926 resultados para Fruit-eating birds


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Although melanin is the most common pigment in animal integuments, the adaptive function of variation in melanin-based coloration remains poorly understood. The individual fitness returns associated with melanin pigments can be variable across species as these pigments can have physical and biological protective properties and genes involved in melanogenesis may vary in the intensity of pleiotropic effects. Moreover, dark and pale coloration can also enhance camouflage in alternative habitats and melanin-based coloration can be involved in social interactions. We investigated whether darker or paler individuals achieve a higher fitness in birds, a taxon wherein associations between melanin-based coloration and fitness parameters have been studied in a large number of species. A meta-analysis showed that the degree of melanin-based coloration was not significantly associated with laying date, clutch size, brood size, and survival across 26 species. Similar results were found when restricting the analyses to non-sexually dimorphic birds, colour polymorphic and monomorphic species, in passerines and non-passerines and in species for which inter-individual variation in melanism is due to colour intensity. However, eumelanic coloration was positively associated with clutch and brood size in sexually dimorphic species and those that vary in the size of black patches, respectively. Given that greater extent of melanin-based coloration was positively associated with reproductive parameters and survival in some species but negatively in other species, we conclude that in birds the sign and magnitude of selection exerted on melanin-based coloration is species- or trait-specific.

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Nematodes representing five species of the genus Heterakis, namely: H. inglisi n. sp., H. alata, H. gallinarum, H. spiculatus and one species of the genus Odontoterakis, O. multidentata, were studied. Heterakis inglisi n. sp. closely resembles H. spiculatus, differing from it by smaller size of spicules, precloacal sucker and terminal spike of the tail in the males. Heterakis arquata and H. brasiliana are only listed, for they were not found during the present study. Odontoterakis multidentata is reported in Brazil for the first time. New host records are estabilished for most of the species. These species are fully illustrated.

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In the present paper, some species of nematodes from Brazilian parrots are studied: Aproctapyrrhurae. Ascaridia hermaphrodita, A. sergiomeirai, Pelecitus circularis and P. helicinus. Single female specimens of Pelecitus sp. and Thelazia sp. are presented. The male of P. circularis is fully illustrated, for the first time, since 1884. Ascaridia sergiomeirai is also restudied 59 years after proposition. New host records are estabilished. Remarks on other species of nematodes occuring in psittacid birds are included.

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Linear measurements and derived indices of trypanosomes from species of Fennoscandian birds were compared to those reported form Trypanosoma avium, T. everetti, T. ontarioensis and T. paddae. The trypanosomes encountered in the Fennoscandian birds were identified as T. avium from Tengmalm's owl Aegolius funereus and the pied flycatcher Ficedula hypoleuca, T. everetti from the great tit Parus major and collared flycatcher F. albicollis and T. ontarioensis from the collared flycatcher; T. paddae was not seen.

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This report deals with the identification of one hundred and fifty-nine samples of nematodes recovered from Brazilian egrets and herons. Contracaecum microcephalum, C. multipapillatum, C. plagiaticium, Desportesius invaginatus, D. longevaginatus, Desmidocercella ardeae, Eustrongylides ignotus, Porrocaecum reticulatum, Tetrameres micropenis, Capillaria sp., Contracaecum sp., Porrocaecum sp., Procyrnea sp., Tetrameres sp. and Viktorocara sp. were studied. The genus Viktorocara and the species C. microcephalum, C. plagiaticium, D. invaginatus, D. ardeae and P. reticulatum are referred in Brazil for the first time.

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Thirty species of nematodes recovered from Piciformes hosts are reported. Procyrnea anterovulvata n. sp. from Chelidoptera tenebrosa brasiliensis is described and compared to P. colaptes and P. pileata. The considered morphometric parameters are mainly related to the ratio between length of the body/distance of the vulva to the anterior end. It is approximately 1:0.5 in P. colaptes and P. pileata compared to 1:0.1 in the new species. The male of Synhimantus (Dispharynx) crassissima is described for the first time. Thelazia (Thelaziella) spizaeti is revalidated and new records are reported for some species.

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This report deals with the identification of 139 samples of nematodes recovered from Brazilian jays. Viktorocara brasiliensis n. sp. is proposed and compared with V. capillaris, V. limosae, V. charadrii and V. garridoi which are the other species included in the genus. The differentiation of V. brasiliensis n. sp. was based on the ratios between muscular and glandular esophagus and spicules, as well. Other referred species are Acuaria mamillaris, A. mayori, Aprocta sp., Cheilospirura sp., Diplotriaena americana, D. bargusinica, Oxyspirura matogrosensis, Oxyspirura sp., Pelecitus helicinus, Procyrnea sp., Skrjabinura spiralis, Subulura papillosa, Synhimantus sp. and Tetrameres (Microtetrameres) sp., with the establishment of some new host records

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El Parc del Garraf (PG) ha estat tradicionalment una important zona agrícola, encara que actualment és molt reduïda (representa el 3% del total de la superfície del parc) i està repartida entre unes poques masies. Aquesta activitat humana conviu amb la fauna silvestre de la zona, que en alimentar-se parcialment dels cultius (cereal, vinya, oliveres, arbres fruiters i hortalisses), hi causa diversos impactes. És el cas de diverses aus, com ara la garsa (Pica Pica) i el pardal (Passer domesticus), i també d’alguns mamífers com el porc senglar (Sus scrofa). Hem observat que l’impacte produït per les aus i el porc senglar (Sus scrofa) és molt petit, el que pot ser degut a dos motius principals: possiblement per una elevada producció de fruits salvatges, esdevenint aquest aliment suficient per a les aus; i la baixa densitat poblacional de porc senglar (Sus scrofa) al parc. Els impactes observats presenten una alta variabilitat i depenen de l’època de l’any en que ens trobem. Per tant, cal fer-ne un seguiment més acurat on s’impliquin administració i pagesos per a millorar el coneixement de l’impacte de la fauna salvatge.

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We evaluated the prevalence, mean intensity and relative density of ticks in 467 wild birds of 67 species (12 families) from forest and cerrado habitats at two protected areas of Minas Gerais, between March and September 1997. Ticks collected (n=177) were identified as larvae and nymphs of Amblyomma cajennense and four other species of Amblyomma. We report for the first time 28 bird species as hosts of the immature stages of A. cajennense, demonstrating the lack of host specificity of the larvae and nymphs. A. cajennense had 15% prevalence on birds, with a mean infestation intensity of 0.37 ticks per host sampled, and 2.5 ticks per infested bird. Prevalence varied in relation to host species, diet and between birds from forests at two successional stages. There were no differences in relation to host forest dependence, participation in mixed flocks of birds, and nest type constructed. A. cajennense is a species of medical and veterinary importance, occurring on domestic animals but is known little of its occurrence on wildlife.