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Animal translocations commonly fail due to predation after release, especially if animals are reared in human care, away from natural predation pressure. Anti-predator training can be a useful tool for combating the predator naivety of released animals, but its effective implementation requires attention to numerous details. We present the step-by-step development of an anti-predator training regime, tailored to the critically endangered `alalā (Corvus hawaiiensis). `Alalā are the last remaining corvid species of the Hawaiian islands, and historically the level of predation they experienced from the Hawaiian hawk, `io (Buteo solitarius) is unclear. However, one factor thought to compromise outcomes of earlier attempts to reintroduce `alalā in the 1990′s was predation by `io, motivating the development of anti-predator training for recent `alalā releases. We documented evidence for what appears to be competent anti-predator behavior in conservation-bred `alalā, with a range of behavioral strategies for coping with `io observed during a series of controlled presentations of `io and `io-related stimuli. These behavioral responses included vigilance, alarm calling, and mobbing during experimental trials conducted in release training aviaries. Our results did not conclusively establish that anti-predator learning occurred as a result of the training, or that the training produced enhanced survival. However, following release, `io-`alalā encounters were observed on more than 35 occasions, and `alalā responses mirrored those observed pre-release, including the first ever recorded mobbing interactions by juvenile flocks of `alalā in the wild. While it is unclear the extent to which training encouraged these species-appropriate anti-predator responses, their occurrence suggests that the `alalā has retained and can express defensive behavioral strategies. By documenting the design process, training execution and behavioral outcomes in `alalā, we highlight details that other reintroduction programs may need to consider when preparing animals for reintroduction alongside natural predators.

Plant–animal interactions are key to sustaining whole communities and ecosystem function. However, their complexity may limit our understanding of the underlying mechanisms and the species involved. The ecological effects of epizoochory remain little known compared to other seed dispersal mechanisms given the few vectors identified. In addition, epizoochory is mostly considered non-mutualistic since dispersers do not obtain nutritional rewards. Here, we show a widespread but unknown mutualistic interaction between parrots and plants through epizoochory. Combining our observations with photos from web-sources, we recorded nearly 2000 epizoochory events in 48 countries across five continents, involving 116 parrot species and nearly 100 plant species from 35 families, including both native and non-native species. The viscid pulp of fleshy fruits and anemochorous structures facilitate the adherence of tiny seeds (mean 3.7 2.56 mm) on the surface of parrots while feeding, allowing the dispersion of these seeds over long distances (mean = 118.5 m). This parrot–plant mutualism could be important in ecosystem functioning across a wide diversity of environments, also facilitating the spread of exotic plants. Future studies should include parrots for a better understanding of plant dispersal processes and for developing effective conservation actions against habitat loss and biological invasions

While most of the knowledge on invasive species focuses on their impacts, little is known about their potential positive effects on other species. Invasive ecosystem engineers can disrupt recipient environments; however, they may also facilitate access to novel resources for native species. The monk parakeet (Myiopsitta monachus) is a worldwide invader and the only parrot that builds its own communal nests, which can be used by other species. However, the ecological effects of these interspecific interactions are barely known. We compared the role of the monk parakeet as a nest-site facilitator in different rural and urban areas, both invaded and native, across three continents and eight breeding seasons. A total of 2690 nests from 42 tenant species, mostly cavity-nesting birds, were recorded in 26% of 2595 monk parakeet nests. Rural and invaded areas showed the highest abundance and richness of tenant species. Multispecies communal nests triggered interspecific aggression between the monk parakeet host and its tenants, but also a cooperative defense against predators. Despite the positive effects for native species, monk parakeets also facilitate nesting opportunities to other non-native species and may also transmit diseases to tenants, highlighting the complexity of biotic interactions in biological invasions., This research was funded by Severo Ochoa Program (SVP-2014-068732), Action COST “ParrotNet” (ES1304), Loro Parque Fundación (PP-146-2018-1), and Ministry of Economy and Competitiveness, Spanish Research Council (CGL-2016-79568-C3-3-P).

The family Psittacidae is comprised of over 400 species, an ever-increasing number of which are considered threatened with extinction. In recent decades, conservation strategies for these species have increasingly employed reintroduction as a technique for reestablishing populations in previously extirpated areas. Because most Psittacines are highly social and flocking species, reintroduction efforts may face the numerical and methodological challenge of overcoming initial Allee effects during the critical establishment phase of the reintroduction. These Allee effects can result from failures to achieve adequate site fidelity, survival and flock cohesion of released individuals, thus jeopardizing the success of the reintroduction. Over the past 20 years, efforts to reestablish and augment populations of the critically endangered Puerto Rican parrot (Amazona vittata) have periodically faced the challenge of apparent Allee effects. These challenges have been mitigated via a novel release strategy designed to promote site fidelity, flock cohesion and rapid reproduction of released parrots. Efforts to date have resulted in not only the reestablishment of an additional wild population in Puerto Rico, but also the reestablishment of the species in the El Yunque National Forest following its extirpation there by the Category 5 hurricane Maria in 2017. This promising release strategy has potential applicability in reintroductions of other psittacines and highly social species in general.

Accurately identifying threats to global biodiversity is the first step towards effectively countering or ameliorating them. However, such threats are usually only qualitatively categorized, without any comparative quantitative assessment of threat levels either within or across ecosystems. As part of recent efforts in Papua New Guinea to develop a long-term strategic plan for reducing threats to biodiversity at the national level, we developed a novel and quantitative method for not only assessing relative effects of specific biodiversity threats across multiple ecosystems, but also identifying and prioritizing conservation actions best suited for countering identified threats. To do so, we used an abbreviated quantitative SWOT (Strengths, Weaknesses, Opportunities, Threats) analysis and multivariate cluster analysis to identify the most significant threats to biodiversity in Papua New Guinea. Of 27 specific threats identified, there were nine major threats (each &gt, 5% of total) which accounted for approximately 72% of the total quantified biodiversity threat in Papua New Guinea. We then used the information to identify underlying crosscutting threat drivers and specific conservation actions that would have the greatest probability of reducing biodiversity threats across multiple ecosystem realms. We categorized recommended actions within three strategic categories, with actions within each category targeting two different spatial scales. Our integrated quantitative approach to identifying and addressing biodiversity threats is intuitive, comprehensive, repeatable and computationally simple. Analyses of this nature can be invaluable for avoiding not only wasted resources, but also ineffective measures for conserving biodiversity.

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., La lista completa de autores puede encontrarse en el archivo asociado., Facultad de Ciencias Naturales y Museo

The Slender-billed Parakeet (Enicognathus leptorhynchus) is a psittacine endemic to southern Chile and an obligate secondary cavity-nester. In the central valley of southern Chile, most (94%) of the known Slender-billed Parakeet nests have occurred in large, mature southern beech (Lophozonia obliqua) trees (locally known as “pellines”). As relicts of the original old-growth forests of southern Chile, most pellines have been lost due to extensive land-clearing throughout the region, potentially threatening long-term persistence of the Slender-billed Parakeet. We conducted our study in the central valley of southern Chile, near the city of Osorno during three consecutive nesting seasons (November–January, 2008–2011). Nest trees used by Slender-billed Parakeets were located by direct observation of parakeet activities and through interviews with local residents, some of whom were former parrot nest poachers. Nest cavities were accessed, inspected and measured using single-rope climbing techniques. We report means, standard errors, 95% confidence intervals and ranges for 11 cavity-related variables. We also report clutch sizes encountered in active nests, and age estimates of nest trees based on known growth rates of Lophozonia trees in southern Chile. Linear regressions were used to evaluate potential relationships between cavity-related variables and clutch size. We located and measured 38 Lophozonia tree cavities used for nesting by Slender-billed Parakeets. Compared to those used by other psittacines, nest trees were relatively large, averaging 30.4 ± 1.1 m in height with a mean diameter at breast height of 134.5 ± 4.7 cm. Based on estimated annual diameter increment, ages of nest trees ranged from approximately 209–485 years. Nest cavities entrances averaged 12.5 ± 0.9 m in height above ground level. Cavity entrance widths averaged 51.0 ± 13.3 cm (vertical) by 11.5 ± 0.7 cm (horizontal). Cavity entrance orientations were apparently random, with no directional preferences detected. Nest cavities were also relatively large, with a mean internal diameter of 39.6 ± 2.4 cm and mean depth of 90.3 ± 24.2 cm. Clutch sizes (2–9) were unusually large for psittacines of this size (ca. 280–300 g) and broods of up to seven well-developed nestlings were observed. We found that the deep and spacious cavities provided by pellines facilitate successful rearing of large broods, thereby maximizing productivity and fitness. The existence of pellines has apparently allowed Slender-billed Parakeets to adapt successfully to a wholesale loss of ancestral habitat to anthropogenic modifications. Immediate and strategic conservation measures, such as protection of existing pellines and the regeneration and recruitment of additional ones, are recommended for ensuring the survival of Slender-billed Parakeet populations throughout the central valley of southern Chile.