Orientador: José Maurício Barbanti Duarte / Banca: José Eduardo Pereira Wilken Bicudo / Banca: Jorge Luiz Berger Albuquerque / Banca: Paulo Henrique Franceschini / Banca: Elisabeth Criscuolo Urbinati / Resumo: Apesar da radiotelemetria ser considerada uma ferramenta valiosa em estudos ornitológicos, algumas teorias relativas ao impacto de radiotransmissores sobre a estimativa de parâmetros comportamentais, ecológicos e reprodutivos podem ser encontradas em literatura. Com o intuito de avaliar os potenciais efeitos fisiológicos de radiotransmissores do tipo mochila em falcões quiri-quiri (Falco sparverius) de vida livre, oito machos desta espécie foram capturados e divididos em dois grupos: indivíduos marcados com radiotransmissores (aproximadamente 5% do peso vivo, n = 6) e indivíduos controle (anilhados, n = 2). Em seguida, amostras fecais foram coletadas duas horas após a captura (dia −1) e durante os dias 0 (definido como o dia de soltura dos animais), 4, 7, 15, 30, 40 e 55. Previamente às análises laboratoriais, o ensaio imunoenzimático para dosagem de glucocorticóides fecais foi testado empregando procedimentos padrões de validação hormonal (paralelismo, curva de dose-resposta, validação fisiológica e coeficientes de variação inter- e intra-ensaio). Em relação aos machos monitorados, ambos os grupos apresentaram um aumento significativo nos níveis de glucocorticóides fecais durante o dia 0 (P < 0,001), mas as concentrações retornaram aos níveis pré-equipagem após 4 dias da soltura. Além disso, os níveis de glucocorticóides fecais não diferiram significativamente entre os falcões radiomarcados e os anilhados durante os 55 dias de monitoramento (P > 0,05). Embora o número de indivíduos neste estudo seja reduzido, estes resultados sugerem que radiotransmissores do tipo mochila não induzem efeitos persistentes sobre a atividade adrenal de machos de falcões quiri-quiri de vida livre. Considerando a literatura consultada, esta é a primeira pesquisa a analisar os efeitos de radiotransmissores sobre a resposta adrecortical de aves de vida livre. / Abstract: Although radiotelemetry is considered a valuable technique for ornithological field studies, several assumptions have been made about the impact that transmitters may cause on the estimation of behavioral, ecological and reproductive parameters. To assess potential effects of backpack radiotransmitters, we captured and assigned 8 male American kestrels (Falco sparverius) in 2 groups: radio-tagged (n = 6) and control individuals (leg-banded, n = 2). Thereafter, we collected feces two hr after capture (day −1), and subsequently during days 0 (releasing day), 1, 4, 7, 15, 30, 40 and 55. Prior to fecal analysis, EIA corticosterone assay was validated using standard procedures (e.g. parallelism, dose-response curve), and physiological significance of fecal glucocorticoid metabolites was confirmed through adrenocorticotropin (ACTH) challenge, which induce an increase of 4-fold (446.10 ± 60.73 ng/ g) above baseline (114.27 ± 15.23 ng/ g) within 4 hr (P < 0.001). Both groups exhibited a significant increase in fecal glucocorticoids during day 0 (P < 0.001), but concentrations returned to pre-attachment values within 4 days. Fecal glucocorticoid concentrations did not differ between samples of radio-tagged and leg-banded kestrels (P > 0.05). In spite of the small number of monitored subjects, these findings suggested that radiotransmitters did not affect adrenocortical activity in male American kestrel. To our knowledge, this is the first research to evaluate the effects of transmitters on stress responses in free-ranging birds. / Doutor

In der vorliegenden Arbeit wurde die Netzhaut einiger tagaktiver Raubvögel hinsichtlich ihrer morphologischen und morphometrischen Eigenschaften mit verschiedenen Methoden untersucht. Über die Histologie werden Gestalt und Subspezialisierungen der Netzhaut von neun Vögel sieben verschiedener Spezies in ihrer nasal-temporalen und superior-inferioren Ausdehnung betrachtet. Besonderes Augenmerk lag hierbei auf dem Verhältnis der Photorezeptor- und Neuronenpopulationen zueinander, da hier über den Grad von Konvergenz oder Divergenz der Verschaltung Informationen über die intraretinale Signalverarbeitung gewonnen werden können. Über das Verfahren der Immunhistochemie wurde zudem untersucht, ob sich die Spezies hinsichtlich der intraretinalen Verteilung einiger ausgewählter Marker von Strukturen der Müllerzellen und der Photorezeptoren unterscheiden. Eine weitere angewandte Methode war die optische Kohärenztomographie, ein bildgebendes Verfahren, das non-invasiv in vivo Schnittbilder der Netzhaut erzeugt. Hier konnte gezeigt werden, dass diese aus der humanen Augenheilkunde bekannte Untersuchungstechnik auch am aviären Patienten anwendbar ist. Desweiteren wurde die Darstellbarkeit der aviären Netzhaut, ihrer Besonderheiten und pathologischer Veränderungen bei den verschiedenen Raubvogelspezies untersucht. Für bestimmte Regionen in der Raubvogelnetzhaut wie die Fovea centralis und temporalis, sind in historischen Untersuchungen Formunterschiede beschrieben worden und es konnte gezeigt werden, dass diese auch in vivo bestehen. Zuletzt wird die Frage behandelt, welche Unterschiede der Vergleich zwischen den beiden Verfahren der Netzhautdarstellung aufdeckt, inwiefern beide fehlerbehaftet sind und was bei der Interpretation beachtet werden sollte.:Inhaltsverzeichnis 1 Einleitung 1 1.1 Grundlagen zur Netzhaut 1 1.2 Die optische Kohärenztomographie (OCT) 6 1.3 Aufgabenstellung und klinische Relevanz 7 2 Material und Methoden 10 2.1 Untersuchungsmaterial 10 2.2 Spezies der histomorphologischen Untersuchung 10 2.3 Histologie und Immunhistochemie 14 2.4 Vergleich von OCT-Abbildung und histologischem Korrelat 25 2.5 Untersuchung der Ultrastruktur der aviären Netzhaut 28 3 Ergebnisse 30 3.1 Histologische und immunhistochemische Analyse der Netzhaut von tagaktiven Raubvogelspezies 30 3.2 Untersuchung retinaler Strukturen bei tagaktiven Raubvögeln mittels OCT 84 3.3 Vergleich der Darstellung in OCT und Histologie 91 3.4 Elektronenmikroskopie der äußeren Netzhaut des Raubvogels 95 4 Diskussion 98 4.1 Morphometrische Untersuchungen in Histologie und Immunhistochemie 98 4.2 OCT-Untersuchung von tagaktiven Raubvögeln 110 4.3 Verhältnis von OCT und histologischem Abbild 113 4.4 Fazit und Ausblick 115 Zusammenfassung 117 Literatur 121 Anhang

Die vorliegende Arbeit beschäftigte sich mit zwei Methoden zur Diagnostik der Aspergillose bei Greifvögeln, um neue Erkenntnisse über die Aussagekraft dieser nicht invasiven Diagnostika zu gewinnen. In der ersten Studie wurden bei ausschließlich Aspergillose-positiven Falken (Falco spp.) (n = 110) spezifische Röntgenzeichen an digital erstellten Röntgenbildern systematisch ermittelt und mit den typischen Röntgenzeichen von Papageien mit Erkrankungen des unteren Respirationstrakts verglichen. In der zweiten Studie wurden gesunde (n = 73) und an Aspergillose erkrankte (n = 32) Jagdfalken (Falco spp.) mittels Serumelektrophorese untersucht, Referenzwerte für die gesunden Falken erstellt und mit den Werten der erkrankten Falken verglichen. In beiden Studien stammten die Tiere aus dem Patientengut derselben Klinik. Bei der Auswertung von Röntgenbildern Aspergillose-positiver Falken wurden hauptsächlich subtile Röntgenzeichen beschrieben. Von den 110 Tieren waren 29 (26,4 %) radiologisch vollkommen unauffällig. Die am häufigsten beschriebenen Befunde waren inhomogene Verschattungen des Lungenfeldes (38,2 % laterolateral [ll]) und strichförmige Verschattungen der kaudalen Lungengrenze (30,0 % ll) sowie inhomogene (34,5 % ll; 29,1 % ventrodorsal [vd]) und streifige (26,4 % ll) Verschattungen der Luftsäcke, aber auch eine schlechte Abgrenzbarkeit des Herzschattens in der laterolateralen Projektion (42,7 %). Im Vergleich zu an Papageien mittels konventioneller Projektionsradiographie durchgeführten Studien war der Anteil an subtilen Röntgenzeichen geringer und der Anteil an massiven Röntgenzeichen größer. Verglichen mit Referenzwerten diverser Greifvogelspezies aus der Literatur zeigten die Referenzwerte der gesunden Falken dieser Studie unter Verwendung des hochauflösenden Elektrophoresesystems SAS 1 unit (Helena, Saint Leu La Forest, Frankreich) relativ niedrige Gesamtproteinwerte und relativ hohe Präalbuminwerte auf. Bei den 32 Serumproben der an Aspergillose erkrankten Falken ließ sich im Gegensatz zu den 73 Serumproben der gesunden Falken ein signifikant erniedrigter Totalalbuminwert (Albumin + Präalbumin) sowie ein hoch signifikant erniedrigter Präalbuminwert mittels Serumelektrophorese feststellen. Obwohl die Falken meist schon in frühen Krankheitsstadien vorgestellt wurden und die Diagnostik in diesen Stadien besonders schwierig ist, konnten mit beiden Untersuchungsmethoden von gesunden Tieren differierende Befunde erhoben werden. Diese in Zusammenhang mit Aspergillose erhobenen Befunde wichen jedoch teilweise deutlich von den in der Literatur beschriebenen „typischen“ Befunden bei an Aspergillose erkrankten Vögeln ab. Dies kann damit erklärt werden, dass die meisten vergleichbaren Studien an als Heimtiere gehaltenen Papageien oder gefangen gehaltenen Zoovögeln (von Falken abweichende Haltungsform, Anatomie und Physiologie sowie Leistungsniveau) und mit unterschiedlicher Technik (digitale versus konventionelle Projektionsradiographie, unterschiedliche Elektrophoresesysteme und Verwendung von Serum anstelle von Plasma) durchgeführt wurden. Die digitale Projektionsradiographie kann aufgrund ihrer schonenden, einfachen und schnellen Durchführbarkeit sowohl den Vogelmedizin spezialisierten Institutionen als auch den Kleintierpraktikern uneingeschränkt empfohlen werden. Die Proteinelektrophorese kann bis zum heutigen Zeitpunkt nur bedingt für den Praktiker, wohl aber für spezialisierte Institutionen bei Beachtung aller Besonderheiten als zusätzliches Diagnostikum empfohlen werden. / The present study concentrates on two methods for diagnosing birds of prey with aspergillosis with the intent to increase the knowledge of the validity of these non-invasive diagnostic methods. In the first study, specific radiographic signs of digitally created radiographs of falcons (Falco spp.) which were exclusively positive for aspergillosis (n = 110) were systematically analyzed and compared to the typical radiographic signs of parrots with diseases of the lower respiratory tract. In the second study, healthy falcons (n = 73) and falcons affected with aspergillosis (n = 32) (Falco spp.) were examined by using serum protein electrophoresis in order to create reference values for healthy falcons and compare them with the values of the affected falcons. In both studies, the animals were patients of the same clinic. While evaluating the radiographs of the falcons with aspergillosis, mainly subtle radiographic signs were described. Radiographically within normal limits were 29 (26.4%) of the 110 animals. The most commonly reported findings were inhomogeneous increased radiodensity of the lung area (38.2% laterolateral [ll]), line-shaped shadowings of the caudal lung border (II 30.0%) as well as an inhomogeneous (34.5% ll, 29.1% ventrodorsal [vd]) and streaky (26.4% II) radiodensity of the air sacs, but also a poor delineation of the cardiac silhouette in the laterolateral projection (42.7%). Compared to studies performed on parrots by conventional radiography, the portion of subtle radiographic signs was lower and the portion of severe signs was higher. Compared to reference values of various raptor species from the literature, this study, which made use of the high-resolution electrophoresis SAS 1 unit (Helena, Saint Leu La Forest, France), revealed relatively low values for total proteins and relatively high values for prealbumin in the reference values of the healthy falcons. The 32 serum samples of the falcons suffering from aspergillosis showed a significantly reduced total albumin (albumin + prealbumin) level and a highly significantly reduced prealbumin level compared to the 73 serum samples of healthy falcons. Although the falcons were for the most part already brought to the clinic in one of the early stages of the disease, when diagnosing aspergillosis is particularly difficult, both examination methods revealed different results for the healthy and diseased animals. However, the findings related to aspergillosis were in some cases significantly different from those described in the literature as the \"typical\" findings in birds suffering from aspergillosis. This can be explained by the fact that most of the comparable studies were conducted with parrots held as pets or with captive zoo birds (when husbandry, anatomy and physiology, as well as performance level are different from falcons) and with a different technique (digital versus conventional radiography, different electrophoresis systems and the use of serum instead of plasma). The digital radiography can be fully recommended for specialized medical institutions for avian medicine as well as for small animal practitioners because of its easy, rapid and gentle feasibility. To date, the protein electrophoresis can only be recommended with restrictions for practitioners, however for specialized institutions, it can be useful as additional diagnostic tool if all its specific features are taken into account.

Reliable estimates of species abundance, distribution, and population trajectories are critical in conservation and management. However, for many tropical species that information is missing. We conducted Sharp-shinned Hawk (SSHA) searches during the breeding seasons of 2013, 2014, and 2016 in eight montane forest reserves and their adjacent private lands of Puerto Rico. Further, we developed a maximum entropy model (MaxEnt) of the SSHA’s potential distribution using the following environmental variables: aspect, canopy closure, elevation, rainfall, slope, and terrain roughness. Elevation accounted for 89.8% of model fit, predicting the greatest probability of occurrence (> 60%) at elevations above 900 m. The model estimated 0.6% Puerto Rico (56.1 km2) has the greatest probability of occurrence. We developed a periodic population matrix model to describe influence of early life stages on population growth of the Red-tailed Hawk (RTHA) in eastern Puerto Rico. Our results suggest that the RTHA population has an average annual population increase of 5%, with rates differing between highlands (λh = 1.05) and 27% lowlands (λl = 1.27). Adult survival was the most important population growth parameter, with more effect in highlands (elasticity = 0.86) than in lowlands (elasticity = 0.53). Sensitivity of λ to changes in nestling survival was greater than for other life-stages (sensitivity lowlands = 0.46, sensitivity highlands = 0.48). I developed an open population N-mixture model to estimate abundance, availability, and detection probability of RTHA in the Luquillo Mountains and western Cordillera Central. The abundance estimates were 0.05 RTHA/ha, with an availability of (ϕ) = ~1 RTHA/per survey point and a detection probability (r) = ~0.25. In Luquillo Mountains, abundance was positively influenced by slope and elevation. In the western Cordillera Central, abundance of RTHA was constant across elevation, slope, and canopy closure. Detection probability decreased with increasing slope and wind conditions and showed a gradual small negative decrease with slope with reduced winds conditions. My findings are a contribution to our knowledge to how population traits and ecological constraints imposed by insular environments are influencing distribution, abundance, and population dynamics of raptors to propose management or conservation schemes.

The aim of the study was to determine the consequences of elephant (Loxodonta africana) impact on selected nesting sites of avian fauna and other species in the Associated Private Nature Reserves. The study also aimed at answering key questions on how the architecture of trees influence nest site suitability and what landscape features affect nest site location. Furthermore the type of impact that elephants have on specific nesting sites was determined and how this would affect the short term persistence of these trees. The facillitatory role of elephants was examined by looking at the type of impact that produces gum exudants as well as what gum is selected for by primates and whether primary branch breaking may lead to the creation of nesting sites for species such as the southern ground hornbill (Bucorvus leadbeateri). / Environmental Sciences / M. Sc. (Environmental Management)

As aves de rapina, assim como os outros grupos animais, não estão distribuídas de maneira uniforme nos diferentes hábitats que compõem a paisagem terrestre. Conhecer e entender os fatores (e as implicações) que levam as espécies a escolher um determinado hábitat é questão essencial nos estudos de ecologia. Esse tema ganha ainda mais importância não só pela escassez de informações sobre a ecologia e história natural das aves de rapina na região Neotropical, mas também, pelo atual cenário de alteração dos hábitats. Estes são modificados rapidamente sem que haja um conhecimento básico da relação espécie/hábitat e dos efeitos provocadas por tais alterações. Dessa maneira, a presente tese teve como objetivo principal verificar o uso e a seleção de hábitat por aves de rapina diurnas em uma paisagem heterogênea (151. 866 ha) na região central do Estado de São Paulo (22° 15&#8242; S; 47° 49&#8242; W), onde a Estação Ecológica de Itirapina (EEI) foi considerada como área núcleo. Ainda, foi também alvo desse estudo estimar a área de vida de três espécies de rapineiros (Falco femoralis, Rupornis magnirostris e Heterospizias meridionalis) por meio de rádio-telemetria; verificar a eficiência de captura das aves de rapina frente a dois tipos de armadilhas, bal-chatri e goshawk; e elaborar um mapa de uso/ocupação do solo da área em questão, bem como analisar a paisagem no entorno da EEI. Entre setembro de 2005 e fevereiro de 2007 foram registradas 19 espécies de Falconiformes (Pandionidae n =1, Falconidae n = 5, Accipitridae n = 13) em uma paisagem essencialmente ocupada por monoculturas (cana-de-açúcar 22 %, laranja 14 %, eucalipto 13 %) e pastagens (21%). A riqueza média dos Falconiformes em áreas de monoculturas foi de 4,6 espécies e nas áreas naturais 10,3. A composição de espécies da taxocenose se mostrou mais relacionada às outras de área abertas sob influência do Cerrado. Um total de 48 indivíduos, pertencentes a cinco espécies, foram capturados pelos dois tipos de armadilhas. O sucesso de captura geral foi de 15,3 % (n = 33) para a armadilha bal-chatri e de 1 captura a cada 11,8 dias (8,5 %) para goshawk trap (n = 15). Implicações e limitações referentes à captura das aves de rapinas em áreas abertas foram também discutidas. A média da área de vida pelo método Kernel adaptativo (KA) 95 % foi de 1.329 ± 780 ha para F. femoralis, 129 ± 140 ha para R. magnirostris e de 1.883 ha para o indivíduo de H. meridionalis. A média da área de vida de F. femoralis foi 2,8 maior em áreas alteradas quando comparada a áreas naturais. De maneira geral, a qualidade do hábitat parece ter influenciado nos diferentes valores de requerimento de área apresentado pelos indivíduos e, também, na seleção/rejeição dos diferentes hábitats. Na maioria dos casos, as monoculturas foram rejeitadas, enquanto as áreas naturais foram selecionadas pelas aves de rapina. Cana-de-açúcar foi rejeitada por todas as aves de rapina. O único ambiente alterado utilizado em maior proporção que o esperado foi pastagem, selecionada por quatro das 10 espécies analisadas. Em contrapartida, três espécies evitaram este hábitat. Este é o primeiro estudo a avaliar a seleção de hábitat por Falconiformes no Brasil e demonstra que o intensivo incremento de áreas para agricultura pode afetar negativamente até mesmo as espécies mais abundantes e generalistas, contrário a algumas generalizações da literatura. A interação entre estrutura do hábitat, disponibilidade de presas, morfologia e comportamento de caça parece explicar tanto o tamanho da área de vida requerida quanto a utilização diferenciada dos diferentes tipos de hábitats. / Raptors, similarly to other animal groups, are not randomly distributed in the different habitats in the terrestrial landscape. Knowing and understanding the factors (and implications) influencing these species to chose a certain habitat are essential in ecological studies. This subject has become even more important not only because of the lack of information on the ecology and natural history of raptors of the Neotropics, but also because of current scenario of habitat changes. Areas are being rapidly modified without a basic knowledge of the species/habitat relationship and the effects it may cause. Thus, the main goal of this thesis was to examine habitat use and selection by diurnal birds of prey in a heterogeneous landscape (151. 866 ha) in the central region of state of São Paulo (22° 15&#8242; S; 47° 49&#8242; W), where the Estação Ecológica de Itirapina (EEI) was considered the central area. Also, this study aimed at estimating the home range size of three raptor species (Falco femoralis, Rupornis magnirostris and Heterospizias meridionalis) through radio-telemetry; examining the efficiency of capture of birds of prey using two types of traps, bal-chatri and goshawk; and mapping land use/occupation of the study area and making the landscape analysis around the EEI. Between September 2005 and February 2007, 19 species of Falconiformes (Pandionidae n = 1, Falconidae n = 5, Accipitridae n = 13) were observed in a landscape basically occupied by monocultures (sugar cane 22 %, orange 14 %, eucalyptus 13 %) and pastures (2 1%). The average richness of Falconiformes in areas occupied by a monoculture was 4,6 species and 10,3 in natural areas. The species composition of the assemblage was more similar to those of other open areas influenced by Cerrado. Forty-eight individuals from five species were captured in the two types of traps. The general capture success was 15.3 % (n = 33) for the bal-chatri trap and 1 capture every 11,8 days (8,5 %) for the goshawk trap (n = 15). Implications and limitations of the capture of birds of preys in the areas were also discussed. The average home range obtained with the 95 % adaptive Kernel method (AK 95%) was 1.329 ± 780 ha for F. femoralis, 129 ± 140 ha for R. magnirostris and 1.883 ha for the individual of H. meridionalis. The average home range of F. femoralis was 2.8 higher in altered areas when compared to natural ones. In general, habitat quality seems to have influenced the different values of home range requirement of individuals, and also, in the selection/rejection of the different habitats. In most cases, monocultures were rejected, while natural areas were selected by raptors. Sugar cane plantations were rejected by all raptors. The only altered habitat used more than expected was pastures, selected by four of ten species analyzed. However, three species avoided this habitat. This is the first study to evaluate habitat selection by Falconiformes in Brazil and demonstrate that the increase of areas for agriculture may negatively affect even the most abundant and generalist species, contrary to some generalizations described in the literature. The interaction among the habitat structure, prey availability, morphology and hunting behavior seems to explain home range size requirements as well as the differential use of the various types of habitats.

As aves de rapina, como predadores de níveis superiores na rede trófica, necessitam de grandes áreas de vida e ocorrem em baixa densidade populacional. São sensíveis a alteração e degradação do habitat, sendo bons indicadores de qualidade de habitat e biodiversidade. Apesar da importância ecológica pouco se conhece sobre a biologia e ecologia da maioria das 91 espécies que ocorrem na América do Sul, o que nos leva ao objetivo mais amplo desta tese: descrever a composição das taxocenoses de aves de rapina dos campos do sul do Brasil e Uruguai e sua relação com as características topográficas e ambientais. Para tanto, foram realizadas amostragens de aves de rapina em 11 áreas campestres entre outono de 2009 e verão de 2011. Um total de 44 transectos rodoviários foi amostrado sazonalmente, duas vezes ao ano, totalizando 176 amostragens. Ao todo foram observadas 18.424 aves de rapina, pertencentes a 33 espécies. Os transectos rodoviários são amplamente utilizados para a amostragem de aves de rapina, no entanto, nossos resultados sugerem que este método pode subestimar a abundância das espécies. Pontos de contagem parecem ser mais eficazes, principalmente para a amostragem de espécies raras. A distribuição das espécies foi associada à altitude e disponibilidade de habitat, e quatro taxocenoses puderam ser identificadas no sudeste da América do Sul. A taxocenose dos campos de altitude (na ecorregião Floresta Úmida com Araucária) se caracterizou pela presença de espécies florestais, ausentes ou pouco abundantes nas demais áreas. Na ecorregião Savana Uruguaia foram distinguidas outras três taxocenoses: 1) campos da planície costeira do sul do Brasil, com espécies associadas às áreas úmidas e ambientes alterados; 2) campos da Serra do Sudeste, uma taxocenose mista com espécies campestres e florestais, porém pouco abundantes e com maior tolerância a habitat alterados; 3) campos da Savana Uruguaia, taxocenose com predominância de espécies campestres e presença pontual de espécies florestais associadas a matas riparias. Foram registradas quatro espécies de necrófagos obrigatórios (Cathartiformes). A organização da taxocenose dos necrófagos aparenta ser mais influenciada pelas características da paisagem que por relações hierárquicas interespecíficas, mas a distribuição atual pode ter sido influenciada pela caça e envenenamento das espécies, ocorrida no século passado. A abundância das aves de rapina variou sazonalmente. A abundância foi significativamente maior no verão que no inverno, mas variou conforme a espécie. Quatro espécies são migratórias (duas migrantes trans-equatorias e duas intratropicais), três são parcialmente migratórias, mas o padrão de migração e as rotas são pouco conhecidos, e três espécies são nômades ou realizam movimentos irruptivos. Os campos do sudeste da América do Sul tem uma alta diversidade de aves de rapina, influenciada pela topografia, disponibilidade de habitat e sazonalidade, características que devem ser consideradas nas políticas de conservação na região. / Raptors, as top predators, have large home ranges and low population densities. They are sensitive to human perturbation and habitat degradation; hence raptors are sentinel species and biodiversity indicators. Despite their ecological importance, the biology and ecology of most of the 91 South American raptors is poorly known. The main objectives of this study were to examine the assemblage composition in grasslands of southern Brazil and Uruguay and to investigate its relation with topography and habitat features. To achieve this, 44 roadside transects were conducted in 11 areas. Each transect was survey four times between autumn/2009 and summer/2011. The 176 transects yielded 18,424 contacts of raptors, belonging to 34 species. Roadside line transect is widely used to survey raptors. However, our results suggest that this method could underestimate the species abundance. Roadside point transect seems to be better, especially to survey rare species. Raptors distribution and assemblage composition were related to altitude and habitat availability, and four assemblages could be identified in southeastern South America. Raptor assemblage at Altitudinal grasslands (in the Araucarian Moist Forest ecoregion) had higher abundances of forest raptors than the other regions. Three assemblages were distinguished in the Uruguayan Savannas ecoregion: 1) south Brazilian coastal plain, with species related wetlands and human modified habitats; 2) Serra do Sudeste grasslands, a mix of forest and grassland raptors assemblage, which showed low abundances and lower sensibility to habitat degradation; 3) Uruguayan Savannas, dominated by grasslands species and few forest species usually found in riparian habitats. Four obligate scavengers (Cathartiformes) were recorded. Landscape features appeared to be more important to the assemblage organization than interspecific hierarchy, but the current distribution and abundance of scavengers could have been driven by species persecution and poisoning in the last century. Raptors abundance changed seasonally. Total abundance was significantly higher during summer than winter, and strategies to deal with seasonality varied between species. Four species are complete migrants (two transequatorial and two intratropical), three are partial migrants, but their routes and migration pattern remain poorly understood; and three species are irruptive or nomadic. The grasslands of southern South America have a high diversity of raptors, influenced by topography, habitat availability and seasonality, features that should be taken into account when divising regional conservation policies.

The White-bellied Sea-Eagle Haliaeetus leucogaster is widespread in Australia, but has been the subject of conservation concern due to suggested localised declines and extinctions. Regionalised monitoring programmes have addressed some aspects of local concern, however a broader approach is needed to gain an understanding of large-scale processes affecting long-term persistence at scales equivalent to the species Australian range. Ultimately, the ability to predict change in population size over time accurately depends on the scale of analysis. By necessity, ecological studies using direct sampling techniques are often made across spatial scales smaller than a species geographic range and across relatively short time frames. This seems counter-intuitive considering that long-term species persistence is often dependent on large-scale processes. The principal aim of this thesis was to identify historical and contemporary forces responsible for the current pattern of population structure in H. leucogaster. This required a multi-scale approach, and the resulting research uses genetic, distributional and morphometric data. Haliaeetus leucogaster is a large territorial raptor that historically has been associated with coastal regions, lakes and perennial river systems. It has an extensive worldwide distribution from the western coast of India throughout the Indomalaysian region, Papua New Guinea and Australia. By virtue of the species' large-scale distribution, in Australia it is fairly cosmopolitan in its use of habitat and prey types. Haliaeetus leucogaster is monomorphic for adult plumage colouration, but in body size displays reversed sexual dimorphism with female birds significantly larger. A discriminant function based on 10 morphometric characters was 100% effective in discriminating between 19 males and 18 females that had been sexed using molecular genetic methods. Re-classification using a jackknife procedure correctly identified 92% of individuals. The discriminant function should be a viable alternative to genetic sexing or laparoscopy for a large proportion of individuals within the Australo-Papuan range of this species; and can also be used to identify a small proportion of "ambiguous" individuals for which reliable sexing will require those other techniques. I used mitochondrial (mtDNA) control region sequence data to investigate the current distribution of genetic variation in this species at the continental level and within and between specified regional units. I was specifically interested in identifying breaks in genetic connectivity between the west and east of the continent and between Tasmania and the Australian mainland. Overall, genetic diversity was low and there was no significant level of genetic subdivision between regions. The observed genetic distribution suggests that the population expanded from a bottleneck approximately 160 000 years ago during the late Pleistocene, and spread throughout the continent through a contiguous range expansion. There is insufficient evidence to suggest division of the population into different units for conservation management purposes based on the theoretical definition of the 'evolutionary significant unit'. It is clear from the analysis that there are signatures of both historical and contemporary processes affecting the current distribution. Given the suggestion that population expansion has been relatively recent, additional sampling and confirmation of the perceived pattern of population structure using a nuclear marker is recommended to validate conservation monitoring and management at a continental scale. To determine the existence of perceived population declines across ecological time scales, I analysed the Australian Bird Atlas Data to identify the extent and pattern of change in range and density of the species between three Atlas Periods (1901-1976, 1977-1981 and 1998-2001) using a new standardised frequency measure, the Occupancy Index (OI) for 1° blocks (approx. 100km2) across the continent. At the continental scale, there was no significant difference in the spatial extent of occupancy between Atlas Periods. However, there were considerable changes in frequency and range extent between defined regions, and there were distinct differences in the pattern of change in OI between coastal and inland blocks over time. Coastal blocks showed much more change than inland blocks, with a clear increase in the use of coastal blocks, accompanied by a decrease in inland blocks, during the 1977-1981 Atlas Period, relative to both other Atlas Periods. The over-riding factor associated with distributional shifts and frequency changes was apparently climatic fluctuation (the 1977-1981 period showing the influence of El Nino associated drought). The impression of abundance was strongly dependent on both the temporal and spatial scale of analysis. To test for correspondence between geographic variation in morphology and geographic variation in mtDNA I analysed morphometric data from 95 individuals from Australia and Papua New Guinea. First, the degree of morphometric variation between specified regions was determined. This was then compared with the pattern of genetic differentiation. There was a strong latitudinal cline in body dimensions. However, there was no relationship between morphometric variation and patterns of genetic variation at least for mtDNA. Females showed a pattern of isolation by distance based on morphometric characters whereas males did not. Three hypotheses to explain the pattern of morphometric variation were considered: phenotypic plasticity, natural selection and secondary contact between previously isolated populations. I conclude that the pattern of morphometric variation is best explained by the suggestion that there is sufficient local recruitment for natural selection to maintain the observed pattern of morphometric variation. This implies that gene flow may not be as widespread as the mtDNA analysis suggested. In this instance either the relatively recent colonisation history of the species or the inability of the mtDNA marker to detect high mutation rates among traits responsible for maintaining morphometric variation may be overestimating the levels of mixing among regions. As might be expected given the physical scale over which this study was conducted, the pattern of genetic, morphometric and physical distribution varied dependent on the scale of analysis. Regional patterns of genetic variation, trends in occupancy and density and morphometric variation did not reflect continental patterns, reinforcing the contention that extrapolation of data from local or regional levels is often inappropriate. The combined indirect methodologies applied in this study circumvent the restrictions imposed by direct ecological sampling, because they allow survey across large geographic and temporal scales effectively covering the entire Australian range of H. leucogaster. They also allow exploration of the evolutionary factors underpinning the species' current distribution.

The aim of the study was to determine the consequences of elephant (Loxodonta africana) impact on selected nesting sites of avian fauna and other species in the Associated Private Nature Reserves. The study also aimed at answering key questions on how the architecture of trees influence nest site suitability and what landscape features affect nest site location. Furthermore the type of impact that elephants have on specific nesting sites was determined and how this would affect the short term persistence of these trees. The facillitatory role of elephants was examined by looking at the type of impact that produces gum exudants as well as what gum is selected for by primates and whether primary branch breaking may lead to the creation of nesting sites for species such as the southern ground hornbill (Bucorvus leadbeateri). / Environmental Sciences / M. Sc. (Environmental Management)

As aves de rapina, como predadores de níveis superiores na rede trófica, necessitam de grandes áreas de vida e ocorrem em baixa densidade populacional. São sensíveis a alteração e degradação do habitat, sendo bons indicadores de qualidade de habitat e biodiversidade. Apesar da importância ecológica pouco se conhece sobre a biologia e ecologia da maioria das 91 espécies que ocorrem na América do Sul, o que nos leva ao objetivo mais amplo desta tese: descrever a composição das taxocenoses de aves de rapina dos campos do sul do Brasil e Uruguai e sua relação com as características topográficas e ambientais. Para tanto, foram realizadas amostragens de aves de rapina em 11 áreas campestres entre outono de 2009 e verão de 2011. Um total de 44 transectos rodoviários foi amostrado sazonalmente, duas vezes ao ano, totalizando 176 amostragens. Ao todo foram observadas 18.424 aves de rapina, pertencentes a 33 espécies. Os transectos rodoviários são amplamente utilizados para a amostragem de aves de rapina, no entanto, nossos resultados sugerem que este método pode subestimar a abundância das espécies. Pontos de contagem parecem ser mais eficazes, principalmente para a amostragem de espécies raras. A distribuição das espécies foi associada à altitude e disponibilidade de habitat, e quatro taxocenoses puderam ser identificadas no sudeste da América do Sul. A taxocenose dos campos de altitude (na ecorregião Floresta Úmida com Araucária) se caracterizou pela presença de espécies florestais, ausentes ou pouco abundantes nas demais áreas. Na ecorregião Savana Uruguaia foram distinguidas outras três taxocenoses: 1) campos da planície costeira do sul do Brasil, com espécies associadas às áreas úmidas e ambientes alterados; 2) campos da Serra do Sudeste, uma taxocenose mista com espécies campestres e florestais, porém pouco abundantes e com maior tolerância a habitat alterados; 3) campos da Savana Uruguaia, taxocenose com predominância de espécies campestres e presença pontual de espécies florestais associadas a matas riparias. Foram registradas quatro espécies de necrófagos obrigatórios (Cathartiformes). A organização da taxocenose dos necrófagos aparenta ser mais influenciada pelas características da paisagem que por relações hierárquicas interespecíficas, mas a distribuição atual pode ter sido influenciada pela caça e envenenamento das espécies, ocorrida no século passado. A abundância das aves de rapina variou sazonalmente. A abundância foi significativamente maior no verão que no inverno, mas variou conforme a espécie. Quatro espécies são migratórias (duas migrantes trans-equatorias e duas intratropicais), três são parcialmente migratórias, mas o padrão de migração e as rotas são pouco conhecidos, e três espécies são nômades ou realizam movimentos irruptivos. Os campos do sudeste da América do Sul tem uma alta diversidade de aves de rapina, influenciada pela topografia, disponibilidade de habitat e sazonalidade, características que devem ser consideradas nas políticas de conservação na região. / Raptors, as top predators, have large home ranges and low population densities. They are sensitive to human perturbation and habitat degradation; hence raptors are sentinel species and biodiversity indicators. Despite their ecological importance, the biology and ecology of most of the 91 South American raptors is poorly known. The main objectives of this study were to examine the assemblage composition in grasslands of southern Brazil and Uruguay and to investigate its relation with topography and habitat features. To achieve this, 44 roadside transects were conducted in 11 areas. Each transect was survey four times between autumn/2009 and summer/2011. The 176 transects yielded 18,424 contacts of raptors, belonging to 34 species. Roadside line transect is widely used to survey raptors. However, our results suggest that this method could underestimate the species abundance. Roadside point transect seems to be better, especially to survey rare species. Raptors distribution and assemblage composition were related to altitude and habitat availability, and four assemblages could be identified in southeastern South America. Raptor assemblage at Altitudinal grasslands (in the Araucarian Moist Forest ecoregion) had higher abundances of forest raptors than the other regions. Three assemblages were distinguished in the Uruguayan Savannas ecoregion: 1) south Brazilian coastal plain, with species related wetlands and human modified habitats; 2) Serra do Sudeste grasslands, a mix of forest and grassland raptors assemblage, which showed low abundances and lower sensibility to habitat degradation; 3) Uruguayan Savannas, dominated by grasslands species and few forest species usually found in riparian habitats. Four obligate scavengers (Cathartiformes) were recorded. Landscape features appeared to be more important to the assemblage organization than interspecific hierarchy, but the current distribution and abundance of scavengers could have been driven by species persecution and poisoning in the last century. Raptors abundance changed seasonally. Total abundance was significantly higher during summer than winter, and strategies to deal with seasonality varied between species. Four species are complete migrants (two transequatorial and two intratropical), three are partial migrants, but their routes and migration pattern remain poorly understood; and three species are irruptive or nomadic. The grasslands of southern South America have a high diversity of raptors, influenced by topography, habitat availability and seasonality, features that should be taken into account when divising regional conservation policies.