Presented thesis is mainly concerned with the conspecific brood parasitism (CBP) in birds. CBP is an alternative reproductive strategy when a parasitic female lay egg or eggs to other (host) female's nest of the same species. Then the parasitic female leaves the host's nest and does not provide any energetic investment in a subsequent parental care. Distinguish parasitic eggs or young is problematic because there are no obvious morphological differences. Thus, the use of molecular method is crucial for proper determination of CBP. CBP can be used as 'a best-of-bad-job' when female does not have her own nest or lost her nest for example through predation. Other option is that female can increase her fecundity ('fecundity enhancement' hypothesis) when she lay parasitic egg/eggs and care about her own clutch afterward. Two different model species were studied. The first one was a precocial diving duck - the common pochard (Aythya ferina; Anseriformes; Anatidae). Protein fingerprinting was used for detection of CBP and for distinguishing between eggs of individual females. It was found that the rate of CBP was relatively high in this species (91%, 72%; Chapter 1, 4). Further results indicated that the host clutch size decreased with the number of parasitic eggs in the clutch. The study of individual...

Molecular techniques have revealed that avian mating system is more diverse and complex than previously thought. Both males and females can use alternative reproductive tactics to increase their fitness. Here, we have determined the prevalence of conspecific brood parasitism (CBP, 22% of nests), quasi-parasitism (QP, 6.5% of nests) and extra-pair paternity (EPP, 51.2% of nests) in European subspecies of barn swallow (Hirundo rustica rustica). In contrast to EPP and CBP, QP is rare and has been described in only a few bird species. Our data indicate nonrandom QP patterns, suggesting that this tactic can be considered a third alternative reproductive strategy, alongside CBP and EPP. Sexual ornaments are usually assumed to evolve as condition-dependent signals of individual quality. In this context, a positive correlation between the expression of ornamental traits and survival, is expected. Evolutionary theory predicts that females seek extra-pair fertilizations from high-quality (more ornamented) males and EPP has consequently been proposed as a principal protagonist in the evolution of male secondary sexual traits, however empirical evidence in support of the assertion is relatively scarce. Despite decades of research into the role of EPP in sexual selection, the potential fitness advantages for...

7 Abstract Bird nests protect eggs and nestlings, allowing the parents to leave their offspring and subsequently return to them. Their thermoregulatory properties reduce energetic costs of incubation and brooding of nestlings. For all these reasons, nests are key structures for the reproduction of a majority of avian species and as such they should be subject to natural selection. Several hypotheses describing selection pressures which affect the size of nests or some of their parts have been suggested. In my PhD thesis, I investigated some of them in the great reed warbler (Acrocephalus arundinaceus) - an open nesting passerine species with very variable nest size. For this purpose, I used a large dataset of several hundred measured great reed warbler nests, nest enlargement experiments and an experiment with artificial nests. In accordance with previous studies, we did not find that nest size affects the probability of common cuckoo (Cuculus canorus) brood parasitism, while it was influenced by other factors, such as timing of breeding, reed density around the nest and nest visibility from the nearest potential cuckoo perch site. More interestingly, we found that cuckoos adjust their nest-searching strategy in relation to availability of host nests. When host nests were scarce, cuckoos parasitized all of...

Nests are key structures for the reproduction of majority of avian species and as such they should be subject to natural selection. Six hypotheses have been suggested to explain variance in avian nest size. In my master thesis I evaluate their validity in the Great Reed Warbler (Acrocephalus arundinaceus). First two hypotheses describe responses of nest size to predation and brood parasitism. These two selection pressures may lead to the reduction of nest size, but no evidence of their impact on nest dimensions was obtained. However, I found a significant but negative relationship between the probability of nest predation and soft nest height. No such relationship was found between the probability of brood parasitism and nest size characteristics. The incidence of brood parasitism was affected only by nest visibility from the nearest cuckoo perch site and distance from open water. More visible nests suffered heavier parasitism while those located deeper in reed beds were better protected from cuckoo parasitism. Another four hypotheses describe selection pressures which favour large nests or some of their functional parts. The thermoregulatory hypothesis, the sexual display hypothesis and the nest support hypothesis did not explain nest size variation. I found support for the clutch size hypothesis,...

One of the best ways how hosts may defend their clutch against brood parasitism is recognition and rejection of parasitic eggs. It has been documented that ability to percept UV light in birds affects their behaviour. By using a spectrophotometer we found that Reed Warbler (Acrocephalus scirpaceus) eggs and Common cuckoo (Cuculus canorus) eggs differ mainly in brightness but also in UV hue. We investigated the influence of birds' UV vision on recognition and rejection of parasitic eggs. Therefore we performed three experiments to reveal the role of eggshell UV reflectance on egg rejection in this host. In the first experiment, we parasitized clutches with artificial white eggs differing only in UV reflectance (UV- and UV+). In the other two, we experimentally reduced UV reflectance from conspecific and host own eggs. We used a UV light blocker, which did not influence the reflectance shape in the other parts of spectra. As a control we used a group of conspecific and own eggs coated in Vaseline, which did not affect eggshell reflectance. In each experiment, we monitored host response to parasitic eggs. Because the Reed Warbler's eggs reflect UV radiation themselves, we expected that white UV- eggs would be rejected as well as the eggs coated in UV blocker at a higher rate than white UV+ eggs and...

Made available in DSpace on 2016-06-02T20:20:30Z (GMT). No. of bitstreams: 1 3280.pdf: 5102569 bytes, checksum: f511b08e43998ea79e0f9b0ac5ed969b (MD5) Previous issue date: 2010-08-06 / Universidade Federal de Sao Carlos / Population genetic parameters and genetic relatedness estimates were carried out for Roseate Spoonbill (Platalea ajaja), Wood Stork (Mycteria americana) and Great Egret (Ardea alba egretta) reproductive colonies in Amapa, Pantanal and Rio Grande do Sul (RS), Brazil. Microsatellite genotypes were used to investigate kinship patterns between nestlings sampled inside the same nests, using a variety of analytical approaches. Unrelated nestling-pairs were observed in Roseate Spoonbill nests (6.12% of analyzed nests) and in Wood Stork nests (11.34%); half-siblings were present in Roseate Spoonbill nests as well (1.36%). Only full-siblings were detected inside Great Egret nests. Conspecific brood parasitism (CBP) and extra-pair paternity were proposed to account for the presence of unrelated nestmates and half-siblings, respectively, in Roseate Spoonbill and Wood Stork nests. Those results suggest the occurrence of a mating system different than genetic monogamy in natural populations of those waterbirds. Genetic relatedness was also investigated for adults and offspring, as well as for supposed siblings in Roseate Spoonbill families kept in three zoological facilities in the U.S. Paternity and maternity allocation analyses through maximum-likelihood revealed that errors were present in zoo‟s studbooks in relation to the familial records. We also identified mating between related individuals that were not detected previously by zookeepers. Population genetic parameters were also estimated and demographic processes were assessed for Great Egret reproductive colonies in the Pantanal and Rio Grande do Su, Brazil. Bayesian clustering analyses, assignment tests, analysis of molecular variance, F-statistics estimates, allelic frequency distribution and the G-W index revealed that: i) Pantanal reproductive colonies are genetically differentiated from Rio Grande do Sul colonies; ii) an IBD-like pattern alone cannot explain that differentiation; and iii) genetic signal of a reduction of population size was present for two colonies in the Pantanal and one in Rio Grande do Sul. Results were discussed considering a metapopulation dynamic and also considering that populations from both Brazilian regions represent distinct units and deserve to be treated separately when planning and carrying out conservation and management programs that aim to preserve the species‟ genetic diversity. / Estudos de genética de populações e de parentesco genético foram desenvolvidos em colhereiro (Platalea ajaja), cabeça-seca (Mycteria americana) e garça-branca-grande (Ardea alba egretta), de colônias reprodutivas do Amapá, Pantanal e Rio Grande do Sul (RS), Brasil. Genótipos em locos de microssatélites foram utilizados para se investigar os padrões de relacionamento entre ninhegos amostrados dentro dos mesmos ninhos com diferentes metodologias de análise. Pares de ninhegos não-relacionados foram encontrados nos ninhos de colhereiro (6,12% dos pares analisados) e de cabeça-seca (11,34%); meio-irmãos foram observados nos ninhos de colhereiro (1,36%). Em garça branca grande foi detectada apenas a presença de irmãos-completos dentro dos ninhos. Parasitismo de ninho intraespecífico e paternidade extra-par podem explicar a presença de ninhegos não-relacionados e meio-irmãos nos ninhos de colhereiro e cabeça-seca, o que indica a presença de um sistema de acasalamento diferente da monogamia genética nas populações naturais dessas espécies. Relações de parentesco entre adultos e filhotes e entre supostos irmãos foram determinadas em famílias de colhereiro de três zoológicos dos EUA. Análises de atribuição de maternidade e paternidade por máxima verossimilhança revelaram erros nos registros dos zoológicos quanto às relações progenitor-progênie e identificaram acasalamentos entre indivíduos aparentados que não tinham sido registrados. Parâmetros genético-populacionais e processos demográficos foram investigados em populações de garça-branca-grande do Pantanal e do Rio Grande do Sul. Análises Bayesianas, testes de alocação de indivíduos, análises de variância molecular, estimativa de estatísticas F, exame da distribuição das freqüências alélicas e cálculo do índice de G-W permitiram identificar que: i) há diferenciação genética significativa entre colônias reprodutivas do Pantanal e do Rio Grande do Sul; ii) o padrão de isolamento pela distância não explica essa diferenciação; e iii) duas populações no Pantanal e uma população no RS apresentaram sinais genéticos de redução demográfica. Os resultados foram discutidos considerando que as populações de garça-branca-grande localizadas no Pantanal e no Rio Grande do Sul são unidades populacionais independentes e devem se tratar separadamente no planejamento e desenvolvimento de programas de manejo para a conservação da diversidade genética total da espécie.

Made available in DSpace on 2016-06-02T20:20:34Z (GMT). No. of bitstreams: 1 4932.pdf: 1990172 bytes, checksum: 7025c9dd589a8c2a6771bc24539895b5 (MD5) Previous issue date: 2013-03-05 / Universidade Federal de Sao Carlos / The genetic diversity of the cattle egret (Bubulcus ibis) was analyzed to investigate reproductive behavior and characterize Brazilian populations of the species. Genotypes at seven microsatellite loci were used to investigate the occurrence of more than one female laying eggs in the same nest, characterizing the occurrence of multiple maternity. DNA was extracted from swabs collected from the outer surface of eggs and sexed; males were excluded. Forty-eight clutches from two breeding seasons (2010 and 2011) were genetically analyzed. Thirty-nine eggs laid by a second or third female were recorded. In five nests, the first egg of the clutch was from a different female, the laying happening prior to that of the incubating female. Suggesting nest takeover by another pair of egrets that kept the pre-existing eggs together with its own clutch. In the other 43 nests, the hypothesis of brood parasitism was posed to explain why one or two additional females were found laying eggs in a nest. A 463-bp fragment of the mitochondrial DNA control region Domain I was amplified for 148 individuals from seven Brazilian populations to investigate genetic-population and demographic parameters. Genetic diversity indices, the population structure tests Fst and AMOVA, a haplotype network, mismatch distribution and neutrality tests (Tajima s D, Fu s Fs, Fu and Li s D* and F*, Ramos-Onsins and Rozas R2) revealed the following: i) a high level of diversity was recorded for the cattle egret in Brazil in comparison to other closely related species studied in the country; ii) genetic diversity levels determined for the Brazilian regions are similar; iii) genetic structuring was not observed between the seven studied populations; and iv) the different tests performed to determine demographic expansion revealed no significant results. This is the first genetic characterization study for Bubulcus ibis to date and the findings indicate a high degree of plasticity in reproductive behavior and confirm a marked dispersion behavior of the species, leading to the homogenization of Brazilian populations. / A diversidade genética da garça-vaqueira (Bubulcus ibis) foi utilizada para se investigar o comportamento reprodutivo e para se caracterizar populações brasileiras da espécie. Genótipos em locos de microssatélites foram utilizados na detecção da presença de mais de uma fêmea ovipositando em um mesmo ninho, o que pode caracterizar a ocorrência de maternidade múltipla. O DNA extraído dos swabs coletados na superfície externa dos ovos foi sexado e eventuais amostras de machos foram excluídas. Quarenta e oito ninhadas, de duas temporadas reprodutivas (2010 e 2011) foram analisadas geneticamente. Foram registrados 39 ovos ovipositados por uma segunda ou terceira fêmea. Em 33 ninhos foram encontrados genótipos distintos de duas fêmeas e em seis ninhos genótipos de três fêmeas. Em cinco ninhos o primeiro ovo na sequência de oviposição mostrou-se ser de uma fêmea diferente, tendo a oviposição acontecido previamente àquela da fêmea incubante. Esse achado foi explicado supondo a tomada de ninho por um segundo casal de garças, com a manutenção do ovo pré-existente juntamente com os da própria ninhada. Nos outros 43 ninhos, a presença das fêmeas extras foi explicada hipotetizando a ocorrência de parasitismo de ninho intraespecífico. Um fragmento de 463 pb do Domínio I da região controladora do DNA mitocondrial foi amplificado para 148 indivíduos para a investigação de parâmetros genéticopopulacionais e processos demográficos nas sete populações estudadas. A estimativa de índices de diversidade genética, testes de estruturação populacional Fst e AMOVA, a construção de uma rede de relação entre haplótipos, a análise de mudanças no tamanho populacional pela mismatch distribution e a realização de testes de neutralidade (D de Tajima, Fs de Fu, D* e F* de Fu e Li, R2 de Ramos-Onsins e Rozas) permitiram identificar: i) um nível alto de diversidade genética para B. ibis no Brasil, quando comparado a espécies proximamente relacionadas estudadas no país; ii) níveis semelhantes de diversidade genética determinados para as regiões brasileiras; iii) ausência de estruturação genética entre as sete populações estudadas; e iv) ausência de sinais de expansão demográfica pelos testes realizados. Os resultados aqui apresentados são os primeiros resultados genéticos na espécie até o momento e apontam para uma alta plasticidade no comportamento reprodutivo e confirmam a dispersão bastante acentuada da espécie, levando a homogeneização das populações brasileiras.