Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 13 de 13
Filter
Add more filters










Publication year range
1.
PeerJ ; 8: e9892, 2020.
Article in English | MEDLINE | ID: mdl-33005489

ABSTRACT

BACKGROUND: Birds can maximize their reproductive success through careful selection of nest-sites. The 'total-foliage' hypothesis predicts that nests concealed in vegetation should have higher survival. We propose an additional hypothesis, the 'predator proximity' hypothesis, which states that nests placed farther from predators would have higher survival. We examined these hypotheses in the world's southernmost forests of Navarino Island, in the Cape Horn Biosphere reserve, Chile (55°S). This island has been free of mammalian ground predators until recently, and forest passerines have been subject to depredation only by diurnal and nocturnal raptors. METHODS: During three breeding seasons (2014-2017), we monitored 104 nests for the five most abundant open-cup forest-dwelling passerines (Elaenia albiceps, Zonotrichia capensis, Phrygilus patagonicus, Turdus falcklandii, and Anairetes parulus). We identified nest predators using camera traps and assessed whether habitat characteristics affected nest-site selection and survival. RESULTS: Nest predation was the main cause of nest failure (71% of failed nests). Milvago chimango was the most common predator, depredating 13 (87%) of the 15 nests where we could identify a predator. By contrast, the recently introduced mammal Neovison vison, the only ground predator, depredated one nest (7%). Species selected nest-sites with more understory cover and taller understory, which according to the total-foliage hypothesis would provide more concealment against both avian and mammal predators. However, these variables negatively influenced nest survival. The apparent disconnect between selecting nest-sites to avoid predation and the actual risk of predation could be due to recent changes in the predator assemblage driven by an increased abundance of native M. chimango associated with urban development, and/or the introduction of exotic mammalian ground predators to this island. These predator assemblage changes could have resulted in an ecological trap. Further research will be needed to assess hypotheses that could explain this mismatch between nest-site selection and nest survival.

2.
Rev. bras. parasitol. vet ; 29(4): e011520, 2020. tab, graf
Article in English | LILACS | ID: biblio-1138140

ABSTRACT

Abstract Haemoproteus spp. are protozoan parasites found in birds around the world. These parasites are identified through the morphology of gametocytes, phylogenetic analysis based on the mitochondrial cytb gene, and the parasite's geographic distribution. The absence of erythrocytic merogony, high intraspecific genetic variation and low parasitemia in wild birds makes it essential to use integrative approaches that assist in the identification of these parasites. Thus, microscopic and molecular analyses, combined with spatial distribution, were carried out to verify the presence of Haemoproteus spp. in wild birds in Brazil. Light microscopy revealed one Tangara sayaca bird was parasitized by Haemoproteus coatneyi and, two specimens of Zonotrichia capensis presented Haemoproteus erythrogravidus. The morphology of the gametocytes of these two parasitic species showed high similarity. The molecular analysis revealed the presence of one lineage of H. coatneyi and two lineages of H. erythrogravidus, one of which is considered a new lineage. These lineages were grouped phylogenetically in separate clades, with low genetic divergence, and the H. erythrogravidus lineage emerged as an internal group of the lineages of H. coatneyi. The geographic distribution demonstrated that the two species occur in the American continent. This is the first report of H. erythrogravidus in Brazil.


Resumo Haemoproteus spp. são protozoários parasitos encontrados em aves de todo o mundo. A identificação desses parasitos é realizada por meio da morfologia dos gametócitos, da análise filogenética, baseada no gene mitoncodrial cytb e na distribuição geográfica do parasito. A ausência de merogonia eritrocítica, a alta variação genética intraespecífica e a baixa parasitemia em aves silvestres, tornam essencial a utilização de abordagens integrativas que auxiliem na identificação desses parasitos. Assim, análises microscópicas e moleculares, aliadas à distribuição espacial, foram realizadas para verificar a presença de Haemoproteus spp. em aves silvestres no Brasil. A microscopia óptica demonstrou que uma ave Tangara sayaca estava parasitada por Haemoproteus coatneyi, e dois espécimes de Zonotrichia capensis apresentavam Haemoproteus erythrogravidus, cujas morfologias dos gametócitos apresentaram alta similaridade. A análise molecular recuperou uma linhagem de H. coatneyi e duas linhagens de H. erythrogravidus, sendo uma dessas considerada nova linhagem. Essas linhagens se agruparam filogeneticamente em clados separados, apresentando baixa divergência genética, sendo que as linhagens de H. erythrogravidus emergiram como grupo interno às linhagens de H. coatneyi. A distribuição geográfica demonstrou que as duas espécies estão ocorrendo no continente americano. Este é o primeiro relato de H. erythrogravidus no Brasil.


Subject(s)
Animals , Protozoan Infections, Animal/epidemiology , Bird Diseases/parasitology , Bird Diseases/epidemiology , Haemosporida/classification , Haemosporida/genetics , Passeriformes/parasitology , Phylogeny , Brazil , Forests , Cytochromes b/genetics
3.
Arq. bras. med. vet. zootec. (Online) ; 71(1): 225-231, jan.-fev. 2019. tab
Article in Portuguese | LILACS, VETINDEX | ID: biblio-989388

ABSTRACT

As aves silvestres podem ser reservatório de bactérias patogênicas e atuar como veiculadoras desses microrganismos para o ambiente, os animais domésticos e o homem. Portanto, o objetivo deste trabalho foi verificar a ocorrência de Campylobacter spp., Yersinia enterocolitica e Salmonella enterica em aves silvestres capturadas nas áreas próximas de aviários e em frangos de corte alojados nesses estabelecimentos, além de verificar a presença dos genes cdtA, cdtB e cdtC nos isolados de Campylobacter e identificar os sorotipos de Salmonella encontrados. Amostras de fezes de 189 aves silvestres capturadas com redes de neblina nas áreas próximas de 10 aviários e de 200 frangos de corte foram processadas para pesquisa de Campylobacter spp., S. enterica e Y. enterocolitica. Duas espécies de aves silvestres, Sicalis flaveola (canário-da-terra) e Zonotrichia capensis (tico-tico), foram positivas para Salmonella e Campylobacter, respectivamente. Foram isolados Campylobacter spp., S. enterica e Y. enterocolitica de frangos. Todos os isolados de Campylobacter analisados apresentaram os genes cdt. Em dois aviários, Campylobacter foi isolado tanto de frangos como de aves silvestres, entretanto a contaminação mútua entre essas aves não foi comprovada. Este foi o primeiro relato de isolamento de Campylobacter de Z. capensis e de Salmonella do sorotipo Derby de S. flaveola.(AU)


Wild birds can be reservoirs of pathogenic bacteria and act as carriers of these microorganisms to the environment, domestic animals, and humans. Therefore, this study had as objective to verify the occurrence of Campylobacter spp., Yersinia enterocolitica and Salmonella enterica in wild birds captured in the surroundings of the aviaries and in the broilers housed in these establishments. The presence of the cdtA, cdtB and cdtC genes in Campylobacter isolates was also investigated and Salmonella serotypes were identified. Stool samples from 189 wild birds captured with mist nets in around 10 aviaries and from 200 broilers were processed for Campylobacter spp., S. enterica and Y. enterocolitica research. Two species of wild birds, Sicalis flaveola (Saffron Finch) and Zonotrichia capensis (Rufous-collared Sparrow) were positive for Salmonella and Campylobacter, respectively. Campylobacter spp., S. enterica and Y. enterocolitica were isolated from broilers. The cdt genes were found in all Campylobacter isolates. In two aviaries, Campylobacter was isolated from both broilers and wild birds, however the mutual contamination among these birds has not been shown. This was the first report of Campylobacter isolation from Z. capensis and of Derby Salmonella serotype isolation from S. flaveola.(AU)


Subject(s)
Birds/microbiology , Campylobacter/pathogenicity , Enterobacteriaceae/pathogenicity
4.
Rev. peru. biol. (Impr.) ; 25(2): 111-116, Apr.-Jun. 2018. ilus, tab
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1094307

ABSTRACT

Se analizó el solapamiento de las dietas de dos especies de gorriones en un agroecosistema de la costa central del Perú, una de las especies es invasora (Passer domesticus), mientras que la otra es nativa (Zonotrichia capensis). El presente trabajo muestra que a pesar de que Z. capensis tiene una dieta más diversa (H’= 2.07) que P. domesticus (H’=1.63), presentan alta similitud entre ellas (Dmax=0.15, p>0.05). El índice de Schoener fue ɸ=0.73 y junto con en el análisis de escalamiento multidimensional no métrico muestran un amplio solapamiento en la dieta de ambos gorriones en los diferentes meses de evaluación. Estos resultados permiten concluir que existe un potencial impacto de la invasión de Passer domesticus sobre la especie nativa Zonotrichia capensis por presentar un marcado solapamiento del alimento.


We analyse the diet overlap of two species of sparrows in an agroecosystem of the Central Coast of Peru, one of the species is invasive House Sparrow, while the other is native Rufous-collared Sparrow. We show that although native species has a more diverse diet (H'= 2.07), than invasive species (H' = 1.63), they present high similarity between them (Dmax = 0.15, p> 0.05). The Schoener index was ɸ = 0.73 and together with the non-metric multidimensional scaling analysis they show a broad diet overlap of both sparrows in the different months of evaluation. These results allow to conclude that there is a potential impact of the invasion of House Sparrow on the native species Rufous-collared Sparrow by food overlap.

5.
Rev. peru. biol. (Impr.) ; 25(2): 175-178, Apr.-Jun. 2018. ilus
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1094315

ABSTRACT

Reportamos la presencia del Gorrión de Collar Rufo Zonotrichia capensis por primera vez en los departamen- tos de Loreto y San Martín a 155 y 240 m de altitud respectivamente, la cual corresponde al primer registro confirmado de la especie para la Amazonía peruana. Es posible que la presencia de la especie se deba a la existencia de la carretera que comunica Tarapoto con Yurimaguas, lo que facilitaría la ocupación de la especie por la modificación del paisaje


We report the presence of the Rufous Collared Sparrow Zonotrichia capensis for the first time in the depart- ments of Loreto and San Martín at 155 and 240 m altitude respectively, which corresponds to the first confirmed record of the species for the Peruvian Amazon. It is possible that the presence of the species is due to the existence of the Tarapoto - Yurimaguas road, which would facilitate the occupation of the species by landscape transformation

6.
Oecologia ; 186(4): 931-938, 2018 04.
Article in English | MEDLINE | ID: mdl-29388024

ABSTRACT

Populations of the same species can vary substantially in their behavioral and morphometric traits when they are subject to different environmental pressures, which may lead to the development of different adaptive strategies. We quantified variation in exploratory behavior and morphometric traits among two rufous-collared sparrow populations that occur at low and high elevations in central Chile. Moreover, we used census and δ2H values of feather and blood to evaluate migration. We found that individual sparrows inhabiting high elevations were larger and showed more intense exploratory behavior in comparison with those that were captured at lower elevation. Moreover, we observed a steady decline in sparrow abundance during the winter and similar δ2H values for blood collected in the winter and summer at this site, which were significantly lower than blood Î´2H values observed at low elevation. This pattern suggests that individuals do not move long distances during winter, and likely they remain at similar elevations in refuge habitats. As predicted, our results support the existent of different adaptive strategies among populations of the same species, and suggest that the combination of behavioral, morphometric, and stable isotope data is a novel and robust integrative approach to assess differences in adaptation across environmental gradients.


Subject(s)
Exploratory Behavior , Sparrows , Acclimatization , Animals , Chile , Ecosystem
7.
Rev. bras. parasitol. vet ; 26(3): 314-322, July-Sept. 2017. tab, graf
Article in English | LILACS | ID: biblio-899289

ABSTRACT

Abstract A total of 277 rufous-collared sparrows, Zonotrichia capensis Müller, 1776 (Emberizidae), were examined for external parasites. The birds were captured using mist nets in seven locations in northern and central Chile. Additionally, seven carcasses from central Chile (the Biobío region) were necropsied to evaluate the presence of endoparasite infection. Ectoparasites were found on 35.8% (99/277) of the examined birds and they were represented by the following arthropods: feather mites Amerodectes zonotrichiae Mironov and González-Acuña, 2014 (Analgoidea: Proctophyllodidae), Proctophyllodes polyxenus Atyeo and Braasch, 1966 (Analgoidea: Proctophyllodidae), and Trouessartia capensis Berla, 1959 (Analgoidea: Trouessartiidae); a louse Philopterus sp. (Phthiraptera: Ischnocera); and ticks Amblyomma tigrinum Koch, 1844 (Acari: Ixodidae) and Ixodes auritulus Neumann, 1904 (Acari: Ixodidae). Two of the seven necropsied carcasses were infected with the acanthocephalan Mediorhynchus papillosus Van Cleave, 1916 (Gigantorhynchida: Gigantorhynchidae). To our knowledge, this study reports P. polyxenus, Philopterus sp., A. tigrinum, and M. papillosus for the first time for Z. capensis and expands the distributional range for T. capensis to Chile.


Resumo Um total de 277 tico-tico Zonotrichia capensis Müller, 1776 (Emberizidae) foram examinados em busca de ectoparasitos. As aves foram capturadas com redes em sete localidades do norte e centro do Chile. Além disso, sete carcaças do centro Chile (Região de Biobío) foram examinadas para avaliar a infecção por endoparasitos. Ectoparasitos foram encontrados em 35,8% (99/277) das aves examinadas com a identificação dos ácaros Amerodectes zonotrichiae Mironov and González-Acuña, 2014 (Analgoidea: Proctophyllodidae), Proctophyllodes polyxenus Atyeo and Braasch, 1966 (Analgoidea: Proctophyllodidae) e Trouessartia capensis Berla, 1959 (Analgoidea: Trouessartiidae), piolho Philopterus sp. (Phthiraptera: Ischnocera) e carrapatos Amblyomma tigrinum Koch, 1844 (Acari: Ixodidea) e Ixodes auritulus Neumann, 1904 (Acari: Ixodidea). Duas das sete carcaças examinadas foram infectadas com o Acantocephala Mediorhynchus papillosus Van Cleave, 1916 (Gigantorhynchida: Gigantorhynchidae). Para o nosso conhecimento, este é o primeiro estudo para descrever P. polyxenus, Philopterus sp., A. tigrinum e M. papillosus em Z. capensis e expande a distribuição de T. capensis ao Chile.


Subject(s)
Animals , Male , Female , Sparrows/parasitology , Ectoparasitic Infestations/veterinary , Intestinal Diseases, Parasitic/veterinary , Chile , Ectoparasitic Infestations/parasitology , Feathers/parasitology , Intestinal Diseases, Parasitic/parasitology , Intestines/parasitology
8.
R Soc Open Sci ; 3(7): 160231, 2016 Jul.
Article in English | MEDLINE | ID: mdl-27493778

ABSTRACT

Birds in cities start singing earlier in the morning than in rural areas; commonly this shift is attributed to light pollution. Some studies have suggested that traffic noise has a stronger influence on singing activity than artificial light does. Changes in the timing of singing behaviour in relation to noise and light pollution have only been investigated in the temperate zones. Tropical birds, however, experience little seasonal variation in day length and may be less dependent on light intensity as a modifier for reproductive behaviours such as song. To test whether noise or light pollution has a stronger impact on the dawn chorus of a tropical bird, we investigated the singing behaviour of rufous-collared sparrows (Zonotrichia capensis) in Bogota, Colombia at two times during the year. We found that birds in places with high noise levels started to sing earlier. Light pollution did not have a significant effect. Birds may begin to sing earlier in noisy areas to avoid acoustic masking by traffic later in the morning. Our results also suggest that some tropical birds may be less sensitive to variations in day length and thus less sensitive to light pollution.

9.
Biodivers Data J ; (4): e8184, 2016.
Article in English | MEDLINE | ID: mdl-27226760

ABSTRACT

BACKGROUND: The Shiny Cowbird, Molothrus bonariensis Gmelin, 1789, is a brood parasite of hundreds of small-bodied birds that is native to South American lowlands. Within the last 100 years this species has been expanding its range throughout the Caribbean, towards North America, but has rarely been seen above 2,000 m asl. NEW INFORMATION: Here, we present records of Shiny Cowbirds in Quito, a city located 2,800 m above sea level that harbors a bird community typical of the Andean valleys. We found two juvenile individuals parasitizing two different pairs of Rufous-collared Sparrow (Zonotrichia capensis Müller, 1776). This report constitutes an altitudinal range expansion of reproductive populations of ca. 500m, which may have beenprompted by anthropogenic disturbance.

10.
Acta Trop ; 159: 83-94, 2016 Jul.
Article in English | MEDLINE | ID: mdl-26995696

ABSTRACT

The great diversity of birds and ecosystems in the Andean mountains has been understudied in terms of their parasite species. We describe a new Haemoproteus parasite, H. (Parahaemoproteus) erythrogravidus infecting Zonotrichia capensis (Rufous-Collared Sparrow) in South America. The description of this blood parasite species is supported by morphological and molecular data based on a fragment of cytochrome b gene (cyt b) and complete mitochondrial genome sequences. The new species is closely related to H. (Parahaemoproteus) coatneyi, and it can be readily distinguished from the latter parasite due to morphology of its blood stages, particularly 1) the formation of a marked protrusion on envelope of infected erythrocytes by the majority of developing gametocytes, a feature which is unique for this Haemoproteus species and 2) the extremely attenuated width of the growing dumbbell-shaped macro- and microgametocytes. Additionally, Haemoproteus erythrogravidus is shown to be a monophyletic taxon that diverges from Haemoproteus coatneyi at the molecular level. We provide the complete mitochondrial DNA genome for both H. coatneyi and H. erythrogravidus. Molecular and morphological evidences indicate that H. erythrogravidus is present in Ecuador and Colombia, and genetic lineages with 100% of identity for the cyt b gene were reported in Chile, Perú, and Venezuela. Our study also indicates that H. erythrogravidus and H. coatneyi are sympatric sister taxa sharing Z. capensis as a host species across its distribution, which could be the result of sympatric speciation or complex biogeographic processes. Further studies on the distribution and evolutionary history of Z. capensis and its parasites H. erythrogravidus and H. coatneyi insight for our better understanding of the factors and dynamics driving parasite speciation.


Subject(s)
Bird Diseases/parasitology , Birds/parasitology , DNA, Protozoan/genetics , Haemosporida/classification , Haemosporida/genetics , Parasites/classification , Protozoan Infections, Animal/parasitology , Animals , Cytochromes b/genetics , DNA, Mitochondrial , Genome, Mitochondrial , Phylogeny , South America
11.
Biota neotrop. (Online, Ed. port.) ; 8(4): 21-31, Oct.-Dec. 2008. ilus, graf, tab
Article in English | LILACS | ID: lil-509804

ABSTRACT

Understanding how birds use vegetation to obtain food resources has implications for habitat conservation and management. Restinga is a poorly known and threatened tropical habitat, associated to the Atlantic forest, that could benefit from this kind of information to know which plants can be used and dispersed by birds that can help on the maintenance of this habitat. Frugivorous and insectivorous birds are important components of tropical ecosystems, such as restinga. To provide more information regarding the ecology of restinga, we studied the feeding behavior and spatial use of this vegetation by birds at Restinga de Jurubatiba National Park, southeastern Brazil. We found that feeding behavior was similar to that recorded for the same species in other vegetation types. In addition, spatial use of the restinga vegetation by the most abundant species did not overlap greatly, except for two insectivorous species that used different foraging maneuvers and two frugivorous birds that foraged in flocks. The two most abundant species were generalists in their diet and were capable of feeding at the ground level on sand substrate.


O conhecimento das estratégias de uso da vegetação pela fauna para forrageio tem implicações para conservação e manejo de habitats. Restinga é um ambiente tropical, associado à Mata Atlântica, ameaçado e ainda pouco conhecido que poderia se beneficiar desse tipo de informação para conhecer quais espécies de plantas podem ser utilizadas e dispersas por aves que atuem na manutenção deste habitat. Aves frugívoras e insetívoras são importantes componentes de ecossistemas tropicais, como a restinga. Para fornecer mais informações sobre a ecologia da restinga, nós estudamos o comportamento de forrageio e o uso do espaço das aves no Parque Nacional da Restinga de Jurubatiba, sudeste do Brasil. Nós encontramos que os comportamentos de forrageio foram similares àqueles registrados para as mesmas espécies em outros ambientes. Além disso, o uso do espaço da vegetação de restinga pelas espécies mais abundantes não apresentou grande sobreposição, exceto por duas espécies insetívoras que usaram manobras de forrageio diferentes e duas aves frugívoras que forragearam em bando. As duas espécies mais abundantes foram generalistas em suas dietas e foram capazes de forragear no chão sobre areia nua.


Subject(s)
Biodiversity , Birds , Behavior/classification , Ecosystem , Flora , Fauna/adverse effects , Insecta
13.
Evolution ; 46(5): 1443-1456, 1992 Oct.
Article in English | MEDLINE | ID: mdl-28568996

ABSTRACT

The geographical patterns of variation shown at 20 allozyme and non-enzymatic protein-coding loci, in 8 external, and in 12 skeletal morphological characters in the rufous-collared sparrow, Zonotrichia capensis, were analyzed in order to test the local (genetic) adaptation hypothesis regarding the origin and maintenance of vocal dialects in birds. Approximately 20 males were collected from each of four sites within each of six different dialect zones. There was significant variability in both external and skeletal morphology among all 24 sites and among dialect groups. Average Wright's corrected fixation coefficient (FST ) was 0.118, indicating significant genetic differentiation among all sites, regardless of dialect. Hierarchical F statistics indicated that only 50% of among site variability was due to a dialect effect. Puna dialect sites were highly differentiated from all other sites with respect to both morphology (external and skeletal measures) and allozyme frequencies. Heterogeneity at the PGM-1 locus among puna scrub sites was the major cause of the high average FST across all sites, and within the puna scrub dialect. Average genetic differentiation among non-puna sites (FST = 0.018) was similar to differentiation among sites within each of the five non-puna dialect groups (mean FST = 0.0132 ± 0.0069). Hierarchical F statistics indicated that none of the among-site differentiation in this subset of samples was due to a dialect effect. These observations are not consistent with the local adaptation hypothesis. All significant genetic heterogeneity occurred among sites in mountainous habitats, and we suggest that topography and patchiness of habitat may have been major factors involved in population differentiation, rather than vocal dialects.

SELECTION OF CITATIONS
SEARCH DETAIL
...