Project description:In recent years, new Chlamydia species, other than Chlamydia psittaci, have been confirmed in birds. One of these new species, Chlamydia avium, was reported mainly in pigeons and parrots in Europe. Analyzing multimucosal swabs obtained from 7 Amazon parrots (Amazona aestiva) from illegal trade and admitted to the Reserva Experimental Horco Molle (Tucuman, Argentina) for their rehabilitation, we describe the finding of the genetic material of C. avium in 2 of these birds. There were no signs compatible with the chlamydiosis-like disease in the studied birds or in the rehabilitation center staff. The use of sensitive and wide-ranging molecular tools is necessary for the detection of all Chlamydiaceae present in birds and would aid in the selection of control measures in wildlife rehabilitation centers to prevent outbreaks in the facilities and the introduction of pathogens in nature. We provide the first molecular evidence of the presence of C. avium in Argentina and a new species of psittacine host.
Project description:Parrots kept in zoos and private households often develop psychological and behavioural disorders. Despite knowing that such disorders have a multifactorial aetiology and that chronic stress is involved, little is known about their development mainly due to a poor understanding of the parrots' physiology and the lack of validated methods to measure stress in these species. In birds, blood corticosterone concentrations provide information about adrenocortical activity. However, blood sampling techniques are difficult, highly invasive and inappropriate to investigate stressful situations and welfare conditions. Thus, a non-invasive method to measure steroid hormones is critically needed. Aiming to perform a physiological validation of a cortisone enzyme immunoassay (EIA) to measure glucocorticoid metabolites (GCM) in droppings of 24 Blue-fronted parrots (Amazona aestiva), two experiments were designed. During the experiments all droppings were collected at 3-h intervals. Initially, birds were sampled for 24 h (experiment 1) and one week later assigned to four different treatments (experiment 2): Control (undisturbed), Saline (0.2 mL of 0.9% NaCl IM), Dexamethasone (1 mg/kg IM) and Adrenocorticotropic hormone (ACTH; 25 IU IM). Treatments (always one week apart) were applied to all animals in a cross-over study design. A daily rhythm pattern in GCM excretion was detected but there were no sex differences (first experiment). Saline and dexamethasone treatments had no effect on GCM (not different from control concentrations). Following ACTH injection, GCM concentration increased about 13.1-fold (median) at the peak (after 3-9 h), and then dropped to pre-treatment concentrations. By a successful physiological validation, we demonstrated the suitability of the cortisone EIA to non-invasively monitor increased adrenocortical activity, and thus, stress in the Blue-fronted parrot. This method opens up new perspectives for investigating the connection between behavioural disorders and stress in this bird species, and could also help in their captive management.
Project description:Psittacidae species are among the most threatened birds in the world. Approximately one-half of the 390 parrot species are experiencing population declines. The Blue-fronted Amazon (Amazona aestiva) is the most traded parrot worldwide and suffers from poaching and habitat loss. Many species of parrots, including the Blue-fronted Amazon, form communal roosts where they spend the night. Under certain circumstances, roost surveys can be a rapid and cost-effective way to obtain information about the demography of parrots or the consequences of threats. We surveyed an area of 2,700 km2 in a large wetland in mid-western of Brazil and located five Blue-fronted Amazon roosts. We conducted monthly counts of the birds arriving at these roosts for 28-61 months and stratified the counts into flock sizes. We used this information to estimate the number of parrots using these roosts to determine whether the roosts follow seasonal patterns and whether they have different flock-size structures and different dynamics throughout the year, as well as to determine the trends of the roosting parrots, which are stratified by flock size. The roosts were different, as they followed different seasonal patterns and had different flock-size structures, which could be interpreted in relation to the parrot breeding cycle. The trends of singletons, which index the number of reproductive couples each year, and the number of pairs parrots increased or fluctuated around a baseline, but the number of fledged young in the year declined throughout the study. This is of concern, as it indicates problems in population recruitment, which could have been unnoticed by the management authorities, as the total numbers were not decreasing. Although every monitored roost had birds of each age or reproductive condition strata, the fact that the roosts were different could be important in terms of management, as it will be more effective for the conservation of the Blue-fronted Amazon to protect a carefully chosen set of complementary roosts.
Project description:The Blue-fronted Amazon (Amazona aestiva) is a Neotropical parrot with a large distribution in South America, including areas in Brazil, Bolivia, Argentina and Paraguay. A substantial part of the population of this parrot is concentrated in the Pantanal, a large wetland located in the center of South America. There, the clearing of forest and savannas has occurred through the years to accommodate beef-cattle pasture, and crops. Our objective was to understand the direct and indirect effects of time, availability of forest and savannas, and rainfall over the number of nestlings and fledged young of Blue-fronted Amazons inhabiting the southern Pantanal. We surveyed their nests from 1997 to 2018 and counted the number of nestlings produced and the number of fledglings capable to leave the nest in each year. Additionally, we used available data on the area covered by arboreal vegetation, and rainfall data collected at a Meteorological Station located in a central area of the study, as predictors of the numbers of nestlings and fledglings produced every year. Then, we applied structural equation modeling to examine both the direct and indirect effects of time, arboreal habitat availability, and annual cumulative rainfall on the number of nestlings and fledgling per nest. Finally, we estimated the long-term trend of the number of fledglings per nest as a surrogate to the populational trend of Blue-fronted Amazon. We found that none of the variables in our model explained the number of nestlings in nests, but the number of nestlings and the arboreal habitat availability directly and positively affected the number of fledglings. Time indirectly and negatively affected the number of fledglings per nest, whereas rainfall affected it indirectly positively. Additionally, we detected a concerning decrease of about 30% of the fledglings during the 22-years study, which could lead to a change in the species conservational status.