Download or read book The Effects of Spatial Heterogeneity on Predators Prey and Their Interactions written by Corbin Cox Kuntze and published by . This book was released on 2024 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Habitat changes and prey depletion are among the most prominent drivers of near-global declines in predator populations. In particular, landscape homogenization - driven by climate change, anthropogenic land use, and management policies - can destabilize essential trophic interactions and represents a continuing threat to biodiversity and ecosystem function. Many predator and prey species occur, and likely evolved, in complex landscapes with heterogeneously distributed resources that shape many of their ecological interactions. A growing body of research has explored the role of spatial heterogeneity in predator-prey interactions, suggesting that heterogeneous landscapes containing prey refuges can decouple prey availability from abundance, with consequences when any one habitat type predominates. However, most of these studies are theoretical or lab-based, limited to controlled settings and by simplifying assumptions. Moreover, many studies of natural predator-prey systems are conducted at limited spatial scales, do not involve mobile predators, or fail to consider the role of alternative prey. As a result, our understanding of spatial heterogeneity - and the consequences of landscape simplification - remain limited by the available literature. This dissertation seeks to reduce key uncertainties and assess the emergent consequences of environmental change and landscape simplification on wildlife populations. Chapter 1 (Kuntze et al., 2024; Journal of Mammalogy) leveraged a 13-year monitoring dataset, stable isotope analysis, and high-resolution climate and habitat imagery to evaluate demographic responses of an isolated and endangered distinct population segment of fishers (Pekania pennanti) to rapid environmental change in the southern Sierra Nevada, California, USA. Fisher survival was sensitive to both biotic and abiotic factors, although the strength and direction of these effects were ultimately mediated by age and sex. These findings suggest that continued climate change will likely have consequences for Fishers through both incremental stressors and extreme weather events but increasing forest heterogeneity may help to buffer against the impacts of such change. Further, this study illustrates the importance of disentangling the effects of intrinsic and extrinsic factors on survival, especially among species with distinct sexual or ontogenetic differences.Chapter 2 (Kuntze et al., 2023; Ecological Applications) is the first of three that focuses on predator-prey dynamics between the spotted owl (Strix occidentalis) - an iconic old-forest species at the center of forest management planning in western North America - and one of its principal prey species, the dusky-footed woodrat (Neotoma fuscipes) - a younger forest species. This chapter explores the hypothesis that heterogeneous landscapes can create sources or spatial refuges for prey that ultimately benefit predator and prey populations when each are associated with different habitats. Here, we combined mark-recapture and survival monitoring of woodrats with direct observations of prey deliveries by spotted owls, and found that (1) woodrat abundance was higher within spotted owl home ranges defined by a heterogeneous mix of mature forest, young forest, and open areas, (2) woodrat mortality rates were low across all forest types (although all observed owl predation occurred within mature forests) and did not differ between heterogeneous and homogeneous owl home ranges, (3) owl consumption of woodrats increased linearly with woodrat abundance, and (4) consumption of alternative prey could not reconcile the deficit of reduced woodrat captures in homogeneous home ranges, as owls in heterogeneous landscapes delivered 30% more total prey biomass - equivalent to the energetic needs of producing one additional young. These findings represent some of the first empirical evidence from natural systems that promoting landscape heterogeneity can provide co-benefits to both predator and prey populations and constitute an effective strategy for conserving endangered predator populations. Chapter 3 (in review at Journal of Animal Ecology) contrasts foraging strategies within the context of a primary and secondary prey species to experimentally evaluate whether the magnitude of perceived risk, and in turn, the nature and strength of anti-predator investment, is governed by both predation intensity and the setting in which an encounter takes place. We studied the effects of spotted owls on two species experiencing asymmetrical predation pressures: dusky-footed woodrats (primary prey) and deer mice (Peromyscus spp., alternative prey). Woodrats exhibited behavioral responses to both background and acute risk at each stage of the foraging process, while deer mice only responded to acute risk. This suggests that prey may conform to or depart from the risk allocation hypothesis (i.e., that background risk modulates responses to immediate cues of predation risk) depending on relative predation risk from a shared predator. Furthermore, woodrats and deer mice employed time allocation and apprehension in different manners and under opposing circumstances, highlighting that primary and secondary prey can exhibit profound differences in both how risk is perceived, as well as how it is managed. Finally, Chapter 4 (prepared for Forest Ecology and Management) characterizes patterns in woodrat site occupancy at site-, patch-, and landscape-scales within landscapes where forest heterogeneity was created by even-aged timber management. Woodrats were more likely to occupy sites with greater canopy cover, understory cover, and hardwoods - particularly tanoak (Notholithocarpus densiflorus) - and smaller patches of young forest. Woodrats were also more likely to occur in mature forests in close proximity to younger forest, suggesting that high-quality habitat patches can produce dense populations that recruit into adjacent, lower-quality patches. These findings highlight the benefit of multiscale studies and provide insight into management activities that may benefit species conservation without compromising resilience in forest ecosystems. These latter three chapters collectively demonstrate that heterogeneity in vegetation types including high-density young forests increased the abundance and availability of early-successional woodrats that, in turn, provided energetic and potentially reproductive benefits to mature forest-associated spotted owls. Overall, this dissertation provides empirical support for theoretical studies on the role of heterogeneity (and the mechanisms conferring co-benefits), as well as contingencies mediating anti-predator behaviors, fit to the appropriate spatial scales.
Download or read book Spatial Heterogeneity and the Stability of a Predator prey Link written by Philip Haney Crowley and published by . This book was released on 1975 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Discreteness and Spatial Heterogeneity on Predator prey Systems written by Yuval R. Zelnik and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ecology of Predator Prey Interactions written by Pedro Barbosa and published by Oxford University Press. This book was released on 2005-08-11 with total page 413 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses the fundamental issues of predator-prey interactions, with an emphasis on predation among arthropods, which have been better studied, and for which the database is more extensive than for the large and rare vertebrate predators. The book should appeal to ecologists interested in the broad issue of predation effects on communities.
Download or read book How Species Interact written by Roger Arditi and published by Oxford University Press. This book was released on 2012-04-08 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the functioning of ecosystems requires the understanding of the interactions between consumer species and their resources. How do these interactions affect the variations of population abundances? How do population abundances determine the impact of predators on their prey? The view defended in this book is that the "null model" that most ecologists tend to use is inappropriate because it assumes that the amount of prey consumed by each predator is insensitive to the number of conspecifics. The authors argue that the amount of prey available per predator, rather than the absolute abundance of prey, is the basic determinant of the dynamics of predation. This so-called ratio dependence is shown to be a much more reasonable "null model."
Download or read book Models in Ecology written by John Maynard-Smith and published by Cambridge University Press. This book was released on 1974-01-17 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is aimed at anyone with a serious interest in ecology. Ecological models of two kinds are dealt with: mathematical models of a strategic kind aimed at an understanding of the general properties of ecosystems and laboratory models designed with the same aim in view. The mathematical and experimental models illuminate one another. A strength of the account is that although there is a good deal of mathematics, Professor Maynard Smith has concentrated on making clear the assumptions behind the mathematics and the conclusions to be drawn. Proofs and derivations have been omitted as far as possible. The book is therefore comprehensible to anyone with a minimal familiarity with mathematical notation. This book was written in the twin convictions that ecology will not come of age until it has a sound theoretical basis and there is a long way to go before that state of affairs is reached.
Download or read book The Effect of Spatial Heterogeneity on Predator prey Dynamics written by Patrick Joseph Sullivan and published by . This book was released on 1985 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transient Dynamics of Predator prey Metapopulations written by Matthew Dana Holland and published by . This book was released on 2008 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Assessing the Dynamics of a Generalist Predator prey Model Across Different Spatial Configurations written by Rosa M. McGuire and published by . This book was released on 2018 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Habitat destruction and fragmentation are major human impacts. Microcosm experiments have shown that habitat fragmentation can alter the persistence and population densities of members of a community. Spatial heterogeneity allows recolonization from other patches resulting in long-term species persistence, preventing species from going extinct. Much of our understanding of these processes have come from protist microcosm studies. However, most microcosm studies of habitat fragmentation have focused on predator/prey interactions that include specialist predators. Here, we use protist microcosms to study the persistence of a predator/prey system using Amoeba proteus, a generalist predator, and Paramecium caudatum as prey. Unlike specialist predators, generalists are expected to be over represented in fragmented habitats and have longer persistence times, meaning that understanding their dynamics is important. This study aims to understand and predict the ecological impacts of habitat fragmentation, a major concern in conservation biology. The objective of this project is to parameterize key population interaction terms of a predator/prey system using Amoeba proteus and Paramecium caudatum. These parameters will be used in future research projects to predict the effects of spatial configuration on the persistence time of both predator and prey. Experiments on patch colonization, chance of extinction, and functional response of the predator have been completed. Analyses using maximum-likelihood estimation (MLE) in R were used to obtain parameters for a predator/prey model. The parameters obtained were the per capita growth rate of Paramecium, r=0.217±0.011, attack rate of Amoeba, a'=0.012±0.013, and handling time, Th= 0.606±0.289. We expect longer predator persistence times and greater variability among spatial configurations due to the generalist diet of our predator.
Download or read book Spatial Predator prey Dynamics written by Tammy Dee Rosner and published by . This book was released on 1999 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spatial Heterogeneity and the Stability of Predator prey Systems written by Alan Hastings and published by . This book was released on 1978 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Influence of Spatial Heterogeneity of Prey on Predator Growth and Energetics written by Audrey Helen Reid and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Essentials of Landscape Ecology written by Kimberly A. With and published by . This book was released on 2019 with total page 654 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents the principles, theory, methods, and applications of landscape ecology and is supplemented by numerous examples and case studies from a variety of systems.
Download or read book Spatial Complexity Informatics and Wildlife Conservation written by Samuel A. Cushman and published by Springer Science & Business Media. This book was released on 2009-12-21 with total page 449 pages. Available in PDF, EPUB and Kindle. Book excerpt: As Earth faces the greatest mass extinction in 65 million years, the present is a moment of tremendous foment and emergence in ecological science. With leaps in advances in ecological research and the technical tools available, scientists face the critical task of challenging policymakers and the public to recognize the urgency of our global crisis. This book focuses directly on the interplay between theory, data, and analytical methodology in the rapidly evolving fields of animal ecology, conservation, and management. The mixture of topics of particular current relevance includes landscape ecology, remote sensing, spatial modeling, geostatistics, genomics, and ecological informatics. The greatest interest to the practicing scientist and graduate student will be the synthesis and integration of these topics to provide a composite view of the emerging field of spatial ecological informatics and its applications in research and management.
Download or read book Spatial Scale and Heterogeneity in Ecological Communities written by John Francis McLaughlin and published by . This book was released on 1990 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Antipredator Defenses in Birds and Mammals written by Timothy M. Caro and published by University of Chicago Press. This book was released on 2005-09 with total page 609 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tim Caro explores the many & varied ways in which prey species have evolved defensive characteristics and behaviour to confuse, outperform or outwit their predators, from the camoflaged coat of the giraffe to the extraordinary way in which South American sealions ward off the attacks of killer whales.
Download or read book Metapopulation Dynamics Empirical and Theoretical Investigations written by Michael Gilpin and published by Academic Press. This book was released on 2012-12-02 with total page 341 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metapopulation Dynamics: Empirical and Theoretical Investigations covers the 1989 proceedings of a metapopulation dynamics workshop held at Lammi Biological Station, Helsinki, Finland. It is divided into 18 chapters that cover various approaches to spatially structured population and community dynamics. After briefly discussing the history of metapopulation ideas and the major conceptual links, the book covers types of studies that have been conducted on single-species and multispecies metapopulations. Then, it examines the relationships between metapopulation dynamics, the equilibrium theory of island biogeography, and the dynamics of populations living in patchy environments. It further tackles practical issues and the links between metapopulation dynamics and landscape ecology, and between metapopulation dynamics and conservation biology. Chapters 4 and 5 present structured models describing changes in the number of individuals within patches and an empirical evaluation of local extinction in metapopulation studies. The subsequent chapters discuss several aspects of metapopulation, including dispersal and connectivity, colonization, conspecific attraction, extinction and isolation, and forest fragmentation. The latter chapters describe the concept of habitat fragmentation, the diversity and competition in metapopulations, the community collapse, and the effects of metapopulation studies in predator-prey systems.
