Barrie Gilbert | Utah State University (original) (raw)

Papers by Barrie Gilbert

Test Methods for Vertebrate Pest Control and Management Materials

Recently several researchers have tested aversive conditioning as a method of reducing damage and... more Recently several researchers have tested aversive conditioning as a method of reducing damage and discouraging approach by carnivores. This paper discusses some general biological considerations in the application of aversive conditioning. Its effectiveness as a control technique will depend, in part, on the characteristics of the wildlife species involved (for example, social organization, individual and species behavior, feeding strategy, annual mortality, and movement); characteristics of the resource being protected (for example, whether it constitutes prey, carrion, space, etc. to the predator, and its desirability and necessity to the predator); and the selection of appropriate aversive stimuli and substrates. Appropriate tests of aversive conditioning are discussed. Specific situations are detailed where aversive conditioning might be most valuable in the control of problem wildlife.

Biological Conservation, 2005

Ecotourism is a rapidly growing industry with unknown impacts on viewed wildlife that may require... more Ecotourism is a rapidly growing industry with unknown impacts on viewed wildlife that may require novel management action. We examined the impact of viewing activities on the behaviour of brown bears (Ursus arctos) in coastal British Columbia. Domination of the best feeding sites and human avoidance by large male bears has consistently been reported. We, however, saw displacement in time rather than space-during the viewing day large males were less active than at other times, while females with cubs tended to be more active. In each year, females with cubs spent similarly high proportions of their time fishing when people were present. In years with large male activity, less time was spent fishing when people were absent. When freed from the potential threat of large male bears, females with cubs showed no measurable impact of controlled human activity. Human presence at a feeding site impacts the behaviour of brown bears, but not as expected. Temporal avoidance of human activity by large males was observed; indications that they departed upon satiation, before the arrival of morning tours, however, suggests that there was little energetic impact. By displacing large males, viewing activities created a temporal refuge, enhancing feeding opportunities for subordinate age/sex classes. With the strong positive relationships between mean female mass and litter size, this may in turn increase population productivity.

The Wilson Bulletin, 1972

THE behavior of the Yellow-faced Grassquit (Tiaris olivacea) apparently ranges from social and no... more THE behavior of the Yellow-faced Grassquit (Tiaris olivacea) apparently ranges from social and nonaggressive on the Central American mainland to territorial and very aggressive on the island of Jamaica (Pulliam, 1970). Why these differences? This paper reports observations on ...

Utah had its first black bear attack in June of 1992 when a young girl was dragged from a camper ... more Utah had its first black bear attack in June of 1992 when a young girl was dragged from a camper at Strawberry campground. Subsequent litigation in Utah and Arizona, following a bear mauling in 1994, has changed our

For many species, reliable evaluation of foraging habitat requires measurement of a multitude of ... more For many species, reliable evaluation of foraging habitat requires measurement of a multitude of variables. Bears, however, provide a unique opportunity to integrate all these variables into a single measure: salmon consumption. As with Van Horne’s measure of habitat quality (Qj ), consumption of salmon affects fecundity, age at first reproduction and survival probability. Our analysis revealed a highly significant (p=0.005) negative relationship between minimum viable population and food availability/habitat quality lending empirical support to the conceptual form of this relationship proposed by Van Horne. Understanding the relationship between habitat quality and minimum viable population has important implications for conservation area design and the dominant paradigm of carnivore conservation, which emphasizes large areas with little or no human access, may in fact be a poor model for conservation efforts. The historic emphasis on the need for large areas has led to the protect...

Introduction Utah had its first black bear attack in June of 1992 when a young girl was dragged f... more Introduction Utah had its first black bear attack in June of 1992 when a young girl was dragged from a camper at Strawberry campground. Subsequent litigation in Utah and Arizona, following a bear mauling in 1994, has changed our awareness regarding alleged negligence. With escalating bear problems, Utah, the U.S. Forest Service and various campground personnel will need to understand their responsibilities and act more preventively. Recent court decisions under the Federal Tort Claims Act too extensive to detail here have affected the way employee directives are worded and the discretionary roles that those employees maintain for inspecting and detecting violations, for implementing operations, and for maintenance plans in organized campgrounds.

The Canadian Field-Naturalist

Over a period of four years, autumn courtship behaviour in Brown Bears (Ursus arctos) was observe... more Over a period of four years, autumn courtship behaviour in Brown Bears (Ursus arctos) was observed on three separate occasions, with copulation observed once and two litters of cubs potentially resulting from autumn breeding. These are the first recorded observations of these behaviours.

A quantitative study of the behavior of brown bears (Ursus arctos) was undertaken at Brooks River... more A quantitative study of the behavior of brown bears (Ursus arctos) was undertaken at Brooks River in Katmai National Park and Preserve 1988-90 to determine whether human activity affected use of the area by females with young. Over the 3 fall seasons 862 hours of systematic observations were recorded or not (late Aug through mid-Oct salmon spawning period). Ten different

Canadian Journal of Forest Research, 2005

Pacific salmon (Oncorhynchus spp.) transport nitrogen (N) from oceans to inland ecosystems. Salmo... more Pacific salmon (Oncorhynchus spp.) transport nitrogen (N) from oceans to inland ecosystems. Salmon δ 15 N is higher than δ 15 N expected in terrestrial plants, so linear two-source mixing models have commonly been used to quantify contributions of marine-derived N (MDN) to riparian ecosystems based on riparian plant δ 15 N. However, isotopic fractionation potentially contributes to error in MDN estimates by changing δ 15 N of salmon-derived N appearing in soil and plants. We used a simulation model to examine potential effects of fractionation on MDN estimates. We also measured changes in δ 15 N and δ 13 C as N and carbon (C) moved from bear feces into soil, and compared MDN estimates using three different estimates for the marine endmember of a linear mixing model. Simulation demonstrated that fractionation during soil N losses could lead to large overestimations of MDN when δ 15 N of salmon tissue is used as the marine endmember. δ 15 N of bear feces was significantly enriched (by 1.9‰) relative to salmon tissue, but did not change during movement of feces-derived N into soil. In contrast, δ 13 C decreased by 1.9‰ between salmon and bear feces and declined an additional 4.2‰ during movement into soil. We propose a new method for estimating the δ 15 N of the marine endmember that accounts for isotope fractionation occurring as marine N is cycled in soil. This method uses the proportional difference in soil 15 N content between reference and spawning sites to calculate the marine endmember δ 15 N. Résumé : Le saumon du Pacifique (Oncorhynchus spp.) transporte de l'azote (N) des océans vers les écosystèmes continentaux. Comme le δ 15 N du saumon est plus élevé que le δ 15 N anticipé pour les plantes terrestres, des modèles linéaires de mélange de deux sources de fluides ont souvent été utilisés pour quantifier les contributions de N dérivé du milieu marin (ADMM) aux écosystèmes riverains en se basant sur le δ 15 N des plantes riveraines. Toutefois, le fractionnement isotopique peut contribuer à fausser les estimations de l'ADMM en changeant le δ 15 N de N du saumon apparaissant dans le sol et les plantes. Les auteurs ont utilisé un modèle de simulation pour examiner les effets potentiels du fractionnement sur les estimations de l'ADMM. Ils ont aussi mesuré les changements dans le δ 15 N et le δ 13 C étant donné que le N et le carbone (C) passent des fèces d'ours au sol, et ils ont comparé les estimations de l'ADMM en utilisant trois estimés différents pour le pôle marin d'un modèle linéaire de mélange de fluides. Les simulations ont démontré que le fractionnement lors des pertes de N du sol peut mener à des surestimations substantielles de l'ADMM quand le δ 15 N des tissus du saumon est utilisé comme pôle marin. Le δ 15 N des fèces d'ours était significativement enrichi (de 1,9 ‰) par rapport aux tissus du saumon, mais ne changeait pas durant le déplacement de N des fèces dans le sol. À l'opposé, le δ 13 C a diminué de 1,9 ‰ en passant du saumon aux fèces d'ours, puis d'un autre 4,2 ‰ durant son déplacement dans le sol. Ils proposent une nouvelle méthode qui tient compte du fractionnement des isotopes lors du recyclage de N marin dans le sol pour l'estimation du δ 15 N du pôle marin. Cette méthode utilise la différence proportionnelle du contenu en 15 N du sol entre les sites de référence et de fraie pour calculer le δ 15 N du pôle marin.

13 Opportunities for social learning in bears Barrie K. Gilbert Introduction The Ursidae-the bear... more 13 Opportunities for social learning in bears Barrie K. Gilbert Introduction The Ursidae-the bears-is a family of carnivores that is geographically ... bears The Asiatic black bear (Ursus thibetanus) is a medium-sized black-coloured bear with large ears and a large white blaze on the ...

Brown bears (Ursus arctos) in North America vary widely in their densities from a maximum of 550 ... more Brown bears (Ursus arctos) in North America vary widely in their densities from a maximum of 550 bears /1000 km2 in coastal Alaska to less than 5 bears /1000 km2 for mountain bears in the north; this variation has been attributed to differences in food base. The impacts of security and perceived risk on the exploitation of energy rich environments also have significant impacts on demographic rates within populations. Increasing the energy density of habitat has been identified as an important step in the restoration and maintenance of small brown bear populations in Europe and this is equally applicable to bear populations at risk in North America. Where bears persist at high densities they are in productive ecosystems, where protection has been of low productivity land populations which survive are marginal. Drawing on examples from Yellowstone, coastal British Columbia and Alaska we will present the case for using areas of enhanced habit security and energy density as source populations within a source-sink model of conservation of a species at the edge of its current range to halt the retreat of bears in Alberta.

... years. Because Warner (1987), Mattson et al. (1992 ... class. We used focal sampling (Altmann... more ... years. Because Warner (1987), Mattson et al. (1992 ... class. We used focal sampling (Altmann 1974) to record bear activity: arrival and departure times and identities were recorded for all bears seen during an observation session. Throughout ...

Test Methods for Vertebrate Pest Control and Management Materials

Recently several researchers have tested aversive conditioning as a method of reducing damage and... more Recently several researchers have tested aversive conditioning as a method of reducing damage and discouraging approach by carnivores. This paper discusses some general biological considerations in the application of aversive conditioning. Its effectiveness as a control technique will depend, in part, on the characteristics of the wildlife species involved (for example, social organization, individual and species behavior, feeding strategy, annual mortality, and movement); characteristics of the resource being protected (for example, whether it constitutes prey, carrion, space, etc. to the predator, and its desirability and necessity to the predator); and the selection of appropriate aversive stimuli and substrates. Appropriate tests of aversive conditioning are discussed. Specific situations are detailed where aversive conditioning might be most valuable in the control of problem wildlife.

Biological Conservation, 2005

Ecotourism is a rapidly growing industry with unknown impacts on viewed wildlife that may require... more Ecotourism is a rapidly growing industry with unknown impacts on viewed wildlife that may require novel management action. We examined the impact of viewing activities on the behaviour of brown bears (Ursus arctos) in coastal British Columbia. Domination of the best feeding sites and human avoidance by large male bears has consistently been reported. We, however, saw displacement in time rather than space-during the viewing day large males were less active than at other times, while females with cubs tended to be more active. In each year, females with cubs spent similarly high proportions of their time fishing when people were present. In years with large male activity, less time was spent fishing when people were absent. When freed from the potential threat of large male bears, females with cubs showed no measurable impact of controlled human activity. Human presence at a feeding site impacts the behaviour of brown bears, but not as expected. Temporal avoidance of human activity by large males was observed; indications that they departed upon satiation, before the arrival of morning tours, however, suggests that there was little energetic impact. By displacing large males, viewing activities created a temporal refuge, enhancing feeding opportunities for subordinate age/sex classes. With the strong positive relationships between mean female mass and litter size, this may in turn increase population productivity.

The Wilson Bulletin, 1972

THE behavior of the Yellow-faced Grassquit (Tiaris olivacea) apparently ranges from social and no... more THE behavior of the Yellow-faced Grassquit (Tiaris olivacea) apparently ranges from social and nonaggressive on the Central American mainland to territorial and very aggressive on the island of Jamaica (Pulliam, 1970). Why these differences? This paper reports observations on ...

Utah had its first black bear attack in June of 1992 when a young girl was dragged from a camper ... more Utah had its first black bear attack in June of 1992 when a young girl was dragged from a camper at Strawberry campground. Subsequent litigation in Utah and Arizona, following a bear mauling in 1994, has changed our

For many species, reliable evaluation of foraging habitat requires measurement of a multitude of ... more For many species, reliable evaluation of foraging habitat requires measurement of a multitude of variables. Bears, however, provide a unique opportunity to integrate all these variables into a single measure: salmon consumption. As with Van Horne’s measure of habitat quality (Qj ), consumption of salmon affects fecundity, age at first reproduction and survival probability. Our analysis revealed a highly significant (p=0.005) negative relationship between minimum viable population and food availability/habitat quality lending empirical support to the conceptual form of this relationship proposed by Van Horne. Understanding the relationship between habitat quality and minimum viable population has important implications for conservation area design and the dominant paradigm of carnivore conservation, which emphasizes large areas with little or no human access, may in fact be a poor model for conservation efforts. The historic emphasis on the need for large areas has led to the protect...

Introduction Utah had its first black bear attack in June of 1992 when a young girl was dragged f... more Introduction Utah had its first black bear attack in June of 1992 when a young girl was dragged from a camper at Strawberry campground. Subsequent litigation in Utah and Arizona, following a bear mauling in 1994, has changed our awareness regarding alleged negligence. With escalating bear problems, Utah, the U.S. Forest Service and various campground personnel will need to understand their responsibilities and act more preventively. Recent court decisions under the Federal Tort Claims Act too extensive to detail here have affected the way employee directives are worded and the discretionary roles that those employees maintain for inspecting and detecting violations, for implementing operations, and for maintenance plans in organized campgrounds.

The Canadian Field-Naturalist

Over a period of four years, autumn courtship behaviour in Brown Bears (Ursus arctos) was observe... more Over a period of four years, autumn courtship behaviour in Brown Bears (Ursus arctos) was observed on three separate occasions, with copulation observed once and two litters of cubs potentially resulting from autumn breeding. These are the first recorded observations of these behaviours.

A quantitative study of the behavior of brown bears (Ursus arctos) was undertaken at Brooks River... more A quantitative study of the behavior of brown bears (Ursus arctos) was undertaken at Brooks River in Katmai National Park and Preserve 1988-90 to determine whether human activity affected use of the area by females with young. Over the 3 fall seasons 862 hours of systematic observations were recorded or not (late Aug through mid-Oct salmon spawning period). Ten different

Canadian Journal of Forest Research, 2005

Pacific salmon (Oncorhynchus spp.) transport nitrogen (N) from oceans to inland ecosystems. Salmo... more Pacific salmon (Oncorhynchus spp.) transport nitrogen (N) from oceans to inland ecosystems. Salmon δ 15 N is higher than δ 15 N expected in terrestrial plants, so linear two-source mixing models have commonly been used to quantify contributions of marine-derived N (MDN) to riparian ecosystems based on riparian plant δ 15 N. However, isotopic fractionation potentially contributes to error in MDN estimates by changing δ 15 N of salmon-derived N appearing in soil and plants. We used a simulation model to examine potential effects of fractionation on MDN estimates. We also measured changes in δ 15 N and δ 13 C as N and carbon (C) moved from bear feces into soil, and compared MDN estimates using three different estimates for the marine endmember of a linear mixing model. Simulation demonstrated that fractionation during soil N losses could lead to large overestimations of MDN when δ 15 N of salmon tissue is used as the marine endmember. δ 15 N of bear feces was significantly enriched (by 1.9‰) relative to salmon tissue, but did not change during movement of feces-derived N into soil. In contrast, δ 13 C decreased by 1.9‰ between salmon and bear feces and declined an additional 4.2‰ during movement into soil. We propose a new method for estimating the δ 15 N of the marine endmember that accounts for isotope fractionation occurring as marine N is cycled in soil. This method uses the proportional difference in soil 15 N content between reference and spawning sites to calculate the marine endmember δ 15 N. Résumé : Le saumon du Pacifique (Oncorhynchus spp.) transporte de l'azote (N) des océans vers les écosystèmes continentaux. Comme le δ 15 N du saumon est plus élevé que le δ 15 N anticipé pour les plantes terrestres, des modèles linéaires de mélange de deux sources de fluides ont souvent été utilisés pour quantifier les contributions de N dérivé du milieu marin (ADMM) aux écosystèmes riverains en se basant sur le δ 15 N des plantes riveraines. Toutefois, le fractionnement isotopique peut contribuer à fausser les estimations de l'ADMM en changeant le δ 15 N de N du saumon apparaissant dans le sol et les plantes. Les auteurs ont utilisé un modèle de simulation pour examiner les effets potentiels du fractionnement sur les estimations de l'ADMM. Ils ont aussi mesuré les changements dans le δ 15 N et le δ 13 C étant donné que le N et le carbone (C) passent des fèces d'ours au sol, et ils ont comparé les estimations de l'ADMM en utilisant trois estimés différents pour le pôle marin d'un modèle linéaire de mélange de fluides. Les simulations ont démontré que le fractionnement lors des pertes de N du sol peut mener à des surestimations substantielles de l'ADMM quand le δ 15 N des tissus du saumon est utilisé comme pôle marin. Le δ 15 N des fèces d'ours était significativement enrichi (de 1,9 ‰) par rapport aux tissus du saumon, mais ne changeait pas durant le déplacement de N des fèces dans le sol. À l'opposé, le δ 13 C a diminué de 1,9 ‰ en passant du saumon aux fèces d'ours, puis d'un autre 4,2 ‰ durant son déplacement dans le sol. Ils proposent une nouvelle méthode qui tient compte du fractionnement des isotopes lors du recyclage de N marin dans le sol pour l'estimation du δ 15 N du pôle marin. Cette méthode utilise la différence proportionnelle du contenu en 15 N du sol entre les sites de référence et de fraie pour calculer le δ 15 N du pôle marin.

13 Opportunities for social learning in bears Barrie K. Gilbert Introduction The Ursidae-the bear... more 13 Opportunities for social learning in bears Barrie K. Gilbert Introduction The Ursidae-the bears-is a family of carnivores that is geographically ... bears The Asiatic black bear (Ursus thibetanus) is a medium-sized black-coloured bear with large ears and a large white blaze on the ...

Brown bears (Ursus arctos) in North America vary widely in their densities from a maximum of 550 ... more Brown bears (Ursus arctos) in North America vary widely in their densities from a maximum of 550 bears /1000 km2 in coastal Alaska to less than 5 bears /1000 km2 for mountain bears in the north; this variation has been attributed to differences in food base. The impacts of security and perceived risk on the exploitation of energy rich environments also have significant impacts on demographic rates within populations. Increasing the energy density of habitat has been identified as an important step in the restoration and maintenance of small brown bear populations in Europe and this is equally applicable to bear populations at risk in North America. Where bears persist at high densities they are in productive ecosystems, where protection has been of low productivity land populations which survive are marginal. Drawing on examples from Yellowstone, coastal British Columbia and Alaska we will present the case for using areas of enhanced habit security and energy density as source populations within a source-sink model of conservation of a species at the edge of its current range to halt the retreat of bears in Alberta.

... years. Because Warner (1987), Mattson et al. (1992 ... class. We used focal sampling (Altmann... more ... years. Because Warner (1987), Mattson et al. (1992 ... class. We used focal sampling (Altmann 1974) to record bear activity: arrival and departure times and identities were recorded for all bears seen during an observation session. Throughout ...