Stochasticity in Natural Forage Production Affects Use of Urban Areas by Black Bears: Implications to Management of Human-Bear Conflicts

Baruch‐Mordo, Sharon; Wilson, Kenneth; Lewis, David L.; Broderick, John; Mao, Julie S.; Breck, Stewart W.

doi:10.1371/journal.pone.0085122

Cited by 152 publications

(108 citation statements)

References 63 publications

(69 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…First, we defined as the frequency of good natural food years and generated an independent identically distributed (iid) environmental sequences of good and poor natural food years using random draws from a binomial distribution. Second, we used vital rate estimates from Aspen (Baruch-Mordo et al, 2014) in conjunction with mean and 95% credible intervals for Western bear populations determined by Beston (2011) as a guide for selecting vital rate means and standard deviations for good and poor natural food years in the three scenario described in Section 2.3. We used these vital rate means and standard deviations to calculate parameters for beta and gamma distributions (see Appendix A).…”

Section: Population Modelmentioning

confidence: 99%

“…For both urban scenarios (Low and High Removal), we assumed that available anthropogenic food sources resulted in normal cub production during poor natural food years (Baruch-Mordo et al, 2014;Beckmann and Lackey, 2008). During the Aspen study all adult females consistently gave birth on a two year cycle and the number of cubs/litter remained steady regardless of good or poor natural food availability, i.e., ar = 1 and 2.21 total cubs/litter (Baruch-Mordo et al, 2014). Because fewer than 10 adult females were monitored annually, we conservatively set ar = 0.95 and L = 1.15 female cubs/litter for good and poor natural food years.…”

Section: Scenario Developmentmentioning

confidence: 99%

“…During poor natural food years cub and sub-adult survival increased along with the transition probabilities and cub production, but adult survival dropped. For the High Removal scenario, during good forage years vital rates were the same as the Low Removal scenario, and during poor forage years, we reduced cub and subadult survival rates to be less than and equal to survival for the Baseline scenario and set adult survival rates near empirical estimates from the Aspen study (Baruch-Mordo et al, 2014) (Table 2). We assumed that vital rate values were normally distributed around a central value and set the standard deviation for good and poor natural food year vital rate distributions as follows: cub and subadult survival ( = 0.05), adults with and without cubs survival ( = 0.025), transition probabilities ( = 0.02), and number of female cubs/litter ( = 0.10).…”

Section: Scenario Developmentmentioning

confidence: 99%

“…During these food failure years adult survival is thought to remain high (Kasbohm et al, 1996;Noyce and Garshelis, 1994;Schrage and Vaughan, 1995), but cub production declines (Beck, 1991;Beckmann and Lackey, 2008;Bridges et al, 2011;Elowe and Dodge, 1989;Rogers et al, 1976). But bears in urban environments can supplement their diets to include available urban food, eliminating seasonal and annual variation in food resources resulting in cub production when natural foods are not available (Baruch-Mordo et al, 2014;Beckmann and Lackey, 2008). While urban food sources can provide the benefit of stable cub production, to prevent property damage and for human safety, wildlife managers often remove or destroy bears that use the urban environment and cause conflict.…”

Section: Introductionmentioning

confidence: 99%

“…While urban food sources can provide the benefit of stable cub production, to prevent property damage and for human safety, wildlife managers often remove or destroy bears that use the urban environment and cause conflict. For example, Aspen, Colorado (USA), experienced two natural food failure years during a 6-year study from 2005 to 2011 (Baruch-Mordo et al, 2014). During these poor natural food years, annual mortalities of adult females increased 2-3 times, with the majority of mortalities being attributed to removal of conflict bears.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Modeling black bear population dynamics in a human-dominated stochastic environment

Lewis

Breck

Wilson

et al. 2014

Ecological Modelling

View full text Add to dashboard Cite

a b s t r a c tMany large carnivore populations exist in human-influenced stochastic environments where availability of natural food sources vary annually and anthropogenic food sources can supplement energetic demands, but at a potential demographic cost due to human-wildlife conflict and subsequent conflict management. Understanding how these competing factors influence a population is complex and difficult to study, but here we demonstrate the utility of using a stochastic projection matrix model and perturbation analysis to gain insight into this problem. We modeled a black bear population subjected to stochastic failures of fruiting and masting species, but with access to garbage in urban environments. We parameratized our model with data from a 6-year study on black bears in Aspen, Colorado and data synthesized from other research studies. Using computer simulation, we investigated the effect that different levels of conflict-bear removal can have on a bear population by comparing a "reference" scenario where bears did not benefit from human food sources or experience conflict-bear removals with two urban scenarios where bears had varying access to human foods, but conflict bears were removed. We used perturbation analyses to evaluate consequences for changing population vital rates and to estimate the impact each vital rate change had on population growth. Simulations were used to identify how much variation in each vital rate influenced variation in the population growth rate. We identified the survival rate of breeding adult females during good natural food years as having the highest elasticity value. We found that the benefit of increased cub production from available human food sources during natural food failure years was quickly negated if management of conflict bears through removal reduced adult female survival. Increasing the frequency of years when natural food production fails resulted in disproportionate impacts from available urban food and conflict-bear removals, where population growth rates in a High Removal scenario declined 1.5 times faster than in the reference scenario. Our findings suggest that for regions where changing climates will increase the frequency of natural food failures, managers may need to utilize non-lethal practices in managing conflict bears and municipalities will need to secure human food sources to reduce the need for conflict-bear removals and potential population declines.

show abstract

Section: Population Modelmentioning

confidence: 99%

Section: Scenario Developmentmentioning

confidence: 99%

Section: Scenario Developmentmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Modeling black bear population dynamics in a human-dominated stochastic environment

Lewis

Breck

Wilson

et al. 2014

Ecological Modelling

View full text Add to dashboard Cite

show abstract

Characteristics of black bear‐related trauma: A retrospective observational study

Tsuchida,

Satoh,

Hirasawa

et al. 2024

Acute Medicine & Surgery

View full text Add to dashboard Cite

AimBear‐related trauma is a significant concern in Japan. This study identified trauma patterns, outcomes, and therapeutic approaches for bear‐related injuries treated.MethodsThis retrospective observational study used medical records from Akita University Hospital, focusing on patients with bear‐related trauma in 2023. Demographic data, injury details, treatment procedures, and outcomes were extracted.ResultsThe study included 20 patients (median age: 74.5 years, 65% males). Most injuries occurred in human habitats, mainly in autumn, with the face being the most affected area (90%). Three patients required emergency transfusions and tracheal intubation. Emergency surgery was performed in 52.6% of patients, and 42.1% were admitted to the intensive care unit. All patients survived with a median hospital stay of 17 days. However, 15.8% of patients had significant sequelae, such as blindness. Despite prophylactic antibiotics, wound infections occurred in 21.1% of patients, particularly in deep wounds that were not adequately washed under general anesthesia.ConclusionsBear‐related trauma often results in severe upper‐body injuries that require prompt medical intervention. These findings highlight the need for improved preventive measures and strategies for initial treatment and long‐term care.

show abstract

Spatial genetic patterns indicate mechanism and consequences of large carnivore cohabitation within development

Evans

Rittenhouse

Hawley

et al. 2018

Ecology and Evolution

View full text Add to dashboard Cite

Patterns of human development are shifting from concentrated housing toward sprawled housing intermixed with natural land cover, and wildlife species increasingly persist in close proximity to housing, roads, and other anthropogenic features. These associations can alter population dynamics and evolutionary trajectories. Large carnivores increasingly occupy urban peripheries, yet the ecological consequences for populations established entirely within urban and exurban landscapes are largely unknown. We applied a spatial and landscape genetics approach, using noninvasively collected genetic data, to identify differences in black bear spatial genetic patterns across a rural‐to‐urban gradient and quantify how development affects spatial genetic processes. We quantified differences in black bear dispersal, spatial genetic structure, and migration between differing levels of development within a population primarily occupying areas with >6 houses/km2 in western Connecticut. Increased development disrupted spatial genetic structure, and we found an association between increased housing densities and longer dispersal. We also found evidence that roads limited gene flow among bears in more rural areas, yet had no effect among bears in more developed ones. These results suggest dispersal behavior is condition‐dependent and indicate the potential for landscapes intermixing development and natural land cover to facilitate shifts toward increased dispersal. These changes can affect patterns of range expansion and the phenotypic and genetic composition of surrounding populations. We found evidence that subpopulations occupying more developed landscapes may be sustained by male‐biased immigration, creating potentially detrimental demographic shifts.

show abstract

Stochasticity in Natural Forage Production Affects Use of Urban Areas by Black Bears: Implications to Management of Human-Bear Conflicts

Cited by 152 publications

References 63 publications

Modeling black bear population dynamics in a human-dominated stochastic environment

Modeling black bear population dynamics in a human-dominated stochastic environment

Characteristics of black bear‐related trauma: A retrospective observational study

Spatial genetic patterns indicate mechanism and consequences of large carnivore cohabitation within development

Contact Info

Product

Resources

About