Conservation and management of the culture of bears

Servheen, Christopher; Gunther, Kerry A.

doi:10.1002/ece3.8840

Cited by 5 publications

(5 citation statements)

References 71 publications

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“…One possible reason for this difference is that captive bears are fed the same type and quantity of food throughout the year in a stable environment, whereas wild bears consume a variety of foods in differing quantities depending on the season (Naves et al 2006;Shirane et al 2021). Additionally, foraging strategies differ among individuals even within a population (Servheen & Gunther 2022;Jimbo et al 2022). Factors linked to lifestyle, including obesity, weight reduction, and overfeeding, have been suggested to affect DNA methylation (Samblas et al 2019;Yamazaki et al 2021).…”

Section: Discussionmentioning

confidence: 99%

Age estimation based on blood DNA methylation levels in brown bears

Nakamura

Yamazaki

Matsumoto³

et al. 2023

Preprint

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Age is an essential trait for understanding the ecology and management of wildlife. A conventional method of estimating age in wild animals is counting annuli formed in the cementum of teeth. This method has been used in bears despite some disadvantages, such as high invasiveness and the requirement for experienced observers. In this study, we established a novel age estimation method based on DNA methylation levels using blood collected from 49 brown bears of known ages living in both captivity and the wild. We performed bisulfite pyrosequencing and obtained methylation levels at 39 cytosine-phosphate-guanine (CpG) sites adjacent to 12 genes. The methylation levels of CpGs adjacent to four genes showed a significant correlation with age. The best model was based on DNA methylation levels at just four CpG sites adjacent to a single gene, SLC12A5, and it had high accuracy with a mean absolute error of 1.3 years and median absolute error of 1.0 year after leave-one-out cross-validation. This model represents the first epigenetic method of age estimation in brown bears, which provides benefits over tooth-based methods, including high accuracy, less invasiveness, and a simple procedure. Our model has the potential for application to other bear species, which will greatly improve ecological research, conservation, and management.

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Section: Discussionmentioning

confidence: 99%

Age estimation based on blood DNA methylation levels in brown bears

Nakamura

Yamazaki

Matsumoto³

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…Additionally, foraging strategies differ among individuals even within a population (Jimbo et al, 2022;Servheen & Gunther, 2022). Factors linked to lifestyle, including obesity, weight reduction, and overfeeding, have been suggested to affect DNA methylation (Samblas et al, 2019;Yamazaki et al, 2021) Wilkinson & South, 2002).…”

Section: Discussionmentioning

confidence: 99%

“…One possible reason for this difference is that captive bears are fed the same type and quantity of food throughout the year in a stable environment, whereas wild bears consume a variety of foods in differing quantities depending on the season (Naves et al, 2006; Shirane et al, 2021). Additionally, foraging strategies differ among individuals even within a population (Jimbo et al, 2022; Servheen & Gunther, 2022). Factors linked to lifestyle, including obesity, weight reduction, and overfeeding, have been suggested to affect DNA methylation (Samblas et al, 2019; Yamazaki et al, 2021).…”

Section: Discussionmentioning

confidence: 99%

Age estimation based on blood DNA methylation levels in brown bears

Nakamura

Yamazaki

Matsumoto³

et al. 2023

Molecular Ecology Resources

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Age is an essential trait for understanding the ecology and management of wildlife. A conventional method of estimating age in wild animals is counting annuli formed in the cementum of teeth. This method has been used in bears despite some disadvantages, such as high invasiveness and the requirement for experienced observers. In this study, we established a novel age estimation method based on DNA methylation levels using blood collected from 49 brown bears of known ages living in both captivity and the wild. We performed bisulfite pyrosequencing and obtained methylation levels at 39 cytosine‐phosphate‐guanine (CpG) sites adjacent to 12 genes. The methylation levels of CpGs adjacent to four genes showed a significant correlation with age. The best model was based on DNA methylation levels at just four CpG sites adjacent to a single gene, SLC12A5, and it had high accuracy with a mean absolute error of 1.3 years and median absolute error of 1.0 year after leave‐one‐out cross‐validation. This model represents the first epigenetic method of age estimation in brown bears, which provides benefits over tooth‐based methods, including high accuracy, less invasiveness, and a simple procedure. Our model has the potential for application to other bear species, which will greatly improve ecological research, conservation, and management.

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“…Bears, particularly females, learn from their mothers and display similar selection patterns (Nielsen et al 2013, Morehouse et al 2016). Differences in selection could create lineages of bears that learn a tradition of spending time in BMAs or not using them (Servheen and Gunther 2022). Of course, bears continually learn about the environment and change their behavior based on current conditions and spatial memory (Thompson et al 2021), which likely also accounts for individual variation in BMA selection.…”

Section: Discussionmentioning

confidence: 99%

Grizzly bear responses to restrictions of recreation in Yellowstone National Park

Loggers,

Litt,

van Manen

et al. 2023

J Wildl Manag

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Avoiding humans will be more difficult and energetically costly for animals as outdoor recreation increases and people venture farther into wildland areas that provide high‐quality habitat for wildlife. Restricting human access can be an attractive management tool to mitigate effects of human recreation activities on wildlife; however, the efficacy of such measures is rarely assessed. In 1982, Yellowstone National Park identified areas important to grizzly bears (Ursus arctos) to help protect critical grizzly bear habitat and reduce the likelihood of human injuries by bears. Referred to as bear management areas (BMAs), human access is restricted in these areas for 2–8 months each year, with timing and type of restrictions varying by area. We examined 2 datasets to evaluate grizzly bear selection of BMAs and differences of bear density in BMAs and non‐BMAs. First, we used 17 years of recent global positioning system telemetry data for grizzly bears to assess their selection of BMAs during periods when human access was allowed, and when access was restricted. We used step‐selection functions to test the hypothesis that bears spend time in places that allow them to avoid people and select quality food sources. There was support that grizzly bears differentially select for BMAs regardless of whether human access was restricted at the time, compared with areas outside BMAs, and that selection changed with sex and season. Only males during the summer and hyperphagic seasons changed their selection of BMAs based on whether access restrictions were in place, and overall, male bears preferred unrestricted BMAs (BMAs without restrictions in place). Females preferentially selected BMAs regardless of whether the area had access restrictions in place only during the mating season. Individuals varied widely in their preference for BMAs and access restrictions. Bears likely choose to spend time in BMAs based on available food resources rather than restrictions to human access. Supporting this interpretation, our analyses indicated that a greater proportion of BMA in an area was associated with higher densities of grizzly bear. Thus, restrictions to human access likely help reduce the potential for human–bear interactions, accomplishing one of the original objectives for establishing the BMAs.

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Conservation and management of the culture of bears

Cited by 5 publications

References 71 publications

Age estimation based on blood DNA methylation levels in brown bears

Age estimation based on blood DNA methylation levels in brown bears

Age estimation based on blood DNA methylation levels in brown bears

Grizzly bear responses to restrictions of recreation in Yellowstone National Park

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