• Home
  • Martyn Ernest Obbard
Martyn Ernest Obbard

Martyn Ernest Obbard
Ontario Ministry of Natural Resources and Forestry · Wildlife Research and Monitoring Section

Ph.D.

About

140
Publications
65,790
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
3,143
Citations
Additional affiliations
December 2016 - present
Ontario Ministry of Natural Resources and Forestry
Position
  • Professor Emeritus
January 1999 - present
Trent University
Position
  • Professor (Associate)
April 1989 - November 2016
Ontario Ministry of Natural Resources
Position
  • Researcher
Education
May 1977 - August 1983
University of Guelph
Field of study
  • Wildlife Ecology
September 1974 - April 1977
University of Guelph
Field of study
  • Wildlife Behaviour

Publications

Publications (140)
Article
Full-text available
Supplemental food from anthropogenic sources is a source of conflict with humans for many wildlife species. Food-seeking behaviours by black bears Ursus americanus and brown bears Ursus arctos can lead to property damage, human injury and mortality of the offending bears. Such conflicts are a well-known conservation management issue wherever people...
Raw Data
Video file showing polar bear depredation of thick-billed murre
Article
Full-text available
Sea-ice distribution and duration are declining across the circumpolar range of the polar bear (Ursus maritimus), resulting in a reduced access to ice-obligate seals, its primary prey. Consequently, polar bears may have increased reliance on alternative food sources in the future. Foraging on land is well documented but foraging in open water is le...
Presentation
Full-text available
Several studies have documented the effectiveness of bear spray in protecting users from aggressive bears. However, bear spray failures have also been reported along with speculation regarding the influences of temperature, wind, repeated canister use, and canister age on spray efficacy. We designed lab and field experiments to document the influen...
Presentation
Reduction of bear-human interactions is a fundamental to black bear management throughout North America. Increased harvest is often suggested as a tool to reduce interactions between bears and humans, despite considerable empirical evidence that interactions are primarily driven by natural food availability. In 2014, the province of Ontario, Canada...
Article
Full-text available
Apparent depredation of Great Blue Heron nest by American black bear
Article
Full-text available
Several studies have documented the effectiveness of bear spray in protecting users from aggressive bears. Bear spray failures, however, have also been reported along with speculation regarding the influences of temperature, wind, repeated canister use, and canister age on spray efficacy. We designed lab and field experiments to document the influe...
Chapter
Bears have fascinated people since ancient times. The relationship between bears and humans dates back thousands of years, during which time we have also competed with bears for shelter and food. In modern times, bears have come under pressure through encroachment on their habitats, climate change, and illegal trade in their body parts, including t...
Poster
Full-text available
Abstract The purpose of this work was to address common misconceptions about the effectiveness of bear spray for polar bear deterrence. We address the three main barriers to spray use in polar bear country: 1) no chemicals can stop an attacking polar bear, 2) the wind and temperature in the Arctic render spray deterrents useless, and 3) it is usefu...
Article
Full-text available
Identifying biologically meaningful populations is essential to the conservation and management of at-risk species. Natural populations can be delineated using a variety of methods including tag recoveries, telemetry, stable isotopes, and population genetics, but understanding the processes that lead to and maintain the demographic and genetic dist...
Article
Full-text available
The Southern Hudson Bay polar bear (Ursus maritimus Phipps, 1774) subpopulation is considered stable but conflicting evidence lends uncertainty to that designation. Capture-recapture studies conducted 1984-86 and 2003-05 and an aerial survey conducted 2011/12 suggested abundance was likely unchanged since the mid-1980s. However, body condition and...
Technical Report
Full-text available
Monitoring abundance of black bears (Ursus americanus) is critical, as this information is required to inform sustainable management of a harvested black bear population. In Ontario, black bears have been monitored using a combination of direct and indirect measures, including determining if harvest is sustainable by examining annual harvest statis...
Article
Full-text available
Polar bears are important socio-cultural symbols in the communities of the Eeyou Marine Region (EMR) in northwestern Québec, Canada. Members of the Cree communities in this region are generally not active polar bear hunters, but they encounter polar bears when fishing, trapping, or hunting during the ice-free season. A growing body of scientific ev...
Technical Report
Full-text available
Fruit production by trees and shrubs varies considerably among years, and consumers respond behaviorally and numerically to the associated fluctuations in food supply. For example, American black bears (Ursus americanus) are more likely to come into conflict with humans when berries and nuts are scarce, and small mammal abundance tracks fluctuation...
Presentation
Full-text available
Re-assessment of abundance of Southern Hudson Bay polar bear subpopulation by comprehensive aerial survey
Article
Full-text available
Protected areas may provide insufficient protection for carnivores such as bears (Ursidae) with large home ranges and extensive seasonal movements. Even in protected areas, harvest can be the main cause of mortality if parks are small or individuals live close to the boundary. At >7,600 km2, Algonquin Provincial Park (APP) is the largest protected...
Article
Full-text available
The processes leading to genetic isolation influence a population's local extinction risk, and should thus be identified before conservation actions are implemented. Natural or human-induced circumstances can result in historical or contemporary barriers to gene flow and/or demographic bottlenecks. Distinguishing between these hypotheses can be ach...
Data
Genotypes of black bears used in this study. This file contains the multilocus genotypes for the 842 American black bears used in this study. The data are formatted with two columns per locus. (XLSX)
Data
Simulation results. This file contains the results of all of the simulations conducted in this study, and provides the parameters used in EASYPOP (Balloux 2001). Results include genetic diversity, differentiation and inbreeding statistics, as well as a relatedness statistic. Supported simulations are indicated in bold, and alternative scenarios are...
Data
Justifications of parameters and procedures used in forward-time simulations. Simulations were performed in EASYPOP (Balloux 2001) and in BottleSim (Kuo and Janzen 2003), via the high-performance computer clusters offered on SHARCNET (www.sharcnet.ca). Results for all simulations are provided in S2 Table. (DOCX)
Article
Full-text available
Methodological differences among laboratories are recognized as significant sources of variation in quantification of hair cortisol concentration (HCC). An important step in processing hair, particularly when collected from wildlife, is the choice of solvent used to remove or “wash” external hair shaft cortisol prior to quantification of HCC. The p...
Article
Full-text available
Tri-axial accelerometers have been used to remotely identify the behaviors of a wide range of taxa. Assigning behaviors to accelerometer data often involves the use of captive animals or surrogate species, as accelerometer signatures are generally assumed to be similar to those of their wild counterparts. However, this has rarely been tested. Valid...
Article
Full-text available
Loss of Arctic sea ice owing to climate change is the primary threat to polar bears throughout their range. We evaluated the potential response of polar bears to sea-ice declines by (i) calculating generation length (GL) for the species, which determines the timeframe for conservation assessments; (ii) developing a standardized sea-ice metric repre...
Article
Full-text available
Defining subpopulations using genetics has traditionally used data from microsatellite markers to investigate population structure; however, single-nucleotide polymorphisms (SNPs) have emerged as a tool for detection of fine-scale structure. In Hudson Bay, Canada, three polar bear (Ursus maritimus) subpopulations (Foxe Basin (FB), Southern Hudson B...
Technical Report
Full-text available
We estimated the population size of black bears on the entire Bruce Peninsula north of Highway 21 and on the smaller area contained by Bruce Peninsula National Park and interspersed lands by sampling bears noninvasively at 90 barbed wire hair corrals on 5 occasions in May and June of 2012. We extracted DNA from hair samples captured on the barbed w...
Article
Full-text available
Birth synchrony is well documented among ungulates and is hypothesised to maximize neonate survival, either by minimizing the risk of predation through predator swamping or by synchronising birthing with increased seasonal food availability. We used encapsulated vaginal implant transmitters to locate and capture neonatal moose calves and document t...
Technical Report
Full-text available
Fruit production by trees and shrubs varies considerably among years, and consumers respond behaviorally and numerically to the associated fluctuations in food supply. For example, American black bears (Ursus americanus) are more likely to come into conflict with humans when berries and nuts are scarce, and small mammal abundance tracks fluctuation...
Data
Date and time of day of parturition for moose calves in central Ontario Canada, 2007–2009. (DOCX)
Article
Full-text available
Sea ice is declining over much of the Arctic. In Hudson Bay the ice melts completely each summer, and advances in break-up have resulted in longer ice-free seasons. Consequently, earlier break-up is implicated in declines in body condition, survival, and abundance of polar bears (Ursus maritimus Phipps, 1774) in the Western Hudson Bay (WH) subpopul...
Article
Full-text available
We provide an expansive analysis of polar bear (Ursus maritimus) circumpolar genetic variation during the last two decades of decline in their sea-ice habitat. We sought to evaluate whether their genetic diversity and structure have changed over this period of habitat decline, how their current genetic patterns compare with past patterns, and how g...
Article
Full-text available
The Southern Hudson Bay (SH) polar bear subpopulation occurs at the southern extent of the species’ range. Although capture–recapture studies indicate abundance was likely unchanged between 1986 and 2005, declines in body condition and survival occurred during the period, possibly foreshadowing a future decrease in abundance. To obtain a current es...
Technical Report
Full-text available
Fruit production by trees and shrubs varies considerably among years, and consumers respond behaviourally and numerically to the associated fluctuations in food supply. For example, American black bears (Ursus americanus) are more likely to come into conflict with humans when berries and nuts are scarce, and small mammal abundance tracks fluctuatio...
Article
Full-text available
We provide an expansive analysis of polar bear (Ursus maritimus) circumpolar genetic variation during the last two decades of decline in their sea-ice habitat. We sought to evaluate whether their genetic diversity and structure have changed over this period of habitat decline, how their current genetic patterns compare with past patterns, and how g...
Article
Full-text available
Managers of American black bears (Ursus americanus) must maintain populations to ensure viability and opportunities for sport harvest, and minimize human–bear conflict (HBC). Harvest is a cost-effective management tool in most jurisdictions, and intuitively it seems that with fewer bears, there should be fewer conflicts. Therefore, managers may att...
Technical Report
Full-text available
Seedfall by trees and shrubs varies considerably among years, and seed consumers respond behaviourally and numerically to the associated fluctuations in food supply. For example, black bears are more likely to come into conflict with humans when berries and nuts are scarce, and small mammal abundance tracks fluctuations in seed production at a 1-ye...
Technical Report
Full-text available
The Southern Hudson Bay (SH) polar bear subpopulation occurs at the southern extent of the species’ range. Although capture-recapture studies indicate that abundance remained stable between 1986 and 2005, declines in body condition and survival were documented during the period, possibly foreshadowing a future decrease in abundance. To obtain a cur...
Article
Full-text available
Spatially explicit capture–recapture (SECR) models are gaining popularity for estimating densities of mammalian carnivores. They use spatially explicit encounter histories of individual animals to estimate a detection probability function described by two parameters: magnitude (g 0), and spatial scale (σ). Carnivores exhibit heterogeneous detection...
Article
Full-text available
Although some populations remain stable, moose (Alces alces) density and distribution have been declining in many areas along the southern edge of their North American distribution. During 2006—2009, we deployed 99 vaginal implant transmitters (VITs) in 86 adult female moose in central Ontario, Canada to assist in locating and radiocollaring neonat...
Article
Full-text available
We used scat analysis to investigate temporal variation in the food habits of American Black Bears (Ursus americanus) in the boreal forest of northern Ontario. specifically, we examined whether there was a seasonal shift in foraging over three years (1990-1992) and which foods, if any, varied in occurrence among years. American Black Bears ate food...
Article
Full-text available
Anthropogenic global warming is occurring more rapidly in the Arctic than elsewhere, and has already caused significant negative effects on sea ice-dependent species such as polar bears. Although observed effects have thus far been gradual, the large amount of annual variation in the climate system may cause habitat changes in individual years that...
Presentation
Hybridization is a widespread evolutionary phenomenon that can play a role in diversification, especially among closely related taxa. Whereas hybridization is well known in plants, natural animal hybrids are considered much less common, although recent genome-wide investigations of canids and hominids suggest that admixture may have shaped the evol...
Article
Full-text available
This review critically evaluates the available mercury (Hg) data in Arctic marine biota and the Inuit population against toxicity threshold values. In particular marine top predators exhibit concentrations of mercury in their tissues and organs that are believed to exceed thresholds for biological effects. Species whose concentrations exceed thresh...
Article
Long-term physiological stress in individual animals may be an important mechanism linking ecological change with impaired wildlife population health. In the Southern Hudson Bay (SH) subpopulation of polar bears (Ursus maritimus), increasing stress associated with climate warming may be related to declining body condition. Accordingly, the developm...