Integrated Ecological Research

Nelson, Canada

Integrated Ecological Research

Nelson, Canada
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Nielsen S.E.,University of Alberta | Cattet M.R.L.,University of Saskatchewan | Boulanger J.,Integrated Ecological Research | Cranston J.,Arctos Ecological Services | And 3 more authors.
BMC Ecology | Year: 2013

Background: Individual body growth is controlled in large part by the spatial and temporal heterogeneity of, and competition for, resources. Grizzly bears (Ursus arctos L.) are an excellent species for studying the effects of resource heterogeneity and maternal effects (i.e. silver spoon) on life history traits such as body size because their habitats are highly variable in space and time. Here, we evaluated influences on body size of grizzly bears in Alberta, Canada by testing six factors that accounted for spatial and temporal heterogeneity in environments during maternal, natal and 'capture' (recent) environments. After accounting for intrinsic biological factors (age, sex), we examined how body size, measured in mass, length and body condition, was influenced by: (a) population density; (b) regional habitat productivity; (c) inter-annual variability in productivity (including silver spoon effects); (d) local habitat quality; (e) human footprint (disturbances); and (f) landscape change. Results: We found sex and age explained the most variance in body mass, condition and length (R2 from 0.48-0.64). Inter-annual variability in climate the year before and of birth (silver spoon effects) had detectable effects on the three-body size metrics (R2 from 0.04-0.07); both maternal (year before birth) and natal (year of birth) effects of precipitation and temperature were related with body size. Local heterogeneity in habitat quality also explained variance in body mass and condition (R2 from 0.01-0.08), while annual rate of landscape change explained additional variance in body length (R2 of 0.03). Human footprint and population density had no observed effect on body size. Conclusions: These results illustrated that body size patterns of grizzly bears, while largely affected by basic biological characteristics (age and sex), were also influenced by regional environmental gradients the year before, and of, the individual's birth thus illustrating silver spoon effects. The magnitude of the silver spoon effects was on par with the influence of contemporary regional habitat productivity, which showed that both temporal and spatial influences explain in part body size patterns in grizzly bears. Because smaller bears were found in colder and less-productive environments, we hypothesize that warming global temperatures may positively affect body mass of interior bears. © 2013 Nielsen et al.; licensee BioMed Central Ltd.

Boulanger J.,Integrated Ecological Research | Cattet M.,University of Saskatchewan | Nielsen S.E.,University of Alberta | Stenhouse G.,Foothills Research Institute | Cranston J.,Arctos Ecological Services
Wildlife Biology | Year: 2013

One of the principal goals of wildlife research and management is to understand and predict relationships between habitat quality, health of individuals and their ability to survive. Infrequent sampling, non-random loss of individuals due to mortality and variation in capture susceptibility create potential biases with conventional analysis methods. To account for such sampling biases, we used a multi-state analytical approach to assess relationships between habitat, health and survival of grizzly bears Ursus arctos horribilis over a 10-year period along the east slopes of the Canadian Rockies in Alberta, Canada. We defined bear health states by body condition estimated from the relationship between weight and body length. We used a sequential model building process to first account for potential sampling biases, and then explored changes in body condition relative to habitat use and survival. Bears that used regenerating forest habitats (mostly due to forest harvesting) containing a diversity of age classes were more likely to see gains in their body condition, whereas bears that used older forests were more likely to see reductions in body condition. Survival rate was reduced most by road densities which in turn were positively correlated with regenerating forest habitat. Human activities which promote young regenerating forests, such as forest harvesting, therefore promotes improved health (increased body condition) in bears, but are offset by reductions in survival rates. Multi-state analyses represents a robust analytical tool when dealing with complex relationships and sampling biases that arise from dynamic environments. © 2013 Wildlife Biology, NKV.

Dumond M.,Environment Canada | Boulanger J.,Integrated Ecological Research | Paetkau D.,Wildlife Genetics International
Wildlife Society Bulletin | Year: 2015

Assessing grizzly bears' (Ursus arctos) abundance in the Arctic has been challenging because of the large scale of their movements and the remoteness of field locations. We modified a post sampling method used for wolverines (Gulo gulo) to allow collection of hair samples from grizzly bears in the Canadian tundra. We deployed 1 post/cell in a sampling grid of 393 10 × 10-km cells sampled in 2008 and 2009 for two 14-day sessions in July-August of both years. We then compared density estimates from mark-recapture estimators that used telemetry data from previous years with spatially explicit mark-recapture models that used only genetic detections. Over the 2 years of sampling, we detected 98 female and 81 male grizzly bears. We found that the DNA degradation rate was related to collection interval and the number of days between rainfall events and sample collection. Estimates of density were in the order of 5 bears/1,000 km2. The estimates from the 2 methods were statistically similar, but spatially explicit estimates were more precise than those using radiocollar data. Our results provide the first demonstration of the viability of posts as hair-snagging stations to obtain DNA from grizzly bears, and of spatially explicit mark-recapture methods to estimate population size and density for grizzly bears above the tree line. © 2015 The Wildlife Society. © The Wildlife Society, 2015.

Proctor M.,University of Alberta | McLellan B.,British Columbia Ministry of forests | Boulanger J.,Integrated Ecological Research | Apps C.,Aspen Wildlife Research | And 3 more authors.
Ursus | Year: 2010

Grizzly bears (Ursus arctos) occur across British Columbia and in Alberta in mostly forested, mountainous, and boreal ecosystems. These dense forests make sighting bears from aircraft uncommon and aerial census impractical. Since 1995, we have used genetic sampling using DNA from bear hair collected with barbed wire hair traps to explore a suite of ecological questions of grizzly bears in western Canada. During 19952005, we conducted large-scale sampling (1,650 to 9,866 km2 grids) in 26 areas (covering a combined 110,405 km2), where genetic identification of 1,412 grizzly bears was recorded. Abundance estimation was the primary goal of most surveys. We also used DNA from bear hair to examine population trend, distribution, and presence in areas where grizzly bears were rare, as well as population fragmentation in a region with a high human population. Combining spatial variation in detecting bears with that of human, landscape, and ecological features has allowed us to quantify factors that influence grizzly bear distribution, population fragmentation, and competition with black bears (U. americanus), and to map variation in bear densities. We summarize these studies and discuss lessons learned that are relevant to improving sampling efficiency, study designs, and resulting inference. © 2010 International Association for Bear Research and Management.

Boulanger J.,Integrated Ecological Research | Poole K.G.,Aurora Wildlife Research | Gunn A.,368 Roland Road | Wierzchowski J.,Consulting Inc.
Wildlife Biology | Year: 2012

Wildlife species may respond to industrial development with changes in distribution. However, discerning a response to development from differences in habitat selection is challenging. Since the early 1990s, migratory tundra Bathurst caribou Rangifer tarandus groenlandicus in the Canadian Arctic have been exposed to the construction and operation of two adjacent open-pit mines within the herd's summer range. We developed a statistical approach to directly estimate the zone of influence (area of reduced caribou occupancy) of the mines during mid-July-mid-October. We used caribou presence recorded during aerial surveys and locations of satellite-collared cow caribou as inputs to a model to account for patterns in habitat selection as well as mine activities. We then constrained the zone of influence curve to asymptote, such that the average distance from the mine complex where caribou habitat selection was not affected by the mine could be estimated. During the operation period for the two open-pit mines, we detected a 14-km zone of influence from the aerial survey data, and a weaker 11-km zone from the satellite-collar locations. Caribou were about four times more likely to select habitat at distances greater than the zone of influence compared to the two-mine complex, with a gradation of increasing selection up to the estimated zone of influence. Caribou are responding to industrial developments at greater distances than shown in other areas, possibly related to fine dust deposition from mine activities in open, tundra habitats. The methodology we developed provides a standardized approach to estimate the spatial impact of stressors on caribou or other wildlife species. © 2012 Wildlife Biology, NKV.

Boulanger J.,Integrated Ecological Research | Gunn A.,368 Roland Road | Adamczewski J.,Natural Resources Canada | Croft B.,Natural Resources Canada
Journal of Wildlife Management | Year: 2011

The Bathurst herd of barren-ground caribou (Rangifer tarandus groenlandicus) in the Canadian central arctic declined from an estimated 203,800 to 16,400 breeding females from 1986 to 2009, with the most rapid decline from 2006 to 2009. A key research and management question was whether the decline was mainly due to decreases in productivity alone or also due to reduced adult female survival. Investigating causes of the decline was hampered by a lack of direct estimates of caribou demographic parameters. We developed a demographic model that could be objectively fitted to field data to explore the mechanisms for the Bathurst decline, with a focus on the recent accelerated decline from 2006 to 2009. Our modeling indicated that the decline was driven by increasing negative trends in adult female and calf survival rates and possibly reduced fecundity The effect of a constant hunter harvest on the declining herd was one potential cause for the recent accelerated decline in adult survival. The demographic model detected negative trends in adult female survival that were not detected using standalone analyses of collar-based survival data. The model allowed rigorous interpretation of trends in productivity by controlling for the simultaneous influence of trends in adult, calf, and yearling survival and adult fecundity on field-based calf-cow ratios. Stochastic simulations suggested that large increases in adult survival and productivity would be needed for the herd to recover. Our methods enable objective modeling of caribou demography that can assist in caribou management based upon all sources of available data. © 2011 The Wildlife Society.

Gervasi V.,University of Rome La Sapienza | Ciucci P.,University of Rome La Sapienza | Boulanger J.,Integrated Ecological Research | Randi E.,Instituto Superiore per la Protezione e la Ricerca Ambientale | Boitani L.,University of Rome La Sapienza
Biological Conservation | Year: 2012

When dealing with small populations of elusive species, capture-recapture methods suffer from sampling and analytical limitations, making abundance assessment particularly challenging. We present an empirical and theoretical evaluation of multiple data source sampling as a flexible and effective way to improve the performance of capture-recapture models for abundance estimation of small populations. We integrated three data sources to estimate the size of the relict Apennine brown bear (Ursus arctos marsicanus) population in central Italy, and supported our results with simulations to assess the robustness of multiple data source capture-recapture models to violations of main assumptions. During May-August 2008, we non-invasively sampled bears using systematic hair traps on a grid of 41 5×5km cells, moving trap locations between five sampling sessions. We also live-trapped, ear-tagged, and genotyped 17 bears (2004-2008), and integrated resights of marked bears and family units (July-September 2008) into a multiple data source capture-recapture dataset. Population size was estimated at 40 (95% CI=37-52) bears, with a corresponding closure-corrected density of 32 bears/1000km 2 (95% CI=28-36). Given the average capture probability we obtained with all data sources combined (p̂=0.311), simulations suggested that the expected degree of correlation among data sources did not seriously affect model performance, with expected level of bias <5%. Our results refine previous simulation work on larger populations, cautioning on the combined effect of lack of independence and low capture probability in application of multiple data source sampling to very small populations (N<100). © 2012 Elsevier Ltd.

Graham K.,Foothills Research Institute | Boulanger J.,Integrated Ecological Research | Duval J.,Foothills Research Institute | Stenhouse G.,Foothills Research Institute
Ursus | Year: 2010

Resource extraction activities in Alberta, Canada, have produced a large increase in the number of roads in grizzly bear (Ursus arctos) habitat. High road densities have been associated with high grizzly bear mortality rates in some areas. We used GPS data from grizzly bears in west-central Alberta, Canada, 1999-2005 to examine (1) frequencies at which grizzly bears crossed roads (standardized by number of locations/bear and length of road segments), using a crossing index analysis among agesex classes, traffic volumes, seasons, and time of day; (2) habitat attributes surrounding crossing locations, using a resource selection function analysis to discern if certain habitats and road types were associated with crossing areas; and (3) grizzly bear distribution near roads as a function of agesex class and season to determine if bears were near roads more or less frequently than expected. Females had higher crossing indices than males for all seasons and daylight hours. Crossings occurred most often at narrow, unpaved roads near creeks and in open areas with high greenness scores. In spring, females with cubs were within 200 m of roads more frequently than expected. In autumn, subadult females were within 200 m of roads more frequently than expected, whereas adult males displayed the reverse pattern. These results indicate that females had a greater chance of encountering humans. Reducing the density of roads in grizzly bear habitat or reducing human presence on these roads, especially during the spring and fall seasons, may reduce the human-caused mortality to female grizzly bears. Creating or leaving a dense tree buffer along roads that traverse open habitats could provide a visual shield from passing vehicles, which may reduce grizzly bearhuman encounters and human-caused mortalities. © International Association for Bear Research and Management.

Boulanger J.,Integrated Ecological Research | Stenhouse G.B.,Foothills Research Institute | Margalida A.,University of Lleida
PLoS ONE | Year: 2014

One of the principal factors that have reduced grizzly bear populations has been the creation of human access into grizzly bear habitat by roads built for resource extraction. Past studies have documented mortality and distributional changes of bears relative to roads but none have attempted to estimate the direct demographic impact of roads in terms of both survival rates, reproductive rates, and the interaction of reproductive state of female bears with survival rate. We applied a combination of survival and reproductive models to estimate demographic parameters for threatened grizzly bear populations in Alberta. Instead of attempting to estimate mean trend we explored factors which caused biological and spatial variation in population trend. We found that sex and age class survival was related to road density with subadult bears being most vulnerable to road-based mortality. A multi-state reproduction model found that females accompanied by cubs of the year and/or yearling cubs had lower survival rates compared to females with two year olds or no cubs. A demographic model found strong spatial gradients in population trend based upon road density. Threshold road densities needed to ensure population stability were estimated to further refine targets for population recovery of grizzly bears in Alberta. Models that considered lowered survival of females with dependant offspring resulted in lower road density thresholds to ensure stable bear populations. Our results demonstrate likely spatial variation in population trend and provide an example how demographic analysis can be used to refine and direct conservation measures for threatened species. © 2014 Boulanger, Stenhouse.

PubMed | University of Alberta, University of Saskatchewan, Integrated Ecological Research and Foothills Research Institute and Alberta Sustainable Resource Development
Type: Journal Article | Journal: Conservation physiology | Year: 2016

A novel antibody-based protein microarray was developed that simultaneously determines expression of 31 stress-associated proteins in skin samples collected from free-ranging grizzly bears (Ursus arctos) in Alberta, Canada. The microarray determines proteins belonging to four broad functional categories associated with stress physiology: hypothalamic-pituitary-adrenal axis proteins, apoptosis/cell cycle proteins, cellular stress/proteotoxicity proteins and oxidative stress/inflammation proteins. Small skin samples (50-100mg) were collected from captured bears using biopsy punches. Proteins were isolated and labelled with fluorescent dyes, with labelled protein homogenates loaded onto microarrays to hybridize with antibodies. Relative protein expression was determined by comparison with a pooled standard skin sample. The assay was sensitive, requiring 80 g of protein per sample to be run in triplicate on the microarray. Intra-array and inter-array coefficients of variation for individual proteins were generally <10 and <15%, respectively. With one exception, there were no significant differences in protein expression among skin samples collected from the neck, forelimb, hindlimb and ear in a subsample of n=4 bears. This suggests that remotely delivered biopsy darts could be used in future sampling. Using generalized linear mixed models, certain proteins within each functional category demonstrated altered expression with respect to differences in year, season, geographical sampling location within Alberta and bear biological parameters, suggesting that these general variables may influence expression of specific proteins in the microarray. Our goal is to apply the protein microarray as a conservation physiology tool that can detect, evaluate and monitor physiological stress in grizzly bears and other species at risk over time in response to environmental change.

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