RESUMO

Body condition is an important ecological attribute that can provide a measure of the energy stored by an animal or population. Body condition is traditionally ascertained with morphometric body condition indices (BCIs), but some researchers have used various physiological and biochemical parameters as predictors of body condition. This study aimed to test reliable biochemical predictors of body condition in individuals of Neopelma pallescens (Lafresnaye, 1853), found in an Atlantic forest patch. For this purpose we examined the relationship between body condition and the concentrations of blood glucose and ketones. We also verified correlations between blood metabolite concentrations and ecological variables, including time of day, seasons, breeding periods, and ectoparasite infestation. Birds were captured with mist nets at Reserva Biológica de Guaribas, state of Paraíba, Brazil. Blood samples were analyzed with a portable glucometer. The correlation between glucose and ketones was negative. Both metabolites showed significant variations according to time of day. Glucose levels were higher in the afternoon and ketones levels were higher in the morning, suggesting a correlation with daily food intake. The BCI of non-breeding birds was negatively correlated with glucose concentrations. However, the correlation between glucose and the BCI of incubating birds was a positive. Ketone bodies did not correlate with body condition. In relation to ectoparasite infestation, only ketones showed significant results, presenting a higher concentration in infested individuals. Glucose is a good predictor of the BCI of incubating birds since it correlates positively with it. However, the lack of seasonal variations in metabolites indicates that the nutritional status of tropical birds does not change when food is abundant. Thus, we conclude that glucose and ketone bodies can predict the nutritional status of birds but in a context-dependent fashion.(AU)

Assuntos

RESUMO

Body condition is an important ecological attribute that can provide a measure of the energy stored by an animal or population. Body condition is traditionally ascertained with morphometric body condition indices (BCIs), but some researchers have used various physiological and biochemical parameters as predictors of body condition. This study aimed to test reliable biochemical predictors of body condition in individuals of Neopelma pallescens (Lafresnaye, 1853), found in an Atlantic forest patch. For this purpose we examined the relationship between body condition and the concentrations of blood glucose and ketones. We also verified correlations between blood metabolite concentrations and ecological variables, including time of day, seasons, breeding periods, and ectoparasite infestation. Birds were captured with mist nets at Reserva Biológica de Guaribas, state of Paraíba, Brazil. Blood samples were analyzed with a portable glucometer. The correlation between glucose and ketones was negative. Both metabolites showed significant variations according to time of day. Glucose levels were higher in the afternoon and ketones levels were higher in the morning, suggesting a correlation with daily food intake. The BCI of non-breeding birds was negatively correlated with glucose concentrations. However, the correlation between glucose and the BCI of incubating birds was a positive. Ketone bodies did not correlate with body condition. In relation to ectoparasite infestation, only ketones showed significant results, presenting a higher concentration in infested individuals. Glucose is a good predictor of the BCI of incubating birds since it correlates positively with it. However, the lack of seasonal variations in metabolites indicates that the nutritional status of tropical birds does not change when food is abundant. Thus, we conclude that glucose and ketone bodies can predict the nutritional status of birds but in a context-dependent fashion.

Assuntos

RESUMO

We tested whether the probability of detecting avian haemosporidia (Plasmodium and Haemoproteus) using molecular techniques differs among blood, liver, heart, and pectoral muscle tissues. We used a paired design, sampling the 4 tissue types in 55 individuals of a wild South American suboscine antbird, the white-shouldered fire-eye (Pyriglena leucoptera). We also identified parasites to cytochrome b lineage. Detection probability was significantly lower in blood compared to the other 3 tissue types combined. Eight of 22 infections were not detected in blood samples; 4-7 infections were not detected in the other individual tissues. The same parasite lineage was recovered from different tissues.

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RESUMO

Parasites may lead bird species to extinction, affect host temporal and spatial population dynamics, alter community structure and alter individual' social status. We evaluated blood parasite prevalence and intensity according to bird families and species, among 925 birds that were caught in 2000 and 2001, in the Atlantic Forest in the State of Minas Gerais, Brazil. We applied Giemsa staining to thin blood smears, to detect blood parasites. The birds (n = 15.8%) in 11 families, were infected by at least one parasite genus, especially Muscicapidae (28.3%) and Conopophagidae (25%). Among the 146 infected birds, Plasmodium was detected in all bird families and had the highest prevalence (54.8%). Trypanosoma, Haemoproteus and microfilaria had lower prevalence rates (23.3, 23.3 and 2.1%, respectively). Birds caught during the rainy season were more infected than birds caught during the dry season. The overall low prevalence of blood parasites in birds is similar to the patterns found elsewhere in the Neotropical region.

Assuntos

RESUMO

Parasites may lead bird species to extinction, affect host temporal and spatial population dynamics, alter community structure and alter individuals social status. We evaluated blood parasite prevalence and intensity according to bird families and species, among 925 birds that were caught in 2000 and 2001, in the Atlantic Forest in the State of Minas Gerais, Brazil. We applied Giemsa staining to thin blood smears, to detect blood parasites. The birds (n = 15.8%) in 11 families, were infected by at least one parasite genus, especially Muscicapidae (28.3%) and Conopophagidae (25%). Among the 146 infected birds, Plasmodium was detected in all bird families and had the highest prevalence (54.8%). Trypanosoma, Haemoproteus and microfilaria had lower prevalence rates (23.3, 23.3 and 2.1%, respectively). Birds caught during the rainy season were more infected than birds caught during the dry season. The overall low prevalence of blood parasites in birds is similar to the patterns found elsewhere in the Neotropical region.(AU)

Parasitos podem levar espécies de aves à extinção, afetar as dinâmicas temporais e espaciais dos hospedeiros, alterar a estrutura de comunidades e o status social de indivíduos. Avaliou-se a prevalência e a intensidade de parasitos em famílias e espécies de 925 aves capturadas, entre 2000 e 2001, na Mata Atlântica de Minas Gerais. Foram coradas com Giemsa extensões de sangue para detectar parasitos hematozoários. As aves (n= 15,8%) 11 famílias estavam infectadas por pelo menos um gênero de parasito, especialmente Muscicapidae (28,3%) e Conopophagidae (25%). Entre as 146 aves infectadas, Plasmodium foi detectado em todas as famílias e possuiu a maior prevalência (54,8%). Trypanosoma,Haemoproteus e microfilaria possuíram baixas prevalências (23,3, 23,3 e 2,1%, respectivamente). Aves capturadasdurante a estação chuvosa estavam mais infectadas do que aves capturadas durante a estação seca. A baixa prevalência geral de parasitos do sangue das aves é semelhante aos padrões encontrados em outras localidades da região Neotropical.(AU)

Assuntos

RESUMO

Parasites may lead bird species to extinction, affect host temporal and spatial population dynamics, alter community structure and alter individuals’ social status. We evaluated blood parasite prevalence and intensity according to bird families and species, among 925 birds that were caught in 2000 and 2001, in the Atlantic Forest in the State of Minas Gerais, Brazil. We applied Giemsa staining to thin blood smears, to detect blood parasites. The birds (n = 15.8%) in 11 families, were infected by at least one parasite genus, especially Muscicapidae (28.3%) and Conopophagidae (25%). Among the 146 infected birds, Plasmodium was detected in all bird families and had the highest prevalence (54.8%). Trypanosoma, Haemoproteus and microfilaria had lower prevalence rates (23.3, 23.3 and 2.1%, respectively). Birds caught during the rainy season were more infected than birds caught during the dry season. The overall low prevalence of blood parasites in birds is similar to the patterns found elsewhere in the Neotropical region.

Parasitos podem levar espécies de aves à extinção, afetar as dinâmicas temporais e espaciais dos hospedeiros, alterar a estrutura de comunidades e o status social de indivíduos. Avaliou-se a prevalência e a intensidade de parasitos em famílias e espécies de 925 aves capturadas, entre 2000 e 2001, na Mata Atlântica de Minas Gerais. Foram coradas com Giemsa extensões de sangue para detectar parasitos hematozoários. As aves (n= 15,8%) 11 famílias estavam infectadas por pelo menos um gênero de parasito, especialmente Muscicapidae (28,3%) e Conopophagidae (25%). Entre as 146 aves infectadas, Plasmodium foi detectado em todas as famílias e possuiu a maior prevalência (54,8%). Trypanosoma,Haemoproteus e microfilaria possuíram baixas prevalências (23,3, 23,3 e 2,1%, respectivamente). Aves capturadasdurante a estação chuvosa estavam mais infectadas do que aves capturadas durante a estação seca. A baixa prevalência geral de parasitos do sangue das aves é semelhante aos padrões encontrados em outras localidades da região Neotropical.

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RESUMO

The Floreana Mockingbird (Mimus trifasciatus) is one of the rarest bird species in the world, with an estimated 550 individuals remaining on two rocky islets off the coast of Floreana, Galápagos, Ecuador, from which the main population was extirpated more than 100 yr ago. Because they have been listed in critical danger of extinction, a plan to reintroduce this species to Floreana has been initiated. Determining the health status of the source mockingbird populations is a top priority within the reintroduction plan. We report the health status, over the course of 4 yr, of 75 Floreana Mockingbirds on Champion Island and 160 Floreana Mockingbirds on Gardner-by-Floreana, based on physical examinations, hematology, hemolysis-hemagglutination assay, exposure to selected infectious disease agents, and ecto- and endoparasite counts. Birds on Gardner-by-Floreana had higher body condition index scores, packed cell volumes, total solids, and lymphocyte counts. Additionally, Gardner-by-Floreana birds had lower heterophil counts, eosinophil counts, and heterophil:lymphocyte ratios. No Chlamydophila psittaci DNA or antibodies to paramyxovirus-I, adenovirus-II, or Mycoplasma gallisepticum were found in any of the mockingbirds tested. Ectoparasites were present on birds from both islands, although species varied between islands. A coccidian species was found in eight of the 45 fecal samples from birds on Gardner-by-Floreana, but none of 33 birds examined from Champion. Birds on Gardner-by-Floreana were classified as healthier than those on Champion based on clinical and laboratory findings. These health data will be analyzed in conjunction with genetics, population structure, and disease presence on Floreana for developing recommendations for the Floreana Mockingbird reintroduction plan.

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