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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The secret in their MHC : variation and selection in a free living population of great tits

Sepil, Irem January 2012 (has links)
Understanding the genetic basis of fitness differences has been a major goal for evolutionary biologists over the last two decades. Although there are many studies investigating how natural selection can promote local adaptation, few have succeeded to find the link between genotype and fitness of the phenotype. Polymorphic genes of the major histocompatibility complex (Mhc) are excellent candidates for such associations as they are a central component of the vertebrate immune system, playing an important role in parasite resistance, and hence can have direct effects on survival of their bearers. Although associations between Mhc and disease resistance are frequently documented, the epidemiological basis of the host-parasite interaction is often lacking and few studies have investigated the role that Mhc genes play in individual variation in fitness; thus comparatively little is known about the fitness consequences of Mhc in wild populations. Furthermore, the majority of work to date has involved testing associations between Mhc genotypes and disease. However, the mechanism by which any direct selection on the Mhc acts, depends on how genotypes map to the functional properties of Mhc molecules. The aim of this thesis was to characterize Mhc alleles in terms of their predicted functional properties and to investigate whether and how selection operates on Mhc class I functional variation using the great tit (Parus major) population at Wytham Woods as a model host species. Through a comprehensive characterization effort and the use of 454 pyrosequencing platform, I performed a detailed analysis of genetic variation at Mhc class I exon 3 and grouped alleles with similar antigen-binding affinities into supertypes to classify functionally distinct Mhc types. There was extreme complexity at the Mhc class I of the great tit both in terms of allelic diversity and gene number. A total of 862 alleles were detected from 857 individuals; the highest number yet characterized in a wild bird species. The functional alleles were clustered into 17 supertypes; there was clear evidence that functional alleles were under strong balancing selection. To understand the role of Mhc in disease resistance, I examined the linkage between Mhc supertypes, Plasmodium infection and great tit survival, and showed that certain functional variants of Mhc confer resistance to two divergent Plasmodium parasite species that are common in the environment. I further investigated the fitness consequences of functional variation at Mhc, using mark-recapture methods and long-term breeding data; and tested the hypotheses that selection: (i) maximizes Mhc diversity; (ii) optimizes Mhc diversity, or (iii) favours specific functional variants. I found that the presence of three different supertypes was associated with three different components of individual fitness: adult survival, annual recruitment probabilities and lifetime reproductive success. In contrast, there was no evidence for a selective advantage of Mhc functional diversity, either in terms of maximal or optimal supertype diversity. Finally, I explored the role that Mhc plays in female mate choice decisions and examined the reproductive fitness consequences of Mhc-dependent mating patterns. There was little evidence to suggest that functional dissimilarity at Mhc has any influence on female mate choice decisions or that dissimilarity at Mhc affects the reproductive output of the social pair. Overall, this thesis provides strong support for the suggestion that selection favours specific functional variants of Mhc, possibly as a result of supertype-specific resistance or susceptibility to parasites that exert strong selective pressures on their hosts; whereas there is no support for selection favouring maximal or optimal Mhc diversity. More importantly it demonstrates that functional variants of Mhc class I loci are an important determinant of individual fitness in natural populations.
2

Reakce ptáků na invazní blánatku lipovou (Oxycarenus lavaterae) / Bird responses to the invasive lime seed bug (\kur{Oxycarenus lavaterae})

MEJDA, Tomáš January 2019 (has links)
Oxycarenus lavaterae is species of Heteroptera and possessing pink blots on corium and distinctive, gleaming membranaceous wings. This appearance could correspond to the definition of a warning color. The design is similar to other coreoid Heteroptera, which live in the Czech Republic; though Oxycarenus lavaterae is a species originating from Mediterranean and quickly spreading north. In Czech Republic it is a new species and predators thus have only short experience with it.The information about chemical protection of Oxycarenus lavaterae is weak and the effect on predators has never been tested. The characteristic behaviour for this species is creating large aggregations, primarily at the time of hibernation. At that time, several thousands of individuals are gathered in apertures or at the surface of tree bark. The aggregation may enhance the warning appearance of this species. The aim of this study was to test the response of bird predators to the adult individuals of Oxycarenus lavaterae. Three species of insectivorous birds differing in the level of foraging and diet specialization was chosen as predator (namely - Great tit (Parus major), Blue tit (Cyanistes caeruleus), Eurasian blackcap (Sylvia atricapilla)). Unmodified individuals of Oxycarenus lavaterae were served to these predators. In the case of the Parus major, the aggregation of Oxycarenus lavaterae (about 100 pieces) was also presented to test the effect of gregarious behavior on the warning signal. This study showed that the Parus major and the Sylvia atricapilla attacked the individual Oxycarenus more often than the Cyanistes caeruleus showing high level of restraint. In experiments with aggregatedOxycarenus lavaterae Parus major attacked them less often than when presented solitarily. However, after eating some Oxycarenus lavaterae, the Parus major showed symptoms of disgust and loss of appetite.
3

Variabilita ve zbarvení vaječné skořápky ve snůškách sýkory koňadry / Variabilityin egg shell pigmentation of great tit clutches

Kratochvílová, Anna January 2017 (has links)
Eggshell coloration in bird clutches shows a striking variability within species which has not yet been fully explained. Its character is determined by the deposition of two main pigments: blue-green biliverdin is responsible for the background colour while brown-red protoporphyrin is associated with the dark spot pattern. Considering the role and matabolism of these two pigments in the avian organism it was suggested that they might have an important impact on the oxidative stress levels and their deposition into the eggshell is therefore suggested to possibly reflect the body condition of laying females during the laying periods. This is also the basic assumption for the signalling hypothesis of eggshell coloration which predicts the eggshell appearance to reflect the female body condition and individual health status or directly indicate aenemia in birds (aenemic hypothesis). Here it was tested whether there is a relationship between parameters representing the body condition of female great tits (Parus major) and the characteristics of protoporphyrin maculation of their eggs. Female body condition was expressed by standardized body weight and the selected haematological parameters (heterophil to lymphocyte ratio and relative immature erythrocyte counts). Eggshell coloration was characterized by spot colour (hue, saturation and brightness), spot counts and the reflectance of the background colour. It was found that females with higher heterophil to lymphocyte ratio laid eggs with more spots and higher reflectance of the background colour in some nesting seasons. Eggs with more spots on its surface were also laid by females with higher immature erythrocyte counts. These results suggest that more intensive deposition of protoporfyring into the eggsell can indicate worse body condition of the laying females. On the other hand, it was also found that heavier females laid eggs with lower reflectance of the background colour. Despite this discrepancy, these results are not inconsistent with the pressumptions of the signalling hypothesis and they partially support the aenemia hypothesis. However, the above mentioned dependencies were inconsistent among the nesting seasons, indicating that further important determinants must be considered in the avian eggshell coloration.
4

Vliv predátora na ostražitost sýkor navštěvujících krmítko / The effect of a predator occurrence on vigilance of tits visiting the winter feeder

Tichá, Irena January 2011 (has links)
This thesis evaluates the vigilance parameters of two species of tits affected by the presence of a predator in wintertime. During preferential experiments, tits have had a choice of two feeders in the vicinity of the installed dummy predator. For that purpose was used a dummy sparrowhawk, incomplete or occluded sparrowhawk torsos, and harmless pigeon. It is known that the tits are able to recognize dangerousness presented by the dummy, and according to expected risk dare to visit one of the feeders. It leads to a question whether the tits are somehow influenced by the presence of the dummies, and if so, how specifically are they influenced. It turned out, that the tits in presence of a dangerous dummy significantly increased their vigilance. Both observed species at the feeders behave oppositely. Behaviour of all the birds at the feeder is also affected by their total count at the precise moment and by the presence of a dummy at the other feeder.
5

Intra- and interspecific social information use in nest site selection of a cavity-nesting bird community

Jaakkonen, T. (Tuomo) 20 May 2014 (has links)
Abstract Animals need information about local conditions to make optimal fitness-enhancing decisions such as where to breed. Information can be acquired by personal sampling of the environment, but it can also be acquired from other individuals. The latter is termed social information use. Social information use has gained a lot of attention in modern ecology because it affects principal ecological phenomena such as animal distribution and resource use. Social information use is not restricted to obviously cognitive mammals and birds but is also found in e.g. reptiles, fish and insects. Social information use studies have thus far been concentrated on situations with one social information user and one (often the same) source species. The community-wide consequences of social information use have almost exclusively been considered in theoretical studies. In this thesis, I studied empirically social information use in the nest site selection within and between species in a cavity-nesting bird community consisting of the collared flycatcher (Ficedula albicollis), the great tit (Parus major) and the blue tit (P. caeruleus). I studied social information use on two time scales: social information gathered just before a breeding attempt, and social information gathered already during the previous breeding season for the following year’s breeding attempt. I used experiments in which different white geometric symbols represented nest site choices of earlier settled tutors and empty nest boxes, and I observed the symbol choices of later-breeding individuals. The symbol approach eradicates bias from innate and learned preferences enabling strong inference. My results demonstrate that collared flycatchers use social information from both con- and heterospecific tutors in different situations in a flexible manner. Hence, social information use seems to be context-dependent. Furthermore, I show that great tits avoid choosing nest site characteristics which were associated with either con- or heterospecifics nests the previous year and prefer symbols which depicted an empty nest box the previous year, probably to avoid nest ectoparasites. I also show that in great tits the male has greater influence on nest site selection than previously assumed even though the female builds the nest. My thesis deepens our understanding about the complexity of social information use and highlights its significance in future ecological research. / Tiivistelmä Eläimet tarvitsevat informaatiota paikallisista olosuhteista tehdäkseen edullisia päätöksiä esimerkiksi siitä, missä lisääntyä. Informaatiota voidaan hankkia tutkimalla ympäristöä itse, mutta sitä voidaan hankkia myös muilta yksilöiltä. Jälkimmäistä kutsutaan sosiaaliseksi informaatioksi. Eläinten sosiaalisen informaation käyttö on saavuttanut viime aikoina paljon huomiota ekologisessa tutkimuksessa, koska se vaikuttaa tärkeisiin ekologisiin ilmiöihin, kuten eläinten levinneisyyteen ja resurssien käyttöön. Sosiaalinen informaation käyttö ei rajoitu vain nisäkkäisiin ja lintuihin, vaan sitä on havaittu myös esimerkiksi matelijoilla, kaloilla ja hyönteisillä. Sosiaalisen informaation käyttöä on tutkittu lähes yksinomaan lajien sisällä tai käyttäen ainoastaan yhtä sosiaalisen informaation lähdelajia. Yhteisötason vaikutuksia on pohdittu miltei pelkästään teoreettisissa tutkimuksissa. Tässä väitöskirjatyössä tutkin kokeellisesti sosiaalisen informaation käyttöä pesäpaikan valinnassa lajin sisällä ja lajien välillä kolopesivien lintujen yhteisössä sepelsiepolla (Ficedula albicollis), talitiaisella (Parus major) ja sinitiaisella (P. caeruleus). Otin tutkimuksissani huomioon kaksi aikatasoa: tutkin juuri ennen pesimisyritystä kerätyn sekä jo edellisen lisääntymiskauden aikana seuraavan vuoden pesintää varten hankitun sosiaalisen informaation käyttöä. Kokeissani käytin linnunpönttöihin kiinnitettyjä erilaisia valkoisia geometrisia symboleita, jotka edustivat aiemmin pesinnän aloittaneiden lintujen eli tuutoreiden pesäpaikanvalintoja. Seurasin tämän jälkeen myöhemmin pesimään saapuvien parien symbolivalintoja. Tulosteni perusteella sepelsiepot hankkivat sosiaalista informaatiota sekä lajitovereiltaan että tiaisilta joustavasti eri tilanteissa. Lisäksi osoitan, että talitiaiset välttävät valitsemasta pesäpaikkoja, jotka olivat asuttuina edellisenä vuonna, ja suosivat sellaisia pesäpaikkoja, joissa ei pesitty edellisenä vuonna - todennäköisesti välttääkseen kirppuja ja muita pesäloisia. Osoitan myös, että talitiaiskoirailla on suurempi vaikutus pesäpaikan valintaan kuin aikaisemmin on oletettu, vaikka naaraat rakentavat pesän. Väitöskirjatyöni syventää käsitystämme sosiaalisen informaation käytön monitahoisuudesta eläinkunnassa ja korostaa sen merkitystä ekologisessa tutkimuksessa.
6

Evolutionay consequences of the population structure of an ectoparasite at different spatial scales : an empirical approach of the hen flea-passerines system / Conséquences évolutives de la structuration des populations d’un ectoparasite à différentes échelles spatiales : approches empiriques sur le système puce des oiseaux-passereaux

Appelgren, Anais 14 December 2015 (has links)
L’évolution divergente est un processus clef générant de la biodiversité. Elle peut avoir lieu entre localités, via la réduction des flux de gènes, et au sein des localités via la spécialisation écologique. Dans le cas des systèmes parasitaires multi-hôtes, l’adaptation dépend des taux relatifs de flux de gènes des hôtes et des parasites entre différentes localités, ainsi que des échanges locaux de parasites entre différents types d’hôtes. En combinant génétique des populations et expérimentations sur le système composé de la puce Ceratophyllus gallinae et deux de ses hôtes, la mésange charbonnière Parus major et le gobe-mouche à collier Ficedula albicollis dans un habitat fragmenté, nous avons examiné comment l’adaptation et l’isolation génétique façonnent l’évolution des parasites. Nous avons aussi testé comment les choix d’habitat des hôtes pouvaient influencer la rencontre avec des populations de parasites spécialisées. Les analyses de microsatellites révèlent que les populations de puce sont différenciées à une échelle spatiale fine, et fréquemment entre espèces hôtes. De plus, des populations de parasites semblent adaptées à chaque type d’hôte. Cependant, aucune variation dans les choix d’habitats par rapport aux parasites n’a été observée chez les hôtes. Enfin, la réponse des hôtes aux parasites variait entre nos deux zones réplica ; l’histoire des populations d’hôtes pourrait donc influer sur la coevolution avec leurs parasites. Ce système semble donc localement façonné à la fois par une isolation génétique et une sélection par différents hôtes. L’étude de nouveaux sites permettraient d’évaluer si cette évolution divergente peut être génératrice de biodiversité / Divergent evolution is a key process generating biodiversity. This can occur between localities, through reduced gene flow followed by local adaptation or genetic drift, and within localities through ecological specialization. In the case of multi-host parasite systems, adaptation can be driven by the relative rate of host-parasite gene flow among spatially isolated populations, and the amount of parasite exchange among local host types. Combining population genetics and field experiments, we examined how adaptation and genetic isolation shape parasite evolution. Focusing on the hen flea Ceratophyllus gallinae, a presumed host generalist, and two of its hosts, the great tit Parus major and the collared flycatcher Ficedula albicollis, we investigated parasite population structure and adaptation within a fragmented landscape. Additionally, we tested how hosts can influence encounter rates with specialized flea populations through their habitat choice. Neutral markers analyses show that flea populations are genetically differentiated at fine spatial scales, and frequently between the two host species. Evidence for parasite adaptation to each host type were also observed. Host specialization may therefore be ongoing in hen fleas. However, birds did not show specific habitat choice strategies regarding flea-infested nests. Host responses differed between two replicate sites, indicating that local population history may impact parasite evolution. Both isolation and host-based selection are therefore acting on hen flea populations at a local scale. Investigations in new localities will help to assess to what extend this divergent evolution may generate biodiversity
7

Impact of floral origin, floral composition and structural fragmentation on breeding success in Blue Tits (Cyanistes caeruleus) and Great Tits (Parus major)

MacKenzie, Julia January 2010 (has links)
Existing research on the foraging ecology and breeding biology of blue tits (Cyanistes caeruleus) and great tits(Parus major) has mainly concentrated on populations in woodland. However increasing urbanisation means much of the suitable tit habitat is represented by fragmented areas, not large woodlands, and little is known about factors that may affect reproductive success in urban environments. Using General and Generalised Linear Models this study compared reproductive performance in four habitat types with differing levels of habitat modification: the Cambridge University Botanic Garden (CUBG) with an abundance of non-native vegetation and structural fragmentation, two marginal sites with native scrubby vegetation and structural fragmentation and small fragments and large fragments of native woodland. Compositional analysis was used in a study focused on how foraging blue tits used the heterogeneous habitat of the CUBG. Additionally frequency tests were used to compare foraging preferences and foraging behaviours of both species in the CUBG. Productivity was poor in the CUBG compared to all of the other habitats, with great tits appearing to do worse than blue tits, rearing lower quality chicks (significantly lower mean mass than in other habitats). Within the CUBG, positive relationships were found between the abundance of native trees and shrubs and breeding success for both blue tits and great tits. A positive relationship was found between breeding success in blue tits and the abundance of Quercus and Betula. However, habitat and year interactions showed that habitat and reproductive relationships were complicated by annual variation. The two species differed in their foraging preferences in the CUBG; blue tits were observed feeding in native deciduous trees significantly more than in non-native species and had a preference for birch trees over other taxa. Great tits however showed no strong preferences for any of the habitat types. With regards to foraging behaviours, great tits used a wider range of foraging heights and different foraging locations and capture techniques than blue tits. Blue tits were observed‘hanging’ from twigs more frequently, and appeared to be more effective at foraging in the wider variety of plants available in the heterogeneous vegetation of the garden. The data presented in this thesis suggest that blue tits have adopted a better foraging strategy by preferentially choosing native deciduous trees over the abundance of non-natives available in the CUBG. However, despite the apparent better foraging strategy of blue tits, reproductive performance of both species is poor in this urban garden compared to marginal sites and woodland. Urbanisation and the associated loss of optimal tit habitat are likely to continue. It is therefore important to offset urbanisation by the addition of appropriate foraging habitats that are likely to improve reproductive success, such as native trees and shrubs.
8

Role sociálního učení při vytváření averze vůči aposematické kořisti u ptačích predátorů / Effect of social learning on avoidance of aposematic prey in avian predators

Bělová, Magdalena January 2018 (has links)
Social learning is a topic of many studies. We tested the effect of social learning on the acquisition of avoidance against aposematic prey. We have chosen wild-caught adult and naive hand-reared juvenile great tits (Parus major) as a model predator species, because their individual avoidance learnig of aposematic prey is well-studied. We used red and green paper dummies of bugs with a mealworm (Tenebrio molitor) stuck underneath as an artificial prey. Mealworms were soaked in water or in bitter-tasting solution of quinine. We used two types of conspecific demonstrators - naive birds that showed aversive reactions while tasting an unpalatable prey and experienced birds that were trained not to handle the unpalatable pray at all. We compared effects of both demonstrators on discrimination learning and we tested whether these effects differ in adult and juvenile birds. Observing an experienced demonstrator had an effect on the performance of observers at the beginning of learning process. The observers did not reject the unpalatable prey completely, but the number of trials in which they correctly chose the palatable prey was higher in comparison with birds that observed naive demonstrators and birds from the control group with no demonstrator. Latencies to handle the unpalatable prey in the first...
9

Demography and dynamics of a partial migrant close to the northern range margin

Karvonen, J. (Juhani) 04 December 2019 (has links)
Abstract Climate change causes range expansions, but neither the population parameters nor the ecological mechanisms behind range expansions are well known. I studied population dynamics and demography of the great tit (Parus major) in northern Finland, close to the northern range margin of the species’ distribution. I further examined winter conditions, such as temperature, as limiting factors on winter site fidelity and survival of human-fed great tits. Temporal variation in the population growth rate was large, but indicated an overall increasing population size, which fits the current large scale increase in the north. Importantly, the study population was a sink (or pseudo-sink) in almost all years because of low adult survival and low local recruitment. Immigration formed 39–43% of the annual population growth rate indicating that the population is demographically dependent on immigration. The demography differs most from other great tit populations in terms of adult survival which is lower than estimates from more southern Europe. This difference may reflect the impact of more difficult winters. Results from the wintering population support this line of reasoning. Within-winter movement was lower during mid-winter (January to February) and decreased during cold periods. This pattern is probably linked to energy saving and predator escaping strategies during these demanding periods when energy expenditure is high and birds have limited daylight hours to forage. Site fidelity was lower for juveniles than adults within a winter, but not between winters. In addition, survival showed strong links to winter weather. There was temporal variation within winters, particularly when the winter was colder than usual. Survival of juveniles showed a stronger response to cold temperatures. When mean daily minimum temperatures declined below –15 C° degrees, survival started to decline. Low winter temperatures thus provide one explanation for the lower annual adult survival and the sink nature of the population. The results suggest that great tits suffer from the cold conditions of the north: higher mortality increases turnover allowing for strong immigration. Great tits should benefit from warming winters caused by climate change. / Tiivistelmä Väitöskirjassani tutkin talitiaisen (Parus major) populaatiodynamiikkaa, talviaikaista paikkauskollisuutta ja säilyvyyttä levinneisyysalueen pohjoisreunan läheisessä populaatiossa Oulussa. Aikuissäilyvyys oli vuosittain hieman alhaisempi kuin lajin ydinalueella Länsi-Euroopassa. Tutkimusalueella syntyneistä poikasista vain pieni osa jäi pesimään tutkimusalueelle, mikä heijastaa voimistunutta lähtömuuttoa huonolaatuiselta alueelta. Ajallinen vaihtelu populaation kasvukertoimessa oli suurta, mutta keskiarvo osoittaa nykyisen populaation kasvavan. Havaitsemani populaation kasvu ei selity kasvulla aikuissäilyvyydessä tai paikallisessa rekrytoinnissa. Oletan, että populaatio on ollut tulomuuton ylläpitämä nielu (tai valenielu) lähes kaikkina tutkimusvuosina. Niinpä populaatio on demografisesti ja geneettisesti riippuvainen ydinalueesta, josta tuleva geenivirta aiheuttaa ongelmia paikallisiin olosuhteisiin sopeutumisessa. Tutkin sekä talvensisäistä että talvien välistä paikkauskollisuutta suhteessa ikään, sukupuoleen, vuodenaikaan, lämpötilaan ja päivän pituuteen. Talvensisäinen liikkuvuus oli vähäisintä keskitalvella erityisesti kylmien jaksojen aikana. Tämä ilmiö on luultavasti yhteydessä energiansäästöön ja saalistajien välttelyyn näiden vaativien jaksojen aikana, jolloin energiankulutus on suurta ja valoisa ruokailuaika on lyhyt. Nuorten talvensisäinen paikkauskollisuus oli huonompi kuin aikuisten, mutta sukupuolten välillä tässä ei ollut eroa. Sen sijaan talvien välisessä paikkauskollisuudessa ei ollut ryhmien välisiä eroja, mikä viittaa paikkauskollisuudesta olevan yhtäläiset hyödyt kaikille. Nuoret luultavasti keräävät tietoa resursseista ensimmäisenä talvenaan ja täten hankkivat samat edut kuin aikuiset palatessaan alueelle seuraavana talvena. Tutkin, onko talvella lintujen ruokintapaikkoja hyödyntävien talitiaisten säilyvyydessä ympäristötekijöistä, kuten lämpötilasta, johtuvaa vaihtelua. Talvisäilyvyys vaihteli paljon etenkin tavallista kylmempänä talvena. Nuoret kärsivät eniten kylmistä lämpötiloista. Kun keskilämpötila laski –15 C°:seen tai sen alapuolelle, säilyvyys alkoi heikentyä. Verrattuna kylmään talveen säilyvyys oli 1,5 kertaa todennäköisempää lauhan talven aikana. Talitiaiset näyttävät kärsivän pohjoisen kylmistä olosuhteista: korkea kuolleisuus lisää vaihtuvuutta ja geenivirtaa, kun alueelle kohdistuu voimakasta tulomuuttoa.
10

Personality and cognitive variation in a wild population of the great tit (Parus major)

Cole, Eleanor January 2011 (has links)
The evolutionary processes that shape individual variation in continuous behavioural traits remain poorly understood. While the emerging discipline of animal personality is providing increasing evidence that consistent individual differences in behaviour have significant fitness consequences, cognitive traits are yet to be explored in the same manner. My general objective in this thesis was twofold. First, I aimed to examine the ecological significance and fitness consequences of the cognitive trait innovative problem solving-performance, using a population of great tits (Parus major). Second, I aimed to explore the mechanisms underlying the functional significance of ‘exploration behaviour’ a captive measure of the reactive- proactive personality axis, focusing specifically on foraging and risk-taking behaviour. This two-trait approach was expected to shed light on whether personality and cognition simultaneously influence fundamental behaviours. By carrying out behavioural assays on birds temporarily held in captivity, I showed that success at solving a food-motivated problem was repeatable within individuals, consistent between two different tasks and independent of exploration behaviour. Problem-solving performance was positively related to clutch size and fledgling number, established when birds were released back into the wild. Furthermore, when rearing offspring, solvers had shorter working day lengths than non-solvers and foraged over smaller ranges without compromising either provisioning quantity or quality. However, solver females were also more likely to desert their broods than non-solvers and consequently there was little evidence to suggest that directional selection acted on problem-solving performance. In comparison to non-solvers, solver males were also found to be poorer at competing for limited food resources during the winter. Together these findings suggest that costs and benefits are associated with problem-solving performance, which together may act to maintain variation in this trait. My thesis also provides some of the first evidence that exploration behaviour is related to both foraging and risk-taking behaviour in the wild. In comparison to relatively slow explorers, fast exploring males were better competitors at feeders during the winter. Relatively fast and slow explorers also differed in a number of foraging behaviours during offspring provisioning, although not always in the direction predicted from captive work on other populations. Finally, while exploration behaviour was positively correlated with risk- taking behaviour amongst breeding females during incubation, it did not predict nest desertion in response to the risk associated with being trapped by field workers. Collectively these findings suggest that personality measured in captivity has specific but not general power to predict behaviour in the wild. An important facet of evolution is that natural selection is rarely likely to act on a single trait in isolation owing to correlations between traits. This thesis demonstrates how important behaviours in the wild can be simultaneously linked to multiple sources of consistent behavioural variation. It also represents the first large-scale investigation of how variation in a cognitive trait relates to natural behaviour, reproductive life-history variation and fitness in wild animals. Using this individual-based approach in a natural setting may prove to be a useful tool for understanding how selection acts on cognitive traits.

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