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Many wild populations of animals conform to the ideal despotic distribution (IDD) in which more competitive individuals exclude less competitive individuals from high quality resources. Body size and aggressiveness are two important traits for resource defense, and they positively covary so that larger individuals are usually more aggressive. Using Bachman's sparrows, we tested the hypothesis that larger birds are more aggressive and are thus able to compete for the best quality territories. We found that larger males were more aggressive, and more aggressive birds fledged at least one young. However, we did not find consistent relationships between aggressiveness and habitat characteristics. Our results suggest that Bachman's sparrows meet most of the predictions of the IDD. Frequent ecological disturbances, such as fires, might disrupt the IDD or make it difficult to detect. Additional studies are needed to test for relationships between ecological disturbances and territorial behaviour. [ABSTRACT FROM AUTHOR]

Movement of individuals links the effects of local variation in habitat quality with growth and persistence of populations at the landscape scale. When the populations themselves are linked by interspecific interactions, such as predation, differential movement between habitats may lead to counterintuitive system-wide dynamics. Understanding the interaction between local drivers and dynamics of widely dispersed species is necessary to predict the impacts of habitat fragmentation and degradation, which may be transmitted across habitat boundaries by species' movements. Here we model predator-prey interactions across unaltered and degraded habitat areas, and we explore the additional effects of adaptive habitat choice by predators on the resilience of prey populations. We show how movement between habitats can produce the 'bad neighbor effect,' in which predators' response to localized habitat degradation causes system-wide loss of prey populations. This effect arises because adaptive foraging results in the concentration of predators in the more productive unaltered habitat, even when this habitat can not support the increased prey mortality. The mechanisms underlying this effect are especially sensitive to prey dispersal rate and adaptive predator behavior. [ABSTRACT FROM AUTHOR]

Metapopulation models have historically treated a landscape as a collection of habitat patches separated by a matrix of uniformly unsuitable habitat. This perspective is still apparent in many studies of marine metapopulations, in which recruitment variation is generally assumed to be primarily the result of variability in ocean currents and interactions with disperser behavior, with little consideration of spatial structure that can affect disperser viability. We use a simple model of dispersal of marine larvae to demonstrate how heterogeneity in dispersal habitat (i.e., the matrix) can generate substantial spatial variation in recruitment. Furthermore, we show how this heterogeneity can interact with larval life-history variation to create alternative patterns of source--sink dynamics. Finally, we place our results in the context of spatially structured matrix population models, and we propose the damping ratio of the connectivity matrix as a general and novel measure of landscape connectivity that may provide conceptual unification to the fields of metapopulation biology and landscape ecology. [ABSTRACT FROM AUTHOR]

Abstract: We develop a suite of models with varying complexity to predict elk movement behavior during the winter on the Northern Range of Yellowstone National Park (YNP). The models range from a simple representation of optimal patch choice to a dynamic game, and we show how the underlying theory in each is related by the presence or absence of state- and frequency-dependence. We compare predictions from each of the models for three variables that are of basic and applied interest: elk survival, aggregation, and use of habitat outside YNP. Our results suggest that despite low overall forage depletion in the winter, frequency-dependence is crucial to the predictions for elk movement and distribution. Furthermore, frequency-dependence interacts with mass-dependence in the predicted outcome of elk decision-making. We use these results to show how models that treat single movement decisions in isolation from the seasonal sequence of decisions are insufficient to capture landscape scale behavior. [Copyright &y& Elsevier]