Plovers was compared with particular reference to breeding biology, feeding ecology and habitat preference. Crowned and Blackwinged Plovers coexisted in mixed flocks in grasslands which aided predator detect ion and defence against predators. Lesser Blackwinged Plovers were opportunistic in their use of habitat and were found in habitats ranging from the muddy edges of pans to woodlands. Body size was found to have an important effect on the breeding biology of these birds, affecting incubation behaviour and reproductive pattern. The behaviour of Lesser Blackwinged Plovers differed considerably from that of Crowned and Blackwinged Plovers. Crowned and Blackwinged Plovers appear to constitute a superspecies on account of their behavioural and morphological similarities while the Lesser Blackwinged Plover is possibly closely related to the ancestral stock of the genus Vanellus. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg.

A model is presented which predicts the simultaneous searching strategy (walking speed) and diet choice of a terrestrial predator, assuming the behaviour is selected to maximize the net rate of energy gain The model predicts an inverse relationship between predator velocity and prey availability, independent of prey type, and that predators should stop foraging below a critical prey availability. It is predicted that diet choice should become more restricted with increases in the availability of highly profitable prey (ie net energy return per second spent handling) but broader with increases in the relative density of low profitability prey. Parameters of the model, prey availability, energy content and handling time were measured for the common prey of two estuarine wading birds - the Redshank (Tringa totanus L.) and the Oystercatcher (Heamatopus ostralegus L ) on the mid—estuarine Firth of Forth, Scotland. Predator energy expenditures whilst handling and searching for prey were estimated using radiotelemetry of the heart rate from six unrestrained Redshank in an outdoor aviary. At the lower critical temperature (16°C), the handling costs averaged l.9xBMR (Aschoff and Pohl 1971) and 2.OxBMR for pecking and probing respectively, whilst searching cost l.7xBMR (walking at 30cm.s-1). Observed walking speeds in both species were well matched with the model's predictions at medium and high encounter rates, but at low encounter rates (2 items m walked-1) were lower than predicted The critical low availability at which it is profitable to stop foraging did not occur in the field during the study period (February 1981-May 1982). In Redshank the observed diet was not consistent with the net energy maximization model in Autumn or Early and Late winter and instead fitted better a model of gross protein maximization. In spring the observed diet was best described by the maximization of net energy gain. Including costs had a significant effect on the diet predictions in the Redshank. Differences between predicted and observed diet choice in the Oystercatcher were a result of the underselection of very large, high profitability items and partial selection of low ranking prey. Including costs had no effect on the model's predictions for the Oystercatcher. Differences between model predictions and the observed behaviour are discussed In the 'prizing' Oystercatcher differences appeared to be a result of inaccuracy in collection of one of the model parameters (unsuccessful manipulation rates) and invalid assumptions concerning the discriminant abilities of the predator. Whilst conflicting selective pressures - protein requirements and the avoidance of bill damage, probably explain the deviations in Redshank and 'hammering' Oystercatchers respectively.

Os vírus da influenza aviária, ou vírus da influenza A, podem acometer inúmeras espécies de aves e mamíferos, e são conhecidos pelos relevantes impactos gerados na economia e Saúde Pública. As aves pertencentes às ordens Anseriformes (patos, marrecos e cisnes) e Charadriiformes (maçaricos, gaivotas e trinta-réis) são consideradas reservatórios, sendo que o comportamento migratório de muitas destas espécies pode favorecer a disseminação viral entre países. Existem poucos estudos sobre a circulação dos vírus da influenza aviária na América do Sul, dificultando a compreensão da ecologia e epidemiologia destes patógenos no Brasil. Este trabalho tem como objetivo monitorar as aves migratórias, em áreas de descanso e invernada na região Amazônica brasileira, por meio da detecção e caracterização dos vírus da influenza A. Através de seis expedições científicas ao norte do estado do Pará entre 2008 e 2010 foram colhidos swabs orotraqueais e cloacais de 1093 aves silvestres, principalmente Anseriformes e Charadriiformes. Pela técnica de Real time RT-PCR, nove aves foram positivas: 2 Actitis macularius, 4 Arenaria interpres, 1 Calidris pusilla, 1 Charadrius semipalmatus e 1 Dendrocygna viduata. Destas, o isolamento viral foi realizado com sucesso a partir das amostras de três Arenaria interpres, corroborando estudos que demonstram uma elevada prevalência do vírus da influenza A nesta espécie. As reações de inibição da hemaglutinação e de inibição da neuraminidase revelaram tratar-se do subtipo viral H11N9, considerado de baixa patogenicidade e relativamente comum nestas aves. O sequenciamento genético indicou estreita relação filogenética entre as estirpes virais deste estudo e aquelas isoladas na América do Norte, evidenciando um vínculo epidemiológico entre estas populações. Assim, é essencial a contínua vigilância epidemiológica dos vírus da influenza aviária em aves silvestres nesta região, visando a obtenção de informações sobre a prevalência do vírus, subtipos circulantes e suas características patogênicas, para subsidiar medidas apropriadas de prevenção e controle caso ocorram surtos no país. / Avian influenza viruses infect a variety of birds and mammals and are known for their relevant enconomic and public health impacts. Anseriformes (ducks, mallards and geese) and Charadriiformes (shorebirds, seagulls and terns) are natural reservoirs of avian influenza viruses, and the migratory behaviour of many of these species can result in the spread of the virus among countries. There are few studies investigating the occorrence of these viruses in South America, hindering understanding of their ecology and epidemiology in Brazil. This study aims to detect and characterize avian influenza viruses in migratory birds in wintering areas on the Amazon coast. Orotracheal and cloacal swabs were obtained from 1093 wild birds, mostly Anseriformes and Charadriiformes, during six expeditions between 2008 and 2010 to the state of Pará, Brazil. Samples from nine birds were positive to Real time RT-PCR: 2 Actitis macularius, 4 Arenaria interpres, 1 Calidris pusilla, 1 Charadrius semipalmatus e 1 Dendrocygna viduata. Virus isolation was successfully carried out for the samples from three Arenaria interpres, in agreement with previous studies reporting high prevalence in this species. Hemaglutinin and neuraminidase inhibition assays indicated these strains belonged to subtype H11N9, considered low pathogenic and relatively common in shorebirds. Gene sequencing demonstrated close phylogenetic relationship between the strains isolated in this study and those found in North America, revealing the existence of epidemiological conectivity among these populations. It is therefore vital to maintain active epidemilogical surveillance of wild birds in this region, collecting information on virus prevalence, subtype and pathogenicity that may in turn be used to implement prevention and control policies for avian influenza outbreaks.

Os vírus da influenza aviária, ou vírus da influenza A, podem acometer inúmeras espécies de aves e mamíferos, e são conhecidos pelos relevantes impactos gerados na economia e Saúde Pública. As aves pertencentes às ordens Anseriformes (patos, marrecos e cisnes) e Charadriiformes (maçaricos, gaivotas e trinta-réis) são consideradas reservatórios, sendo que o comportamento migratório de muitas destas espécies pode favorecer a disseminação viral entre países. Existem poucos estudos sobre a circulação dos vírus da influenza aviária na América do Sul, dificultando a compreensão da ecologia e epidemiologia destes patógenos no Brasil. Este trabalho tem como objetivo monitorar as aves migratórias, em áreas de descanso e invernada na região Amazônica brasileira, por meio da detecção e caracterização dos vírus da influenza A. Através de seis expedições científicas ao norte do estado do Pará entre 2008 e 2010 foram colhidos swabs orotraqueais e cloacais de 1093 aves silvestres, principalmente Anseriformes e Charadriiformes. Pela técnica de Real time RT-PCR, nove aves foram positivas: 2 Actitis macularius, 4 Arenaria interpres, 1 Calidris pusilla, 1 Charadrius semipalmatus e 1 Dendrocygna viduata. Destas, o isolamento viral foi realizado com sucesso a partir das amostras de três Arenaria interpres, corroborando estudos que demonstram uma elevada prevalência do vírus da influenza A nesta espécie. As reações de inibição da hemaglutinação e de inibição da neuraminidase revelaram tratar-se do subtipo viral H11N9, considerado de baixa patogenicidade e relativamente comum nestas aves. O sequenciamento genético indicou estreita relação filogenética entre as estirpes virais deste estudo e aquelas isoladas na América do Norte, evidenciando um vínculo epidemiológico entre estas populações. Assim, é essencial a contínua vigilância epidemiológica dos vírus da influenza aviária em aves silvestres nesta região, visando a obtenção de informações sobre a prevalência do vírus, subtipos circulantes e suas características patogênicas, para subsidiar medidas apropriadas de prevenção e controle caso ocorram surtos no país. / Avian influenza viruses infect a variety of birds and mammals and are known for their relevant enconomic and public health impacts. Anseriformes (ducks, mallards and geese) and Charadriiformes (shorebirds, seagulls and terns) are natural reservoirs of avian influenza viruses, and the migratory behaviour of many of these species can result in the spread of the virus among countries. There are few studies investigating the occorrence of these viruses in South America, hindering understanding of their ecology and epidemiology in Brazil. This study aims to detect and characterize avian influenza viruses in migratory birds in wintering areas on the Amazon coast. Orotracheal and cloacal swabs were obtained from 1093 wild birds, mostly Anseriformes and Charadriiformes, during six expeditions between 2008 and 2010 to the state of Pará, Brazil. Samples from nine birds were positive to Real time RT-PCR: 2 Actitis macularius, 4 Arenaria interpres, 1 Calidris pusilla, 1 Charadrius semipalmatus e 1 Dendrocygna viduata. Virus isolation was successfully carried out for the samples from three Arenaria interpres, in agreement with previous studies reporting high prevalence in this species. Hemaglutinin and neuraminidase inhibition assays indicated these strains belonged to subtype H11N9, considered low pathogenic and relatively common in shorebirds. Gene sequencing demonstrated close phylogenetic relationship between the strains isolated in this study and those found in North America, revealing the existence of epidemiological conectivity among these populations. It is therefore vital to maintain active epidemilogical surveillance of wild birds in this region, collecting information on virus prevalence, subtype and pathogenicity that may in turn be used to implement prevention and control policies for avian influenza outbreaks.

Ecological immunology is the study of the ecological and evolutionary factors that explain variation in the function of, and investment in, the immune system. Within this field, reproduction-based trade-offs are an important focus, where studies often address the immunological costs associated with the expression of secondary sexual traits used in mate choice. Specifically, the Immunocompetence Handicap Hypothesis (ICHH) links the expression of secondary sexual traits to immune function, stating that testosterone promotes the expression of these traits while suppressing the immune system. In doing so, testosterone may maintain the honest expression of such traits, but also ultimately cause sex differences in immunity because males tend to have high levels of testosterone. I explore aspects of these topics using two model systems: the Psittaciformes (Parrots: Chapter 2) and the Charadriiformes (shorebirds), in particular the sex-role reversed Red phalarope (Phalaropus fulicarius). In Chapter 2, I employed a phylogenetically informed approach to investigate the relationships among immune investment, plumage colouration and longevity in parrots. I found that immune investment was greater in more colourful species, as well as in those with a slower pace-of-life (i.e., longer incubation periods), but not specifically in those with longer lifespans. In Chapter 3, I investigated the role that reproductive behaviours play in determining sex differences in corticosterone levels. One explanation for sex differences in the stress response is that selection favours a reduced response in incubating birds to reduce nest abandonment. I generally found little support for sex differences in corticosterone being driven by behaviours related to incubation. Moreover, in phalaropes, sex differences in corticosterone were already present prior to incubation. In Chapter 4, I found that males have higher levels of testosterone than females, but that females were immunosuppressed compared to males. However, I found evidence that testosterone may regulate immune function in females, but not males. The observation of female-biased immunosuppression is consistent with Bateman’s Principle, and although there was some evidence of a testosterone-mediated handicap acting through immune function, these results attest to a fundamental lability in the relationship between testosterone and immunity. In Chapter 5, I demonstrated that plumage colouration in phalaropes is condition-dependent and so potentially conveys useful information to conspecifics. Yet, the relationship was negative in both sexes such that more colourful individuals had poorer immunocompetence, which was contrary to predictions. In Chapter 6, I demonstrated that phalaropes pair assortatively (positively) based on plumage colouration, but negatively based on aspects of size. I discuss the results of this dissertation in the light of life history theory, as well as in the context of mechanisms maintaining signal honesty.

No description available.

O talha-mar Rynchops niger (Rynchopinae) e o trinta-réis-grande Phaetusa simplex (Sterninae), são aves aquáticas migratórias que se reproduzem simultaneamente em muitas praias fluviais da América do Sul. A taxonomia e a sistemática destas subfamílias foram objetos de poucos estudos. Além disso, possuem subespécies cuja delimitação e a caracterização ainda são confusas, além do que, uma revisão rigorosa da validade destes táxons nunca foi feita. E, como consequência dos poucos estudos, existe uma enorme imprecisão sobre a real área de distribuição de cada táxon, não havendo muita informação sobre os locais para onde se movimentam após o período reprodutivo. Assim sendo, este trabalho teve como objetivo caracterizar geneticamente e revisar a taxonomia destas duas espécies polítipas, definindo os seus táxons válidos e distribuição. Para tal, foram utilizados caracteres morfológicos (de plumagem e morfométricos), sequências do gene mitocondrial ND2 e de marcadores associados a sítios de restrição (ddRADseq), a fim de estimar a variação intra e interpopulacional, o fluxo gênico e a estrutura genética; visando também entender o padrão de migração destes táxons na América do Sul e a influência dos rios na taxonomia e na história evolutiva destas aves. De acordo com os resultados conclui-se: P. simplex passa a ser considerado um táxon monotípico, pois não é possível separar as subespécies entre si, nem morfologicamente e nem geneticamente. Apesar das variações genéticas entre as três subespécies de R. niger não serem significativas, estas continuam a ser consideradas como subespécies válidas, pois puderam ser plenamente diagnosticáveis quanto aos caracteres de plumagem e de distribuição. Não existem variações genéticas significativas entre as populações. As populações podem estar passando por um processo de expansão recente ou seleção positiva; ou podem estar se comportando como uma metapopulação. Os grandes rios sul-americanos, juntamente com o ciclo sazonal de precipitação da América do Sul (que altera a dinâmica destes rios), influenciam diretamente na distribuição, e, consequentemente, na evolução das aves aqui analisadas. Neste caso, os rios funcionam como vias de contato (e não como barreiras) entre os indivíduos, contribuindo para o intenso fluxo gênico dos táxons aqui apresentados / The Black Skimmer (Rynchops niger) and the Large-billed Tern (Phaetusa simplex) are migratory waterbirds that breed simultaneously on river beaches throughout South America. Few studies have been conducted on the taxonomy and systematics of these polytypic species and the delimitation and validity of each taxa described has never been studied in detail. As a result, the geographical distribution of both species is poorly understood and there is little information about the whereabouts of their non-breeding grounds. Therefore, the purpose of this study was to characterize genetically and revise the taxonomy and distribution of these two polytypic species. For this it was integrated morphological characters (plumage and morphometrics), mitochondrial sequences (ND2), and single nucleotide polymorphisms (SNPs) inferred from double digestion restriction associated DNA sequencing (ddRADseq) to estimate: 1) intra- and inter-populational variation, 2) gene flow, 3) population genetic structure, 4) migration patterns of these taxa within South America, and 5) assess the influence of rivers on the taxonomy and evolutionary history of these birds. The results lead to the following conclusions: P. simplex should now be considered a monotypic taxon because currently recognized subspecies are neither morphologically nor genetically diagnosable. Although genetic variation between the three subspecies currently recognized in R. niger is not significant, these taxa continue to be considered as valid subspecies because they are fully diagnosable in plumage characters and distributional patterns. There are no significant genetic variation between the populations of both species (R. niger and P. simplex). Populations may be undergoing a process of recent expansion or positive selection or they may be behaving like a metapopulation. Main South American rivers, together with the seasonal precipitation cycles of South America (which changes the dynamics of these rivers), have direct influence on the distribution, and, consequently, on the evolution of these birds. In this case, the rivers function as pathways of contact (and not as barriers) between individuals, contributing to the intense gene flow between these taxa

Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2017-03-08T12:01:57Z No. of bitstreams: 1 PDF - Leomyr Sângelo Alves da Silva.pdf: 8192669 bytes, checksum: 4a337a15070f7bb47be66578de81125b (MD5) / Made available in DSpace on 2017-03-08T12:01:57Z (GMT). No. of bitstreams: 1 PDF - Leomyr Sângelo Alves da Silva.pdf: 8192669 bytes, checksum: 4a337a15070f7bb47be66578de81125b (MD5) Previous issue date: 2016-02-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Estuarine habitats are critical in the life cycle of shorebirds. In estuaries, these birds perform daily movements, feeding in intertidal zones at low tides and lounging on beaches and other supratidais areas during high tides. To reduce energy costs, the rest rooms must be near the feeding areas, but many of these sites are used by people for recreational activities and other occupations which probably disturb the birds. This study aimed to investigate the choices made by waders as their resting places near and adjacent to the estuary of the River Paraiba, northeastern Brazil. Were performed 4 monthly census from October 2014 to May 2015, quantifying the data abundance of birds and anthropogenic disturbances in two beaches of Paraíba coast, and in an artificial habitat (roof) that was used during the wintering period in the area urban Cabedelo, PB, Brazil. Censuses were carried out simultaneously in all counting sites, and were divided into day weekend and midweek. four species were recorded of wading birds belonging to the family Charadriidae (Charadrius semipalmatus and Charadrius collaris) and Scolopacidae (Calidris alba and Calidris pusilla). The species C. semipalmatus was the most representative for the study areas. The mean abundance of birds that occupied the roof were higher during the weekends, days that also there were major disturbances on the beaches from the days midweek when they were recorded smaller amounts of recreational activity. However, despite the positive influence on the increase of disturbances in poultry artificial housing, as well as the variation in the abundance of birds who used two beaches, the effects were significantly weaker, as shown by the dependency analysis. This study suggests that the number of anthropogenic occupations in both beaches, probably were not enough to scare away the birds nearctic areas rests indicating that the birds that have been using the artificial habitat are coming from other areas of Paraíba coast. In addition, we emphasize the importance of a greater number of sample areas for future research that seek to address the waders response in relation to anthropogenic influences, as possibly the small geographical scale of our study may have influenced our data. / Hábitats estuarinos são fundamentais no ciclo de vida das aves limícolas. Nos estuários, estas aves realizam movimentos diários, se alimentando nas zonas intertidais durante as marés baixas e descansando nas praias e outras áreas supratidais durante as marés altas. Para reduzir gastos energéticos, os locais de descanso precisam ser próximos às áreas de alimentação, porém muitos destes locais são utilizados por pessoas para atividades recreativas e outras ocupações, que, provavelmente, perturbam as aves. O presente estudo teve por objetivo investigar as escolhas feitas por aves limícolas quanto aos seus locais de descanso próximo e adjacentes ao estuário do Rio Paraíba, Nordeste do Brasil. Foram realizados 4 censos mensais entre outubro de 2014 à maio de 2015, quantificando os dados de abundância de aves e os distúrbios antrópicos em duas praias da costa paraibana, e em um habitat artificial (telhado) que foi utilizado durante o período de invernada na zona urbana de Cabedelo-PB, Brasil. Os censos foram realizados simultaneamente em todos os locais de contagem, e foram distribuídos em dias de final de semana e meio de semana. Foram registradas quatro espécies de aves limícolas pertencentes as famílias Charadriidae (Charadrius semipalmatus e Charadrius collaris) e Scolopacidae (Calidris alba e Calidris pusilla). A espécie C. semipalmatus foi a mais representativa para as áreas de estudo. As médias das abundâncias de aves que ocuparam o telhado foram maiores durante os finais de semana, dias em que também verificaram-se os maiores distúrbios nas praias em relação aos dias no meio da semana, quando foram registradas menores quantidades de atividade recreativas. No entanto, apesar dos distúrbios influenciarem positivamente o aumento de aves no habitat artificial, assim como a variação da abundância de aves que utilizaram as duas praias, os efeitos foram estatisticamente fracos, como revelado pela análise de dependência. O presente estudo sugere que o número de ocupações antrópicas nas duas praias, provavelmente não foram suficientes para afugentar as aves neárticas das áreas de descansos indicando que, as aves que vem utilizando o habitat artificial estão vindo de outras áreas da costa paraibana. Além disso, ressaltamos a importância de um maior número de áreas amostrais em futuras pesquisas que busquem abordar a resposta de aves limícolas em relação às influências antrópicas, já que, possivelmente a pequena escala geográfica de nosso estudo pode ter influenciado nossos dados.

Endoparasite community structure has been poorly studied in migratory birds, particularly among the seabirds of south Florida. We examined parasite communities in seven south Florida seabird species: brown pelican Pelecanus occidentalis (n=33), northern gannet Morus bassanus (n=31), double-crested cormorant Phalacrocorax auritus (n=33), osprey Pandion haliaetus (n=27), royal tern Thalasseus maximus (n=30), herring gull Larus argentatus (n=12), and laughing gull Leucophaeus atricilla (n=40). We identified 33 parasitic helminth species: 6 nematodes, 2 cestodes, 3 acanthocephalans, and 22 digeneans. Subsequent pairwise tests and similarity profile analysis identified four distinct clusters with similar parasite community structures: (1) pelican and gannet; (2) cormorant; (3) osprey; and (4) tern and both gull species. The mean infracommunity observed species richness differed among the several seabird host species with the highest observed values in pelicans (5.7±0.4) and gannets (5.1±0.4), while the lowest values were seen in herring (0.8±0.7) and laughing (0.4±0.4) gulls. RELATE analyses indicated that the factors of host phylogeny (Rho=0.564, p=0.017), host feeding range (Rho=0.553, p=0.005), and host feeding technique (Rho=0.553, p=0.039) were significant and had similar magnitudes of effect on the structure of observed parasite communities within the several seabird species of this study. Host prey preference was not significant from the RELATE analyses (Rho=0.124, p=0.278), suggesting that preferred prey items of the several seabird hosts had a negligible impact in the structuring of parasite communities. From our results, host phylogeny and host feeding ecology are important driving factors of parasite community composition and structure of these south Florida seabirds, while host prey preference had little influence on parasite communities.

Anthropogenic impacts, such as habitat destruction and spread of exotic species, are contributing to the sixth major extinction event in Earth’s history. To develop effective management and conservation plans, it is important to understand the ecological drivers of at-risk populations, assess the ability of a population to adapt to environmental change, and develop research methods for long-term ecosystem monitoring. I used wading birds nesting in the Florida Everglades, USA as a model system to address the challenges of managing and monitoring populations within an ecosystem greatly impacted by anthropogenic activities. Specifically, my project investigated 1) the prey selection of wading bird species, and the role of prey and foraging habitat availability on annual nesting numbers, 2) the ability of using diet change to predict species adaptability to a rapidly changing environment, and 3) the use of sensory data to provide low-cost, long-term monitoring of dynamic wetlands. I found that tricolored herons, snowy egrets, and little blue herons consumed marsh fish larger than those generally available across the landscape. Additionally, number of nests initiated by tricolored herons, snowy egrets, and little blue herons was strongly correlated with the annual densities of large fish available within the Everglades landscape. Conversely, number of nests initiated by wood storks, great egrets, and white ibises was more correlated with the amount of foraging habitat availability across the nesting season. Wood stork diets changed considerably since the 1960’s, consisting of mainly sunfish and exotic fish as opposed to marsh fishes dominant in historical diet studies. Storks also consumed more exotic fish species than they did historically. This diet plasticity and the species’ ability to exploit anthropogenic habitats may be conducive to maintaining population viability as storks experience widespread human-induced changes to their habitat. Sensory-only data models generated complementary results to models that used site-specific field data. Additionally, sensory-only models were able to detect different responses between size classes of fish to the processes that increase their concentrations in drying pools. However, the degree to which sensory variables were able to fit species data was dependent upon the ability of sensors to measure species-specific population drivers and the scale at which sensors can measure environmental change. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection