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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.
Dailos Hernández-Brito; Martina Carrete; Guillermo Blanco; Pedro Romero-Vidal; Juan Senar; Emiliano Mori; Thomas White; Álvaro Luna; José Tella. The Role of Monk Parakeets as Nest-Site Facilitators in Their Native and Invaded Areas. Biology 2021, 10, 683 .
AMA StyleDailos Hernández-Brito, Martina Carrete, Guillermo Blanco, Pedro Romero-Vidal, Juan Senar, Emiliano Mori, Thomas White, Álvaro Luna, José Tella. The Role of Monk Parakeets as Nest-Site Facilitators in Their Native and Invaded Areas. Biology. 2021; 10 (7):683.
Chicago/Turabian StyleDailos Hernández-Brito; Martina Carrete; Guillermo Blanco; Pedro Romero-Vidal; Juan Senar; Emiliano Mori; Thomas White; Álvaro Luna; José Tella. 2021. "The Role of Monk Parakeets as Nest-Site Facilitators in Their Native and Invaded Areas." Biology 10, no. 7: 683.
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 >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.
Thomas White; Patricia Bickley; Cory Brown; Dave Busch; Guy Dutson; Holly Freifeld; Douglas Krofta; Sean Lawlor; Dan Polhemus; Rachel Rounds. Quantifying Threats to Biodiversity and Prioritizing Responses: An Example from Papua New Guinea. Diversity 2021, 13, 248 .
AMA StyleThomas White, Patricia Bickley, Cory Brown, Dave Busch, Guy Dutson, Holly Freifeld, Douglas Krofta, Sean Lawlor, Dan Polhemus, Rachel Rounds. Quantifying Threats to Biodiversity and Prioritizing Responses: An Example from Papua New Guinea. Diversity. 2021; 13 (6):248.
Chicago/Turabian StyleThomas White; Patricia Bickley; Cory Brown; Dave Busch; Guy Dutson; Holly Freifeld; Douglas Krofta; Sean Lawlor; Dan Polhemus; Rachel Rounds. 2021. "Quantifying Threats to Biodiversity and Prioritizing Responses: An Example from Papua New Guinea." Diversity 13, no. 6: 248.
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.
Dailos Hernández-Brito; Pedro Romero-Vidal; Fernando Hiraldo; Guillermo Blanco; José Díaz-Luque; Jomar Barbosa; Craig Symes; Thomas White; Erica Pacífico; Esther Sebastián-González; Martina Carrete; José Tella. Epizoochory in Parrots as an Overlooked Yet Widespread Plant–Animal Mutualism. Plants 2021, 10, 760 .
AMA StyleDailos Hernández-Brito, Pedro Romero-Vidal, Fernando Hiraldo, Guillermo Blanco, José Díaz-Luque, Jomar Barbosa, Craig Symes, Thomas White, Erica Pacífico, Esther Sebastián-González, Martina Carrete, José Tella. Epizoochory in Parrots as an Overlooked Yet Widespread Plant–Animal Mutualism. Plants. 2021; 10 (4):760.
Chicago/Turabian StyleDailos Hernández-Brito; Pedro Romero-Vidal; Fernando Hiraldo; Guillermo Blanco; José Díaz-Luque; Jomar Barbosa; Craig Symes; Thomas White; Erica Pacífico; Esther Sebastián-González; Martina Carrete; José Tella. 2021. "Epizoochory in Parrots as an Overlooked Yet Widespread Plant–Animal Mutualism." Plants 10, no. 4: 760.
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.
Jr. Thomas H. White; Wilfredo Abreu; Gabriel Benitez; Arelis Jhonson; Marisel Lopez; Limary Ramirez; Iris Rodriguez; Miguel Toledo; Pablo Torres; Jafet Velez. Minimizing Potential Allee Effects in Psittacine Reintroductions: An Example from Puerto Rico. Diversity 2021, 13, 13 .
AMA StyleJr. Thomas H. White, Wilfredo Abreu, Gabriel Benitez, Arelis Jhonson, Marisel Lopez, Limary Ramirez, Iris Rodriguez, Miguel Toledo, Pablo Torres, Jafet Velez. Minimizing Potential Allee Effects in Psittacine Reintroductions: An Example from Puerto Rico. Diversity. 2021; 13 (1):13.
Chicago/Turabian StyleJr. Thomas H. White; Wilfredo Abreu; Gabriel Benitez; Arelis Jhonson; Marisel Lopez; Limary Ramirez; Iris Rodriguez; Miguel Toledo; Pablo Torres; Jafet Velez. 2021. "Minimizing Potential Allee Effects in Psittacine Reintroductions: An Example from Puerto Rico." Diversity 13, no. 1: 13.
Background 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. Methods 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. Results 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. Conclusions 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. Keywords Conservation Deforestation Habitat loss Lophozonia obliqua Pellines Psittacidae Regeneration
Thomas H. White; Jaime E. Jiménez. Lophozonia tree cavities used for nesting by Slender-billed Parakeets (Enicognathus leptorhynchus) in the central valley of southern Chile: a potentially vanishing keystone resource. Avian Research 2017, 8, 317 .
AMA StyleThomas H. White, Jaime E. Jiménez. Lophozonia tree cavities used for nesting by Slender-billed Parakeets (Enicognathus leptorhynchus) in the central valley of southern Chile: a potentially vanishing keystone resource. Avian Research. 2017; 8 (1):317.
Chicago/Turabian StyleThomas H. White; Jaime E. Jiménez. 2017. "Lophozonia tree cavities used for nesting by Slender-billed Parakeets (Enicognathus leptorhynchus) in the central valley of southern Chile: a potentially vanishing keystone resource." Avian Research 8, no. 1: 317.
Recent decades have seen increasing use and importance of translocations and reintroductions as tools for species’ conservation and ecological restorations. Most such efforts face substantial logistical complexities and high costs, both biological and financial. These and other challenges have contributed to numerous failures or partial successes of reintroductions, a trend which has improved little over time. Given the negative ramifications of reintroduction failures, practitioners have adopted or developed numerous analytical and procedural methods in efforts to promote successful outcomes. However, many such methods are often ad hoc or taxon-specific, particularly regarding the evaluation and selection of reintroduction areas and sites. Despite the recognized importance of this phase of reintroduction planning, there is to date no comprehensive methodology for selecting suitable reintroduction sites. We describe in detail the application of quantitative SWOT (Strengths, Weaknesses, Opportunities, Threats) analysis for objectively evaluating candidate reintroduction areas or sites, and how results of this analysis are used for identifying the most effective and efficient management actions for promoting reintroduction success. We use examples drawn from recent reintroduction plans for three avian species in Puerto Rico (1) and Brazil (2) to illustrate specific methodologies used as well as the results obtained and their application to the reintroduction planning and implementation process. From our findings, quantitative SWOT analysis is a simple, versatile, repeatable and intuitive method for reintroduction area and site selection. The method also provides a valuable mechanism for evaluating and prioritizing management actions relative to their efficiency and effectiveness for achieving reintroduction objectives.
Thomas H. White; Yara De Melo Barros; Pedro F. Develey; Iván C. Llerandi-Román; Omar A. Monsegur-Rivera; Ana M. Trujillo-Pinto. Improving reintroduction planning and implementation through quantitative SWOT analysis. Journal for Nature Conservation 2015, 28, 149 -159.
AMA StyleThomas H. White, Yara De Melo Barros, Pedro F. Develey, Iván C. Llerandi-Román, Omar A. Monsegur-Rivera, Ana M. Trujillo-Pinto. Improving reintroduction planning and implementation through quantitative SWOT analysis. Journal for Nature Conservation. 2015; 28 ():149-159.
Chicago/Turabian StyleThomas H. White; Yara De Melo Barros; Pedro F. Develey; Iván C. Llerandi-Román; Omar A. Monsegur-Rivera; Ana M. Trujillo-Pinto. 2015. "Improving reintroduction planning and implementation through quantitative SWOT analysis." Journal for Nature Conservation 28, no. : 149-159.
Jaime A. Collazo; Paul L. Fackler; Krishna Pacifici; Thomas H. White; Ivan Llerandi-Roman; Stephen J. Dinsmore. Optimal allocation of captive-reared Puerto Rican parrots: Decisions when divergent dynamics characterize managed populations. The Journal of Wildlife Management 2013, 77, 1124 -1134.
AMA StyleJaime A. Collazo, Paul L. Fackler, Krishna Pacifici, Thomas H. White, Ivan Llerandi-Roman, Stephen J. Dinsmore. Optimal allocation of captive-reared Puerto Rican parrots: Decisions when divergent dynamics characterize managed populations. The Journal of Wildlife Management. 2013; 77 (6):1124-1134.
Chicago/Turabian StyleJaime A. Collazo; Paul L. Fackler; Krishna Pacifici; Thomas H. White; Ivan Llerandi-Roman; Stephen J. Dinsmore. 2013. "Optimal allocation of captive-reared Puerto Rican parrots: Decisions when divergent dynamics characterize managed populations." The Journal of Wildlife Management 77, no. 6: 1124-1134.
Ana Paula B. Carneiro; Jaime E. Jiménez; Pablo M. Vergara; Thomas H. White. Nest-site selection by Slender-billed Parakeets in a Chilean agricultural-forest mosaic. Journal of Field Ornithology 2013, 84, 13 -22.
AMA StyleAna Paula B. Carneiro, Jaime E. Jiménez, Pablo M. Vergara, Thomas H. White. Nest-site selection by Slender-billed Parakeets in a Chilean agricultural-forest mosaic. Journal of Field Ornithology. 2013; 84 (1):13-22.
Chicago/Turabian StyleAna Paula B. Carneiro; Jaime E. Jiménez; Pablo M. Vergara; Thomas H. White. 2013. "Nest-site selection by Slender-billed Parakeets in a Chilean agricultural-forest mosaic." Journal of Field Ornithology 84, no. 1: 13-22.
With 28% of the 350 species of parrots considered threatened, numerous conservation efforts have been initiated for these species. Among these, the restoration or establishment of new populations has increasingly relied on reintroductions as a conservation strategy, often with mixed or uncertain results. We reviewed the results and methodologies of 47 distinct releases and reintroductions of psittacines in nine different countries worldwide over the past 25 years to identify common denominators of successful efforts. To do so, we established a uniform and objective definition of reintroduction success (first-year survival >0.50 and released birds breeding with conspecifics, either captive-reared or wild), and applied generalized linear models and information-theoretic model selection to multiple datasets to identify important predictor variables. We identified several likely predictors of successful psittacine reintroductions, relating to predation mitigation, habitat quality, and post-release supplementation that may provide guidance for future efforts. We also advocate SWOT analysis for objectively evaluating the suitability of potential reintroduction sites.
Thomas H. White; Nigel J. Collar; Ron J. Moorhouse; Virginia Sanz; Eric D. Stolen; Donald Brightsmith. Psittacine reintroductions: Common denominators of success. Biological Conservation 2012, 148, 106 -115.
AMA StyleThomas H. White, Nigel J. Collar, Ron J. Moorhouse, Virginia Sanz, Eric D. Stolen, Donald Brightsmith. Psittacine reintroductions: Common denominators of success. Biological Conservation. 2012; 148 (1):106-115.
Chicago/Turabian StyleThomas H. White; Nigel J. Collar; Ron J. Moorhouse; Virginia Sanz; Eric D. Stolen; Donald Brightsmith. 2012. "Psittacine reintroductions: Common denominators of success." Biological Conservation 148, no. 1: 106-115.
Thomas H. White; Wilfredo Abreu-González; Miguel Toledo-González; Pablo Torres-Báez. Artificial nest cavities for Amazona parrots. Wildlife Society Bulletin 2005, 33, 756 -760.
AMA StyleThomas H. White, Wilfredo Abreu-González, Miguel Toledo-González, Pablo Torres-Báez. Artificial nest cavities for Amazona parrots. Wildlife Society Bulletin. 2005; 33 (2):756-760.
Chicago/Turabian StyleThomas H. White; Wilfredo Abreu-González; Miguel Toledo-González; Pablo Torres-Báez. 2005. "Artificial nest cavities for Amazona parrots." Wildlife Society Bulletin 33, no. 2: 756-760.