74 resultados para Parrots
Resumo:
We examined nest site selection by Puerto Rican Parrots, a secondary cavity nester, at several spatial scales using the nest entrance as the central focal point relative to 20 habitat and spatial variables. The Puerto Rican Parrot is unique in that, since 2001, all known nesting in the wild has occurred in artificial cavities, which also provided us with an opportunity to evaluate nest site selection without confounding effects of the actual nest cavity characteristics. Because of the data limitations imposed by the small population size of this critically endangered endemic species, we employed a distribution-free statistical simulation approach to assess site selection relative to characteristics of used and unused nesting sites. Nest sites selected by Puerto Rican Parrots were characterized by greater horizontal and vertical visibility from the nest entrance, greater density of mature sierra palms, and a more westerly and leeward orientation of nest entrances than unused sites. Our results suggest that nest site selection in this species is an adaptive response to predation pressure, to which the parrots respond by selecting nest sites offering advantages in predator detection and avoidance at all stages of the nesting cycle. We conclude that identifying and replicating the “nest gestalt” of successful nesting sites may facilitate conservation efforts for this and other endangered avian species.
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Chlamydophila psittaci (C. psittaci) infection was evaluated in 77 free-living nestlings of Blue-fronted Amazon parrots (Amazona aestiva) and Hyacinth macaws (Anodorhynchus hyacinthinus) in the Pantanal of Mato Grosso do Sul, Brazil. Tracheal and cloacal swab samples from 32 wild parrot and 45 macaw nestlings were submitted to semi-nested PCR, while serum samples were submitted to complement fixation test (CFT). Although all 32 Amazon parrot serum samples were negative by CFT, cloacal swabs from two birds were positive for Chlamydophila DNA by semi-nested PCR (6.3%); these positive birds were 32 and 45 days old. In macaws, tracheal and cloacal swabs were positive in 8.9% and 26.7% of the samples, respectively. Complement-fixing antibodies were detected in 4.8% of the macaw nestlings; macaw nestlings with positive findings were between 33 and 88 days old. These results indicate widespread dissemination of this pathogen in the two evaluated psittacine populations. No birds had clinical signs suggestive of chlamydiosis. To the best of our knowledge, this is the first report on C. psittaci in free-living Blue-fronted Amazon parrots and Hyacinth macaws in Brazil. (c) 2006 Elsevier B.V. All rights reserved.
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The prevalence of Chlamydophila psittaci (formerly Chlamydia psittaci) infection was assessed in 95 apparently healthy, captive Amazon parrots from three breeder collections in southeastern and west-central Brazil. Cloacal swabs from 95 birds were tested for chlamydial antigen, which was detected by direct immunofluorescence (DIF), and serum samples from 44 of these birds were tested for antibodies to C. psittaci using an enzyme-linked immunosorbent assay. The prevalences of active infection as detected by DIF were 16.7%, 22.2%, and 56.1%, and seroprevalences were 100%, 87.5%, and 60% in flocks A, B, and C, respectively. We can therefore infer that C. psittaci may be widespread in captive parrot populations in Brazil.
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The objective of this study was to compare the capacity of adult (more than 3 yr old) and young (less than 1 yr old) true parrots to digest seeds that are normally included in their diet in captivity, particularly soybean, sunflower, and corn. All the seeds were offered for 5 d with an interval of 15 d between different diets. The seeds of soybean and corn were boiled for 15 min and soaked in water at ambient temperature for 12 h before being fed to the birds. There were no differences in the digestibilities of crude protein and fats (ether extract) among animals, but the digestibilities of dry matter and crude fiber by the adult animals were higher than those of the young ones. The digestibility of carbohydrate (nitrogen-free extract) by adult birds was higher only for sunflower seeds. It is concluded that the capacity of parrots to digest fiber may change according to the age of the animal. Since the digestion of fiber depends on the action of microorganisms, these results suggest that the colonization of the gastrointestinal tract is delayed or very slow in young parrots.
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The karyotypes of 12 species of Psittaciformes new to cytology are described: Lorius hypoinochrous, L. lory and Phigys solitarius of the Loriidae, and Amazona autumnallis, Aratinga jandaya, Eclectus roratus, Pionus maximiliani, P. menstruus, P. senilis, P. seniloides, Poicephalus senegalus and Polytelis alexandrae of the Psittacidae. The karyotypes of Amazona ochrocephala, Ara ararauna, Ara macao, Psittacula krameri, Psittacus erithacus and Pyrrhura molinae of the Psittacidae have been previously described. For reasons of comparison the karyotypes of Aratinga aurea, Forpus xanthopterygius, Brotogeris sanctithomae and B. versicolorus of the Psittacidae are also described. These karyotypes are compared to those in the literature and the karyological relationships in the Psittaciformes are briefly discussed. Microchromosome fusions and translocations and pericentric inversions probably are responsible for the heterogeneity of karyotypes in the Psittaciformes.
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Renata G. Vieira R.G. & Acqua Coutinho S.D. 2009. Phenotypical characterization of Candida spp. isolated from crop of parrots (Amazona spp.). Pesquisa Veterinaria Brasileira 29(6):452-456. Curso de Pos-Graduagdo em Imunopatologia Veterinaria, Universidade Paulista, Rua Agariba 48, São Paulo, SP 05053010, Brazil. E-mail: selene@uol.com.brThe purpose of this study was to characterize Candida isolates from crop of parrots. Forty baby parrots of genus Amazona, species aestiva and amazonica that were apprehended from wild animal traffic were used: 18 presented ingluvitis and 22 other alterations, but showing general debilitation. Samples were seeded on Sabouraud dextrose agar with chloramphenicol after be obtained by the introduction of urethral probe through the esophagus. Based on morphology and biochemical reactions (API 20C) Candida was confirmed; it was still searched the production of proteinase and phospholipase, virulence factors for Candida species. Candida spp. were isolated from 57.5% parrots, being 72.2% from birds with ingluvitis and 45.5% from without ones. Twenty-five strains of Candida were isolated, 60% and 40%, respectively from parrots with and without ingluvitis, and were speciated: 28% C. humicola, 24% C. parapsilosis, 20% C. guilliermondii, 20% C. famata, and 8% C. albicans. These results demonstrate that C. albicans is not the most frequent species isolated, and it is the first report that shows C. guilliermondii, C. famata, and C. humicola causing infection in parrots. Many isolates presented filamentation (76%), 100% produced proteinase and 68% phospholipase. The observation of Candida spp. producing virulence factors reinforce the pathogenic role of these yeasts in the cases studied.
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Fifty-eight blue-fronted Amazon parrot (Amazona aestiva) nestlings, recovered from the illegal trade, became ill at a wildlife rehabilitation center in São Paulo State, Brazil. Clinical signs observed were nonspecific, and the mortality rate was 96.5% despite initial treatment with norfloxacin. Postmortem examinations were performed on 10 birds. Liver and spleen smears showed structures suggestive of Chlamydophila psittaci in four cases. Diagnosis was confirmed by seminested polymerase chain reaction on tissue samples. Other birds from the same location showed no clinical signs of the disease, although high complement fixation titers to C. psittaci were found in 10 adult psittacines. All birds in the facility were treated with doxycycline. The two surviving nestlings did not recover after two doxycycline treatments and were euthanatized. The high mortality rate observed in this outbreak was attributed to poor conditions of husbandry and delays in the diagnosis and treatment of the disease. After diagnosis, improved control measures for chlamydiosis were instituted.
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Although parrots share with corvids and primates many of the traits believed to be associated with advanced cognitive processing, knowledge of parrot cognition is still limited to a few species, none of which are Neotropical. Here we examine the ability of three Neotropical parrot species (Blue-Fronted Amazons, Hyacinth and Lear`s macaws) to spontaneously solve a novel physical problem: the string-pulling test. The ability to pull up a string to obtain out-of-reach food has been often considered a cognitively complex task, as it requires the use of a sequence of actions never previously assembled, along with the ability to continuously monitor string, food and certain body movements. We presented subjects with pulling tasks where we varied the spatial relationship between the strings, the presence of a reward and the physical contact between the string and reward to determine whether (1) string-pulling is goal-oriented in these parrots, (2) whether the string is recognized as a means to obtain the reward and (3) whether subjects can visually determine the continuity between the string and the reward, selecting only those strings for which no physical gaps between string and reward were present. Our results show that some individuals of all species were able to use the string as a means to reach a specific goal, in this case, the retrieval of the food treat. Also, subjects from both macaw species were able to visually determine the presence of physical continuity between the string and reward, making their choices consistently with the recognition that no gaps should be present between the string and the reward. Our findings highlight the potential of this taxonomic group for the understanding of the underpinnings of cognition in evolutionarily distant groups such as birds and primates.
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Abstract Background Premedication is rarely used in avian species. The aim of this study was to evaluate the effect of premedication on the quality of sevoflurane induction and anaesthesia in parrots. We hypothesised that premedication would facilitate handling and decrease the minimum anaesthetic dose (MAD). Thirty-six adult parrots were randomly distributed in three groups: group S (n = 12) was premedicated with NaCl 0.9%; group KS (n = 12) was premedicated with 10 mg.kg-1 ketamine; and group KDS (n = 12) was premedicated with 10 mg.kg-1 ketamine and 0.5 mg.kg-1 diazepam, delivered intramuscularly. After induction using 4.5% sevoflurane introduced through a facemask, the MAD was determined for each animal. The heart rate (HR), respiratory rate (RR), systolic arterial blood pressure (SAP), and cloacal temperature (CT) were recorded before premedication (T0), 15 minutes after premedication (T1), and after MAD determination (T2). Arterial blood gas analyses were performed at T0 and T2. The quality of anaesthesia was evaluated using subjective scales based on animal behaviour and handling during induction, maintenance, and recovery. Statistical analyses were performed using analysis of variance or Kruskal-Wallis tests followed by Tukey’s or Dunn’s tests. Results The minimal anaesthetic doses obtained were 2.4 ± 0.37%, 1.7 ± 0.39%, and 1.3 ± 0.32% for groups S, KS, and KDS, respectively. There were no differences in HR, RR, or CT among groups, but SAP was significantly lower in group S. Sedation was observed in both the premedicated S-KS and S-KDS groups. There were no differences in the quality of intubation and recovery from anaesthesia among the three groups, although the induction time was significantly shorter in the pre-medicated groups, and the KS group showed less muscle relaxation. Conclusions Ketamine alone or the ketamine/diazepam combination decreased the MAD of sevoflurane in parrots (Amazona aestiva). Ketamine alone or in combination with diazepam promoted a good quality of sedation, which improved handling and reduced the stress of the birds. All protocols provided safe anaesthesia in this avian species.
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Aim Parrots are thought to have originated on Gondwana during the Cretaceous. The initial split within crown group parrots separated the New Zealand taxa from the remaining extant species and was considered to coincide with the separation of New Zealand from Gondwana 82-85 Ma, assuming that the diversification of parrots was mainly shaped by vicariance. However, the distribution patterns of several extant parrot groups cannot be explained without invoking transoceanic dispersal, challenging this assumption. Here, we present a temporal and spatial framework for the diversification of parrots using external avian fossils as calibration points in order to evaluate the relative importance of the influences of past climate change, plate tectonics and ecological opportunity. Location Australasian, African, Indo-Malayan and Neotropical regions. Methods Phylogenetic relationships were investigated using partial sequences of the nuclear genes c-mos, RAG-1 and Zenk of 75 parrot and 21 other avian taxa. Divergence dates and confidence intervals were estimated using a Bayesian relaxed molecular clock approach. Biogeographic patterns were evaluated taking temporal connectivity between areas into account. We tested whether diversification remained constant over time and if some parrot groups were more species-rich than expected given their age. Results Crown group diversification of parrots started only about 58 Ma, in the Palaeogene, significantly later than previously thought. The Australasian lories and possibly also the Neotropical Arini were found to be unexpectedly species-rich. Diversification rates probably increased around the Eocene/Oligocene boundary and in the middle Miocene, during two periods of major global climatic aberrations characterized by global cooling. Main conclusions The diversification of parrots was shaped by climatic and geological events as well as by key innovations. Initial vicariance events caused by continental break-up were followed by transoceanic dispersal and local radiations. Habitat shifts caused by climate change and mountain orogenesis may have acted as a catalyst to the diversification by providing new ecological opportunities and challenges as well as by causing isolation as a result of habitat fragmentation. The lories constitute the only highly nectarivorous parrot clade, and their diet shift, associated with morphological innovation, may have acted as an evolutionary key innovation, allowing them to explore underutilized niches and promoting their diversification.
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Vicariance is thought to have played a major role in the evolution of modern parrots. However, as the relationships especially of the African taxa remained mostly unresolved, it has been difficult to draw firm conclusions about the roles of dispersal and vicariance. Our analyses using the broadest taxon sampling of old world parrots ever based on 3219 bp of three nuclear genes revealed well-resolved and congruent phylogenetic hypotheses. Agapornis of Africa and Madagascar was found to be the sister group to Loriculus of Australasia and Indo-Malayasia and together they clustered with the Australasian Loriinae, Cyclopsittacini and Melopsittacus. Poicephalus and Psittacus from mainland Africa formed the sister group Of the Neotropical Arini and Coracopsis from Madagascar and adjacent islands may be the closest relative of Psittrichas from New Guinea. These biogeographic relationships are best explained by independent colonization of the African continent via trans-oceanic dispersal from Australasia and Antarctica in the Paleogene following what may have been vicariance events in the late Cretaceous and/or early Paleogene. Our data support a taxon pulse model for the diversification of parrots whereby trans-oceanic dispersal played a more important role than previously thought and was the prerequisite for range expansion into new continents. (C) 2009 Elsevier Inc. All rights reserved
Resumo:
Specialization to nectarivory is associated with radiations within different bird groups, including parrots. One of them, the Australasian lories, were shown to be unexpectedly species rich. Their shift to nectarivory may have created an ecological opportunity promoting species proliferation. Several morphological specializations of the feeding tract to nectarivory have been described for parrots. However, they have never been assessed in a quantitative framework considering phylogenetic nonindependence. Using a phylogenetic comparative approach with broad taxon sampling and 15 continuous characters of the digestive tract, we demonstrate that nectarivorous parrots differ in several traits from the remaining parrots. These trait-changes indicate phenotype–environment correlations and parallel evolution, and may reflect adaptations to feed effectively on nectar. Moreover, the diet shift was associated with significant trait shifts at the base of the radiation of the lories, as shown by an alternative statistical approach. Their diet shift might be considered as an evolutionary key innovation which promoted significant non-adaptive lineage diversification through allopatric partitioning of the same new niche. The lack of increased rates of cladogenesis in other nectarivorous parrots indicates that evolutionary innovations need not be associated one-to-one with diversification events.
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Documenting changes in distribution is necessary for understanding species' response to environmental changes, but data on species distributions are heterogeneous in accuracy and resolution. Combining different data sources and methodological approaches can fill gaps in knowledge about the dynamic processes driving changes in species-rich, but data-poor regions. We combined recent bird survey data from the Neotropical Biodiversity Mapping Initiative (NeoMaps) with historical distribution records to estimate potential changes in the distribution of eight species of Amazon parrots in Venezuela. Using environmental covariates and presence-only data from museum collections and the literature, we first used maximum likelihood to fit a species distribution model (SDM) estimating a historical maximum probability of occurrence for each species. We then used recent, NeoMaps survey data to build single-season occupancy models (OM) with the same environmental covariates, as well as with time- and effort-dependent detectability, resulting in estimates of the current probability of occurrence. We finally calculated the disagreement between predictions as a matrix of probability of change in the state of occurrence. Our results suggested negative changes for the only restricted, threatened species, Amazona barbadensis, which has been independently confirmed with field studies. Two of the three remaining widespread species that were detected, Amazona amazonica, Amazona ochrocephala, also had a high probability of negative changes in northern Venezuela, but results were not conclusive for Amazona farinosa. The four remaining species were undetected in recent field surveys; three of these were most probably absent from the survey locations (Amazona autumnalis, Amazona mercenaria and Amazona festiva), while a fourth (Amazona dufresniana) requires more intensive targeted sampling to estimate its current status. Our approach is unique in taking full advantage of available, but limited data, and in detecting a high probability of change even for rare and patchily-distributed species. However, it is presently limited to species meeting the strong assumptions required for maximum-likelihood estimation with presence-only data, including very high detectability and representative sampling of its historical distribution.