La construction du nid chez les fourmis génère des structures assumant de nombreuses fonctions, qui sont en grande partie dépendantes de l’architecture produite. L’omniprésence de ces fonctionnalités contraste avec la forte diversité intra et inter-spécifique de la morphologie du nid. Ce travail a pour objectifs de déterminer d’une part la morphogenèse du nid durant son excavation par les fourmis (Chapitre 3), et d’autre part de quantifier l’impact de la taille du groupe (Chapitre 3) et de la qualité de l’environnement (qualité du matériau, gravité; Chapitres 4 & 5) sur cette séquence. Pour répondre à ces questions, nous avons utilisé un dispositif de creusement en deux dimensions (2D) afin de suivre la dynamique d’excavation et l’évolution de la morphologie du nid au cours du temps. Nous avons tout d’abord mis en évidence (Chapitre 3) un changement brutal de la morphologie du nid au cours de sa croissance. Durant une première période d’excavation homogène, le nid est constitué d’une seule cavité de forme circulaire et au contour régulier. Par la suite, le pourtour de la cavité devient plus irrégulier, l’apparition de ‘‘bourgeons’’ lui donnant une apparence plus plissée. Enfin, la cavité centrale cesse de croître lorsque des ramifications se déploient depuis certains des ‘‘bourgeons’’. Nous avons qualifié de transitions morphologiques ces brusques changements de forme, dont la fréquence d’apparition augmente avec la taille de la population. Notre analyse et le recours à la simulation semblent indiquer que ce phénomène soit basé non pas sur un changement de comportement des ouvrières excavatrices mais sur la densité d’activité au front de creusement. Lorsque celle-ci est importante, des phénomènes d’encombrement se manifestent et le nid est excavé de manière homogène. À l’inverse, lorsque l’encombrement diminue les ouvrières peuvent focaliser leur travail et excavent des galeries. Un modèle analytique (Chapitre 6) a permis d’étudier les conditions d’apparition de cette transition morphologique. Nos autres résultats indiquent que le matériau de construction influence très fortement la morphogenèse du nid (Chapitre 4) : les nids excavés dans un milieu cohésif sont plus fréquemment ramifiés et la transition morphologique apparaît à des surfaces de nid plus petites que dans un milieu granulaire. Il semblerait qu’à nouveau, il n’y ait aucune variation comportementale impliquée, mais que l’environnement joue un rôle de ‘‘médiateur’’ des interactions entre les fourmis: le milieu change le temps d’extraction et donc la probabilité individuelle d’excavation, cette variation est exacerbée par les mécanismes d’amplification à l’œuvre, modifiant alors sensiblement la dynamique collective de creusement et la structure du nid. Enfin, une série d’expériences (Chapitre 5) nous a permis de déterminer l’influence de la gravité sur la morphogenèse. Il apparait que la gravité sert de gabarit à la construction, puisque les nids excavés dans un dispositif à l’orientation verticale sont tous dirigés vers le bas. Aussi, si le nid prend directement une forme de long puit vertical sans jamais présenter de chambre, le mécanisme de transition morphologique reste visible, sous forme de bifurcation des galeries à leur extrémités. Ce phénomène de tip-splitting semble aussi apparaître sous la contrainte de la densité d’ouvrières excavant au fond des galeries. Notre travail a donc mis en évidence un phénomène de transition morphologique capable de produire les modules de base de tout nid - chambres et galeries -, et qui semble découler non pas de modifications comportementales, mais de la seule interaction de l’amplification de l’activité et de l’encombrement au front d’excavation. Ce phénomène ubiquiste propose une explication à la grande variété de structures observées sur le terrain, en lien notamment avec la diversité et l’hétérogénéité des milieux, et la dynamique des colonies. Enfin, les similitudes de la transition morphologique avec les instabilités de croissance observées dans de nombreux systèmes biologiques et physico-chimique invitent à considérer ces derniers phénomènes à la lumière de nos résultats.

In Italy, the period directly following World War II was marked by confusion and turbulence as the people struggled to reconstruct both the ideological and physical infrastructure of the nation. While much study has been dedicated to the evolution of femininity and the figure of the woman in this particular period, comparatively little has been written on the refashioning of masculinity in the texts produced in the period between 1940 and 1955. After the fall of the Fascist Regime, Italian masculinity undergoes a drastic transformation as the generation of young men born and raised under the tutelage of Mussolini’s reign attempt to separate themselves from the now-tainted codes of conduct governing male behavior. This report analyzes the renegotiation of Italian masculinity in G. Silvano Spinetti’s non-fictional account Difesa di una generazione (scritti e appunti), Italo Calvino’s Il sentiero dei nidi di ragno, Beppe Fenoglio’s short story “Gli inizi del partigiano Raoul” and Pier Paolo Pasolini’s Ragazzi di vita. These works, written and published in the postwar period, manipulate the vi marginality and privation experienced by the Italian population during the war and postwar period into a liminal state brimming with revolutionary potentiality. The protagonists of these texts (both fictional and non-fictional), isolated from the larger social context and deprived of individual identity, property and privilege, circumvent their polluted patriarchal lines in favor of an alternative ideological patriarchy. While Spinetti, Calvino and Fenoglio’s works advance their liminal narratives as a means of creating an emblematic Italian man capable of rejoining the generative discourse, Pasolini’s text renounces such a progressive view. In Ragazzi di vita, the only possibility for a masculine identity free of Fascism resides in a maintaining a perennial liminality. / text

Understanding the patterns and processes that create differences among individuals in components of fitness, like the probability of survival or reproductive rates, is essential to our knowledge of population dynamics and for informing conservation efforts. For organisms in seasonal environments, early-breeding individuals regularly attain higher fitness than their late-breeding counterparts. Two primary hypotheses, related to quality and date, have been proposed to explain lower reproductive success of late breeders, but the veracity of these ideas has not been fully resolved. I tested predictions associated with these hypotheses to assess the effects of indices of parental and environmental quality on nestling quality and survival in an insectivorous passerine, the tree swallow (Tachycineta bicolor), at two widely separated breeding locations in western Canada. I combined experiments and statistical modelling of observational data to evaluate two mechanisms proposed to contribute to seasonal decline in environmental quality: an increase in nest parasite abundance and a decrease in food abundance with later breeding dates. A parasite reduction experiment revealed a disproportionate benefit of parasite removal on length of primary feather for early-hatched nestlings, suggesting greater energetic constraints early in the breeding season. Furthermore, late-hatched nestlings from parasite-reduced nests had longer head-bill lengths than their control counterparts, and developed head-bills of similar length to those of early-hatched nestlings. Other than these findings, there were few detectable effects of parasites on nestling size, growth and immunity, as has been reported from several previous studies. Indeed, negative effects of parasites were only apparent when food (i.e., insect) biomass was considered. In a second series of experiments in which parental quality was controlled, I also tested whether food abundance declined during the breeding season, as predicted if environmental conditions deteriorate seasonally (i.e., date). Reduced reproductive success of late-breeding individuals was causally related to a seasonal decline in environmental quality. Declining insect biomass and enlarged brood sizes resulted in nestlings that were lighter, in poorer body condition, had shorter head-bills, shorter and slower growing ninth primary feathers and that were less likely to survive to fledge. Next, I asked whether results obtained from long-term mark-recapture data corroborated findings of short-term manipulations. I examined seasonal variation in first-year apparent survival to investigate the relative influence of large-, small- and individual-scale factors associated with the quality and date hypotheses. Although parental quality was an important predictor of first-year apparent survival of tree swallows, my results further suggested that quality of parents was not the primary factor influencing seasonal variation in first-year apparent survival. Rather, findings were most consistent with the date hypothesis. The relationship between apparent survival and a direct measurement of environmental quality indicated that annual variation in moisture had important consequences for first-year apparent survival of tree swallows in Saskatchewan. First-year apparent survival probabilities were higher during wet years and wetter conditions are generally linked to greater insect abundance. In British Columbia, nestlings from larger broods were less likely to survive, possibly as a result of receiving less food. Apparent survival probabilities were also higher when food was more abundant. I demonstrated that both parental and environmental quality influenced seasonal variation in fitness-related traits of tree swallows. However, the strongest evidence suggests that environmental quality, and in particular food abundance, had the greatest effect on seasonal variation in nestling quality, reproductive success and first-year apparent survival in tree swallows. My results highlight the importance of considering regional precipitation trends when projecting effects of climate change on demography of aerial insectivores.

No description available.

以英語為母語以及非英語為母語之教師，兩者間之協同教學國家級計劃，從1990年代開始在日本、韓國及香港各地執行。過去十年，台灣地區共有兩個相關計劃：一個位於中部某縣轄市；另一個則在北部地區，由該地方教育局與某知名學術基金會合作執行。關於這類的計畫，目前已有文獻探討執行上的困難，主要包括文化歧見、老師教學效能、與行政單位之運作問題，但其實卻並無整體評析之深入研究可供參考。 本研究遵循質化與量化的方法，針對北部之計畫為對象，深入評析中外師協同教學執行一年後之師生學習成效。研究首先以量化方式以成就測驗與態度問卷了解計畫中80名四年級與六年級小學生的英文學習成果、他們對英文的態度以及學習動機。另外又以訪談、課室觀察以及教學日記蒐集資料，分三組追蹤調查六位中外師之專業成長，藉衛考斯基的社會文化理論做分析，而文化體認方面，則以第三向度觀點，了解不同文化背景的老師之發展。 研究結果顯示此項中外師協同教學計劃對學生學習有正面作用，但程度則多有不同。學生之閱讀與聽力有成長，四年級學生受益又比六年級學生更多，但成果則因時間較短而稍顯淺薄。另一方面，中外教師在專業知識與文化體認上有顯著成長，可以說是本計畫最大受益者。 整體而言，計畫單位對中外師雙方合作關係之培養具備完善的機制，而在文化體認方面又有一群能夠以持平立場看待文化差距的諮詢專家，為中外師創造第三向度合作空間，使雙方能夠大方擁抱兩種文化且無需掩飾彼此之不同。這些設計使計劃更有效能，整體執行方式具參考價值。 / National co-teacher programs involving native English speaker teachers (NESTs) and non-native English speaker teachers (NNESTs) have been in operation since the 1990’s in Japan, Korea and Hong Kong. Two major programs have been established in Taiwan in the last ten years, one by a city government in the central part of Taiwan, the other by the education bureau of a rural county in the north, in collaboration with a well known academic exchange foundation. The cultural, pedagogical and administrative challenges such schemes face are well documented but there has been little evaluation of the benefits for stakeholders This study focused on the program in northern Taiwan and followed a mixed methods approach in order to trace learning gains from co-teaching for teachers and students over the course of one year. Students’ gains in English proficiency and changes in attitude and motivation were measured in a quantitative study involving over 80 4th and 6th grade students who were tested and surveyed. A triple case study investigated growth in professional knowledge and cultural awareness in three teaching pairs through interviews, class observation and teacher journals. Teacher learning was studied through the prism of socio-cultural theory and growth in cultural awareness from the perspective of thirdness. The program was found to have a positive effect on students, but in varying degrees. Student scores in both reading and listening proficiency improved while their attitudes and motivation were positive. Proficiency gains were greater among 4th graders than 6th graders, but the results also showed that for students, the impact of a one year program is relatively shallow. Teachers grew considerably in both professional knowledge and cultural awareness and were the greatest beneficiaries of the program. This study also found that the effectiveness of the program was facilitated by certain enabling mechanisms which nurtured the relationship between NESTs and NNESTs. Cultural awareness was facilitated by a culturally fair panel which helped create third spaces where teachers could embrace both cultures without hiding the differences between them.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-07-21T11:39:31Z No. of bitstreams: 1 monalisadepaularocha.pdf: 972026 bytes, checksum: 1d1124c048f5e7456925bd61ed099336 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-07-22T15:28:17Z (GMT) No. of bitstreams: 1 monalisadepaularocha.pdf: 972026 bytes, checksum: 1d1124c048f5e7456925bd61ed099336 (MD5) / Made available in DSpace on 2016-07-22T15:28:17Z (GMT). No. of bitstreams: 1 monalisadepaularocha.pdf: 972026 bytes, checksum: 1d1124c048f5e7456925bd61ed099336 (MD5) Previous issue date: 2011-02-28 / Polybia platycephala (Richards, 1978) é uma vespa social enxameante que possui seu ninho constituído de várias filas de favos horizontais cobertos favo-a-favo por um envelope. Neste estudo caracterizou-se o padrão de fundação, arquitetura do ninho, o padrão de estocagem de recursos nas colônias, o ciclo colonial, a população, os estágios imaturos, e o número de ínstares larvais de P. platycephala. Além disso, o macho da espécie é descrito e ilustrado. No período de novembro de 2009 a novembro de 2010, foram estudadas 95 colônias em áreas antrópicas do município de Juiz de Fora, MG. Para descrição do padrão de fundação, foram realizadas observações ―ad libitum‖ em quatro enxames. Para analisar a arquitetura do ninho foram considerados os seguintes dados: coloração, comprimento e largura do orifício de entrada, e dimensões do ninho. O ângulo de orientação das colônias foi estabelecido com uma bússola posicionada abaixo dos ninhos. Através da dissecção de 15 colônias, foi verificada a fase de desenvolvimento e o número de: adultos, total de células, células vazias, ovos, larvas, e pupas. Foram mensuradas, a maior largura e o maior comprimento de 100 ovos, e a largura máxima da cápsula cefálica de 400 larvas e 120 pupas, sendo o número de ínstares larvais determinado de acordo com a Regra de Dyar. Foi possível determinar que antes da construção das primeiras células, P.platycephala constrói uma fina base de material vegetal sobre o substrato. O processo de construção inicial do ninho durou de 10 a 15 dias. A nidificação na vegetação foi maior do que em substratos construídos (x²= 53,063; p < 0,0001). Em média, os ninhos apresentaram 2115 ± 1234 (328 - 4723) células, podendo conter até oito favos, e estavam situados a cerca de 3,0 metros do solo. A distância média entre os favos foi de 0,67 ± 0,09 cm (0,53 - 0,85). Houve diferença sazonal no sentido de orientação dos ninhos fundados pela espécie, com ninhos na estação chuvosa orientados principalmente para o sul e ninhos na estação seca orientados para o norte. Os eventos de fundação e abandono das colônias ocorreram em todas as épocas do ano. As colônias produziram 510,26 ± 403,21 (71 – 1492) adultos e encontravam-se em diferentes fases do ciclo colonial. As oviposturas nos favos ocorreram geralmente do centro para a periferia, com pupas nas células centrais circundadas de larvas em diferentes ínstares, seguida de ovos e células vazias na periferia. Constatou-se a presença de casulos de parasitóides no interior das células de cinco ninhos. Foi observada a estocagem de substância açucarada em 80% das colônias (seis em fase de produção de operárias, três em fase de quiescência, duas na produção de machos e um na pré-emergência). O armazenamento ocorreu sempre em células vazias (92,63%), células com presas (4,88%), células com ovos (2,0%) ou células com larvas pequenas (0,5%). A estocagem de presas foi observada em duas colônias, dentro das células ou entre os favos dos ninhos. As larvas possuem cinco ínstares, com uma razão média de crescimento de 1,57. Os machos de P. platycephala distinguem-se das fêmeas por características como o clípeo amarelo com ou sem pilosidade prateada; antena não tão robusta, com 13 segmentos; gena estreita; gáster com 1-6 tergitos. / Polybia platycephala (Richards, 1978) is a social swarming wasp which has its nest constituted of several lines of horizontal combs covered each one of them by an envelope. In this study, it was characterized the foundation pattern, the nest architecture, the storage pattern of resources in the colony, the colonial cycle, the population, the immature stages, and the number of larval instars of P. platycephala. Furthermore, the male of the species is described and illustrated. During the period from November 2009 the November 2010, 95 colonies were studied in antropic areas of the city of Juiz de Fora, MG. For the description of the foundation pattern, some ―ad libitum‖ observations were performed on four swarms. For analyzing the architecture of the nest, the following data were considered: coloration, length and width of the entrance orifice, and nest dimensions. The orientation angle of the colonies was established with a compass. Through the dissection of 15 colonies, it was verified the development phase and the number of adults, total of cells, vacant cells, eggs, larvae, and pupae. The largest width and the largest length of 100 eggs and the maximum width of the cephalic capsule of 400 larvae and 120 pupae were measured, and the number of larval instars is determined according to the Dyar’s Rule. It was possible to determinate that before the construction of the first cells, P. platycephala builds a slim base of vegetal material on the substrate. The initial process of construction has lasted from 10 to 15 days. The nidification in the vegetation was bigger than in constructed substrates (x²= 53.063; p < 0.0001). On average, the nests presented 2115 ± 1234 (328 - 4723) cells, which can contain up to eight combs, and they were situated about 3.0 meters above ground. The average distance between the combs was about 0.67 ± 0.09 cm (0.53 – 0.85). There was a seasonal difference in the orientation meaning of the nests founded by the species, with nests oriented mainly towards the south in the rainy season, and the north in the dry season. The events of foundation and abandonment of the colonies occurred all the year round. The colonies produced 510.26 ± 403.21 (71 – 1492) adults and these were found in different phases of the colonial cycle. The postures in the combs occurred generally from the center to the periphery, with pupae in the central cells surrounded by larvae in different instars, followed by eggs and vacant cells in the periphery. It was verified the presence of cocoons of parasitoids in the cells of five nests. It was observed the storage of sugary substance in 80% of the colonies (six in worker production stage, three in quiescence stage, two in the production of males and one in the pre-emergence). The storing always occurred in vacant cells (92.63%), cells with preys (4.88%), cells with eggs (2.0%) or cells with small larvae (0.5%). The storing of preys was observed in two colonies, inside the cells and between the combs of the nests. The larvae have five instars, with a a mean ratio of growth of 1.57. The males of P. platycephala differ from the females with characteristics like the yellow clypeus with or without silver hairiness; antenna not so robust, with 13 segments; narrow gena; gaster with 1-6 tergitos.

Abstract Anthropogenic climate change and habitat loss and deterioration affect populations worldwide. Climate warming has changed phenologies of many species across trophic levels. Some predator populations now experience temporal mismatches with their prey, as timings of peak prey abundance and of the predator’s highest food demands no longer meet. The temporal mismatch hypothesis suggests that the population’s recruitment rate is related to its degree of synchrony with the food resources needed to feed offspring. However, species’ and populations’ responses to climate warming differ. Human land use alters and destroys habitats of countless species. For example, many boreal forest bird populations have declined, presumably due to intensive forestry. It has decreased the amount of dead wood, causing a threat to saproxylic species. Identification of the key characteristics of high-quality habitats is essential for conservation planning and for developing sustainable forestry. As individuals are suspected to settle in habitats that maximize their fitness, analysis of nest site selection can be used to identify the key habitats. My dissertation concerns the impacts of climate change and habitat deterioration on boreal populations. I use hole-nesting passerines as model species. By utilizing long-term data I show that breeding phenologies of Parus major and Poecile montanus, but not of Cyanistes caeruleus, have shifted earlier. Also, the timing of the food peak has advanced, improving the synchrony between P. montanus and caterpillars. In P. major and C. caeruleus, synchrony has remained good. However, the positive effect of good synchrony on breeding success seems to be conditional, arising only in certain circumstances, such as in years of high caterpillar abundance. I suggest that in boreal populations temperature affects timing of breeding mostly as a proximate factor. The availability of standing decaying trees used for nesting sites was the most important habitat characteristic determining the nest site selection of P. montanus. Remote sensing data alone was insufficient to produce reliable models, as the ecologically important small-scale factor can only be determined by direct field surveys. Omission of forest thinning in selected forest sites would ensure the continuous availability of decaying wood with positive influence on biodiversity in managed forests. / Tiivistelmä Ihmisen aiheuttama habitaattien katoaminen ja huononeminen sekä ilmastonmuutos vaikuttavat populaatioihin kaikkialla maailmassa. Ilmaston lämpeneminen on muuttanut monien lajien fenologioita eri trofiatasoilla. Osalla saalistajalajien populaatioista suurin ravinnontarve ei enää ajoitu samaan aikaan saaliin runsaushuipun kanssa. Ajoituksen eriaikaisuus -hypoteesin mukaan todennäköisyys populaatioon rekrytoitumiselle riippuu synkronian asteesta saaliin kanssa. Ilmaston lämpenemisen vaikutuksissa lajeihin ja populaatioihin on kuitenkin vaihtelua. Ihmisen maankäyttö muuttaa ja tuhoaa lukuisien lajien elinympäristöjä. Esimerkiksi useiden boreaalisten metsien lintupopulaatioiden pienentymistä on selitetty intensiivisellä metsätaloudella. Lahopuun määrä metsissä on vähentynyt, mikä on uhka lahopuusta riippuvaisille lajeille. Korkealaatuisten habitaattien keskeisten piirteiden tunnistaminen on tärkeää luonnonsuojelun ja kestävän metsätalouden suunnittelulle. Koska yksilöiden oletetaan valitsevan niiden kelpoisuutta maksimoivia elinympäristöjä, pesäpaikanvalinta-analyysiä voidaan käyttää tärkeiden habitaattipiirteiden tunnistamiseen. Tarkastelen väitöskirjassani ilmastonmuutoksen ja habitaattien laadun vaikutuksia boreaalisiin populaatioihin. Mallilajeina käytän koloissa pesiviä varpuslintuja. Hyödyntämällä pitkäaikaisaineistoja osoitan, että lisääntymisen ajoittuminen on aikaistunut tali- ja hömötiaisella, mutta ei sinitiaisella. Myös ravintohuippu on aikaistunut, mikä on parantanut synkroniaa hömötiaisen ja sen pääasiallisen ravinnon eli toukkien välillä. Tali- ja sinitiaisella synkronia on pysynyt hyvänä. Hyvän synkronian myönteinen vaikutus lisääntymismenestykseen vaikuttaa kuitenkin ehdolliselta: se tulee esiin vain tietyissä olosuhteissa, kuten vuosina jolloin toukkia on runsaasti. Kevään lämpötilat näyttävät vaikuttavan pesinnän ajoittumiseen erityisesti proksimaattisena tekijänä. Pesäpaikkoina toimivien seisovien lahopuiden määrä on tärkein hömötiaisen pesäpaikanvalintaa määräävä tekijä. Kaukokartoitusaineisto yksinään ei riitä luotettavien mallien tuottamiseen, sillä ekologisesti tärkeät pienen skaalan tekijät voidaan kartoittaa vain suorin maastomittauksin. Metsien harventamatta jättäminen valituilla laikuilla turvaisi lahopuun jatkuvan saatavuuden, mikä vaikuttaisi myönteisesti talousmetsien biodiversiteettiin.

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.

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