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Biotic and abiotic drivers of harbor seal ( Phoca vitulina ) fine‐scale densities in the Salish SeaNARA Subscribed
Understanding relationships between environmental characteristics and variation in species occurrence and density can provide information for managing human activities, protected species, and species of commercial importance in a dynamic system. To identify environmental drivers associated with variation in harbor seal ( Phoca vitulina ) densities in the Salish Sea, Washington, we analyzed 20 years of boat‐based survey data an...
Predator–prey space use and landscape features influence movement behaviors in a large‐mammal communityNARA Subscribed
Predator hunting strategies, such as stalking versus coursing behaviors, are hypothesized to influence antipredator behaviors of prey and can describe the movement behaviors of predators themselves. Predators and prey may alter their movement in relation to predator hunting modes, yet few studies have evaluated how these strategies influence movement behaviors of free‐ranging animals in a multiple‐predator, multiple‐prey syste...
Integrated animal movement and spatial capture–recapture models: Simulation, implementation, and inferenceNARA Subscribed
Over the last decade, spatial capture–recapture (SCR) models have become widespread for estimating demographic parameters in ecological studies. However, the underlying assumptions about animal movement and space use are often not realistic. This is a missed opportunity because interesting ecological questions related to animal space use, habitat selection, and behavior cannot be addressed with most SCR models, despite the fac...
Ecologists and conservation biologists increasingly rely on spatial capture–recapture (SCR) and movement modeling to study animal populations. Historically, SCR has focused on population‐level processes (e.g., vital rates, abundance, density, and distribution), whereas animal movement modeling has focused on the behavior of individuals (e.g., activity budgets, resource selection, migration). Even though animal movement is clea...
A spatial capture–recapture model for group‐living speciesNARA Subscribed
Group living in species can have complex consequences for individuals, populations, and ecosystems. Therefore, estimating group density and size is often essential for understanding population dynamics, interspecific interactions, and conservation needs of group‐living species. Spatial capture–recapture (SCR) has been used to model both individual and group density in group‐living species, but modeling either individual‐level...
Prolonging survival in good health is a fundamental societal goal. However, the leading determinants of disability-free survival in healthy older people have not been well established. Data from ASPREE, a bi-national placebo-controlled trial of aspirin with 4.7 years median follow-up, was analysed. At enrolment, participants were healthy and without prior cardiovascular events, dementia or persistent physical disability. Disab...
Integrating multiple data sources in species distribution modeling: a framework for data fusionNARA Subscribed
The last decade has seen a dramatic increase in the use of species distribution models ( SDM s) to characterize patterns of species’ occurrence and abundance. Efforts to parameterize SDM s often create a tension between the quality and quantity of data available to fit models. Estimation methods that integrate both standardized and non‐standardized data types offer a potential solution to the tradeoff between data quality and...
An open‐population hierarchical distance sampling modelNARA Subscribed
Modeling population dynamics while accounting for imperfect detection is essential to monitoring programs. Distance sampling allows estimating population size while accounting for imperfect detection, but existing methods do not allow for estimation of demographic parameters. We develop a model that uses temporal correlation in abundance arising from underlying population dynamics to estimate demographic parameters from repeat...
Increasingly, fisheries are being managed under catch quotas that are often further allocated to specific permit holders or sectors. At the same time, serious consideration is being given to the effects of discards on the health of target and non‐target species. Some quota systems have incorporated discard reduction as an objective by counting discards (including unmarketable fish) against the overall quota. The potential effe...
Use of Multispecies Occupancy Models to Evaluate the Response of Bird Communities to Forest Degradation Associated with LoggingNARA Subscribed
Forest degradation is arguably the greatest threat to biodiversity, ecosystem services, and rural livelihoods. Therefore, increasing understanding of how organisms respond to degradation is essential for management and conservation planning. We were motivated by the need for rapid and practical analytical tools to assess the influence of management and degradation on biodiversity and system state in areas subject to rapid envi...
A spatial mark–resight model augmented with telemetry dataNARA Subscribed
Abundance and population density are fundamental pieces of information for population ecology and species conservation, but they are difficult to estimate for rare and elusive species. Mark–resight models are popular for estimating population abundance because they are less invasive and expensive than traditional mark–recapture. However, density estimation using mark–resight is difficult because the area sampled must be explic...
Use of Spatial Capture‐Recapture Modeling and DNA Data to Estimate Densities of Elusive AnimalsNARA Subscribed
Assessment of abundance, survival, recruitment rates, and density (i.e., population assessment) is especially challenging for elusive species most in need of protection (e.g., rare carnivores). Individual identification methods, such as DNA sampling, provide ways of studying such species efficiently and noninvasively. Additionally, statistical methods that correct for undetected animals and account for locations where animals...
Spatially explicit inference for open populations: estimating demographic parameters from camera‐trap studiesNARA Subscribed
We develop a hierarchical capture–recapture model for demographically open populations when auxiliary spatial information about location of capture is obtained. Such spatial capture–recapture data arise from studies based on camera trapping, DNA sampling, and other situations in which a spatial array of devices records encounters of unique individuals. We integrate an individual‐based formulation of a Jolly‐Seber type model wi...
Aim (1) To increase awareness of the challenges induced by imperfect detection, which is a fundamental issue in species distribution modelling; (2) to emphasize the value of replicate observations for species distribution modelling; and (3) to show how ‘cheap’ checklist data in faunal/floral databases may be used for the rigorous modelling of distributions by site‐occupancy models. Location Switzerland. Methods We used checkli...
The importance of understanding spatial variation in processes driving animal population dynamics is widely recognized. Yet little attention has been paid to spatial modeling of vital rates. Here we describe a hierarchical spatial autoregressive model to provide spatially explicit year‐specific estimates of apparent survival (ϕ) and residency (π) probabilities from capture–recapture data. We apply the model to data collected o...
Genetic sampling is increasingly used as a tool by wildlife biologists and managers to estimate abundance and density of species. Typically, DNA is used to identify individuals captured in an array of traps (e.g., baited hair snares) from which individual encounter histories are derived. Standard methods for estimating the size of a closed population can be applied to such data. However, due to the movement of individuals on a...
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