Vital rates of two small populations of brown bears in Canada and range‐wide relationship between population size and trend

McLellan, Michelle; McLellan, Bruce N.; Sollmann, Rahel; Wittmer, Heiko

doi:10.1002/ece3.7301

Cited by 5 publications

(4 citation statements)

References 73 publications

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“…Survival estimates were high and comparable among age classes. Adult survival estimates were similar to those previously found in this (Chapron et al 2009, Vanpé et al 2022) and other bear populations (Garshelis et al 2005, McLellan et al 2021). The study of Vanpé et.…”

Section: Discussionsupporting

confidence: 89%

“…al (2022) based on a longer time frame yielded higher subadult survival estimates (Mean+ sd = 0.95 + 0.028), so survival of this age class might be decreasing; however, differences may also stem from their non-spatial modelling framework. Our estimates of juvenile survival were higher than in previous studies of the same (Vanpé et al 2022) and other populations (e.g., McLellan et al 2021). Owing to sample size limitations, our 'juvenile' age class included individuals until 2 years-old, and the non-invasive data are likely biased towards older juveniles: once cubs are detectable, they are moving with their mother and have already survived the most vulnerable period when leaving their den (Planella et al 2019).…”

Section: Discussionmentioning

confidence: 63%

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Lonely males at the front: A new open SCR model reveals the spatial sex-age structure of an expanding brown bear population

Perez,

Sazatornil,

Palazon

et al. 2024

Preprint

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Range expansion is a common feature from invasive to reintroduced or recovering populations. This process is mainly driven by population growth and dispersal and, consequently, different species’ intrinsic characteristics and dispersal mechanisms will result in contrasting population structures in space. How individuals of different sex and age classes are spatially distributed is key to understand and forecast range expansions, but remains largely unexplored. Here, we developed an age-structured open population spatial capture recapture (OPSCR) model to understand how spatial sex and age structures can shape population dynamics, as well as recovery processes. We use the expanding and endangered Pyrenean brown bear population as case study, taking advantage of a comprehensive non-invasive monitoring dataset collected between 2017 and 2021. The expansion front was dominated by adult (>4 years) and subadult males (2-4 years), while females and juveniles (<2 years) prevailed at the core. Overall, density declined with distance to the population core (area where last bears remained in the ‘90s and where translocated females established). Bear expansion was affected by the locations of the remnant range (i.e., the core areas) and constrained by female philopatry. Future projections suggest that increasing reproduction events at the periphery could speed up future population spread, and that this population will continue growing even under some level of demographic stochasticity. Our novel OPSCR model opens new pathways to understand complex spatiotemporal patterns of expanding populations and, in the case of large carnivores, could inform conservation action, for example, anticipating the adoption of damage prevention measures and raising awareness campaigns on how to coexist with bears in future expansion areas.

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Section: Discussionsupporting

confidence: 89%

Section: Discussionmentioning

confidence: 63%

Lonely males at the front: A new open SCR model reveals the spatial sex-age structure of an expanding brown bear population

Perez,

Sazatornil,

Palazon

et al. 2024

Preprint

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“…Several populations have since recovered, some of which were once small, isolated, and in peril. Grizzly bear populations are now increasing in many areas in and around the defined US Recovery Zones in four US states, and in portions of southern Canada, such as in central British Columbia (Apps et al, 2014; Hatter et al, 2018; Lamb et al, 2018; McLellan, 1989; McLellan et al, 2021) or expanding eastward into portions of their historic range in Alberta (Morehouse & Boyce, 2016). The grizzly bear population in the Greater Yellowstone Ecosystem that was estimated at 175 individuals in 1975 has since increased 5‐fold, and more than 1000 grizzlies now range into landscapes that have been dramatically transformed by people since the animals last walked there a century ago (Haroldson et al, 2021; Schwartz et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

Unsecured attractants, collisions, and high mortality strain coexistence between grizzly bears and people in theElk Valley, southeastBritish Columbia

Lamb,

Smit,

Mowat

et al. 2023

Conservat Sci and Prac

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Historical persecution of grizzly bears in North America reduced the species range by 55%. Today, dedicated recovery efforts and shifting societal perceptions have supported the recovery and expansion of grizzly bear populations in many areas. With increasing overlap between people and bears, conservation actions and scientific inquiry are now shifting efforts toward supporting coexistence with bears. Here, we assessed the demography and behavior of grizzly bears in a coexistence landscape in southeast British Columbia, Canada, where abundant grizzly bear populations occur among busy, human‐settled valleys. Between 2016 and 2022, we captured 76 individual grizzly bears and monitored their conflict behavior, survival, and reproduction for 160 animal‐years. The cause of death for 14 animals with a functioning collar was human–wildlife conflict (n = 6), road or rail collision (n = 6), unknown but human suspected (n = 1), and natural (n = 1). Subadult survival was the lowest recorded in North America, while adult survival was similar to other studies, suggesting an intense demographic filter for young animals. We estimate that human‐caused mortality is underreported in government databases by 65%, or for every recorded mortality, there are ~2 that go unreported. Reporting was especially low for road and rail mortalities. Grizzly bear mortality in the Elk Valley due to collisions and conflicts with people is an order of magnitude greater than elsewhere in British Columbia. Combining DNA‐ and collar‐based estimates of population growth, we show that grizzly bear abundance is stable due to source‐sink dynamics, whereby ~7 immigrant bears per year offset the high mortality rates in the area. Grizzly bears dispersing into the valley are often young and more conflict‐naïve, creating a conflict spiral that can be interrupted by reducing mortality of young animals. Creating a self‐sustaining population of bears in the Elk Valley that is not reliant on immigration will require targeted efforts to reduce or secure attractants on private property and strategies to minimize collisions with trains and vehicles.

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“…To collect the information needed, it is often necessary to study some number of individual animals using tracking (telemetry) devices, especially for secretive species that are otherwise difficult to observe, such as many felids [1,2]. Telemetry studies can provide valuable data relevant to species biology, including movement dynamics, resource selection, foraging behavior, and demographic processes like cause-specific mortality, fecundity, and dispersal, e.g., [1,[3][4][5][6][7]. Fitting tracking devices-typically collars in the case of terrestrial carnivores-requires that animals are captured and immobilized.…”

Section: Introductionmentioning

confidence: 99%

Guidelines for Telemetry Studies on Snow Leopards

Johansson

Kachel

Weckworth

2022

Animals

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Animal-borne tracking devices have generated a wealth of new knowledge, allowing us to better understand, manage and conserve species. Fitting such tracking devices requires that animals are captured and often chemically immobilized. Such procedures cause stress and involve the risk of injuries and loss of life even in healthy individuals. For telemetry studies to be justifiable, it is vital that capture operations are planned and executed in an efficient and ethical way. Project objectives must be clearly articulated to address well-defined knowledge gaps, and studies designed to maximize the probability of achieving those goals. We provide guidelines for how to plan, design, and implement telemetry studies with a special emphasis on snow leopards that are typically captured using foot snares. We also describe the necessary steps to ensure that captures are conducted safely, and with minimal stress to animals.

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Vital rates of two small populations of brown bears in Canada and range‐wide relationship between population size and trend

Abstract: This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Cited by 5 publications

References 73 publications

Lonely males at the front: A new open SCR model reveals the spatial sex-age structure of an expanding brown bear population

Lonely males at the front: A new open SCR model reveals the spatial sex-age structure of an expanding brown bear population

Unsecured attractants, collisions, and high mortality strain coexistence between grizzly bears and people in theElk Valley, southeastBritish Columbia

Guidelines for Telemetry Studies on Snow Leopards

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