On the origin of <i>Halipeurus heraldicus</i> on Round Island petrels: cophylogenetic relationships between petrels and their chewing lice

Lice phylogenetic relationships have often been used to elucidate host relationships and vice versa. In this study, we investigate the louse genus Halipeurus which parasitizes bird hosts in the families Procellariidae, Hydrobatidae and Pelecanoididae. The presence of two lice species on Pterodroma arminjoniana in different breeding grounds (Halipeurus heraldicus on Round Island, off Mauritius in the Indian Ocean and Halipeurus kermadecensis on Trindade Island in the Atlantic Ocean) has led to some confusion in the distribution of Pt. arminjoniana and its close relatives Pt. heraldica and Pt. neglecta. By using a cophylogenetic approach that incorporates uncertainties in phylogenetic reconstructions, we show significant overall coevolution between Halipeurus lice and their hosts. However, the study also indicates that the presence of H. heraldicus on Pt. arminjoniana and Pt. neglecta on Round Island and on Pt. heraldica on Gambier Island are the result of a host switch whereas H. kermadecensis is the ancestral parasite of Pt. arminjoniana. This suggests that H. kermadecensis was lost during or after colonisation of Round Island by Pt. arminjoniana. We conclude that cophylogenetic analyses are central to inferring the evolutionary history and biogeographical patterns of hosts and their parasites

Feeding and foraging ecology of Trindade petrels Pterodroma arminjoniana during the breeding period in the South Atlantic Ocean

Seabirds breeding in tropical environments experience high energetic demands, when foraging in an oligotrophic environment. The globally threatened Trindade petrel Pterodroma arminjoniana has its largest colony in Trindade Island (20°30′S–29°19′W) inside the oligotrophic South Atlantic Subtropical Gyre. Diet sampling methods, geolocator tracking and stable isotope analysis were used to describe its diet, compare foraging trips and distributions, and assess temporal variations in the trophic niche throughout the breeding period. Diet consisted mainly of squid and fish. The high species diversity and wide range of prey sizes consumed suggests the use of multiple foraging techniques. Stable isotope mixing models confirm that Trindade petrels rely mainly on squid throughout the breeding period. Its broad isotopic niche seems to reflect both a diverse diet and foraging range, since birds can reach up to 3335 km from the colony. Isotopic niche showed limited variation even in an 8-year interval, apparently due to oceanographic stability, although changes in the isotopic niche have demonstrated an adjustment to different conditions in different seasons. Petrels change foraging areas and prey during the breeding period: pre-incubating birds use more productive areas west of Trindade Island and obtain low trophic position prey; incubating petrels perform longer trips southward to consume prey of high trophic position; and chick-rearing petrels use areas around the island. These results demonstrate that to deal with high demand breeding in a colony surrounded by oligotrophic waters, Trindade petrels need to explore wide foraging areas and utilize a diverse diet, besides adjusting trophic niche according to breeding stage

Blood parasites in noddies and boobies from Brazilian offshore islands : differences between species and influence of nesting habitat

Seabirds are often free from blood parasites, and a recent review suggested that phylogenetic, ecological and life-history parameters can determine the prevalence of blood parasites in seabirds. However, there is a lack of data available frommany seabird groups, and a larger database is needed to understand prevalence patterns of blood parasites. We used a molecular screening approach to detect parasites of the genera Plasmodium, Haemoproteus, Leucocytozoon and Babesia in five species of two genera of seabirds that breed on Atlantic Ocean islands off Brazil. The observed patterns differed between the two bird genera. Like other Laridae, brown noddy, Anous stolidus adults were infected with Haemoproteus with low prevalence. Masked boobies, Sula dactylatra and brown boobies, Sula leucogaster were infected with Babesia. Of the latter, mainly juveniles were infected. In all species, intensity of infection (i.e. number of infected erythrocytes) was so low that parasites remained undetected in blood smears. This may explain the absence of major effects on the body condition of birds, although infected juvenile masked boobies were lighter than juveniles that were not infected with Babesia. Two tree-nesting species; black noddy, Anous minutus and red-footed booby, Sula sula did not have blood parasites, suggesting that treenesting may reduce the exposure to arthropod vectors compared with ground nesting in these species

Ecology and conservation of albatrosses and petrels at sea off Brazil

In this study I investigated Procellariiformes (albatrosses, petrels and shearwaters) at sea in the southwestern Atlantic Ocean. Fourteen species and 301 individuals were sampled non-destructively using a cast net method described here. A method is described for ageing Atlantic Yellow-nosed (Thalassarche chlororhynchos) and Black-browed (T. melanophris) Albatrosses based on bill colour and moult. Procellariiformes appear to have two distinct moulting strategies: petrels and shearwaters have complete annual moult, start to moult during the breeding period, and replace several primaries and tail feathers at one time, whereas albatrosses undergo long moulting cycles, replace less feathers at once, and suspend the wing moult during breeding periods. Primary moult starting at P2 rather than P1 was demonstrated to be a common feature in this taxon, with important implications for studies of stable isotopes, trace elements and pollutants in feathers. Overlap between moulting and breeding is demonstrated to be common with tail and contour feathers, but limited in wing, which suggests that flight constraint in long distance foragers rather than nutritional and energetic limitations is the ultimate factor determining primary moult timing. Based on molecular sexing and linear measurements, sexual size dimorphism was shown to vary according to species, with females in general smaller than males, more pronounced in bill measurements than in other traits, and more conspicuous in Giant Petrels (Macronectes spp.) and Diomedea albatrosses. Closely related species pairs of Thallassarche albatrosses and Procellaria petrels had differing levels of sexual dimorphism. The pelagic seabird community sampled comprises birds from different ages and breeding status according to species. Skewed Adult Sex Ratio (ASR) has been proposed as a common pattern in birds, frequently biased towards males and with larger biases in globally threatened species. In albatrosses and petrels, differential mortality of one gender in fisheries is suggested to be caused by sexual size dimorphism giving males a competitive advantage, which allows more access of the larger sex to discards and baits, or to at sea segregation of sexes. These hypotheses were tested by sampling birds at sea and reviewing ASR of birds incidentally captured in fisheries. Skewed ASR is common in albatrosses and petrels from the community attending vessels, but there was no correlation between skewed ASR and conservation status, both in terms of population size or global level of threat, or between ASR and sexual size dimorphism. Thus, sexual dimorphism in size does not explain skewed ASR in the community sampled or in incidental captures in fisheries reported in the review. Differential at sea distributions of males and females appear to explain better the patterns found in the community sampled at sea, as well as skewed ASR in seabird fatalities. Kernel density analysis of satellite tracked Spectacled Petrels (Procellaria conspicillata) in 2006 and 2007 demonstrated intense use of waters in the Brazilian Exclusive Economic Zone, from 26 to 31S, mainly over the continental shelf break and offshore waters. The marine habitats used by Spectacled Petrel and described by bathymetry, SST and productivity are remarkably different from those of the sister species White-chinned Petrel (Procellaria aequinoctialis), which occurs in the area during the winter, but remains over the continental shelf, on Sub-Antarctic and oligotrophic waters. A close association between birds and pelagic longline fishery was demonstrated through comparison of the main kernel areas used by Spectacled Petrels and the pelagic longline fleet. Stable isotopes of nitrogen (δ15N) and carbon (δ13C) in blood preserved in different ways and simultaneously growing feathers were analysed in Spectacled Petrel. Mean δ13C and δ15N values in growing feathers were higher than in blood, suggesting tissue-specific fractionation. Different methods of preserving tissues such as blood may bias stable isotope values. Air drying is proposed as a practical and unbiased method for blood preservation in field situations where freezing is not a practical option, and a mathematical approach is suggested to permit comparison between studies using different preservation methods or tissues. By analysing stable isotopes in blood of all species of Procellariiformes sampled it is demonstrated that availability of discard, mainly the preferred shark liver, which is shared among species with contrasting body masses and feeding techniques, is the ultimate cause of overlapping in trophic levels. Carbon isotopic signature overlapped among the species and was typical of subtropical and offshore region. Early migrant individuals from Antarctica and sub-Antarctic (e.g. Cape Petrel Daption capense, White-chinned Petrel, Wilson’s Storm-petrel Oceanites oceanicus) and species still rearing chicks when sampled (Wandering Albatross Diomedea exulans) had clear carbon isotopic signatures from the austral region. All southern latitude species underwent a clear shift in carbon and nitrogen isotope signatures, increasing in trophic level after arriving in the SW Atlantic. Cory’s Shearwater (Calonectris diomedea), the only species not attending vessels, has low nitrogen values resulting from a diet of flyingfish and squids naturally occurring in the area. While some abundant and widespread petrels and shearwaters, particularly those small in size, benefit from discards from pelagic longline vessels, the balance between benefits and the incidental mortality in hooks is negative for albatrosses and some petrels. Information on bycatch rates of seabirds in the Brazilian domestic pelagic longline fishery from 2001 to 2007 in the Exclusive Economic Zone and adjacent international waters of the southwestern Atlantic Ocean is presented, and bycatch rates for the area are reviewed. Overall, seabird capture rate for the Brazilian pelagic longline fleet was 0.229 birds/1000 hooks, varying from zero to 0.542 birds/1000 according to season. Capture rates were higher between June and November (cold season) and affected mainly the Black-browed Albatross (55% of birds captured), the White-chinned Petrel, the Spectacled Petrel and the Atlantic Yellow-nosed Albatross. Capture rates previously reported in the SW Atlantic varied from 0 to 5.03 birds/1000 hooks, with those based on logbooks or fishermen interviews tending to underestimate capture rates, whereas those based on small numbers of hooks or short time periods tend to greatly overestimate rates in both pelagic and demersal longline fisheries. A range of poorly-known hook-and-line commercial fisheries carried out by the Itaipava fleet, southeastern Brazil, composed by 497 vessels, was described with seven fisheries defined. Capture rates were higher for the surface longline for Dolphinfish (0.15 birds/1000 hooks and 1.08 turtles/1000 hooks), slow trolling for Bigeye Tuna (0.41 birds/day) and handlining targeting Yellowfin Tuna (0.61 birds/day). Bycatch of 47 seabirds, mainly the endangered Spectacled Petrel, Atlantic Yellow-nosed, and Black-browed Albatrosses, and 45 turtles of four species were recorded. Longline and other hook-and-line fisheries are the major threat for albatrosses and petrels from different origins when foraging in the SW Atlantic Ocean, and require urgent conservation measures

Sex-related variation in the vulnerability of wandering albatrosses to pelagic longline fleets

The population of wandering albatrosses Diomedea exulans at South Georgia is decreasing because of bycatch in longline fisheries. Until at least the early 1990s, the survival rate of females was lower than males, consistent with the adult female-biased bycatch reported for fisheries operating around the Brazil-Falklands Confluence (BFC). Here we use extensive tracking data (1990–2012) from breeding birds at South Georgia to investigate overlap with longline fishing effort reported to the International Commission for the Conservation of Atlantic Tunas (ICCAT). Using data from multiple years, we conclude that breeding females are at higher risk than males from all the main pelagic longline fleets in the south-west Atlantic. Our overlap index (based on fishing effort and bird distributions) correlated positively with numbers of ringed birds reported dead on longliners, indicating that the metric was a good proxy of bycatch risk. The consistent sex bias in overlap across years, and the likely resulting sex-biased mortality, could account for lower adult female survival rate at the colony. The risk from fisheries changed seasonally; both sexes overlapped with pelagic longline effort during incubation (January–March), and particularly during post-brood chick-rearing (May–December), whereas overlap was negligible during brooding (April). The highest percentage of overlap was with the Taiwanese fleet, then vessels flagged to Brazil, Uruguay, Spain, Japan and Portugal. Females were consistently at greatest risk in the BFC region, whereas males showed lower and more variable levels of overlap with fisheries from 35 to 45°S. Our results have important implications for management of ICCAT longline fisheries and conservation of this highly threatened albatross population

Plant-pollinator networks in the tropics : lessons from hummingbird-plant interactions

Orientadores: Marlies Sazima, Bo DalsgaardTese (doutorado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: A abordagem de redes complexas tem permitido avanços rápidos no entendimento das interações entre populações de espécies em comunidades, incluindo a descrição dos padrões e processos determinantes das interações. Apesar do crescente acúmulo de estudos sobre redes mutualísticas planta-polinizador, estudos em regiões tropicais são mais escassos, especialmente os que investigam os processos que determinam tais interações. Neste sentido, esta tese contribui para o avanço no entendimento das redes de interações planta-polinizador, com particular ênfase em comunidades Neotropicais. No capítulo 1, realizamos uma revisão da distribuição global de estudos sobre redes de polinização, bem como dos padrões e processos determinantes destas redes, com foco no entendimento de lacunas de investigação e nas diferenças das redes em regiões tropicais. Nos capítulos 2 e 3, utilizamos redes mutualísticas planta ? beija-flor como um sistema-modelo. No capítulo 2, investigamos como o esforço de amostragem influencia na detecção de padrões de interação e na compreensão dos processos estruturadores de interações. Utilizamos para isso, dados coletados intensivamente ao longo de dois anos em uma comunidade de Floresta Atlântica Montana no sudeste do Brasil. No capítulo 3 expandimos estudos prévios para uma escala macroecológica através da análise de um banco de dados de 25 redes de interações quantitativas distribuídas do México ao sul do Brasil, que possuíam dados de morfologia, fenologia e abundância para cada espécie. De forma ampla, esta tese aponta lacunas geográficas e metodológicas no estudo de redes planta-polinizador nos trópicos, bem como discute generalizações sobre padrões de interação e seus processos estruturadores (capítulo 1); indica métricas robustas ao esforço para a descrição da estrutura das interações e argumenta que, no sistema estudado, a importância de atributos como estruturadores de interações em sistemas especializados pode ser identificada mesmo com esforço amostral relativamente baixo (capítulo 2); e que restrições impostas por desacoplamentos na morfologia e fenologia (mais do que a chance de encontro baseada em abundância) são processos dominantes na determinação das interações planta ¿ beija-flor nas Américas, os quais são pouco influenciados por clima, heterogeneidade topográfica e riqueza de espécies, e que promovem estruturas similares nas redes (capítulo 3). Em suma, demonstramos que as interações entre plantas e beija-flores são estruturadas fundamentalmente por restrições impostas por nicho, o que argumentamos ocorrer devido à (frequente) alta diversidade de atributos (e.g. variação em morfologias e fenologias). Finalmente, expandimos um modelo que prevê a formação de um continuum na importância de processos baseados em nicho e neutralidade na estruturação das interações em comunidades e apresentamos evidências de que este continuum depende da diversidade de atributos funcionais na assembleia. Sugerimos que outros sistemas com alta diversidade funcional localizam-se neste mesmo extremo do continuum, i.e. onde processos baseados em nichos são determinantes fundamentais das interações. Este é provavelmente o caso de diversos grupos especializados de polinizadores e plantas nos trópicos, tais como observado aqui para beija-flores e suas floresAbstract: Complex networks approach has promoted fast advances in the understanding of species interactions in communities, including the description of patterns and processes structuring interactive assemblages. Despite of the accumulation of studies on plant-pollinator networks, such investigations on tropical regions are still scarce, especially on the determinants of such interactions. Here we aimed to advance the understanding of tropical plant-pollinator networks in the Tropics. In the first chapter, we review the global distribution of studies on pollination networks and their patterns and structuring processes, with particular focus to understand research gaps and potential differences in tropical networks. In the next chapters we focus on mutualistic plant-hummingbirds networks as a `model system¿. In the second chapter, we investigated the influences of sampling effort on the detection of patterns of interaction and on the identification of the main structuring processes. For that, we sampled a Montane Atlantic Rainforest community in Southeastern Brazil intensively along two years. In the third chapter, we expand our previous studies to marcroecological scale by analyzing a unique dataset of 25 quantitative networks collected from Mexico to Southern Brazil, encompassing data on species morphology, phenology and abundances. Based on our findings, we indicate geographical and methodological gaps on the studies of pollination networks in the tropics and discussed recurrent patterns and their structuring processes (chapter 1); we point out that quantitative metrics tend to be more robust to sampling effort, and we report that the importance of traits as determinants of interactions in this specialized system is evident even under little sampling effort (chapter 2). We present evidences that constraints imposed by morphological and phenological mismatching (more that random meeting driven by species abundances) are dominant processes structuring plant-hummingbird networks throughout Americas; overall, climate, topographic heterogeneity and species richness have few influence on the importance of these processes, and produce similar network structures (chapter 3). In sum, we demonstrate that plant-hummingbird networks are fundamentally structured by constraints imposed by some dimensions of the species niches, which we argue to be linked to the high trait diversity in the assemblages (i.e. variation in morphology and phenology). Finally, we expand a model which hypothesizes a continuum of importance from niche- to neutral-based processes as drivers of species interactions in communities. We present evidences that this continuum depends of the variation in species traits within assemblages. We suggest that other systems encompassing high functional diversity are located at this extreme of the continuum in which niche based-processes tend to be the most important drivers of species interactions. This is likely the case of several plants and pollinators communities in the tropics, as we observed here for hummingbirds and their plantsDoutoradoEcologiaDoutor em Ecologia008012/2014-08CAPE

Age composition and sexual size dimorphism of albatrosses and petrels off Brazil

We present data on age composition and sexual size dimorphism (SSD) of albatrosses, petrels and shearwaters in southern Brazil for 301 birds of 14 species captured live at sea. The pelagic community of seabirds off Brazil comprises birds of different ages and breeding status according to species. Although juveniles of some species such as Black-browed Albatross Thalassarche melanophris and Southern Giant Petrel Macronectes giganteus predominated, all age classes (including breeding birds) were recorded for Atlantic Yellow-nosed T. chlororhynchos and Wandering Diomedea exulans albatrosses. For this heterogeneous community composed of individuals from different colonies, with adults and immature birds pooled, the SSD was more pronounced in bill measurements than in other traits (confirming previous studies) and more conspicuous in giant petrels and Diomedea albatrosses. Closely related species pairs of Thalassarche albatrosses and Procellaria petrels had differing levels of sexual dimorphism. All linear external traits measured within Thalassarche and Procellaria overlapped considerably and, despite being significantly different, were not adequate for species determination or sexing

Analysis of stable isotope ratios in blood of tracked wandering albatrosses fails to distinguish a δ13C gradient within their winter foraging areas in the southwest Atlantic Ocean

Rationale The main limitation of isotopic tracking for inferring distribution is the lack of detailed reference maps of the isotopic landscape (i.e. isoscapes) in the marine environment. Here, we attempt to map the marine δ13C isoscape for the southwestern sector of the Atlantic Ocean, and assess any temporal variation using the wandering albatross as a model species. Methods Tracking data and blood and diet samples were collected monthly from wandering albatrosses rearing chicks at Bird Island, South Georgia, during the austral winter between May and October 2009. The δ13C and δ15N values were measured by mass spectrometry in plasma and blood cells, and related to highly accurate data on individual movements and feeding activity obtained using three types of device: GPS, activity (immersion) loggers and stomach temperature probes. Results The tracked birds foraged in waters to the north or northwest of South Georgia, including the Patagonian shelf-break, as far as 2000 km from the colony. The foraging region encompassed the two main fronts in the Southern Ocean (Polar and Subantarctic fronts). The δ13C values varied by only 2.1 ‰ in plasma and 2.5 ‰ in blood cells, and no relationships were found between the δ13C values in plasma and the mean latitude or longitude of landings or feeding events of each individual. Conclusions The failure to distinguish a major biogeographic gradient in δ13C values suggest that these values in the south Atlantic Ocean are fairly homogeneous. There was no substantial variation among months in either the δ13C or the δ15N values of plasma or blood cells of tracked birds. As birds did not show a significant change in diet composition or foraging areas during the study period, these results provide no evidence for major temporal variation in stable isotope ratios in consumer tissues, or in the regional marine isoscape in the austral winter of 2009

Breeding biology and conservation of the Marsh Seedeater Sporophila palustris

El Capuchino Pecho Blanco Sporophila palustris es uno de los capuchinos menos conocidos y uno de los más amenazados. Sus poblaciones reproductivas son locales, fragmentadas y ocurren en el nordeste de Argentina, sudeste de Brasil y en Uruguay. Presentamos datos reproductivos describiendo nidos y huevos, comportamiento (incluyendo cortejo, nidificación, incubación y cuidado parental), sitios de anidación y datos sobre alimentación. El Capuchino Pecho Blanco nidifica en pastizales altos y húmedos en buen estado de conservación. Estos hábitats en general se han convertido en áreas ganaderas. Las principales amenazas son sobrepastoreo, uso generalizado del fuego, drenaje de humedales, reemplazo total del hábitat por pasturas y forestaciones y captura ilegal. La mayoría de los sitios se localizan en AICAs, pero sólo uno en Brasil y otro en Argentina se encuentran protegidos. Finalmente, proponemos una serie de medidas que contribuyen a la preservación del Capuchino Pecho Blanco y de otras aves amenazadas que conviven con este.The Marsh Seedeater Sporophila palustris is one of the most endangered and least known of the capuchino seedeaters. Breeding populations are patchy, occurring in north-east Argentina,southern Brazil, and Uruguay. We present data on the breeding biology of the species, and describe nests and eggs, behaviour (including courtship, nesting, incubation and parental care), breeding sites and food items. Marsh Seedeaters breed in well-preserved grasslands with wet soils and tall vegetation. In general, these habitats are used for extensive livestock ranching. Main threats are overgrazing, widespread use of fire, conversion of grasslands to pastures of exotic grasses and rice fields, afforestation, and illegal trapping. Most breeding sites are located in Important Bird Areas, but only one in Brazil and one in Argentina are protected. We propose a series of actions to promote the conservation of Marsh Seedeaters and other endangered birds that coexist in grassland habitats.Fil: Vizentin Bugoni, Jefferson. Universidade Estadual de Campinas; Brasil;Fil: Areta, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Bio y Geociencias del Noroeste Argentino; Argentina;Fil: Di Giacomo, Alejandro G.. Asociación Ornitológica del Plata. Aves Argentinas. Departamento de Conservación; Argentina;Fil: Di Giacomo, Adrian Santiago. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Ecología y Comportamiento Animal; Argentina;Fil: Jacobs, Fernando. Universidade Federal de Pelotas. Instituto de Biologia. Departamento de Zoologia e Genética; Brasil;Fil: Afonso Coimbra, Marco A.. Universidade Federal de Pelotas. Instituto de Biologia. Núcleo de Reabilitação da Fauna Silvestre e Centro de Triagem de Animais Silvestres; Brasil;Fil: Dias, Rafael A.. Universidade Católica de Pelotas. Laboratório de Biologia e Ecologia de Cordados. Setor de Ornitologia; Brasil