With the advancement of radiotracking techniques, there has been a dramatic increase in the quant... more With the advancement of radiotracking techniques, there has been a dramatic increase in the quantity and quality of locational and movement data obtained for a variety of wildlife species. Automated tracking systems, in particular, produce enormous amounts of data. These data help researchers determine movements, home ranges, and habitat use by individuals and populations. One of many challenges is determining not only which home-range estimators to use, but also which home-range program will best fulfill study objectives. We used data from a moose (Alces alces) fitted with a test Global Positioning System (GPS) collar to compare home-range sizes estimated by 5 commonly used software packages (CALHOME, HOME RANGE, RANGES IV, RANGES V, TRACKER). We found large differences in calculated home-range sizes using minimum convex polygon, harmonic mean, and kernel estimators at 3 levels of resolution (95%, 75%, and 50% of locations). Comparing home ranges among different research studies can be misleading unless researchers report choices for software program, home-range estimators, user-selected options, and input values of required parameters.
Moose-vehicle collisions are a serious concern in many areas of North America and Fennoscandia. I... more Moose-vehicle collisions are a serious concern in many areas of North America and Fennoscandia. In northwestern Ontario, more than 400 moose-vehicle collisions occur annually, and 26 fatal collisions have occurred over the last 10 years. To avoid colliding with a moose, a motorist must: (1) successfully see or detect the presence of the animal; (2) determine whether or not the moose poses a threat requiring evasive action; (3) determine what action, if necessary, is required; and (4) implement the action. Whereas perception-reaction times of motorists have been studied in detail, allowing calculations of post-detection distances travelled by a vehicle at different speeds, distances to determine the distances at which an animal could be detected at night when it was positioned on each shoulder and in the middle of a highway using high and low beam headlamp settings of different vehicles. Overall, we found the mean detection distance across all vehicle types, headlamp settings, tor; on the low beam setting, mean detection distance was 74 m and on the high beam setting it was 137 m. Moose decoy location was also important; combining the data for both headlamp settings, mean detection distances were 89 m, 93 m, and 133 m for the left, right, and centre positions, respectively. There was no relationship between headlamp height of different vehicles and moose detection distance. nation capabilities of their headlamps for moose encounters. For drivers using a low beam headlamp ALCES VOL. 42: 75-87 (2006)
Publisher Summary This chapter provides an update on the most significant technological advances ... more Publisher Summary This chapter provides an update on the most significant technological advances of terminology of the past decade along with an overview on the most recent telemetry systems. Telemetry refers to the remote determination of an animal's status, which includes the individual's current level of activity, some physiological measurement, and its physical location. Telemetry is used in an extensive array of agricultural, physiological, and medical research activities to monitor the status of individuals. In these studies, measurements are usually made at close range, typically within a few hundred meters. Ecologists, field biologists, and wildlife researchers, on the other hand, generally use “telemetry” to estimate a series of geographic locations for individual animals, often from distances exceeding several hundred meters. Furthermore, since radio signals emanating from a device attached to each animal are commonly used to estimate locations, the technique is often referred to as “radiotelemetry.” Telemetry technology has continued to progress throughout the 1990s. Advances in power management, electronic components, and microcomputers, as well as the emergence of several innovative systems based on the new technology, have all contributed to an ever-increasing variety of telemetry options available to field researchers.
We tracked 122 female moose in northwestern Ontario, Canada, using global positioning system (GPS... more We tracked 122 female moose in northwestern Ontario, Canada, using global positioning system (GPS) radio-collars between 1995 and 2001. We used step-selection functions (SSF) to evaluate changes in moose habitat selection as a function of temperature across seasons (summer and winter), stand types, and stand heights. We obtained mean activity levels of moose within stand types and across seasons from motion sensors in the collars. Selection increased for aquatic stand types as a function of temperature across both summer and winter. Selection for stand height was also temperature-dependent, with tall stands being most favored at warm temperatures and least favored at cold temperatures. Moose activity levels increased slightly at higher temperatures during the winter but were mostly constant, whereas summer activity declined significantly with increasing temperature. Seasonal activity levels were mostly constant within habitats, but activity was consistently higher in aquatic habitats compared to woody habitats, with the highest mean activity levels observed when moose were located in open water and marshes during the summer. Our findings corroborate the work of others that moose primarily select habitat based on documented foraging requirements, whereas they may alter midday selection for specific stand types providing thermal cover under varied temperatures, indicating a behavioral response to thermoregulatory needs. Increased activity levels at low summer temperatures, and in habitats found to provide thermal cover, support the conclusion that moose may alter their activity to alleviate heat stress, and that temperaturemediated changes in habitat selection may facilitate otherwise energetically costly behavior (e.g., movement).
The food habits of animals may be studied in the laboratory or in the field. Field studies descri... more The food habits of animals may be studied in the laboratory or in the field. Field studies describe diet selection of populations but do not permit analysis of the factors causing individual variation in the foraging behaviour of animals. Although numerous indices have been developed to compare use and availability of foods in field diets of animals, little attention has been given to laboratory approaches for comparing food choices. Tests of food choice must account for the order, consumption rate, and total amount of each food type eaten. Current measures fail to account for one or more of these parameters. This often results in highly ambiguous preference rankings, making comparisons among individuals or species difficult. To solve this problem, I propose using the area under the curve of the cumulative proportion eaten versus time for each food type. This index may be used to assess individual variation and determine the relative importance of each major component of the diet selection process in animals.
Habitat-based prediction of population density relies on relationships between landscape configur... more Habitat-based prediction of population density relies on relationships between landscape configuration (i.e., abundance of land-cover types) and equilibrium density. This may be accomplished by estimating resource selection probability functions (RSPFs) based on presence-absence data, or by relating carrying capacity to landscape covariates. We used RSPFs for moose (Alces alces) from 2 study sites and carrying capacities from 34 wildlife management units across northern Ontario, Canada, to create 2 estimators of moose density. We compared the predictions of both models to moose density in a novel site obtained via aerial census. We also projected the RSPF across 34 management units and compared predicted density to estimated carrying capacity of each unit. The RSPF and carrying capacity models predicted moose equilibrium densities that were statistically indistinguishable from the estimated density of moose at the novel study site, but the carrying capacity model generated uninformatively broad prediction intervals. The RSPF failed to predict carrying capacities in management units across Ontario; however, the differences between RSPF estimates and carrying capacities varied predictably with differences in covariates related to forage availability, suggesting habitat selection strength and RSPF transferability vary with landscape quality. Estimating densities using RSPFs relies on a consistent relationship between habitat selection and animal density; thus, RSPF applicability across space will depend heavily on similarity between the novel and original sites. Demographic projection benefits from broad spatiotemporal datasets that improve reliability but that are relatively rare and subject to broad error. Our findings suggest that selection-based population estimation is preferable to demographically based models because of increased precision of estimates, the immediacy of available data (e.g., single survey or radio-telemetry in multiple sites vs. many generations of population estimates in a time series across space), and the capacity to predict fine-scale patterns of distribution and abundance.
Understanding the impacts of disturbance on individual fitness is important for wildlife manageme... more Understanding the impacts of disturbance on individual fitness is important for wildlife management, and critical for the conservation of species at risk. We compared the fitness and seasonal range use of 39 woodland caribou in Ontario study areas contrasted by their level of human disturbance. We previously showed that wolf density in the disturbed site was higher, likely due to human-modified landscapes favoring moose, the primary prey of wolves. In this paper we address three objectives. First, because the assimilation of dietary nitrogen is heavily influenced by metabolic processes related to stress, we hypothesized that ratios of nitrogen isotopes (N) may indicate changes in body condition in ungulates and be useful proxies for changes in fitness. Second, we predicted that increased predation risk from wolves in disturbed areas would result in measurable declines in caribou body condition. Third, we hypothesized that one mechanism for fitness declines among caribou in the disturbed area was increased wolf activity restricting caribou seasonal movements. We showed change in N in the tissues of caribou was correlated with body condition scoring using fat assessment. We used GPS collars to quantify seasonal range use and found that fitness was higher, and seasonal range overlap was lower, in caribou using the nondisturbed area. Winter fitness declines were significantly larger in the more disturbed area. Our study identifies another mechanism by which the cumulative effects of human-disturbed landscapes on caribou fitness could contribute to global declines in caribou populations.
American black bears (Ursus americanus Pallas, 1780) are opportunistic foragers, and across most ... more American black bears (Ursus americanus Pallas, 1780) are opportunistic foragers, and across most of their range in North America, their diet is predominantly vegetation with limited consumption of vertebrates and invertebrates. However, they are also predators of ungulates, especially neonates, with regional variation in the amount of predation pressure they exert. We used scat analysis to examine the diet of black bears during the calving season in a moose (Alces alces (Linnaeus, 1758))woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) system in the Boreal forest of northern Ontario, Canada. Bears consumed herbaceous plants (46.5%), fruits and (or) seeds (20.0%), moose (3.3% adults; 4.3% calves), American beaver (Castor canadensis Kuhl, 1820; 8.5%), and insects (mostly ants; 4.2%). Bears had the highest consumption of moose and beaver in early spring, before switching to a more vegetation-dominated diet. We did not detect evidence of caribou consumption. Based on our results, black bear consumption of moose, particularly neonates, may warrant further investigation.
Understanding the impacts of disturbance on individual fitness is important for wildlife manageme... more Understanding the impacts of disturbance on individual fitness is important for wildlife management, and critical for the conservation of species at risk. We compared the fitness and seasonal range use of 39 woodland caribou in Ontario study areas contrasted by their level of human disturbance. We previously showed that wolf density in the disturbed site was higher, likely due to human-modified landscapes favoring moose, the primary prey of wolves. In this paper we address three objectives. First, because the assimilation of dietary nitrogen is heavily influenced by metabolic processes related to stress, we hypothesized that ratios of nitrogen isotopes (N) may indicate changes in body condition in ungulates and be useful proxies for changes in fitness. Second, we predicted that increased predation risk from wolves in disturbed areas would result in measurable declines in caribou body condition. Third, we hypothesized that one mechanism for fitness declines among caribou in the distu...
Woodland caribou (Rangifer tarandus caribou) in Ontario are a threatened species that have experi... more Woodland caribou (Rangifer tarandus caribou) in Ontario are a threatened species that have experienced a substantial retraction of their historic range. Part of their decline has been attributed to increasing densities of anthropogenic linear features such as trails, roads, railways, and hydro lines. These features have been shown to increase the search efficiency and kill rate of wolves. However, it is unclear whether selection for anthropogenic linear features is additive or compensatory to selection for natural (water) linear features which may also be used for travel. We studied the selection of water and anthropogenic linear features by 52 resident wolves (Canis lupus x lycaon) over four years across three study areas in northern Ontario that varied in degrees of forestry activity and human disturbance. We used Euclidean distance-based resource selection functions (mixed-effects logistic regression) at the seasonal range scale with random coefficients for distance to water linear features, primary/secondary roads/railways, and hydro lines, and tertiary roads to estimate the strength of selection for each linear feature and for several habitat types, while accounting for availability of each feature. Next, we investigated the trade-off between selection for anthropogenic and water linear features. Wolves selected both anthropogenic and water linear features; selection for anthropogenic features was stronger than for water during the rendezvous season. Selection for anthropogenic linear features increased with increasing density of these features on the landscape, while selection for natural linear features declined, indicating compensatory selection of anthropogenic linear features. These results have implications for woodland caribou conservation. Prey encounter rates between wolves and caribou seem to be strongly influenced by increasing linear feature densities. This behavioral mechanism - a compensatory functional response to anthropogenic linear feature density resulting in decreased use of natural travel corridors - has negative consequences for the viability of woodland caribou
ABSTRACTWildlife models focused solely on a single strong influence (e.g., habitat components, wi... more ABSTRACTWildlife models focused solely on a single strong influence (e.g., habitat components, wildlife harvest) are limited in their ability to detect key mechanisms influencing population change. Instead, we propose integrated modeling in the context of cumulative effects assessment using multispecies population dynamics models linked to landscape‐climate simulation at large spatial and temporal scales. We developed an integrated landscape and population simulation model using ALCES Online as the model‐building platform, and the model accounted for key ecological components and relationships among moose (Alces alces), grey wolves (Canis lupus nubilus), and woodland caribou (Rangifer tarandus caribou) in northern Ontario, Canada. We simulated multiple scenarios over 5 decades (beginning 2020) to explore sensitivity to climate change and land use and assessed effects at multiple scales. The magnitude of effect and the relative importance of key factors (climate change, roads, and ha...
ABSTRACTAdult female survival and calf recruitment influence population dynamics, but there is li... more ABSTRACTAdult female survival and calf recruitment influence population dynamics, but there is limited information on calving and neonatal mortality of boreal woodland caribou (Rangifer tarandus caribou; caribou) in Ontario, Canada. We identified calf parturition sites and 5‐week neonatal mortality using a movement‐based approach across 3 northern Ontario study regions (Pickle Lake, Nakina, and Cochrane) that vary in their capacity to support caribou populations. In comparing 22 caribou‐years of video‐collar footage during 2010–2013 to predictions of the movement‐based approach, we found live parturition events were 100% correctly classified, date of parturition was within 1.08 ± 0.28 ( ± SE) days, and mortality events up to 5 weeks postpartum were 88% correctly classified. Across study regions, 87% of 186 caribou were pregnant and 76% of 107 caribou‐years indicated birth events with median parturition dates a week later in Cochrane (23 May) than in Pickle Lake (17 May) and Nakina (...
Site-specific variation in relative habitat abundance and disturbance regimes may produce differe... more Site-specific variation in relative habitat abundance and disturbance regimes may produce differences in habitat preferences of associated populations. An evaluation of the predictive power of habitat selection models across space would benefit our understanding of the reliability of models of selection and space use in predicting animal occurrence. We used presence–absence data from winter surveys of moose (Alces alces (L., 1758)) to estimate resource selection functions (RSFs) across two study sites using Far North Land Cover updated with recent disturbance from fire and timber harvest. Moose selected foraging habitat (e.g., deciduous land cover) and for increasing deciduous foliage cover (ΔNDVI, i.e., the difference in the normalized difference vegetation index). Snow depth negatively influenced habitat selection, likely due to increased predation risk and reduced movement and foraging efficiency. Models lost little predictive power when applied to another site based on compariso...
We tracked 122 female moose in northwestern Ontario, Canada, using global positioning system (GPS... more We tracked 122 female moose in northwestern Ontario, Canada, using global positioning system (GPS) radio-collars between 1995 and 2001. We used step-selection functions (SSF) to evaluate changes in moose habitat selection as a function of temperature across seasons (summer and winter), stand types, and stand heights. We obtained mean activity levels of moose within stand types and across seasons from motion sensors in the collars. Selection increased for aquatic stand types as a function of temperature across both summer and winter. Selection for stand height was also temperature-dependent, with tall stands being most favored at warm temperatures and least favored at cold temperatures. Moose activity levels increased slightly at higher temperatures during the winter but were mostly constant, whereas summer activity declined significantly with increasing temperature. Seasonal activity levels were mostly constant within habitats, but activity was consistently higher in aquatic habitats compared to woody habitats, with the highest mean activity levels observed when moose were located in open water and marshes during the summer. Our findings corroborate the work of others that moose primarily select habitat based on documented foraging requirements, whereas they may alter midday selection for specific stand types providing thermal cover under varied temperatures, indicating a behavioral response to thermoregulatory needs. Increased activity levels at low summer temperatures, and in habitats found to provide thermal cover, support the conclusion that moose may alter their activity to alleviate heat stress, and that temperaturemediated changes in habitat selection may facilitate otherwise energetically costly behavior (e.g., movement).
Publisher Summary This chapter provides an update on the most significant technological advances ... more Publisher Summary This chapter provides an update on the most significant technological advances of terminology of the past decade along with an overview on the most recent telemetry systems. Telemetry refers to the remote determination of an animal's status, which includes the individual's current level of activity, some physiological measurement, and its physical location. Telemetry is used in an extensive array of agricultural, physiological, and medical research activities to monitor the status of individuals. In these studies, measurements are usually made at close range, typically within a few hundred meters. Ecologists, field biologists, and wildlife researchers, on the other hand, generally use “telemetry” to estimate a series of geographic locations for individual animals, often from distances exceeding several hundred meters. Furthermore, since radio signals emanating from a device attached to each animal are commonly used to estimate locations, the technique is often referred to as “radiotelemetry.” Telemetry technology has continued to progress throughout the 1990s. Advances in power management, electronic components, and microcomputers, as well as the emergence of several innovative systems based on the new technology, have all contributed to an ever-increasing variety of telemetry options available to field researchers.
For many species of animals, obtaining basic life‐history data is difficult and even some common ... more For many species of animals, obtaining basic life‐history data is difficult and even some common aspects, such as diet choice, remain unknown. To overcome this problem, we deployed what is, to our knowledge, the first successful application of a terrestrial high‐resolution animal‐borne video camera with on‐board long‐term recording and an associated Global Positioning (GPS) unit. Five cameras recorded video and audio and associated GPS locations of woodland caribou (Rangifer tarandus caribou) activities during 20 weeks from March to July 2011, although the units can run for >36 weeks depending on the rate of data collection. About 6% of videos were unusable because of fogging or snow on the lens, and clarity of plant images, especially ground covers, was a problem in a few of the files but overall quality of the videos was high and identification of diet by plant species can be achieved. We present a sample of data on several aspects of previously unknown behaviors of woodland ca...
With the advancement of radiotracking techniques, there has been a dramatic increase in the quant... more With the advancement of radiotracking techniques, there has been a dramatic increase in the quantity and quality of locational and movement data obtained for a variety of wildlife species. Automated tracking systems, in particular, produce enormous amounts of data. These data help researchers determine movements, home ranges, and habitat use by individuals and populations. One of many challenges is determining not only which home-range estimators to use, but also which home-range program will best fulfill study objectives. We used data from a moose (Alces alces) fitted with a test Global Positioning System (GPS) collar to compare home-range sizes estimated by 5 commonly used software packages (CALHOME, HOME RANGE, RANGES IV, RANGES V, TRACKER). We found large differences in calculated home-range sizes using minimum convex polygon, harmonic mean, and kernel estimators at 3 levels of resolution (95%, 75%, and 50% of locations). Comparing home ranges among different research studies can be misleading unless researchers report choices for software program, home-range estimators, user-selected options, and input values of required parameters.
Moose-vehicle collisions are a serious concern in many areas of North America and Fennoscandia. I... more Moose-vehicle collisions are a serious concern in many areas of North America and Fennoscandia. In northwestern Ontario, more than 400 moose-vehicle collisions occur annually, and 26 fatal collisions have occurred over the last 10 years. To avoid colliding with a moose, a motorist must: (1) successfully see or detect the presence of the animal; (2) determine whether or not the moose poses a threat requiring evasive action; (3) determine what action, if necessary, is required; and (4) implement the action. Whereas perception-reaction times of motorists have been studied in detail, allowing calculations of post-detection distances travelled by a vehicle at different speeds, distances to determine the distances at which an animal could be detected at night when it was positioned on each shoulder and in the middle of a highway using high and low beam headlamp settings of different vehicles. Overall, we found the mean detection distance across all vehicle types, headlamp settings, tor; on the low beam setting, mean detection distance was 74 m and on the high beam setting it was 137 m. Moose decoy location was also important; combining the data for both headlamp settings, mean detection distances were 89 m, 93 m, and 133 m for the left, right, and centre positions, respectively. There was no relationship between headlamp height of different vehicles and moose detection distance. nation capabilities of their headlamps for moose encounters. For drivers using a low beam headlamp ALCES VOL. 42: 75-87 (2006)
Publisher Summary This chapter provides an update on the most significant technological advances ... more Publisher Summary This chapter provides an update on the most significant technological advances of terminology of the past decade along with an overview on the most recent telemetry systems. Telemetry refers to the remote determination of an animal's status, which includes the individual's current level of activity, some physiological measurement, and its physical location. Telemetry is used in an extensive array of agricultural, physiological, and medical research activities to monitor the status of individuals. In these studies, measurements are usually made at close range, typically within a few hundred meters. Ecologists, field biologists, and wildlife researchers, on the other hand, generally use “telemetry” to estimate a series of geographic locations for individual animals, often from distances exceeding several hundred meters. Furthermore, since radio signals emanating from a device attached to each animal are commonly used to estimate locations, the technique is often referred to as “radiotelemetry.” Telemetry technology has continued to progress throughout the 1990s. Advances in power management, electronic components, and microcomputers, as well as the emergence of several innovative systems based on the new technology, have all contributed to an ever-increasing variety of telemetry options available to field researchers.
We tracked 122 female moose in northwestern Ontario, Canada, using global positioning system (GPS... more We tracked 122 female moose in northwestern Ontario, Canada, using global positioning system (GPS) radio-collars between 1995 and 2001. We used step-selection functions (SSF) to evaluate changes in moose habitat selection as a function of temperature across seasons (summer and winter), stand types, and stand heights. We obtained mean activity levels of moose within stand types and across seasons from motion sensors in the collars. Selection increased for aquatic stand types as a function of temperature across both summer and winter. Selection for stand height was also temperature-dependent, with tall stands being most favored at warm temperatures and least favored at cold temperatures. Moose activity levels increased slightly at higher temperatures during the winter but were mostly constant, whereas summer activity declined significantly with increasing temperature. Seasonal activity levels were mostly constant within habitats, but activity was consistently higher in aquatic habitats compared to woody habitats, with the highest mean activity levels observed when moose were located in open water and marshes during the summer. Our findings corroborate the work of others that moose primarily select habitat based on documented foraging requirements, whereas they may alter midday selection for specific stand types providing thermal cover under varied temperatures, indicating a behavioral response to thermoregulatory needs. Increased activity levels at low summer temperatures, and in habitats found to provide thermal cover, support the conclusion that moose may alter their activity to alleviate heat stress, and that temperaturemediated changes in habitat selection may facilitate otherwise energetically costly behavior (e.g., movement).
The food habits of animals may be studied in the laboratory or in the field. Field studies descri... more The food habits of animals may be studied in the laboratory or in the field. Field studies describe diet selection of populations but do not permit analysis of the factors causing individual variation in the foraging behaviour of animals. Although numerous indices have been developed to compare use and availability of foods in field diets of animals, little attention has been given to laboratory approaches for comparing food choices. Tests of food choice must account for the order, consumption rate, and total amount of each food type eaten. Current measures fail to account for one or more of these parameters. This often results in highly ambiguous preference rankings, making comparisons among individuals or species difficult. To solve this problem, I propose using the area under the curve of the cumulative proportion eaten versus time for each food type. This index may be used to assess individual variation and determine the relative importance of each major component of the diet selection process in animals.
Habitat-based prediction of population density relies on relationships between landscape configur... more Habitat-based prediction of population density relies on relationships between landscape configuration (i.e., abundance of land-cover types) and equilibrium density. This may be accomplished by estimating resource selection probability functions (RSPFs) based on presence-absence data, or by relating carrying capacity to landscape covariates. We used RSPFs for moose (Alces alces) from 2 study sites and carrying capacities from 34 wildlife management units across northern Ontario, Canada, to create 2 estimators of moose density. We compared the predictions of both models to moose density in a novel site obtained via aerial census. We also projected the RSPF across 34 management units and compared predicted density to estimated carrying capacity of each unit. The RSPF and carrying capacity models predicted moose equilibrium densities that were statistically indistinguishable from the estimated density of moose at the novel study site, but the carrying capacity model generated uninformatively broad prediction intervals. The RSPF failed to predict carrying capacities in management units across Ontario; however, the differences between RSPF estimates and carrying capacities varied predictably with differences in covariates related to forage availability, suggesting habitat selection strength and RSPF transferability vary with landscape quality. Estimating densities using RSPFs relies on a consistent relationship between habitat selection and animal density; thus, RSPF applicability across space will depend heavily on similarity between the novel and original sites. Demographic projection benefits from broad spatiotemporal datasets that improve reliability but that are relatively rare and subject to broad error. Our findings suggest that selection-based population estimation is preferable to demographically based models because of increased precision of estimates, the immediacy of available data (e.g., single survey or radio-telemetry in multiple sites vs. many generations of population estimates in a time series across space), and the capacity to predict fine-scale patterns of distribution and abundance.
Understanding the impacts of disturbance on individual fitness is important for wildlife manageme... more Understanding the impacts of disturbance on individual fitness is important for wildlife management, and critical for the conservation of species at risk. We compared the fitness and seasonal range use of 39 woodland caribou in Ontario study areas contrasted by their level of human disturbance. We previously showed that wolf density in the disturbed site was higher, likely due to human-modified landscapes favoring moose, the primary prey of wolves. In this paper we address three objectives. First, because the assimilation of dietary nitrogen is heavily influenced by metabolic processes related to stress, we hypothesized that ratios of nitrogen isotopes (N) may indicate changes in body condition in ungulates and be useful proxies for changes in fitness. Second, we predicted that increased predation risk from wolves in disturbed areas would result in measurable declines in caribou body condition. Third, we hypothesized that one mechanism for fitness declines among caribou in the disturbed area was increased wolf activity restricting caribou seasonal movements. We showed change in N in the tissues of caribou was correlated with body condition scoring using fat assessment. We used GPS collars to quantify seasonal range use and found that fitness was higher, and seasonal range overlap was lower, in caribou using the nondisturbed area. Winter fitness declines were significantly larger in the more disturbed area. Our study identifies another mechanism by which the cumulative effects of human-disturbed landscapes on caribou fitness could contribute to global declines in caribou populations.
American black bears (Ursus americanus Pallas, 1780) are opportunistic foragers, and across most ... more American black bears (Ursus americanus Pallas, 1780) are opportunistic foragers, and across most of their range in North America, their diet is predominantly vegetation with limited consumption of vertebrates and invertebrates. However, they are also predators of ungulates, especially neonates, with regional variation in the amount of predation pressure they exert. We used scat analysis to examine the diet of black bears during the calving season in a moose (Alces alces (Linnaeus, 1758))woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) system in the Boreal forest of northern Ontario, Canada. Bears consumed herbaceous plants (46.5%), fruits and (or) seeds (20.0%), moose (3.3% adults; 4.3% calves), American beaver (Castor canadensis Kuhl, 1820; 8.5%), and insects (mostly ants; 4.2%). Bears had the highest consumption of moose and beaver in early spring, before switching to a more vegetation-dominated diet. We did not detect evidence of caribou consumption. Based on our results, black bear consumption of moose, particularly neonates, may warrant further investigation.
Understanding the impacts of disturbance on individual fitness is important for wildlife manageme... more Understanding the impacts of disturbance on individual fitness is important for wildlife management, and critical for the conservation of species at risk. We compared the fitness and seasonal range use of 39 woodland caribou in Ontario study areas contrasted by their level of human disturbance. We previously showed that wolf density in the disturbed site was higher, likely due to human-modified landscapes favoring moose, the primary prey of wolves. In this paper we address three objectives. First, because the assimilation of dietary nitrogen is heavily influenced by metabolic processes related to stress, we hypothesized that ratios of nitrogen isotopes (N) may indicate changes in body condition in ungulates and be useful proxies for changes in fitness. Second, we predicted that increased predation risk from wolves in disturbed areas would result in measurable declines in caribou body condition. Third, we hypothesized that one mechanism for fitness declines among caribou in the distu...
Woodland caribou (Rangifer tarandus caribou) in Ontario are a threatened species that have experi... more Woodland caribou (Rangifer tarandus caribou) in Ontario are a threatened species that have experienced a substantial retraction of their historic range. Part of their decline has been attributed to increasing densities of anthropogenic linear features such as trails, roads, railways, and hydro lines. These features have been shown to increase the search efficiency and kill rate of wolves. However, it is unclear whether selection for anthropogenic linear features is additive or compensatory to selection for natural (water) linear features which may also be used for travel. We studied the selection of water and anthropogenic linear features by 52 resident wolves (Canis lupus x lycaon) over four years across three study areas in northern Ontario that varied in degrees of forestry activity and human disturbance. We used Euclidean distance-based resource selection functions (mixed-effects logistic regression) at the seasonal range scale with random coefficients for distance to water linear features, primary/secondary roads/railways, and hydro lines, and tertiary roads to estimate the strength of selection for each linear feature and for several habitat types, while accounting for availability of each feature. Next, we investigated the trade-off between selection for anthropogenic and water linear features. Wolves selected both anthropogenic and water linear features; selection for anthropogenic features was stronger than for water during the rendezvous season. Selection for anthropogenic linear features increased with increasing density of these features on the landscape, while selection for natural linear features declined, indicating compensatory selection of anthropogenic linear features. These results have implications for woodland caribou conservation. Prey encounter rates between wolves and caribou seem to be strongly influenced by increasing linear feature densities. This behavioral mechanism - a compensatory functional response to anthropogenic linear feature density resulting in decreased use of natural travel corridors - has negative consequences for the viability of woodland caribou
ABSTRACTWildlife models focused solely on a single strong influence (e.g., habitat components, wi... more ABSTRACTWildlife models focused solely on a single strong influence (e.g., habitat components, wildlife harvest) are limited in their ability to detect key mechanisms influencing population change. Instead, we propose integrated modeling in the context of cumulative effects assessment using multispecies population dynamics models linked to landscape‐climate simulation at large spatial and temporal scales. We developed an integrated landscape and population simulation model using ALCES Online as the model‐building platform, and the model accounted for key ecological components and relationships among moose (Alces alces), grey wolves (Canis lupus nubilus), and woodland caribou (Rangifer tarandus caribou) in northern Ontario, Canada. We simulated multiple scenarios over 5 decades (beginning 2020) to explore sensitivity to climate change and land use and assessed effects at multiple scales. The magnitude of effect and the relative importance of key factors (climate change, roads, and ha...
ABSTRACTAdult female survival and calf recruitment influence population dynamics, but there is li... more ABSTRACTAdult female survival and calf recruitment influence population dynamics, but there is limited information on calving and neonatal mortality of boreal woodland caribou (Rangifer tarandus caribou; caribou) in Ontario, Canada. We identified calf parturition sites and 5‐week neonatal mortality using a movement‐based approach across 3 northern Ontario study regions (Pickle Lake, Nakina, and Cochrane) that vary in their capacity to support caribou populations. In comparing 22 caribou‐years of video‐collar footage during 2010–2013 to predictions of the movement‐based approach, we found live parturition events were 100% correctly classified, date of parturition was within 1.08 ± 0.28 ( ± SE) days, and mortality events up to 5 weeks postpartum were 88% correctly classified. Across study regions, 87% of 186 caribou were pregnant and 76% of 107 caribou‐years indicated birth events with median parturition dates a week later in Cochrane (23 May) than in Pickle Lake (17 May) and Nakina (...
Site-specific variation in relative habitat abundance and disturbance regimes may produce differe... more Site-specific variation in relative habitat abundance and disturbance regimes may produce differences in habitat preferences of associated populations. An evaluation of the predictive power of habitat selection models across space would benefit our understanding of the reliability of models of selection and space use in predicting animal occurrence. We used presence–absence data from winter surveys of moose (Alces alces (L., 1758)) to estimate resource selection functions (RSFs) across two study sites using Far North Land Cover updated with recent disturbance from fire and timber harvest. Moose selected foraging habitat (e.g., deciduous land cover) and for increasing deciduous foliage cover (ΔNDVI, i.e., the difference in the normalized difference vegetation index). Snow depth negatively influenced habitat selection, likely due to increased predation risk and reduced movement and foraging efficiency. Models lost little predictive power when applied to another site based on compariso...
We tracked 122 female moose in northwestern Ontario, Canada, using global positioning system (GPS... more We tracked 122 female moose in northwestern Ontario, Canada, using global positioning system (GPS) radio-collars between 1995 and 2001. We used step-selection functions (SSF) to evaluate changes in moose habitat selection as a function of temperature across seasons (summer and winter), stand types, and stand heights. We obtained mean activity levels of moose within stand types and across seasons from motion sensors in the collars. Selection increased for aquatic stand types as a function of temperature across both summer and winter. Selection for stand height was also temperature-dependent, with tall stands being most favored at warm temperatures and least favored at cold temperatures. Moose activity levels increased slightly at higher temperatures during the winter but were mostly constant, whereas summer activity declined significantly with increasing temperature. Seasonal activity levels were mostly constant within habitats, but activity was consistently higher in aquatic habitats compared to woody habitats, with the highest mean activity levels observed when moose were located in open water and marshes during the summer. Our findings corroborate the work of others that moose primarily select habitat based on documented foraging requirements, whereas they may alter midday selection for specific stand types providing thermal cover under varied temperatures, indicating a behavioral response to thermoregulatory needs. Increased activity levels at low summer temperatures, and in habitats found to provide thermal cover, support the conclusion that moose may alter their activity to alleviate heat stress, and that temperaturemediated changes in habitat selection may facilitate otherwise energetically costly behavior (e.g., movement).
Publisher Summary This chapter provides an update on the most significant technological advances ... more Publisher Summary This chapter provides an update on the most significant technological advances of terminology of the past decade along with an overview on the most recent telemetry systems. Telemetry refers to the remote determination of an animal's status, which includes the individual's current level of activity, some physiological measurement, and its physical location. Telemetry is used in an extensive array of agricultural, physiological, and medical research activities to monitor the status of individuals. In these studies, measurements are usually made at close range, typically within a few hundred meters. Ecologists, field biologists, and wildlife researchers, on the other hand, generally use “telemetry” to estimate a series of geographic locations for individual animals, often from distances exceeding several hundred meters. Furthermore, since radio signals emanating from a device attached to each animal are commonly used to estimate locations, the technique is often referred to as “radiotelemetry.” Telemetry technology has continued to progress throughout the 1990s. Advances in power management, electronic components, and microcomputers, as well as the emergence of several innovative systems based on the new technology, have all contributed to an ever-increasing variety of telemetry options available to field researchers.
For many species of animals, obtaining basic life‐history data is difficult and even some common ... more For many species of animals, obtaining basic life‐history data is difficult and even some common aspects, such as diet choice, remain unknown. To overcome this problem, we deployed what is, to our knowledge, the first successful application of a terrestrial high‐resolution animal‐borne video camera with on‐board long‐term recording and an associated Global Positioning (GPS) unit. Five cameras recorded video and audio and associated GPS locations of woodland caribou (Rangifer tarandus caribou) activities during 20 weeks from March to July 2011, although the units can run for >36 weeks depending on the rate of data collection. About 6% of videos were unusable because of fogging or snow on the lens, and clarity of plant images, especially ground covers, was a problem in a few of the files but overall quality of the videos was high and identification of diet by plant species can be achieved. We present a sample of data on several aspects of previously unknown behaviors of woodland ca...
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Papers by Arthur Rodgers