and consorting pairs combined (17%; n = 18). Estimated kill rate was highest for sows with young (6.3 kills/bear/day; n = 4), followed by barren sows (4.6 kills/bear/day; n = 5), boars (1.9 kills/bear/day; n = 5), and. finally, consorting pairs (1.0 kills/bear/day; n = 8). Estimated kill rate obtained via conventional radiotracking point surveys (4.8 kills/bear/day) was higher than that obtained via concurrent bear observations (3.1 kills/bear/day). Our research provides baseline estimates of predation rates by grizzly bears on caribou calves that will enhance the capability of wildlife professionals in managing populations of both predators and their prey.

@article{doi1023073802102,
    author = "Young, Donald D. and McCabe, Thomas R.",
    title = "Grizzly Bear Predation Rates on Caribou Calves in Northeastern Alaska",
    year = "1997",
    journal = "Journal of Wildlife Management",
    abstract = "During June 1993 and 1994, 11 radiocollared and 7 unmarked grizzly bears (Ursus arctos) were monitored visually (observation) from fixed-wing aircraft to document predation on calves of the Porcupine Caribou (Rangifer tarandus) Herd (PCH) in northeastern Alaska. Twenty-six (72\%) grizzly bear observations were completed (≥60 min) successfully (median duration = 180 min; ±95\% CI = 136-181 min; range = 67-189 min) and 10 were discontinued (duration ≤24 min) due to disturbance to the bear, or unfavorable weather conditions. Of the 26 successfully completed observations, 15 (58\%) included predatory activity (encounter) directed at caribou calves and 8 (31\%) included kills. Of 32 encounters, 9 resulted in kills, for a success rate of 28\%. The median duration of encounters was 1 minute (±95\% CI = 1-2 min; range = 1-6 min; n = 32;), and the median time spent at a kill was 14 minutes (±95\% CI = 9-23 min; range = 6-56 min; n = 9). Sows with young (n = 4) killed more frequently (75\%; P = 0.0178) than barren sows, boars, and consorting pairs combined (17\%; n = 18). Estimated kill rate was highest for sows with young (6.3 kills/bear/day; n = 4), followed by barren sows (4.6 kills/bear/day; n = 5), boars (1.9 kills/bear/day; n = 5), and. finally, consorting pairs (1.0 kills/bear/day; n = 8). Estimated kill rate obtained via conventional radiotracking point surveys (4.8 kills/bear/day) was higher than that obtained via concurrent bear observations (3.1 kills/bear/day). Our research provides baseline estimates of predation rates by grizzly bears on caribou calves that will enhance the capability of wildlife professionals in managing populations of both predators and their prey.",
    url = "https://doi.org/10.2307/3802102",
    doi = "10.2307/3802102",
    openalex = "W1992320089"
}

@incollection{shideler2000grizzly,
    author = "Shideler, Richard and Hechtel, John",
    title = "Grizzly Bear",
    year = "2000",
    booktitle = "The Natural History of an Arctic Oil Field",
    url = "https://doi.org/10.1016/b978-012701235-3/50008-8",
    doi = "10.1016/b978-012701235-3/50008-8",
    openalex = "W147230277",
    pages = "105-132",
    references = "doi101016000632079190044a, doi1014430arctic1098, doi1014430arctic3870, doi1023072421652, doi1023072530091, doi1023073802102, doi1023073872790, doi1023073872887, doi1023073872940, openalexw1498603190"
}

Cave bears (Ursus spelaeus) existed in Europe and western Asia until the end of the last glaciation some 10,000 years ago. To investigate the genetic diversity, population history, and relationship among different cave bear populations, we have determined mitochondrial DNA sequences from 12 cave bears that range in age from about 26,500 to at least 49,000 years and originate from nine caves. The samples include one individual from the type specimen population, as well as two small-sized high-Alpine bears. The results show that about 49,000 years ago, the mtDNA diversity among cave bears was about 1.8-fold lower than the current species-wide diversity of brown bears (Ursus arctos). However, the current brown bear mtDNA gene pool consists of three clades, and cave bear mtDNA diversity is similar to the diversity observed within each of these clades. The results also show that geographically separated populations of the high-Alpine cave bear form were polyphyletic with respect to their mtDNA. This suggests that small size may have been an ancestral trait in cave bears and that large size evolved at least twice independently.

@article{doi101093oxfordjournalsmolbeva004185,
    author = "Hofreiter, Michael and Capelli, Cristian and Krings, Matthias and Waits, Lisette P. and Conard, Nicholas J. and Münzel, Susanne C. and Rabeder, Gernot and Nagel, Doris and Paunović, Maja and Jambrešić, Gordana and Meyer, Sonja and Weiß, Günter and Pääbo, Svante",
    title = "Ancient DNA Analyses Reveal High Mitochondrial DNA Sequence Diversity and Parallel Morphological Evolution of Late Pleistocene Cave Bears",
    year = "2002",
    journal = "Molecular Biology and Evolution",
    abstract = "Cave bears (Ursus spelaeus) existed in Europe and western Asia until the end of the last glaciation some 10,000 years ago. To investigate the genetic diversity, population history, and relationship among different cave bear populations, we have determined mitochondrial DNA sequences from 12 cave bears that range in age from about 26,500 to at least 49,000 years and originate from nine caves. The samples include one individual from the type specimen population, as well as two small-sized high-Alpine bears. The results show that about 49,000 years ago, the mtDNA diversity among cave bears was about 1.8-fold lower than the current species-wide diversity of brown bears (Ursus arctos). However, the current brown bear mtDNA gene pool consists of three clades, and cave bear mtDNA diversity is similar to the diversity observed within each of these clades. The results also show that geographically separated populations of the high-Alpine cave bear form were polyphyletic with respect to their mtDNA. This suggests that small size may have been an ancestral trait in cave bears and that large size evolved at least twice independently.",
    url = "https://doi.org/10.1093/oxfordjournals.molbev.a004185",
    doi = "10.1093/oxfordjournals.molbev.a004185",
    openalex = "W2156254413",
    references = "doi101007bf02100115, doi10103835016000, doi101093bioinformatics152174, doi101093bioinformatics17121244, doi101093genetics1233585, doi101093genetics1333693, doi101093oxfordjournalsmolbeva025664, doi101093oxfordjournalsmolbeva040023, doi102307jctv1nzfgj7, doi105860choice375647"
}

@article{freer2002grizzly,
    author = "Freer, Luanne",
    title = "Grizzly Bears",
    year = "2002",
    journal = "Wilderness \& Environmental Medicine",
    url = "https://doi.org/10.1580/1080-6032(2002)013[0087:gb]2.0.co;2",
    doi = "10.1580/1080-6032(2002)013[0087:gb]2.0.co;2",
    number = "1",
    openalex = "W2915013475",
    pages = "85-86",
    volume = "13"
}

Despite the greater information content of genomic DNA, ancient DNA studies have largely been limited to the amplification of mitochondrial sequences. Here we describe metagenomic libraries constructed with unamplified DNA extracted from skeletal remains of two 40,000-year-old extinct cave bears. Analysis of approximately 1 megabase of sequence from each library showed that despite significant microbial contamination, 5.8 and 1.1% of clones contained cave bear inserts, yielding 26,861 base pairs of cave bear genome sequence. Comparison of cave bear and modern bear sequences revealed the evolutionary relationship of these lineages. The metagenomic approach used here establishes the feasibility of ancient DNA genome sequencing programs.

@article{doi101126science1113485,
    author = "Noonan, James P. and Hofreiter, Michael and Smith, Doug and Priest, James R. and Rohland, Nadin and Rabeder, Gernot and Krause, Johannes and Detter, John C. and Pääbo, Svante and Rubin, Edward M.",
    title = "Genomic Sequencing of Pleistocene Cave Bears",
    year = "2005",
    journal = "Science",
    abstract = "Despite the greater information content of genomic DNA, ancient DNA studies have largely been limited to the amplification of mitochondrial sequences. Here we describe metagenomic libraries constructed with unamplified DNA extracted from skeletal remains of two 40,000-year-old extinct cave bears. Analysis of approximately 1 megabase of sequence from each library showed that despite significant microbial contamination, 5.8 and 1.1\% of clones contained cave bear inserts, yielding 26,861 base pairs of cave bear genome sequence. Comparison of cave bear and modern bear sequences revealed the evolutionary relationship of these lineages. The metagenomic approach used here establishes the feasibility of ancient DNA genome sequencing programs.",
    url = "https://doi.org/10.1126/science.1113485",
    doi = "10.1126/science.1113485",
    openalex = "W2156610160",
    references = "doi101016s0092867400803104, doi10103835072071, doi101073pnas0403618101, doi101093bioinformatics183502, doi101093nar25173389, doi101093nar29234793, doi101093nargkg500, doi101093oxfordjournalsmolbeva004185, doi101126science1107851, doi101146annurevgenet37110801143214, doi1013851592591922365, openalexw2139291338"
}

We assess the potential for American black bears (Ursus americanus) to limit the growth of colonizing or severely reduced grizzly bear (Ursus arctos) populations. Managers are faced with the challenge of increasing the size of small (N < 75) grizzly bear populations in the North Cascade, Selkirk, Cabinet–Yaak, and Bitterroot recovery areas of the USA and Canada. These populations are mainly limited by human-caused mortality. However, other factors such as competition from black bears could impose additional constraints. Brown and grizzly bears and American black bears evolved separately until about 13,000 years ago and, as a probable consequence, they can have substantial diet overlap. Where meat and roots are available, grizzly bears consume more of these foods than do black bears. Where fleshy fruits and succulent forbs are the primary high quality bear foods, as in the North Cascade, Selkirk, and Cabinet–Yaak ecosystems, dietary overlap between grizzly and black bears can be almost complete. Largely because they are smaller, black bears can exist at roughly 10 times the density of grizzly bears, use ranges that are, on average, four-fifths smaller, and are more efficient than grizzly bears at using low densities of small berries. We postulate that the primary impact of black bears on grizzly bears is through reduced reproduction and recruitment caused by exploitation competition, despite the documented ability of most grizzly bears to dominate most black bears during physical confrontations. Such an effect would be greatest in areas where both species rely on berries and forbs, where grizzly bear populations have been extirpated, substantially reduced, or are absent but within dispersal distance, and where black bear populations are comparatively robust. On this basis we postulate that exploitation competition by resident black bears, together with mortality caused by Native Americans, slowed or even curbed the invasion of grizzly bears east across North America during the late Pleistocene and early Holocene. We also postulate that grizzly bears are absent on some coastal islands within dispersal distance of robust grizzly bear populations because of competitive exclusion by black bears.

@article{doi1021921537617620050160011abbafi20co2,
    author = "Mattson, David J. and Herrero, Stephen and Merrill, Troy",
    title = "Are black bears a factor in the restoration of North American grizzly bear populations?",
    year = "2005",
    journal = "Ursus",
    abstract = "We assess the potential for American black bears (Ursus americanus) to limit the growth of colonizing or severely reduced grizzly bear (Ursus arctos) populations. Managers are faced with the challenge of increasing the size of small (N < 75) grizzly bear populations in the North Cascade, Selkirk, Cabinet–Yaak, and Bitterroot recovery areas of the USA and Canada. These populations are mainly limited by human-caused mortality. However, other factors such as competition from black bears could impose additional constraints. Brown and grizzly bears and American black bears evolved separately until about 13,000 years ago and, as a probable consequence, they can have substantial diet overlap. Where meat and roots are available, grizzly bears consume more of these foods than do black bears. Where fleshy fruits and succulent forbs are the primary high quality bear foods, as in the North Cascade, Selkirk, and Cabinet–Yaak ecosystems, dietary overlap between grizzly and black bears can be almost complete. Largely because they are smaller, black bears can exist at roughly 10 times the density of grizzly bears, use ranges that are, on average, four-fifths smaller, and are more efficient than grizzly bears at using low densities of small berries. We postulate that the primary impact of black bears on grizzly bears is through reduced reproduction and recruitment caused by exploitation competition, despite the documented ability of most grizzly bears to dominate most black bears during physical confrontations. Such an effect would be greatest in areas where both species rely on berries and forbs, where grizzly bear populations have been extirpated, substantially reduced, or are absent but within dispersal distance, and where black bear populations are comparatively robust. On this basis we postulate that exploitation competition by resident black bears, together with mortality caused by Native Americans, slowed or even curbed the invasion of grizzly bears east across North America during the late Pleistocene and early Holocene. We also postulate that grizzly bears are absent on some coastal islands within dispersal distance of robust grizzly bear populations because of competitive exclusion by black bears.",
    url = "https://doi.org/10.2192/1537-6176(2005)016[0011:abbafi]2.0.co;2",
    doi = "10.2192/1537-6176(2005)016[0011:abbafi]2.0.co;2",
    openalex = "W2110616414",
    references = "ross1988late"
}

@misc{caulkett2007bears,
    author = "Caulkett, Nigel",
    title = "Bears",
    year = "2007",
    booktitle = "Zoo Animal and Wildlife Immobilization and Anesthesia",
    url = "https://doi.org/10.1002/9780470376478.ch35",
    doi = "10.1002/9780470376478.ch35",
    pages = "409-415"
}

@article{crossref2008grizzly,
    title = "Grizzly Bears",
    year = "2008",
    journal = "Bulletin of the Ecological Society of America",
    url = "https://doi.org/10.1890/0012-9623(2008)89[126:gb]2.0.co;2",
    doi = "10.1890/0012-9623(2008)89[126:gb]2.0.co;2",
    number = "2",
    openalex = "W4210298710",
    pages = "126-127",
    volume = "89"
}

The cave bear (Ursus spelaeus) was one of several spectacular megafaunal species that became extinct in northern Eurasia during the late Quaternary. Vast numbers of their remains have been recovered from many cave sites, almost certainly representing animals that died during winter hibernation. On the evidence of skull anatomy and low δ 15 N values of bone collagen, cave bears appear to have been predominantly vegetarian. The diet probably included substantial high quality herbaceous vegetation. In order to address the reasons for the extinction of the cave bear, we have constructed a chronology using only radiocarbon dates produced directly on cave bear material. The date list is largely drawn from the literature, and as far as possible the dates have been audited (screened) for reliability. We also present new dates from our own research, including results from the Urals. U. spelaeus probably disappeared from the Alps and adjacent areas – currently the only region for which there is fairly good evidence – c. 24 000 radiocarbon years BP (c. 27 800 cal. yr BP), approximately coincident with the start of Greenland Stadial 3 (c. 27 500 cal. yr BP). Climatic cooling and inferred decreased vegetational productivity were probably responsible for its disappearance from this region. We are investigating the possibility that cave bear survived significantly later elsewhere, for example in southern or eastern Europe.

@article{doi101111j15023885200800071x,
    author = "Pacher, Martina and Stuart, Anthony J.",
    title = "Extinction chronology and palaeobiology of the cave bear (Ursus spelaeus)",
    year = "2008",
    journal = "Boreas",
    abstract = "The cave bear (Ursus spelaeus) was one of several spectacular megafaunal species that became extinct in northern Eurasia during the late Quaternary. Vast numbers of their remains have been recovered from many cave sites, almost certainly representing animals that died during winter hibernation. On the evidence of skull anatomy and low δ 15 N values of bone collagen, cave bears appear to have been predominantly vegetarian. The diet probably included substantial high quality herbaceous vegetation. In order to address the reasons for the extinction of the cave bear, we have constructed a chronology using only radiocarbon dates produced directly on cave bear material. The date list is largely drawn from the literature, and as far as possible the dates have been audited (screened) for reliability. We also present new dates from our own research, including results from the Urals. U. spelaeus probably disappeared from the Alps and adjacent areas – currently the only region for which there is fairly good evidence – c. 24 000 radiocarbon years BP (c. 27 800 cal. yr BP), approximately coincident with the start of Greenland Stadial 3 (c. 27 500 cal. yr BP). Climatic cooling and inferred decreased vegetational productivity were probably responsible for its disappearance from this region. We are investigating the possibility that cave bear survived significantly later elsewhere, for example in southern or eastern Europe.",
    url = "https://doi.org/10.1111/j.1502-3885.2008.00071.x",
    doi = "10.1111/j.1502-3885.2008.00071.x",
    openalex = "W2017224622",
    references = "doi101073pnas0403618101"
}

@misc{conyers2011grizzly,
    author = "Conyers, Claude",
    title = "Grizzly bear",
    year = "2011",
    booktitle = "Oxford Music Online",
    url = "https://doi.org/10.1093/gmo/9781561592630.article.a2092470",
    doi = "10.1093/gmo/9781561592630.article.a2092470",
    openalex = "W4245471878"
}

Although an inverse relationship is expected in ancient DNA samples between the number of surviving DNA fragments and their length, ancient DNA sequencing libraries are strikingly deficient in molecules shorter than 40 bp. We find that a loss of short molecules can occur during DNA extraction and present an improved silica-based extraction protocol that enables their efficient retrieval. In combination with single-stranded DNA library preparation, this method enabled us to reconstruct the mitochondrial genome sequence from a Middle Pleistocene cave bear (Ursus deningeri) bone excavated at Sima de los Huesos in the Sierra de Atapuerca, Spain. Phylogenetic reconstructions indicate that the U. deningeri sequence forms an early diverging sister lineage to all Western European Late Pleistocene cave bears. Our results prove that authentic ancient DNA can be preserved for hundreds of thousand years outside of permafrost. Moreover, the techniques presented enable the retrieval of phylogenetically informative sequences from samples in which virtually all DNA is diminished to fragments shorter than 50 bp.

@article{doi101073pnas1314445110,
    author = "Dabney, Jesse and Knapp, Michael and Glocke, Isabelle and Gansauge, Marie-Theres and Weihmann, Antje and Nickel, Birgit and Valdiosera, Cristina and Garcı́a, Nuria and Pääbo, Svante and Arsuaga, Juan Luís and Meyer, Matthias",
    title = "Complete mitochondrial genome sequence of a Middle Pleistocene cave bear reconstructed from ultrashort DNA fragments",
    year = "2013",
    journal = "Proceedings of the National Academy of Sciences",
    abstract = "Although an inverse relationship is expected in ancient DNA samples between the number of surviving DNA fragments and their length, ancient DNA sequencing libraries are strikingly deficient in molecules shorter than 40 bp. We find that a loss of short molecules can occur during DNA extraction and present an improved silica-based extraction protocol that enables their efficient retrieval. In combination with single-stranded DNA library preparation, this method enabled us to reconstruct the mitochondrial genome sequence from a Middle Pleistocene cave bear (Ursus deningeri) bone excavated at Sima de los Huesos in the Sierra de Atapuerca, Spain. Phylogenetic reconstructions indicate that the U. deningeri sequence forms an early diverging sister lineage to all Western European Late Pleistocene cave bears. Our results prove that authentic ancient DNA can be preserved for hundreds of thousand years outside of permafrost. Moreover, the techniques presented enable the retrieval of phylogenetically informative sequences from samples in which virtually all DNA is diminished to fragments shorter than 50 bp.",
    url = "https://doi.org/10.1073/pnas.1314445110",
    doi = "10.1073/pnas.1314445110",
    openalex = "W2050254973",
    references = "doi102144000112383"
}

Reduction of summer sea ice extent has led some polar bear (Ursus maritimus) populations to increase their use of land during the summer/autumn open-water period. While terrestrial food resources are generally not sufficient to compensate for lost hunting opportunities on the sea ice, marine mammal carcasses, where available, could help reduce the energetic cost of longer periods of land use. Subsistence-harvested bowhead whale (Balaena mysticetus) remains are available annually near local communities along the Alaskan portion of the Beaufort Sea coast to bears that come to shore. Relatively large numbers of polar bears and some grizzly bears (U. arctos) use these resources, creating a competitive environment among species and social classes. We documented competitive interactions among polar bears and between polar and grizzly bears for bowhead whale remains adjacent to a small community in northeastern Alaska in September 2005-2007. We observed temporal partitioning of the resource by bears, with lone adult polar bears and grizzly bears primarily feeding at night, and higher use by polar bear family groups and subadults during dawn and dusk. Interspecific interactions were less frequently aggressive than intraspecific interactions, but polar bears were more likely to be displaced from the feeding site by grizzly bears than by conspecifics. Female polar bears with cubs were more likely to display aggressive behavior than other social classes during intra-and interspecific aggressive interactions. Our results indicate that grizzly bears are socially dominant during interspecific competition with polar bears for marine mammal carcasses during autumn.

@article{doi101093jmammalgyv140,
    author = "Miller, Susanne and Wilder, James M. and Wilson, Ryan R.",
    title = "Polar bear–grizzly bear interactions during the autumn open-water period in Alaska",
    year = "2015",
    journal = "Journal of Mammalogy",
    abstract = "Reduction of summer sea ice extent has led some polar bear (Ursus maritimus) populations to increase their use of land during the summer/autumn open-water period. While terrestrial food resources are generally not sufficient to compensate for lost hunting opportunities on the sea ice, marine mammal carcasses, where available, could help reduce the energetic cost of longer periods of land use. Subsistence-harvested bowhead whale (Balaena mysticetus) remains are available annually near local communities along the Alaskan portion of the Beaufort Sea coast to bears that come to shore. Relatively large numbers of polar bears and some grizzly bears (U. arctos) use these resources, creating a competitive environment among species and social classes. We documented competitive interactions among polar bears and between polar and grizzly bears for bowhead whale remains adjacent to a small community in northeastern Alaska in September 2005-2007. We observed temporal partitioning of the resource by bears, with lone adult polar bears and grizzly bears primarily feeding at night, and higher use by polar bear family groups and subadults during dawn and dusk. Interspecific interactions were less frequently aggressive than intraspecific interactions, but polar bears were more likely to be displaced from the feeding site by grizzly bears than by conspecifics. Female polar bears with cubs were more likely to display aggressive behavior than other social classes during intra-and interspecific aggressive interactions. Our results indicate that grizzly bears are socially dominant during interspecific competition with polar bears for marine mammal carcasses during autumn.",
    url = "https://doi.org/10.1093/jmammal/gyv140",
    doi = "10.1093/jmammal/gyv140",
    openalex = "W2193237756",
    references = "shideler2000grizzly"
}

Muskoxen (Ovibos moschatus) are thought to be highly effective at defending themselves from predators. However, a decline in muskox abundance in northeastern Alaska, USA, that coincided with several instances of grizzly bear (Ursus arctos) predation observed during 2000–2006 raised concerns about the effects of predation on this population. In response, from 2007 to 2011 we estimated rates of reproduction and survival and determined rates and causes of muskox mortality on the arctic coastal plain of northeastern Alaska. Annual counts of muskox abundance (x̄ = 191) and estimates of population growth (x̄ = 0.94) indicated a stable or slowly declining population. Annual natality ranged from 0.45 to 0.86 (x̄ = 0.68) births/adult female, whereas annual survival ranged from 0.40 to 0.63 (x̄ = 0.49) for calves and from 0.73 to 0.91 (x̄ = 0.83) for adult females. Predation by grizzly bears was the most common cause of death among cases where a cause could be identified, accounting for 58% and 62% of deaths of calves and adults, respectively. Most bear predation occurred during late winter and spring when little other food was available to bears. The importance of predation compared with other mortality factors, and the change from a growing to a declining muskox population, suggest a change in either predator abundance or behavior. There is no evidence that bear abundance changed dramatically during this period, but abundance of moose (Alces alces) and caribou (Rangifer tarandus) declined substantially in the area where the muskox decline was most pronounced. This suggests bears may have increased predation on muskoxen in response to reduced availability of other ungulates. Maintaining diversity of native ungulates may help bears cope with the natural fluctuations in prey abundance often seen in arctic ecosystems.

@article{doi102192ursud16000231,
    author = "Arthur, Stephen M. and Vecchio, Patricia A. Del",
    title = "Effects of grizzly bear predation on muskoxen in northeastern Alaska",
    year = "2017",
    journal = "Ursus",
    abstract = "Muskoxen (Ovibos moschatus) are thought to be highly effective at defending themselves from predators. However, a decline in muskox abundance in northeastern Alaska, USA, that coincided with several instances of grizzly bear (Ursus arctos) predation observed during 2000–2006 raised concerns about the effects of predation on this population. In response, from 2007 to 2011 we estimated rates of reproduction and survival and determined rates and causes of muskox mortality on the arctic coastal plain of northeastern Alaska. Annual counts of muskox abundance (x̄ = 191) and estimates of population growth (x̄ = 0.94) indicated a stable or slowly declining population. Annual natality ranged from 0.45 to 0.86 (x̄ = 0.68) births/adult female, whereas annual survival ranged from 0.40 to 0.63 (x̄ = 0.49) for calves and from 0.73 to 0.91 (x̄ = 0.83) for adult females. Predation by grizzly bears was the most common cause of death among cases where a cause could be identified, accounting for 58\% and 62\% of deaths of calves and adults, respectively. Most bear predation occurred during late winter and spring when little other food was available to bears. The importance of predation compared with other mortality factors, and the change from a growing to a declining muskox population, suggest a change in either predator abundance or behavior. There is no evidence that bear abundance changed dramatically during this period, but abundance of moose (Alces alces) and caribou (Rangifer tarandus) declined substantially in the area where the muskox decline was most pronounced. This suggests bears may have increased predation on muskoxen in response to reduced availability of other ungulates. Maintaining diversity of native ungulates may help bears cope with the natural fluctuations in prey abundance often seen in arctic ecosystems.",
    url = "https://doi.org/10.2192/ursu-d-16-00023.1",
    doi = "10.2192/ursu-d-16-00023.1",
    openalex = "W2740885337",
    references = "shideler2000grizzly"
}

@misc{crossref2019bears,
    title = "Bears",
    year = "2019",
    booktitle = "Zoo and Wild Mammal Formulary",
    url = "https://doi.org/10.1002/9781119515098.ch10",
    doi = "10.1002/9781119515098.ch10",
    pages = "131-144"
}

Abstract Industrial off‐road activity in winter overlaps denning habitat of polar bear (Ursus maritimus) and grizzly bear (Ursus arctos) in the North Slope oilfields of Alaska (United States). To prevent disturbance of dens, managers have used forward‐looking infrared (FLIR) cameras to detect dens, but the effectiveness of FLIR under different environmental conditions is unresolved. Our objective was to evaluate the effects of environmental variables on FLIR‐based techniques for arctic bear den detection. Using a FLIR‐equipped unmanned aircraft system (UAS), we conducted observations of artificial polar bear (APD) and grizzly bear (AGD) dens from horizontal and vertical perspectives between December 2016 and April 2017. We recorded physical characteristics of artificial dens and weather conditions present during each observation. We captured 291 images and classified each as detection or nondetection based on the number of pixels representative of a den “hot spot.” We used logistic regression to model the effects of four weather variables on the odds of detection (detection). We found that UAS‐FLIR detects APDs two times better than AGDs, and that for both species detections are four times more likely from the vertical than horizontal perspective. Lower air temperature and wind speed, and the absence of precipitation and sunlight increased detection for APDs. A 1°C increase in air temperature lowered detection by 12% for APDs and by 8% for AGDs. We recommend that UAS‐FLIR surveys be conducted early in the denning season, on cold, clear days, with calm winds, in the absence of sunlight (e.g., civil twilight). Our study further refines the application of FLIR techniques for arctic bear den detection and offers practical recommendations for optimizing detection. Putative den locations should be confirmed by a secondary method to minimize disturbance as anthropogenic activity continues in the Arctic.

@article{doi101111csp2215,
    author = "Pedersen, Nils J. S. and Brinkman, Todd J. and Shideler, Richard T. and Perham, Craig J.",
    title = "Effects of environmental conditions on the use of forward‐looking infrared for bear den detection in the Alaska Arctic",
    year = "2020",
    journal = "Conservation Science and Practice",
    abstract = "Abstract Industrial off‐road activity in winter overlaps denning habitat of polar bear (Ursus maritimus) and grizzly bear (Ursus arctos) in the North Slope oilfields of Alaska (United States). To prevent disturbance of dens, managers have used forward‐looking infrared (FLIR) cameras to detect dens, but the effectiveness of FLIR under different environmental conditions is unresolved. Our objective was to evaluate the effects of environmental variables on FLIR‐based techniques for arctic bear den detection. Using a FLIR‐equipped unmanned aircraft system (UAS), we conducted observations of artificial polar bear (APD) and grizzly bear (AGD) dens from horizontal and vertical perspectives between December 2016 and April 2017. We recorded physical characteristics of artificial dens and weather conditions present during each observation. We captured 291 images and classified each as detection or nondetection based on the number of pixels representative of a den “hot spot.” We used logistic regression to model the effects of four weather variables on the odds of detection (detection). We found that UAS‐FLIR detects APDs two times better than AGDs, and that for both species detections are four times more likely from the vertical than horizontal perspective. Lower air temperature and wind speed, and the absence of precipitation and sunlight increased detection for APDs. A 1°C increase in air temperature lowered detection by 12\% for APDs and by 8\% for AGDs. We recommend that UAS‐FLIR surveys be conducted early in the denning season, on cold, clear days, with calm winds, in the absence of sunlight (e.g., civil twilight). Our study further refines the application of FLIR techniques for arctic bear den detection and offers practical recommendations for optimizing detection. Putative den locations should be confirmed by a secondary method to minimize disturbance as anthropogenic activity continues in the Arctic.",
    url = "https://doi.org/10.1111/csp2.215",
    doi = "10.1111/csp2.215",
    openalex = "W3024675075",
    references = "shideler2000grizzly"
}

Throughout history and across their geographic distribution, bear species (Ursidae) have been portrayed and valued for their beauty, physical power, or ecological significance, while concurrently disliked and feared for their ferocity, negative economic impacts, and safety risks they can pose to people. How bear species are depicted in stories—including myths, legends, fables, or tales—can influence how people come to value bears and act toward them. It is our belief that reviewing the stories people tell about bears can be useful in understanding people's proclivity to conservation action, given that stories told about bears can be a powerful demonstration of how local culture influences human relations with wildlife. We conducted a review of English-language literature for stories about bears across their global range, to better understand how these stories reflect human thought and imagination, experiences, and behaviors concerning bears. We identify 4 themes about bears as told through different narratives—including kinship, utilitarianism, threat, and political bears—and illustrate how understanding stories told about the wild animals that share our lives can provide important insights into developing conservation policy and action.

@article{doi102192ursusd19000022,
    author = "Hughes, Courtney and Frank, Béatrice and Melnycky, Natalka A. and Yarmey, Nicholas T. and Glikman, Jenny Anne",
    title = "From worship to subjugation: Understanding stories about bears to inform conservation efforts",
    year = "2020",
    journal = "Ursus",
    abstract = "Throughout history and across their geographic distribution, bear species (Ursidae) have been portrayed and valued for their beauty, physical power, or ecological significance, while concurrently disliked and feared for their ferocity, negative economic impacts, and safety risks they can pose to people. How bear species are depicted in stories—including myths, legends, fables, or tales—can influence how people come to value bears and act toward them. It is our belief that reviewing the stories people tell about bears can be useful in understanding people's proclivity to conservation action, given that stories told about bears can be a powerful demonstration of how local culture influences human relations with wildlife. We conducted a review of English-language literature for stories about bears across their global range, to better understand how these stories reflect human thought and imagination, experiences, and behaviors concerning bears. We identify 4 themes about bears as told through different narratives—including kinship, utilitarianism, threat, and political bears—and illustrate how understanding stories told about the wild animals that share our lives can provide important insights into developing conservation policy and action.",
    url = "https://doi.org/10.2192/ursus-d-19-00002.2",
    doi = "10.2192/ursus-d-19-00002.2",
    openalex = "W3099124865",
    references = "hughes2020problem"
}

@article{hughes2020problem,
    author = "Hughes, Courtney and Yarmey, Nicholas and Morehouse, Andrea and Nielsen, Scott",
    title = "Problem Perspectives and Grizzly Bears: A Case Study of Alberta’s Grizzly Bear Recovery Policy",
    year = "2020",
    journal = "Frontiers in Ecology and Evolution",
    url = "https://doi.org/10.3389/fevo.2020.00038",
    doi = "10.3389/fevo.2020.00038",
    openalex = "W3010967635",
    volume = "8",
    references = "doi101002nur20259, doi101016026840129090041p, doi101016jbiocon200807014, doi10108013645570701401305, doi1010970000505319910200000025, doi101111j15231739200400077x, doi101177004912418101000205, doi103316qrj0902027, doi1041359781036235611, doi10467432160371520152281"
}

Grizzly bears are a threatened species in Alberta, Canada, and their conservation and management is guided by a provincial recovery plan. While empirical abundance and densities estimates have been completed for much of the province, empirical data are lacking for the northwest region of Alberta, a 2.8 million hectare area called Bear Management Area 1 (BMA 1). In part, this is due to limited staff capacity and funding to cover a vast geographic area, and a boreal landscape that is difficult to navigate. Using a collaborative approach, a multi-stakeholder working group called the Northwest Grizzly Bear Team (NGBT) was established to represent land use and grizzly bear interests across BMA 1. Collectively, we identified our project objectives using a Theory of Change approach, to articulate our interests and needs, and develop common ground to ultimately leverage human, social, financial and policy resources to implement the project. This included establishing 254 non-invasive genetic hair corral sampling sites across BMA 1, and using spatially explicit capture-recapture models to estimate grizzly bear density. Our results are two-fold: first we describe the process of developing and then operating within a collaborative, multi-stakeholder governance arrangement, and demonstrate how our approach was key to both improving relationships across stakeholders but also delivering on our grizzly bear project objectives; and, secondly we present the first-ever grizzly bear population estimate for BMA 1, including identifying 16 individual bears and estimating density at 0.70 grizzly bears/1,000 km 2 -the lowest recorded density of an established grizzly bear population in Alberta. Our results are not only necessary for taking action on one of Alberta's iconic species at risk, but also demonstrate the value and power of collaboration to achieve a conservation goal.

@article{doi103389fcosc2021719044,
    author = "Hughes, Courtney and Steenweg, Rolanda J. and Vennen, Lucas M. Vander and Melnycky, Natalka A. and Fullerton, Lyle and Witiw, James T. and Morehouse, Andrea T.",
    title = "Working Together for Grizzly Bears: A Collaborative Approach to Estimate Population Abundance in Northwest Alberta, Canada",
    year = "2021",
    journal = "Frontiers in Conservation Science",
    abstract = "Grizzly bears are a threatened species in Alberta, Canada, and their conservation and management is guided by a provincial recovery plan. While empirical abundance and densities estimates have been completed for much of the province, empirical data are lacking for the northwest region of Alberta, a 2.8 million hectare area called Bear Management Area 1 (BMA 1). In part, this is due to limited staff capacity and funding to cover a vast geographic area, and a boreal landscape that is difficult to navigate. Using a collaborative approach, a multi-stakeholder working group called the Northwest Grizzly Bear Team (NGBT) was established to represent land use and grizzly bear interests across BMA 1. Collectively, we identified our project objectives using a Theory of Change approach, to articulate our interests and needs, and develop common ground to ultimately leverage human, social, financial and policy resources to implement the project. This included establishing 254 non-invasive genetic hair corral sampling sites across BMA 1, and using spatially explicit capture-recapture models to estimate grizzly bear density. Our results are two-fold: first we describe the process of developing and then operating within a collaborative, multi-stakeholder governance arrangement, and demonstrate how our approach was key to both improving relationships across stakeholders but also delivering on our grizzly bear project objectives; and, secondly we present the first-ever grizzly bear population estimate for BMA 1, including identifying 16 individual bears and estimating density at 0.70 grizzly bears/1,000 km 2 -the lowest recorded density of an established grizzly bear population in Alberta. Our results are not only necessary for taking action on one of Alberta's iconic species at risk, but also demonstrate the value and power of collaboration to achieve a conservation goal.",
    url = "https://doi.org/10.3389/fcosc.2021.719044",
    doi = "10.3389/fcosc.2021.719044",
    openalex = "W3202042230",
    references = "hughes2020problem"
}

@incollection{crossref2022grizzly,
    title = "Grizzly Bears",
    year = "2022",
    booktitle = "Atlas of Yellowstone",
    url = "https://doi.org/10.2307/j.ctv1xbc22w.111",
    doi = "10.2307/j.ctv1xbc22w.111",
    openalex = "W4200044715",
    pages = "220-221"
}

Human-wildlife dynamics is a growing field and one of considerable importance to conservation. Wild spaces are in short supply, and consequently wildlife and people increasingly share the landscape, though not necessarily by choice. As a result, peoples’ needs might not be prioritized over those of wildlife, even in cases of human-wildlife conflict. For wildlife conservation to be effective and human-wildlife coexistence possible, the needs of both wildlife and people must be simultaneously addressed. Rather than an afterthought or a sentence in the conservation/management implications section of a paper, community engagement should be addressed before, during, and after a research project. However, this can be a difficult and often complicated task, for multiple reasons. Building relationships founded on trust, respect and reciprocity with community members takes commitment, time, skill, and a willingness by researchers to be open-minded in terms of methodologies and new ideas. Different cultural norms, beliefs, perspectives and biases can further exacerbate these challenges. Here, we share three short case studies reflecting our own research experiences engaging with communities in the field of grizzly bear (Ursus arctos) ecology and conservation science. We conclude with guidelines for advancing effective community engagement and suggestions for tackling some common barriers. Overall, we offer considerations for a practical and more holistic approach to large carnivore conservation, established on a foundation of strong community support.

@article{doi103389fcosc2022913668,
    author = "Hughes, Courtney and Elmeligi, Sarah and Morehouse, Andrea T.",
    title = "Conservation through connection: Approaches to engaging communities in applied grizzly bear research",
    year = "2022",
    journal = "Frontiers in Conservation Science",
    abstract = "Human-wildlife dynamics is a growing field and one of considerable importance to conservation. Wild spaces are in short supply, and consequently wildlife and people increasingly share the landscape, though not necessarily by choice. As a result, peoples’ needs might not be prioritized over those of wildlife, even in cases of human-wildlife conflict. For wildlife conservation to be effective and human-wildlife coexistence possible, the needs of both wildlife and people must be simultaneously addressed. Rather than an afterthought or a sentence in the conservation/management implications section of a paper, community engagement should be addressed before, during, and after a research project. However, this can be a difficult and often complicated task, for multiple reasons. Building relationships founded on trust, respect and reciprocity with community members takes commitment, time, skill, and a willingness by researchers to be open-minded in terms of methodologies and new ideas. Different cultural norms, beliefs, perspectives and biases can further exacerbate these challenges. Here, we share three short case studies reflecting our own research experiences engaging with communities in the field of grizzly bear (Ursus arctos) ecology and conservation science. We conclude with guidelines for advancing effective community engagement and suggestions for tackling some common barriers. Overall, we offer considerations for a practical and more holistic approach to large carnivore conservation, established on a foundation of strong community support.",
    url = "https://doi.org/10.3389/fcosc.2022.913668",
    doi = "10.3389/fcosc.2022.913668",
    openalex = "W4307706829",
    references = "hughes2020problem"
}

Citizen science offers an excellent opportunity to engage the public in scientific data collection, educational opportunities, and applied management. However, the practicalities of developing and implementing citizen science programming are often more complex than considered. Some challenges to effective citizen science include scientists' skepticism about the ability of public participants to rigorously collect quality data; a lack of clarity on or confidence in the utility of data; scientists' hesitancy in engaging the public in projects; limited financial commitments; and challenges associated with the temporal and geographic scales of projects. To address these challenges, and provide a foundation upon which practitioners, scientists, and the public can credibly engage in citizen science, the Government of Alberta developed a set of citizen science principles. These principles offer a framework for planning, designing, implementing, and evaluating citizen science projects that extend beyond Alberta. Here, we present a case study using these principles to evaluate GrizzTracker, a citizen science program developed to help inform provincial species-at-risk recovery efforts. While we found that GrizzTracker applied each of the six principles in some way, including successful public engagement, strengthened relationships, and raising public awareness about northwest Alberta's grizzly bears, we also identified a number of challenges. These included ongoing skepticism from the traditional scientific community about the utility of citizen science and governance challenges related to program leadership, staff capacity, and funding. By using the principles as a guideline, we provide policy recommendations for future citizen science efforts, including considerations for program design, implementation, and evaluation.

@article{doi103390ani12091068,
    author = "Hughes, Courtney and Tremblett, Krista and Kummer, Justine A. and Lee, Tracy S. and Duke, Danah",
    title = "How Can We Do Citizen Science Better? A Case Study Evaluating Grizzly Bear Citizen Science Using Principles of Good Practice in Alberta, Canada",
    year = "2022",
    journal = "Animals",
    abstract = "Citizen science offers an excellent opportunity to engage the public in scientific data collection, educational opportunities, and applied management. However, the practicalities of developing and implementing citizen science programming are often more complex than considered. Some challenges to effective citizen science include scientists' skepticism about the ability of public participants to rigorously collect quality data; a lack of clarity on or confidence in the utility of data; scientists' hesitancy in engaging the public in projects; limited financial commitments; and challenges associated with the temporal and geographic scales of projects. To address these challenges, and provide a foundation upon which practitioners, scientists, and the public can credibly engage in citizen science, the Government of Alberta developed a set of citizen science principles. These principles offer a framework for planning, designing, implementing, and evaluating citizen science projects that extend beyond Alberta. Here, we present a case study using these principles to evaluate GrizzTracker, a citizen science program developed to help inform provincial species-at-risk recovery efforts. While we found that GrizzTracker applied each of the six principles in some way, including successful public engagement, strengthened relationships, and raising public awareness about northwest Alberta's grizzly bears, we also identified a number of challenges. These included ongoing skepticism from the traditional scientific community about the utility of citizen science and governance challenges related to program leadership, staff capacity, and funding. By using the principles as a guideline, we provide policy recommendations for future citizen science efforts, including considerations for program design, implementation, and evaluation.",
    url = "https://doi.org/10.3390/ani12091068",
    doi = "10.3390/ani12091068",
    openalex = "W4224252795",
    references = "hughes2020problem"
}

Abstract Coexistence between large carnivores and humans is a global conservation concern. Montana (USA) is home to recovering grizzly bear (Ursus arctos) populations and increasing human–grizzly interactions. In 2019, we administered a survey of Montanans to investigate factors influencing normative beliefs about grizzly bear population sizes and quantify the relationship between these beliefs and satisfaction with grizzly management in the state. Using a linear regression (r 2 =.61), we found that residents with positive attitudes and emotional dispositions toward grizzlies or who trusted the agency were more likely to believe grizzly populations were too low. Residents who believed hunting should be used to manage conflict, were themselves hunters, had vicarious wildlife experience with property damage, believed grizzly populations were expanding, or were older were more likely to believe populations were too high. We found a negative quadratic relationship between normative grizzly bear population size beliefs and satisfaction with management, suggesting an optimal “Goldilocks” zone where coexistence is most possible. In practice, if observed Goldilocks zones are incompatible with population numbers required to meet conservation goals, considering factors influencing these beliefs may help bolster acceptance of larger population sizes.

@article{doi101111csp212885,
    author = "Nesbitt, Holly K. and Metcalf, Alexander L. and Metcalf, Elizabeth Covelli and Costello, Cecily M. and Roberts, Lori L. and Lewis, Mike S. and Gude, Justin A.",
    title = "Human dimensions of grizzly bear conservation: The social factors underlying satisfaction and coexistence beliefs in Montana, USA",
    year = "2023",
    journal = "Conservation Science and Practice",
    abstract = "Abstract Coexistence between large carnivores and humans is a global conservation concern. Montana (USA) is home to recovering grizzly bear (Ursus arctos) populations and increasing human–grizzly interactions. In 2019, we administered a survey of Montanans to investigate factors influencing normative beliefs about grizzly bear population sizes and quantify the relationship between these beliefs and satisfaction with grizzly management in the state. Using a linear regression (r 2 =.61), we found that residents with positive attitudes and emotional dispositions toward grizzlies or who trusted the agency were more likely to believe grizzly populations were too low. Residents who believed hunting should be used to manage conflict, were themselves hunters, had vicarious wildlife experience with property damage, believed grizzly populations were expanding, or were older were more likely to believe populations were too high. We found a negative quadratic relationship between normative grizzly bear population size beliefs and satisfaction with management, suggesting an optimal “Goldilocks” zone where coexistence is most possible. In practice, if observed Goldilocks zones are incompatible with population numbers required to meet conservation goals, considering factors influencing these beliefs may help bolster acceptance of larger population sizes.",
    url = "https://doi.org/10.1111/csp2.12885",
    doi = "10.1111/csp2.12885",
    openalex = "W4318831568",
    references = "hughes2020problem"
}

This review explores whether recent hybridization events between polar bears (Ursus maritimus) and grizzly bears (Ursus arctos horribilis) will eventually contribute to the extinction of the modern polar bear. In April 2006, genetic analysis of an odd‐looking bear killed in the Northwest Territories, Canada, revealed this specimen to be a polar bear–grizzly bear hybrid, and additional hybrid bears were harvested beginning in April 2010. These events have been sensationalized by some in the media, who have speculated that the modern polar bear may become extinct due to crossbreeding with grizzly bears. Although studies support the introgression of brown bear genes into the polar bear genome during the Pleistocene, no evidence supports the occurrence of a similar event today. Even if such an introgression event occurred, hybrids evolving rapidly enough to adapt to ongoing sea ice depletion is not scientifically plausible. The loss of genetic integrity and modified morphology due to inbreeding between polar bears and grizzly bears are not considered threats to polar bear survival. As many scientists have stressed for decades, the greatest threat to the survival of the modern polar bear is sea ice depletion due to climate change.

@article{shafer2023contribution,
    author = "Shafer, Craig L.",
    title = "Contribution of hybridization between polar bears and grizzly bears to polar bear extinction",
    year = "2023",
    journal = "Wildlife Letters",
    abstract = "This review explores whether recent hybridization events between polar bears (Ursus maritimus) and grizzly bears (Ursus arctos horribilis) will eventually contribute to the extinction of the modern polar bear. In April 2006, genetic analysis of an odd‐looking bear killed in the Northwest Territories, Canada, revealed this specimen to be a polar bear–grizzly bear hybrid, and additional hybrid bears were harvested beginning in April 2010. These events have been sensationalized by some in the media, who have speculated that the modern polar bear may become extinct due to crossbreeding with grizzly bears. Although studies support the introgression of brown bear genes into the polar bear genome during the Pleistocene, no evidence supports the occurrence of a similar event today. Even if such an introgression event occurred, hybrids evolving rapidly enough to adapt to ongoing sea ice depletion is not scientifically plausible. The loss of genetic integrity and modified morphology due to inbreeding between polar bears and grizzly bears are not considered threats to polar bear survival. As many scientists have stressed for decades, the greatest threat to the survival of the modern polar bear is sea ice depletion due to climate change.",
    url = "https://doi.org/10.1002/wll2.12024",
    doi = "10.1002/wll2.12024",
    number = "4",
    openalex = "W4389780487",
    pages = "178-193",
    volume = "1",
    references = "doi101016jtree200401003, doi101016jtree200502010, doi101016s016953470102290x, doi101046j1365294x200101216x, doi101093oso97801950997440010001, doi101111j1365294x1995tb00227x, doi101111j14209101201202599x, doi101126science1117368, doi101126scienceaaf7671, doi101146annurevecolsys27183"
}

@article{doi101007s00442025058300,
    author = "Pagano, Anthony M. and Rode, Karyn D. and Nicholson, Kerry L. and Leacock, William B. and Stricker, Craig A. and Robbins, Charles T.",
    title = "The effects of carnivory and herbivory on the energy balance of Arctic grizzly bears",
    year = "2025",
    journal = "Oecologia",
    url = "https://doi.org/10.1007/s00442-025-05830-0",
    doi = "10.1007/s00442-025-05830-0",
    openalex = "W4416786932",
    references = "shideler2000grizzly"
}

Monitoring populations of large carnivores that are often elusive and occur at low densities is intrinsically difficult. The challenges are often exacerbated in developing nations with less infrastructure or resources for wildlife surveys. In regions where little is known about wildlife populations, even basic information about the presence of large carnivores in a landscape is an important first step towards implementing sustainable management practices to promote co-existence with humans. Here, we conducted a first-ever pilot study in the Altai Mountain Region of Kazakhstan using camera traps to assess the presence of brown bear (Ursus arctos) and their primary prey species in the study region, and to better understand potential drivers of variation in activity. Between 2019 and 2023, we deployed 10 camera traps which collected data for a total of 4654 days. Bear activity varied seasonally; all activity occurred during the 'active season' with activity peaking in May/June. Camera traps also detected 13 other species including a range of potential ungulate prey and other carnivores. Our study was conducted at a relatively local scale, but represents a first step towards understanding the presence of brown bears and other mammals in a remote region of central Asia. There is currently limited scientific understanding of where bears occur in the Altai Mountains of Kazakhstan or the neighboring countries of China, Mongolia, and Russia. Our results are therefore useful for the adaptive management of brown bears at the local scale, and the lessons learned from our study can be used to scale up and optimize wildlife monitoring efforts by local managers and researchers in Kazakhstan.

@article{doi101002ece373272,
    author = "Kantarbayev, Sanzhar and Tallian, Aimee and Grainger, Matthew and Sandercock, Brett K and Kopatz, Alexander",
    title = "Monitoring Brown Bears in Kazakhstan: A Pilot Study from the Altai Mountain Region.",
    year = "2026",
    journal = "Ecology and evolution",
    abstract = "Monitoring populations of large carnivores that are often elusive and occur at low densities is intrinsically difficult. The challenges are often exacerbated in developing nations with less infrastructure or resources for wildlife surveys. In regions where little is known about wildlife populations, even basic information about the presence of large carnivores in a landscape is an important first step towards implementing sustainable management practices to promote co-existence with humans. Here, we conducted a first-ever pilot study in the Altai Mountain Region of Kazakhstan using camera traps to assess the presence of brown bear (Ursus arctos) and their primary prey species in the study region, and to better understand potential drivers of variation in activity. Between 2019 and 2023, we deployed 10 camera traps which collected data for a total of 4654 days. Bear activity varied seasonally; all activity occurred during the 'active season' with activity peaking in May/June. Camera traps also detected 13 other species including a range of potential ungulate prey and other carnivores. Our study was conducted at a relatively local scale, but represents a first step towards understanding the presence of brown bears and other mammals in a remote region of central Asia. There is currently limited scientific understanding of where bears occur in the Altai Mountains of Kazakhstan or the neighboring countries of China, Mongolia, and Russia. Our results are therefore useful for the adaptive management of brown bears at the local scale, and the lessons learned from our study can be used to scale up and optimize wildlife monitoring efforts by local managers and researchers in Kazakhstan.",
    url = "https://pmc.ncbi.nlm.nih.gov/articles/PMC13093707/",
    doi = "10.1002/ece3.73272",
    pmcid = "PMC13093707",
    pmid = "42016933"
}

Sex, body size and environmental conditions are key determinants of home range size in large mammals, yet their relative importance within populations remains unclear for many wide-ranging carnivores such as brown bears. This study combined GPS-collar data and detailed morphometrics from 69 free-ranging brown bears (46 males, 23 females) in Türkiye to test how home range size relates to sex, body mass, and body dimensions. Individual home ranges were estimated using 95% minimum convex polygon (MCP95) and kernel utilisation distribution methods, and the MCP95 area was log-transformed and analysed with linear models that included sex, log body mass, representative linear size measures, sampling effort covariates, and principal component scores derived from a multivariate analysis of eight morphometric traits. Home range size varied markedly among individuals (5.1-203.9 km2), with males consistently having nearly twice the MCP95 area of females, with sex accounting for most of the variance in log home range size. In contrast, neither body mass nor linear body dimensions showed significant within-sex relationships with home range size, and sex × mass interactions were not supported. Principal component analysis revealed a dominant body size axis, but this multivariate size component, as well as a secondary shape axis, did not explain additional variation once sex was included. Models that accounted for the number of GPS fixes, tracking duration, and influential points confirmed the robustness of the sex effect and indicated only modest contributions of sampling effort. Overall, the results showed that sex, rather than fine-scale variation in body size or shape, is the primary intrinsic driver of home range size in this southern brown bear population, highlighting the need for sex-specific but not size-specific spatial planning and conservation strategies in the future.

@article{doi101002ece373531,
    author = "Naderi, Morteza and Çoban, Emrah and Çelik, Uygar Can and Kusak, Josip and Şekercioğlu, Çağan H",
    title = "Why Size Does Not Matter: Sex Driven Home Range Differences in Brown Bears.",
    year = "2026",
    journal = "Ecology and evolution",
    abstract = "Sex, body size and environmental conditions are key determinants of home range size in large mammals, yet their relative importance within populations remains unclear for many wide-ranging carnivores such as brown bears. This study combined GPS-collar data and detailed morphometrics from 69 free-ranging brown bears (46 males, 23 females) in Türkiye to test how home range size relates to sex, body mass, and body dimensions. Individual home ranges were estimated using 95\% minimum convex polygon (MCP95) and kernel utilisation distribution methods, and the MCP95 area was log-transformed and analysed with linear models that included sex, log body mass, representative linear size measures, sampling effort covariates, and principal component scores derived from a multivariate analysis of eight morphometric traits. Home range size varied markedly among individuals (5.1-203.9 km2), with males consistently having nearly twice the MCP95 area of females, with sex accounting for most of the variance in log home range size. In contrast, neither body mass nor linear body dimensions showed significant within-sex relationships with home range size, and sex × mass interactions were not supported. Principal component analysis revealed a dominant body size axis, but this multivariate size component, as well as a secondary shape axis, did not explain additional variation once sex was included. Models that accounted for the number of GPS fixes, tracking duration, and influential points confirmed the robustness of the sex effect and indicated only modest contributions of sampling effort. Overall, the results showed that sex, rather than fine-scale variation in body size or shape, is the primary intrinsic driver of home range size in this southern brown bear population, highlighting the need for sex-specific but not size-specific spatial planning and conservation strategies in the future.",
    url = "https://pmc.ncbi.nlm.nih.gov/articles/PMC13095866/",
    doi = "10.1002/ece3.73531",
    pmcid = "PMC13095866",
    pmid = "42023041"
}

Europe has experienced multiple crises, including inflation, rising food and living costs, the COVID-19 pandemic, and the 2007-2009 financial crisis, which have contributed to widening social inequalities. These economic pressures may threaten the material well-being of adults aged 50 and older, yet little is known about how they affect those who provide care. This study examined the risk of material deprivation among those with different caring roles in 2021-2022 using the SHARE data. The findings show that co-resident family caregivers, those experiencing financial strain, and individuals with a migrant background are particularly vulnerable to material deprivation. Women carry a disproportionate share of caregiving responsibilities and face higher deprivation risks than men. In contrast, individuals who provide care outside their households or care for grandchildren tend to exhibit better material well-being than those without these roles. Targeted policy measures that both alleviate energy poverty and financial strain are needed.

@article{doi10117707334648261446037,
    author = "Savela, Roosa-Maria and McKenzie, John",
    title = "Who Bears the Burden? The Risk of Material Deprivation Among Adults Aged 50 and Older With Varying Caring Roles in Europe.",
    year = "2026",
    journal = "Journal of applied gerontology: the official journal of the Southern Gerontological Society",
    abstract = "Europe has experienced multiple crises, including inflation, rising food and living costs, the COVID-19 pandemic, and the 2007-2009 financial crisis, which have contributed to widening social inequalities. These economic pressures may threaten the material well-being of adults aged 50 and older, yet little is known about how they affect those who provide care. This study examined the risk of material deprivation among those with different caring roles in 2021-2022 using the SHARE data. The findings show that co-resident family caregivers, those experiencing financial strain, and individuals with a migrant background are particularly vulnerable to material deprivation. Women carry a disproportionate share of caregiving responsibilities and face higher deprivation risks than men. In contrast, individuals who provide care outside their households or care for grandchildren tend to exhibit better material well-being than those without these roles. Targeted policy measures that both alleviate energy poverty and financial strain are needed.",
    url = "https://pubmed.ncbi.nlm.nih.gov/42029133/",
    doi = "10.1177/07334648261446037",
    pmid = "42029133"
}