Animal Behavioral Ecology Research Articles

Parentage, reproductive success and breeding behaviour in the greater horseshoe bat (Rhinolophus ferrumequinum).

Female greater horseshoe bats form maternity colonies each summer in order to give birth and raise young. During the mating period, females visit males occupying territorial sites, copulation takes place and sperm are stored until ovulation occurs, normally in April. Using microsatellite markers and a likelihood method of parentage analysis, we studied breeding behaviour and male reproductive success over a five-year period in a population of bats in south-west Britain. Paternity was assigned with 80% confidence to 44% of young born in five successive cohorts. While a small annual skew in male reproductive success was detected, the variance increased over five years due to the repeated success of a few individuals. Mating was polygynous, although some females gave birth to offspring sired by the same male in separate years. Such repeated partnerships probably result from fidelity for either mating sites or individuals or from sperm competition. Females mated with males born both within and outside their own natal colony; however, relatedness between parents was no less than the average recorded for male female pairs. Gene flow between colonies is likely to be primarily mediated by both female and male dispersal during the mating period rather than more permanent movements.

The Role of Animal Psychology in Evolutionary Biology

Evolutionary biology of behavior and animal psychology are often regarded as separate disciplines. However, both fields depend strongly on each other. Examples of field studies of an ant navigation system and the fighting behavior of a spider are used to illustrate the interrelatedness of animal psychology and behavioral ecology. Both studies are based on research in the natural habitat. Yet, even one who knows this habitat well cannot analyze the evolution of observed behavior patterns without making basic assumptions about the animal's psychology. These assumptions relate to the animal's capability of information processing and the structural organization of this processing. The concept of strategic analysis in evolutionary game theory makes it an obligatory task to state such assumptions. Strategic analysis at the phenotypic level is well founded in population genetics theory despite its apparent lack of taking genetics into account. It helps to bridge the gap between psychology and evolutionary biology.

Modelling food web complexity: The consequences of individual-based, spatially explicit behavioural ecology on trophic interactions

We present a prototype simulator that enables one to explore the influence of individual behaviour on the dynamics and structural complexity of food webs. In the simulations, individuals act according to simple, biologically plausible rules in a spatially explicit setting. We present the results of a series of simulation experiments on artificial, tri-trophic level food chains used to calibrate the simulator against real-world systems and to demonstrate the simulator's promise for ecological modelling. Our primary objective was to discover the biological features leading to stability of artificial food chains over ecological time and under different conditions of trophic efficiency. This involved a qualitative analysis of food chains comprised of a plant, a herbivore and a carnivore species. We explored the consequences of allowing individual heterotrophs to make active choices about resource selection (perception and intentional behaviour) under high and low degrees of trophic efficiency. We found that individuals had to adopt realistic behavioural ecological strategies, such as active resource selection, for systems to persist, especially under conditions in which trophic efficiencies were of the magnitude observed in real systems (e.g. 10%). Our results reaffirm previous convictions that a better understanding of food web interactions in real-world systems will require approaches that blend animal behavioural ecology with population and community ecology. However, the evidence comes from a new mathematical perspective.

Animals in science: some areas revisited

Science is a human activity, and as such, it is not value-free. Not only do subjective views permeate all types of science, they also prevail in many moral debates concerning how animals are used for primarily anthropocentric ends, even when formal philosophical argument is put forth. Four issues are addressed that demand closer attention by those who are seriously engaged in the collection, interpretation, and explanation of behavioural data. (1) It is important to recognize that an animal's point of view is actually an animal's point of view from a human's point of view. (2) Attempts to quantify pain and suffering in animals are fraught with difficulties, and despite the best intentions, do not eliminate human responsibilities. (3) Appeals to science to resolve difficult questions concerning animal suffering must be combined with other factors including common sense and moral and ethical commitments. (4) When in doubt, err on the side of the animals. Those who study animal behaviour and behavioural ecology need to be particularly aware of problems of animal welfare for these types of research involve field observations, studies of captive animals, and experiments. In addition, findings from cognitive ethological investigations are used to inform and motivate discussion of human moral and ethical obligations to animals.

Sexual ornaments as animal signals

Workers in both animal communication and behavioral ecology have long been interested in animal signals. Animal-communication researchers often have a background in ethology or comparative psychology, and place priority on signal analysis, whereas modern behavioral ecologists are concerned with the effects of natural selection on the exaggeration or development of a trait. Although the two fields examine the same problems, this division has hindered the solution of the problems themselves. Recent theoretical and empirical work has started to bridge the gap, but several important questions, particularly regarding sexual selection, have remained unanswered. Here I examine the differences in these two approaches to the study of animal signals, and suggest additional areas that would benefit by combining the two viewpoints.