Spatial models in animal behavior and ecology

This thesis comprises four chapters that study different ecological problems sharing a common theme: the importance of space. Chapter 1 studies how a social insect colony allocates workers to the different tasks in a manner that tracks the environment. We examine which decision rules at the individual level, using information from the local environment and from other workers, result in the appropriate task allocation at the colony level. Workers should switch tasks in response to social cues only when they have not found stimulus for work in their tasks. It is more efficient for a worker to respond only to cues from individuals that have recently found stimulus for work in other tasks. Chapter 2 studies how a group of sit-and-wait foragers should divide space. When there are not enough resources for all foragers to have the optimal amount, a conflict arises that can be settled by a negotiation. The outcome of that negotiation is an evolutionary stable configuration of territories. In an homogeneous environment there is economic equity among the foragers at the evolutionary stable territories. However, fighting asymmetries among the foragers or heterogeneous environmental conditions can result in economic inequity. Chapter 3 presents empirical data on the social organization of Anolis gingivinus and Anolis pogus. Anolis pogus has a monogamous social structure, rare among lizards, and Anolis gingivinus appears to be polygynous. Interspecific interactions between these two species are very common and indicate potential for interspecific territoriality. Chapter 4 develops a new approach for the forecast of biodiversity loss. We present a model that predicts if a species can survive in a landscape based on 3 life-history parameters: habitat affinity, population growth and annual dispersal. We use this model to forecast bird extinctions in Costa Rica. We estimate the model parameters for each bird species. Then, using data on land use change, we predict how many and which species are likely to go extinct if current deforestation trends are maintained.