Limited Attention: The Constraint Underlying Search Image

Recent models of predator search behavior integrate proximate neurobiological constraints with ultimate economic considerations. These models are based on two assumptions, which we have critically examined in experiments with blue jays searching for artificial prey images presented on a computer monitor. We found, first, that when jays had to switch between searching for two distinct prey types, they showed no reduction in detection rates compared to no-switching to no-switching conditions, and second, that when jays divided attention between searching for two prey types at the same time, they had lower detection rates than when they focused attention on one prey type at a time. Our results suggest that limited attention strongly affects predator search patterns and diet choice, including the ubiquitous tendency to form search images

Evolutionary biology of social expertise

Funding: Natural Sciences and Engineering Council of Canada. Grant Number: 05420There is increasing evidence that competent handling of social interactions among conspecifics has positive effects on individual fitness. While individual variation in social competence has been appreciated, the role of long-term experience in the acquisition of superior social skills has received less attention. With the goal of promoting further research, we integrate knowledge across disciplines to assess social expertise, defined as the characteristics, skills and knowledge allowing individuals with extensive social experience to perform significantly better than novices on a given social task. We focus on three categories of social behaviour. First, animals can gain from adjusting social behaviour towards individually recognised conspecifics that they interact with on a regular basis. For example, there is evidence that some territorial animals individually recognise their neighbours and modify their social interactions based on experience with each neighbour. Similarly, individuals in group-living species learn to associate with specific group members based on their expected benefits from such social connections. Individuals have also been found to devote considerable time and effort to learning about the spatial location and timing of sexual receptivity of opposite-sex neighbours to optimise reproduction. Second, signallers can enhance their signals, and receivers can refine their response to signals with experience. In many birds and insects, individuals can produce more consistent signals with experience, and females across a wide taxonomic range can adaptively adjust mating preferences after perceiving distinct male signals. Third, in many species, individuals that succeed in reproducing encounter the novel, complex task of caring for vulnerable offspring. Evidence from a few species of mammals indicates that mothers improve in providing for and protecting their young over successive broods. Finally, for social expertise to evolve, heritable variation in social expertise has to be positively associated with fitness. Heritable variation has been shown in traits contributing to social expertise including social attention, empathy, individual recognition and maternal care. There are currently limited data associating social expertise with fitness, most likely owing to sparse research effort. Exceptions include maternal care, signal refinement, and familiarity with neighbours and group members. Overall, there is evidence that individuals in many species keep refining their social skills with experience throughout life. Hence we propose promising lines of research that can quantify more thoroughly the development of social expertise and its effects on fitness. [Abstract copyright: © 2024 The Author(s). Biological Reviews published by John Wiley & Sons Ltd on behalf of Cambridge Philosophical Society.]Peer reviewe

Aggression, mate guarding and fitness in male fruit flies

Aggression is a central trait affecting fitness, which has been well studied in many animals. As a part of a research programme integrating mechanisms and fitness consequences of aggression, we examined the adaptive functions of antagonistic interactions in fruit flies, Drosophila melanogaster, a species in which aggression has been studied primarily in the context of territorial behaviour. In our experiments, males at an attractive food patch were more aggressive towards other males when they were in the presence of their recent mates than when they were in the presence of females mated with other males. Furthermore, while recently mated males accompanied by their mates were more aggressive than virgin males, recently mated males and virgin males showed similar levels of aggression in the presence of females mated with other males. When we allowed focal males to mate inside experimental arenas and then added intruder males, the intruder males spent less time on the food patch, remated with the resident females at lower frequencies and fathered a smaller proportion of offspring when the focals males remained in the arenas than when we removed the focal males. Our results reveal a novel adaptive function of aggression in fruit flies: in addition to fighting to defend attractive food sources that attract prospective mates, males rely on aggression to guard their mates, and such mate guarding enhances their fitness

Abnormal social interactions in a Drosophila mutant of an autism candidate gene: Neuroligin 3

Social interactions are typically impaired in neuropsychiatric disorders such as autism, for which the genetic underpinnings are very complex. Social interactions can be modeled by analysis of behaviors, including social spacing, sociability, and aggression, in simpler organisms such as Drosophila melanogaster. Here, we examined the effects of mutants of the autism-related gene neuroligin 3 (nlg3) on fly social and non-social behaviors. Startled-induced negative geotaxis is affected by a loss of function nlg3 mutation. Social space and aggression are also altered in a sex-and social-experience-specific manner in nlg3 mutant flies. In light of the conserved roles that neuroligins play in social behavior, our results offer insight into the regulation of social behavior in other organisms, including humans

The cost of limited attention in blue jays

Experiments with fish and birds suggest that animals are unable to simultaneously allocate sufficient attention to tasks such as the detection of an approaching predator while searching for cryptic prey. We quantified the effects of limited attention on performance in controlled laboratory settings and report here the first direct evidence that attending to a difficult central task simulating foraging deters a bird’s ability to detect a peripheral target, which could be a predator. Our results fill a gap between ecological and neurobiological studies by illustrating that, although attention is an efficient filtering mechanism, limited attention may be a major cause of mortality in natur

Dryad_Experiment_2

Covers Experiments 2A-2C. Collected in the lab. Created in Microsoft Excel

Dryad_Experiment_3

Covers Experiments 3A and 3B. Collected in the lab. Created in Microsoft excel

Dryad_Experiment_4

Data for Experiments 4A-4C

Dryad_Experiment_1

Data for Experiment 1A-1E. Collected in the lab. Created in microsoft excel

Learning affects mate choice in female fruit flies

Learning in the context of mate choice can influence sexual selection and speciation. Relatively little work, however, has been conducted on the role of learning in the context of mate choice, and this topic has been mostly ignored in insects even though insects have served as a prime model system in research on sexual selection and incipient speciation. Extending recent work indicating apparently adaptive learning in the context of sexual behavior by male fruit flies (Drosophila melanogaster), I tested for the effect of learning on mate choice by female fruit flies. Compared to young virgin females that experienced courtship by large males, young virgin females that experienced courtship by small males were more likely to mate with small and large males in a test conducted a day after the experience phase. These results, which are the first clear empirical demonstration of learning in the context of mate choice by female insects, lay the foundation for research on the role of learning in insect sexual selection and speciation. Copyright 2005.courtship; Drosophila; fruit flies; learning; mate choice; speciation