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• 1. [Article] Predator Conservation and Trophic Ecology

  Many of Earth’s terrestrial large carnivore species are threatened with extinction. As a result, some of the ecological effects associated with these species may be lost. With the goal of furthering ...

  Citation × Citation Citation Abstract Copy Title: Predator Conservation and Trophic Ecology Author: Wolf, Christopher Year: 2017 Many of Earth’s terrestrial large carnivore species are threatened with extinction. As a result, some of the ecological effects associated with these species may be lost. With the goal of furthering large carnivore conservation research, I conduct three global scale analyses involving these species. First, I explore prey depletion as a threat to large carnivores, finding that loss of prey base is a widespread occurrence and that many prey species are themselves threatened with extinction. Second, I analyze how large carnivore species’ geographic ranges have contracted, linking range contractions to spatial covariates: rural human population density, cropland, and livestock (cattle) density. Finally, I explore options for large carnivore reintroductions, identifying hundreds of potential sites around the world (protected areas and low human footprint regions) where rewilding may have the greatest likelihood of success. In the second part of this dissertation, I transition to considering the basic ecology of predation, with a focus on statistically estimating functional response parameters, which are closely linked to food web interaction strengths. I first show how an observational method for estimating these parameters may be extended using a Bayesian framework that incorporates multiple sources of uncertainty while producing biologically realistic credible intervals. I pay particular attention to the problem of prior selection for modeling multinomial predator feeding survey data, showing that a ‘neutral’ prior is most appropriate. Finally, I consider prior choice in more general nonlinear regression settings, proposing two new prior distributions designed to have low frequentist-sense bias and unifying a set of non-informative priors for a particular function family. I compare these and other non-informative prior distributions using a simulation study and a case study involving whelk feeding behavior in a rocky intertidal ecosystem. Title: Predator Conservation and Trophic Ecology Author: Wolf, Christopher Year: 2017 Many of Earth’s terrestrial large carnivore species are threatened with extinction. As a result, some of the ecological effects associated with these species may be lost. With the goal of furthering large carnivore conservation research, I conduct three global scale analyses involving these species. First, I explore prey depletion as a threat to large carnivores, finding that loss of prey base is a widespread occurrence and that many prey species are themselves threatened with extinction. Second, I analyze how large carnivore species’ geographic ranges have contracted, linking range contractions to spatial covariates: rural human population density, cropland, and livestock (cattle) density. Finally, I explore options for large carnivore reintroductions, identifying hundreds of potential sites around the world (protected areas and low human footprint regions) where rewilding may have the greatest likelihood of success. In the second part of this dissertation, I transition to considering the basic ecology of predation, with a focus on statistically estimating functional response parameters, which are closely linked to food web interaction strengths. I first show how an observational method for estimating these parameters may be extended using a Bayesian framework that incorporates multiple sources of uncertainty while producing biologically realistic credible intervals. I pay particular attention to the problem of prior selection for modeling multinomial predator feeding survey data, showing that a ‘neutral’ prior is most appropriate. Finally, I consider prior choice in more general nonlinear regression settings, proposing two new prior distributions designed to have low frequentist-sense bias and unifying a set of non-informative priors for a particular function family. I compare these and other non-informative prior distributions using a simulation study and a case study involving whelk feeding behavior in a rocky intertidal ecosystem. Close