DETERMINATION OF CONSPECIFIC ALARM CONSTITUENT AND STUDY OF LEARNED PREDATOR RECOGNITION IN AQUATIC AND TERRESTRIAL ENVIRONMENTS USING NEWTS


Book Description

The constant threat of predation has forced many prey species to evolve efficient strategies to survive. It has been demonstrated that amphibians elicit an innate anti-predator response to conspecific injury-released alarm cue. Yet the active component of conspecific alarm cues in newts is unknown. Using HPLC techniques to separate the components of newt skin extract (NSE) for two species of newt (Cynops pyrrhogaster and Notophthalmus viridescens) and common behavioural assays, I attempted to identify the location of the active component in newt damage-released alarm cue. The results indicated that there may be more than one active component that elicits an alarm response in NSE. The identity of these active components in NSE remains unknown. Previously it has been thought that amphibians employ only innate predator recognition but it has been shown that they also have the ability to learn a novel predator using olfaction and facilitated by injury-released alarm cue. Until now, the learning of novel predator cues has only been demonstrated by newts in aquatic environments. I tested the ability of N. viridescens to learn unfamiliar predators in both an aquatic and terrestrial environment. I found that red-spotted newts were able to learn novel largemouth bass odour in an aquatic environment. However, in a terrestrial environment, no learning occurred. The lack of learning on land is potentially due to latent inhibition based on previous life stage experiences in a terrestrial environment where the newt was less vulnerable to predation. My study provides new insight into the complexity of conspecific alarm cues in newts and the possible effects of life history on risk allocation and future learning.




Threat-sensitive Learning and Generalization of Predator Recognition by Aquatic Vertebrates


Book Description

Many prey species lack innate recognition of their potential predators. Hence, learning is required for them to recognize and respond to predation threats. When wild-caught, these same species may show amazing sophistication in their responses to predator cues. They are able to adjust the intensity of their antipredator responses to a particular predator according to the degree of threat posed by that predator. This ability is therefore acquired through learning. While many studies have shown that prey can learn to respond to predator cues through different learning modes, little is known about what the prey are actually learning. The results presented in this thesis show that learned predator recognition goes beyond the simple labelling of predators as dangerous. Using fathead minnows (Pimephales promelas), woodfrog (Rana sylvatica) tadpoles and boreal chorus frog (Pseudacris maculata) tadpoles, I demonstrated that a one time learning event, either through pairing with alarm cues or through social learning, was enough for prey to learn the level of threat associated with the novel predator cues. I showed that the level of danger associated with the predator cues was determined by the concentration of alarm cues when learning through pairing of alarm cues, or by the intensity of antipredator response displayed by the tutors and by the tutor-to-observer ratio when learning occurred through cultural transmission. Moreover, when subsequently exposed to predator cues, prey adjusted their antipredator responses according to the change in concentration of predator cues between the learning event and the subsequent exposure. Prey displayed stronger antipredator responses when exposed to higher concentrations of predator cues and vice versa. When minnows were provided with conflicting information about the danger level associated with a predator, they displayed a safety strategy and used the most recent information available to respond to predation threats. On a longer time.







Predator Recognition in Birds


Book Description

This SpringerBrief answers the question on how birds recognize their predators using multidisciplinary approaches and outlines paths of the future research of predator recognition. A special focus is put on the role of key features to discriminate against predators and non-predators. The first part of the book provides a comprehensive review of the mechanisms of predator recognition based on classical ethological studies in untrained birds. The second part introduces a new view on the topic treating theories of cognitive ethology. This approach involves examination of conditioned domestic pigeons and highlights the actual abilities of birds to recognize and categorize.




Chemosensory Assessment of Predation Risk by Fishes


Book Description

Throughout their lives, prey organisms must balance the tradeoff between fitness-related activities and the risk of predation. To successfully mediate such tradeoffs, prey must have an accurate method to gauge current predation risk. For many aquatic organisms, the use of chemosensory information has been shown to be a ubiquitous and useful tool in mediating predation risk. The chemical cues to which aquatic organisms respond include the odour of known predators and the odour of a damaged conspecific or known or closely related heterospecific. In fishes, the response to damage-released cues from conspecifics or closely related heterospecifics has been shown to be innate, while the response to distantly related unknown heterospecific cues are likely learned. In a series of laboratory and field studies I examined the role of learning in the ability of fathead minnows to respond to damage-released cues of brook stickleback as an indication of predation risk. My results indicate that minnows from a population without stickleback do not recognize stickleback cues as dangerous. However, following the introduction of stickleback, minnows learn to recognize stickleback cues as dangerous. Further study indicated a low ratio of stickleback to minnows in a given population will decrease the likelihood of learning when compared with a similar sized population containing a higher ratio of stickleback to minnows. I also demonstrated that an increase in habitat complexity decreases the ability of minnows to learn to recognize stickleback cues. Studies have further demonstrated that in the face of predation (as indicated by chemical cues from minnows and stickleback) minnows will decrease their antipredator response when in the presence of a fish shoal, especially a shoal of conspecifics. Finally, an examination of the effects of a minnows length, body condition and breeding status indicate that morphological parameters can play a significant role in the intensity of response to he.




Escaping From Predators


Book Description

When a predator attacks, prey are faced with a series of 'if', 'when' and 'how' escape decisions – these critical questions are the foci of this book. Cooper and Blumstein bring together a balance of theory and empirical research to summarise over fifty years of scattered research and benchmark current thinking in the rapidly expanding literature on the behavioural ecology of escaping. The book consolidates current and new behaviour models with taxonomically divided empirical chapters that demonstrate the application of escape theory to different groups. The chapters integrate behaviour with physiology, genetics and evolution to lead the reader through the complex decisions faced by prey during a predator attack, examining how these decisions interact with life history and individual variation. The chapter on best practice field methodology and the ideas for future research presented throughout, ensure this volume is practical as well as informative.




Parasite Biodiversity


Book Description

This comprehensive, groundbreaking book on the biodiversity of parasites offers a clear and accessible explanation of how parasite biodiversity provides insight into the history and biogeography of other organisms, the structure of ecosystems, and the processes that lead to the diversification of life.




Ecology


Book Description

This best-selling majors ecology book continues to present ecology as a series of problems for readers to critically analyze. No other text presents analytical, quantitative, and statistical ecological information in an equally accessible style. Reflecting the way ecologists actually practice, the book emphasizes the role of experiments in testing ecological ideas and discusses many contemporary and controversial problems related to distribution and abundance. Throughout the book, Krebs thoroughly explains the application of mathematical concepts in ecology while reinforcing these concepts with research references, examples, and interesting end-of-chapter review questions. Thoroughly updated with new examples and references, the book now features a new full-color design and is accompanied by an art CD-ROM for instructors. The field package also includes The Ecology Action Guide, a guide that encourages readers to be environmentally responsible citizens, and a subscription to The Ecology Place (www.ecologyplace.com), a web site and CD-ROM that enables users to become virtual field ecologists by performing experiments such as estimating the number of mice on an imaginary island or restoring prairie land in Iowa. For college instructors and students.




Parasitism


Book Description

In Parasitism, Claude Combes explores the fascinating adaptations parasites have developed through their intimate interactions with their hosts. He begins with the biology of parasites—their life cycles, habitats, and different types of associations with their hosts. Next he discusses genetic interactions between hosts and parasites, and he ends with a section on the community ecology of parasites and their role in the evolution of their hosts. Throughout the book Combes enlivens his discussion with a wealth of concrete examples of host-parasite interactions.




Pheromones and Animal Behavior


Book Description

This book explains how animals use chemical communication, emphasising the evolutionary context and covering fields from ecology to neuroscience and chemistry.