Paramètres de reproduction de l'amazone à front bleu (<i>Amazona aestiva</i>) dans la forêt sèche du Chaco

The progressive exploitation and destruction of nesting habitat in recent years, combined with the substantial pressure from legal and illegal removal of wild nestlings and adults, justifies the development of a comprehensive study on the reproductive biology of the Turquoise-fronted Parrot (Amazona aestiva). We analyzed breeding parameters in a wild protected population of Turquoise-fronted Parrots in the Chaco forest, Argentina, examining variation among years, over the course of the breeding season, and in relation to the age of the nest. Mean clutch-size per nesting attempt was 3.68 eggs. Hatching success (proportion of eggs laid that hatch) was 0.73. Fledging success (proportion of nestlings that fledge) was 0.88. The overall breeding success (mean number of fledglings per laying female per year) was 0.95. Clutch size did not vary among years but it decreased with the delay of the nest initiation date. Hatching failure was the greatest cause of egg partial losses, and brood reduction was the main cause of nestling partial loses. Brood reduction was positively correlated with clutch size and with egg-laying date. We did not find interannual variation in any of the clutch or brood size variables. Our results showed that the population of Turquoise-fronted Parrots in the dry Chaco forest has high values of clutch size and nestling survival, and low values of hatching success. However, some aspects of the breeding biology need more attention, especially if the species continues to be harvested.L'exploitation et la destruction progressives de l'habitat de nidification advenues ces récentes années, combinées à la pression élevée de captures légale et illégale d'oisillons et d'adultes sauvages, justifient la mise en place d'une étude globale sur la biologie de reproduction de l'Amazone à front bleu (Amazona aestiva). Nous avons analysé les paramètres de reproduction d'une population sauvage protégée de cette amazone dans la forêt du Chaco, en Argentine, examinant les variations interannuelles, tout au long de la saison de reproduction, en relation avec l'âge du nid. La taille moyenne de la ponte par tentative de nidification était de 3,68 oeufs. Le succès d'éclosion (proportion d'oeufs pondus qui ont éclos) était de 0,73. Le succès à l'envol (proportion de jeunes qui ont pris leur envol) était de 0,88. Le succès de nidification d'ensemble (nombre moyen de jeunes à l'envol par femelle nicheuse par année) était de 0,95. La taille de la ponte n'a pas varié d'une année à l'autre, mais était plus faible lorsque la date d'initiation du nid était retardée. L'échec de l'éclosion était la cause la plus importante de perte partielle d'oeufs et une couvée réduite était la cause principale de perte partielle d'oisillons. La couvée réduite était positivement corrélée avec la taille de la ponte et la date de celle-ci. Nous n'avons pas observé de variations interannuelles des variables relatives à la taille de la ponte ou de la couvée. Nos résultats indiquent que la population de l'Amazone à front bleu de la forêt sèche du Chaco montre des valeurs élevées de la taille de ponte et de la survie des oisillons, mais des valeurs faibles du succès d'éclosion. Néanmoins, nous pensons qu'il serait important de se pencher davantage sur certains éléments de la biologie de reproduction de l'espèce, particulièrement si elle continue d'être prélevée.Facultad de Ciencias Naturales y Muse

Reproductive parameters of the Turquoise-fronted Parrot (Amazona aestiva) in the dry Chaco forest

The progressive exploitation and destruction of nesting habitat in recent years, combined with the substantial pressure from legal and illegal removal of wild nestlings and adults, justifies the development of a comprehensive study on the reproductive biology of the Turquoise-fronted Parrot (Amazona aestiva). We analyzed breeding parameters in a wild protected population of Turquoise-fronted Parrots in the Chaco forest, Argentina, examining variation among years, over the course of the breeding season, and in relation to the age of the nest. Mean clutch-size per nesting attempt was 3.68 eggs. Hatching success (proportion of eggs laid that hatch) was 0.73. Fledging success (proportion of nestlings that fledge) was 0.88. The overall breeding success (mean number of fledglings per laying female per year) was 0.95. Clutch size did not vary among years but it decreased with the delay of the nest initiation date. Hatching failure was the greatest cause of egg partial losses, and brood reduction was the main cause of nestling partial loses. Brood reduction was positively correlated with clutch size and with egg-laying date. We did not find interannual variation in any of the clutch or brood size variables. Our results showed that the population of Turquoise-fronted Parrots in the dry Chaco forest has high values of clutch size and nestling survival, and low values of hatching success. However, some aspects of the breeding biology need more attention, especially if the species continues to be harvested

Current threats faced by Neotropical parrot populations

Berkunsky I, Quillfeldt P, Brightsmith DJ, et al. Current threats faced by Neotropical parrot populations. Biological Conservation. 2017;214:278-287.Psittaciformes (parrots, cockatoos) are among the most endangered birds, with 31% of Neotropical species under threat. The drivers of this situation appear to be manifold and mainly of anthropogenic origin. However, this assessment is based on the last extensive consultation about the conservation situation of parrots carried out in the 1990s. Given the rapid development of anthropogenic threats, updated data are needed to strategize conservation actions. Using a population approach, we addressed this need through a wide-ranging consultation involving biologists, wildlife managers, government agencies and non-governmental conservation organizations. We gathered up-to-date information on threats affecting 192 populations of 96 Neotropical parrot species across 21 countries. Moreover, we investigated associations among current threats and population trends. Many populations were affected by multiple threats. Agriculture, Capture for the Pet Trade, Logging, each of them affected > 55% of the populations, suggesting a higher degree of risk than previously thought. In contrast to previous studies at the species level, our study showed that the threat most closely associated with decreasing population trends is now Capture for the local Pet Trade. Other threats associated with decreasing populations include Small-holder Farming, Rural Population Pressure, Nest Destruction by Poachers, Agro-industry Grazing, Small-holder Grazing, and Capture for the international Pet Trade. Conservation actions have been implemented on < 20% of populations. Our results highlight the importance of a population-level approach in revealing the extent of threats to wild populations. It is critical to increase the scope of conservation actions to reduce the capture of wild parrots for pets