Dennis Murray

Dennis Murray
Trent University · Department of Biology

About

228
Publications
44,796
Reads
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7,784
Citations
Citations since 2016
74 Research Items
3924 Citations
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20162017201820192020202120220100200300400500600
20162017201820192020202120220100200300400500600
20162017201820192020202120220100200300400500600

Publications

Publications (228)
Article
Full-text available
Environmental DNA (eDNA) monitoring is rapidly becoming an established approach for detecting the presence of aquatic organisms and may also be useful for indexing or estimating species abundance. However, the link between eDNA concentration and abundance of individuals (i.e., density or biomass) remains tenuous and may vary widely across species a...
Article
Full-text available
Ecological communities are fundamentally connected through a network of trophic interactions that are often complex and difficult to model. Substantial variation exists in the nature and magnitude of these interactions across various predators and prey and through time. However, the empirical data needed to characterize these relationships are diff...
Article
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Snowshoe hare cycles are one of the most prominent phenomena in ecology. Experimental studies point to predation as the dominant driving factor, but previous experiments combining food supplementation and predator removal produced unexplained multiplicative effects on density. We examined the potential interactive effects of food limitation and pre...
Article
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Chytridiomycosis, a primary disease driving widespread and unprecedented amphibian declines, is caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd). Tracking Bd through space and time requires monitoring protocols that efficiently and reliably assess pathogen prevalence and intensity, which in turn requires an understanding of environ...
Article
Landscape-scale predictions of species abundance or density are of fundamental importance to conservation and management of ecosystems. Yet, developing these models remains challenging, as they require linking broad-scale population data with habitat characteristics that influence species abundance. Advances in remote sensing technology have result...
Article
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The boreal forest is one of the world’s ecosystems most affected by global climate warming. The snowshoe hare, its predators, and their population dynamics dominate the mammalian component of the North American boreal forest. Our past research has shown the 9–11-year hare cycle to be predator driven, both directly as virtually all hares that die ar...
Article
Full-text available
The COVID-19 pandemic profoundly affected research in ecology and evolution, with lockdowns resulting in the suspension of most research programs and creating gaps in many ecological datasets. Likewise, monitoring efforts directed either at tracking trends in natural systems or documenting the environmental impacts of anthropogenic activities were...
Article
Food availability and temporal variation in predation risk are both important determinants of the magnitude of antipredator responses, but their effects have rarely been examined simultaneously, particularly in wild prey. Here, we determine how food availability and long‐term predation risk affect antipredator responses to acute predation risk by m...
Article
Characterizing variation in predator behaviour and, specifically, quantifying kill rates is fundamental for parameterizing predator–prey and food web models. Yet, current methods for recording kill rates of free‐ranging predators, particularly those that consume small‐bodied (<2 kg) prey, present a number of associated challenges. In this paper, we...
Article
The eastern wolf (Canis lycaon), a species of conservation concern in Canada, is currently restricted to small fragmented populations in south-central Ontario and hybridizes with both encroaching gray wolves and coyote-like canids. We examined niche dynamics in canids undergoing hybridization to determine whether competition among individuals with...
Article
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Understanding the factors governing predation remains a top priority in ecology. Using a dragonfly nymph-tadpole system, we experimentally varied predator density, prey density, and prey species ratio to investigate: (i) whether predator interference varies between prey types that differ in palatability, (ii) whether adding alternate prey influence...
Article
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The application of species distribution models (SDMs) to areas outside of where a model was created allows informed decisions across large spatial scales, yet transferability remains a challenge in ecological modeling. We examined how regional variation in animal‐environment relationships influenced model transferability for Canada lynx (Lynx canad...
Article
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Canada lynx (Lynx canadensis) and snowshoe hares (Lepus americanus) form a keystone predator–prey cycle that has large impacts on the North American boreal forest vertebrate community. Snowshoe hares and lynx are both well-suited for snowy winters, but climate change-associated shifts in snow conditions could lower hare survival and alter cyclic dy...
Article
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Organisms with multiple biotic attributes may also have conflicting niche determinants, and we assessed whether the realized niche reflects single or multiple biotic attributes. A group of all‐female salamanders found in eastern North America (unisexual salamanders; Ambystoma spp.) embody two potentially competing biotic states: hybridism and oblig...
Article
Clock genes exhibit substantial control over gene expression and ultimately life-histories using external cues such as photoperiod, and are thus likely to be critical for adaptation to shifting seasonal conditions and novel environments as species redistribute their ranges under climate change. Coding trinucleotide repeats (cTNRs) are found within...
Article
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Environmental decision-makers and practitioners need and deserve high quality environmental evidence for effective decision-making. We collate and share a suite of best practices for applied environmental researchers to support their capacity to inform such decision-making processes. This raises a number of important questions: What does “relevant”...
Article
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Current targets for protected area network coverage call for increased protection but lack specificity in terms of criteria for parcel type, placement, and landscape connectivity. We assessed land conservation achieved by protected area networks in the contiguous United States, and assessed whether private lands contributed substantially to network...
Book
A synthesis of contemporary analytical and modeling approaches in population ecology The book provides an overview of the key analytical approaches that are currently used in demographic, genetic, and spatial analyses in population ecology. The chapters present current problems, introduce advances in analytical methods and models, and demonstrate...
Article
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Amphibian population declines have been associated with emerging diseases including ranaviruses, which can cause mass die-offs across entire amphibian communities. Understanding and mitigating disease spread requires knowledge of spatial and temporal patterns of pathogen distribution, but also how environmental factors influence pathogen occurrence...
Article
A wide variety of prey use defensive postures as a means of protection from predators. Many salamanders engage in broadly similar defensive postures, which may function as a warning signal and reduce the probability of attack, or may deflect predator attacks away from vital body parts. The extent to which these strategies (i.e., aposematism and def...
Article
With unprecedented losses in biodiversity, the need for stronger environmental policy has emerged as a conservation priority. Yet recovery planning for imperiled species remains a cumbersome, slow legislative process. In the present article, we examine features of recovery planning for species listed under Canada's Species at Risk Act to determine...
Article
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Extensive research confirms that environmental stressors like predation risk can profoundly affect animal condition and physiology. However, there is a lack of experimental research assessing the suite of physiological responses to risk that may arise under realistic field conditions, leaving a fragmented picture of risk-related physiological chang...
Article
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There is increasing interest in how animals respond to multiple stressors, including potential synergistic or antagonistic interaction between pathogens and perceived predation risk (PPR). For prey that exhibit phenotypic plasticity, it is unclear whether infection and PPR affect behaviour and morphology independently, or in an antagonistic or syne...
Article
Large‐scale anthropogenic changes to landscapes will cause species to move and shift their ranges against a backdrop of international political boundaries. Transboundary conservation efforts are therefore key to preserving intact and connected landscapes, particularly if such efforts can be implemented within the framework of protected area network...
Article
Amphibian populations are declining worldwide, and these declines have been linked to a number of anthropogenic factors, including disease. Among the pathogens associated with amphibian mortality, ranaviruses have caused massive die-offs across continents. In North America, frog virus 3 (FV3) is a widespread ranavirus that can infect wild and capti...
Article
Full-text available
Protection and management of adaptively diverse populations is critical to meet the goals of conservation policy and to conserve the evolutionary potential of species into the future. The identification of conservation units below the species level can be a helpful tool in this regard. In Canada, such conservation units are referred to as Designata...
Article
Determining the molecular signatures of adaptive differentiation is a fundamental component of evolutionary biology. A key challenge is to identify such signatures in wild organisms, particularly between populations of highly mobile species that undergo substantial gene flow. The Canada lynx (Lynx canadensis) is one species where mainland populatio...
Article
Full-text available
Technological miniaturization is driving a biologging revolution that is producing detailed and sophisticated techniques of assessing individual behavioral responses to environmental conditions. Among the many advancements this revolution has brought is an ability to record behavioral responses of nocturnal, free-ranging species. Here, we combine c...
Article
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We present a reply to a recent article in Ecology and Evolution (“Measuring agreement among experts in classifying camera images of similar species” by Gooliaff and Hodges) that demonstrated a lack of consistency in expert‐based classification of images of similar‐looking species. We disagree with several conclusions from the study, and show that w...
Article
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Frog virus 3 (FV3) and FV3-like ranaviruses can infect a variety of cold-blooded aquatic species and present a primary threat to amphibians across the globe. Previous studies of FV3-like viruses have largely investigated higher-level phylogenetic distinctions of these pathogens via portions of the conserved major protein (MCP), and the putative vir...
Article
While resource quality and predator‐derived chemical cues can each have profound effects on zooplankton populations and their function in ecosystems, the strength and direction of their interactive effects remain unclear. We conducted laboratory experiments to evaluate how stoichiometric food quality (i.e., algal carbon [C] : phosphorus [P] ratios)...
Preprint
Full-text available
Determining the molecular signatures of adaptive differentiation is a fundamental component of evolutionary biology. A key challenge remains for identifying such signatures in wild organisms, particularly between populations of highly mobile species that undergo substantial gene flow. The Canada lynx ( Lynx canadensis ) is one species where mainlan...
Article
Full-text available
Intraspecific aggression represents a major source of mortality for many animals and is often experienced alongside the threat of predation. The presence of predators can strongly influence ecological systems both directly by consuming prey and indirectly by altering prey behavior or habitat use. As such, the threat of attack by higher level predat...
Article
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Prey abundance and prey vulnerability vary across space and time, but we know little about how they mediate predator-prey interactions and predator foraging tactics. To evaluate the interplay between prey abundance, prey vulnerability, and predator space use, we examined patterns of black bear (Ursus americanus) predation of caribou (Rangifer taran...
Article
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In aquatic environments, chemical cues are believed to be associated with prey response to predation risk, yet few basic cue compositions are known despite the pronounced ecological and evolutionary significance of such cues. Previous work indicated that negatively-charged ions of m/z 501 are possibly a kairomone that induces anti-predator response...
Article
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For many organisms, climate change can directly drive population declines, but it is less clear how such variation may influence populations indirectly through modified biotic interactions. For instance, how will climate change alter complex, multi-species relationships that are modulated by climatic variation and that underlie ecosystem-level proc...
Article
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International political boundaries challenge species conservation because they can hinder coordinated management. Peripheral transboundary species, those with a large portion of their range in one country and a small, peripheral portion in an adjacent country, may be particularly vulnerable to mismatches in management because peripheral populations...
Article
Full-text available
Climate change is predicted to affect the reproductive ecology of wildlife; however, we have yet to understand if and how species can adapt to the rapid pace of change. Clock genes are functional genes likely critical for adaptation to shifting seasonal conditions through shifts in timing cues. Many of these genes contain coding trinucleotide repea...
Article
Population cycling is a widespread phenomenon, observed across a multitude of taxa in both laboratory and natural conditions. Historically, the theory associated with population cycles was tightly linked to pairwise consumer-resource interactions and studied via deterministic models, but current empirical and theoretical research reveals a much ric...
Article
Full-text available
Climate change threatens natural landscapes through shifting distribution and abundance of species and attendant change in the structure and function of ecosystems. However, it remains unclear how climate-mediated variation in species' environmental niche space may lead to large-scale fragmentation of species distributions, altered meta-population...
Data
Table A presents the number of presence records, target group, beta-multiplier, and feature types used for the top MaxEnt models developed for each species. Table B describes the number of suitable patches and mean patch size for boreal forest species under current and future climate projections (2050, 2080), within the current distribution of the...
Article
Full-text available
Movement influences a myriad of ecological processes operating at multiple spatial and temporal scales. Yet our understanding of animal movement is limited by the resolution of data that can be obtained from individuals. Traditional approaches implicitly assume that movement decisions are made at the spatial and temporal scales of observation, alth...
Article
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Island populations have long been important for understanding the dynamics and mechanisms of evolution in natural systems. While genetic drift is often strong on islands due to founder events and population bottlenecks, the strength of selection can also be strong enough to counteract the effects of drift. Here, we used several analyses to identify...
Article
To improve understanding of the complex and variable patterns of predator foraging behavior in natural systems, it is critical to determine how density-dependent predation and predator hunting success are mediated by alternate prey or predator interference. Despite considerable theory and debate seeking to place predator–prey interactions in a more...
Article
Human-caused habitat alteration and disturbance have promoted widespread loss of species’ reproductive barriers, leading to hybridization and attendant changes in the distribution, abundance and interactions of most species. In theory, hybrids should have intermediate niche occupancy features compared to parental groups, thereby potentially leading...
Article
Full-text available
Species interactions like parasitism influence the outcome of climate-driven shifts in species ranges. For some host species, parasitism can only occur in that part of its range that overlaps with a second host species. Thus, predicting future parasitism may depend on how the ranges of the two hosts change in relation to each other. In this study,...
Article
Full-text available
Animals spend considerable time and energy acquiring food to meet their metabolic requirements, but if energetic or fitness costs are substantive, such as during winter, then some individuals may limit daily energy expenditure by reducing foraging duration. To date, the prevalence and magnitude of such compensatory foraging responses are poorly kno...
Article
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Sex-specific senescence has been construed as a function of mating system and differential investment in parental care, with males exhibiting low parental investment predicted to have more rapid senescence due to costly reproductive behavior. In monogamous mating systems, however, where parental investment may be more evenly distributed, rates of s...
Article
Climate change is expected to lead to greater temporal climatic variability across broad spatial extents. A potential consequence is that shifts in climatic conditions might alter how local habitat affects the population growth of animals dependent on those habitats for at least part of their life cycle. We tested whether such a phenomenon occurred...
Article
A potential cause of amphibian population declines are the impacts of environmental degradation on tadpole development. We conducted RNA sequencing on developing northern leopard frog tadpoles and through de novo transcriptome assembly we annotated a large number of open reading frames comparable in number and extent to genes identified in Xenopus....
Article
A wide range of taxa respond to perceived predation risk (PPR) through inducible defenses, and many prey are capable of responding both behaviorally and morphologically to the same risk event. In cases where multiple defenses confer protection by independent means (i.e. they are mechanistically independent) responses will either be co-expressed, or...