45 research outputs found
Natural selection and avian personality in a fluctuating environment
Individual animals differ in the way they cope with challenges in their environment, comparable with variation in human personalities. The proximate basis of variation in personality traits has received considerable attention, and one general finding is that personality traits have a substantial genetic basis. This poses the question how variation in personality is maintained in natural populations. The aim of this thesis was to study study the fitness consequences of animal personality in a natural population. This thesis addresses the consequences of individual personality at different stages of the life-history of the model species, the great tit Parus major, studying the relation between personality and dominance, dispersal, survival, reproduction, and offspring recruitment in the wild.
A first step in studying how natural selection acts on personalities is the measurement of individual behaviour of wild individuals. Chapter 2 describes the method that we used to measure individual personality exploratory behaviour in a novel laboratory environment of great tits that were temporarily removed from the wild. We show that individual great tits differ consistently in their exploratory behaviour, and that the behaviour has a heritable component in the wild. In chapter 3 we study whether position in the dominance hierarchy measured on feeding tables in winter correlates with individual personality in the wild. We show that fast-exploring great tits have highest dominance ranks in territorial birds but lowest dominance ranks among non-territorial birds. In chapter 4 we assessed whether natal dispersal the movement between the place of birth and first reproduction is related to avian personality by measuring both the relation between natal dispersal distance and parental personality as well as differences in behaviour between immigrants and locally born juveniles. We show that fast-exploring parents have offspring that disperse furthest and that immigrants are faster explorers than locally born birds. The finding that fast-exploring birds have lowest dominance ranks in non-territorial birds suggests that they disperse further because they are outcompeted by others. In chapter 5 we describe how breeding performance (i.e. timing of breeding, clutch size, offspring condition, number of fledglings) correlates with male and female personality of the breeding pair. We show that reproductive success depends on the personality of both parents: pairs of fast-exploring birds (fast-fast) and pairs of slow-exploring birds (slow-slow) produce offspring of highest body mass at fledging. In chapter 6 we measure annual adult survival and number of recruiting offspring, to study how they relate to individual personality of male and female great tits. We show that selection fluctuates across years. Annual adult survival was related to exploratory behaviour but the effects were always opposite for males and females, and reversed between years. The number of offspring surviving to breeding also related to their parents personality, and again selection changed between years. The observed annual variation in selection pressures coincided with changes in environmental conditions (masting of beeches) that affects competitive regimes of the birds. We expect that the fluctuations in selection pressures play an important role in maintaining genetic variation in personalities
Nonâconsumptive effects of predation: does perceived risk strengthen the genetic integration of behaviour and morphology in stickleback?
Predators can shape genetic correlations in prey by altering prey perception of risk. We manipulated perceived risk to test whether such nonâconsumptive effects tightened behavioural trait correlations in wildâcaught stickleback from highâ compared to lowârisk environments due to genetic variation in plasticity. We expected tighter genetic correlations within perceived risk treatments than across them, and tighter genetic correlations in highârisk than in lowârisk treatments. We identified genetic variation in plasticity, with genetic correlations between boldness, sociality, and antipredator morphology, as expected, being tighter within treatments than across them, for both of two populations. By contrast, genetic correlations did not tighten with exposure to risk. Tighter phenotypic correlations in wild stickleback may thus arise because predators induce correlational selection on environmental components of these traits, or because predators tighten residual correlations by causing environmental heterogeneity that is controlled in the laboratory. Our study places phenotypic integration firmly into an ecological context
Universal principles in the repair of communication problems
There would be little adaptive value in a complex communication system like human language if there were no ways to detect and correct problems. A systematic comparison of
conversation in a broad sample of the worldâs languages reveals a universal system for the
real-time resolution of frequent breakdowns in communication. In a sample of 12 languages
of 8 language families of varied typological profiles we find a system of âother-initiated
repairâ, where the recipient of an unclear message can signal trouble and the sender can
repair the original message. We find that this system is frequently used (on average about
once per 1.4 minutes in any language), and that it has detailed common properties, contrary
to assumptions of radical cultural variation. Unrelated languages share the same three functionally
distinct types of repair initiator for signalling problems and use them in the same
kinds of contexts. People prefer to choose the type that is the most specific possible, a principle
that minimizes cost both for the sender being asked to fix the problem and for the dyad
as a social unit. Disruption to the conversation is kept to a minimum, with the two-utterance
repair sequence being on average no longer that the single utterance which is being fixed.
The findings, controlled for historical relationships, situation types and other dependencies,
reveal the fundamentally cooperative nature of human communication and offer support for
the pragmatic universals hypothesis: while languages may vary in the organization of grammar
and meaning, key systems of language use may be largely similar across cultural groups. They also provide a fresh perspective on controversies about the core properties of
language, by revealing a common infrastructure for social interaction which may be the universal bedrock upon which linguistic diversity rests
Connecting the data landscape of long-term ecological studies: The SPI-Birds data hub
The integration and synthesis of the data in different areas of science is drastically slowed and hindered by a lack of standards and networking programmes. Long-term studies of individually marked animals are not an exception. These studies are especially important as instrumental for understanding evolutionary and ecological processes in the wild. Furthermore, their number and global distribution provides a unique opportunity to assess the generality of patterns and to address broad-scale global issues (e.g. climate change). To solve data integration issues and enable a new scale of ecological and evolutionary research based on long-term studies of birds, we have created the SPI-Birds Network and Database (www.spibirds.org)\u2014a large-scale initiative that connects data from, and researchers working on, studies of wild populations of individually recognizable (usually ringed) birds. Within year and a half since the establishment, SPI-Birds has recruited over 120 members, and currently hosts data on almost 1.5 million individual birds collected in 80 populations over 2,000 cumulative years, and counting. SPI-Birds acts as a data hub and a catalogue of studied populations. It prevents data loss, secures easy data finding, use and integration and thus facilitates collaboration and synthesis. We provide community-derived data and meta-data standards and improve data integrity guided by the principles of Findable, Accessible, Interoperable and Reusable (FAIR), and aligned with the existing metadata languages (e.g. ecological meta-data language). The encouraging community involvement stems from SPI-Bird's decentralized approach: research groups retain full control over data use and their way of data management, while SPI-Birds creates tailored pipelines to convert each unique data format into a standard format. We outline the lessons learned, so that other communities (e.g. those working on other taxa) can adapt our successful model. Creating community-specific hubs (such as ours, COMADRE for animal demography, etc.) will aid much-needed large-scale ecological data integration
Is âHuh?â a universal word? Conversational infrastructure and the convergent evolution of linguistic items
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