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El Alilicucú Orejudo o Ribereño (Megascops sanctaecatarinae) fue ignorado en la mayoría de las obras ornitológicas de la Argentina y es muy escaso el conocimiento sobre esta lechucita en el país. Comentamos el tratamiento de la especie por diferentes autores durante el siglo XX, brindamos 41 registros en 18 localidades en la provincia de Misiones y aportamos información sobre la identificación, distribución, morfología, dieta y hábitat. Para la identificación de esta lechuza en el campo, resultan claves las vocalizaciones, esencialmente de la hembra. También puede ser distinguida de sus congéneres simpátricos por el mayor tamaño corporal y el plumaje ‘escamado’ del pecho, pero en ocasiones no se distinguen estas características, especialmente en las fotos; el largo de las ‘orejas’ y el color del iris, frecuentemente citados como marcas de campo, no resultan diagnósticos. La encontramos asociada a arroyos de distintos caudales, en bosques degradados o en recuperación, o fajas de selva, pero no en bosques prístinos. Una dieta que incluye anfibios y peces podría ser la clave en la asociación con ambientes riparios. Los registros del Alilicucú Grande (Megascops atricapilla) en la provincia de Corrientes podrían ser confusiones con Megascops sanctaecatarinae: la voz del macho de M. sanctaecatarinae y la variación de coloración de plumaje y en los iris, en ambas especies podrían contribuir a estos errores. Recomendamos búsquedas con playback en el sur de Misiones y sectores más australes para evaluar la verdadera distribución, abundancia y conservación de M. sanctaecatarinae en Argentina.

Global-scope scientific journals have played an important role in upholding a colonial legacy of north-south inequities in ornithology, and they now have a key role to play in increasing equity in scientific publishing. We explore common barriers faced by ornithologists in the Neotropics (Latin America and the Caribbean) and suggest priority actions that Ornithological Applications, Ornithology, and other global-scope ornithological journals can take to increase equity in publication and research uptake. Among the most important problems, we identified (1) restrictive (and north-biased) criteria for assessing research “importance” and “novelty,” (2) the high publication costs of the Author Pay (Gold) Open Access model, (3) language hegemony, (4) under-representation of ornithologists from the Neotropics on editorial boards and as lead authors on invited articles, and (5) lack of attention to ethics of collaboration and citation. We recommend that Ornithological Applications, Ornithology, and other global-scope ornithological journals (1) adjust their criteria for publication with the aim to publish all scientifically robust and ethically rigorous ornithology research submitted by first authors based in the Neotropics, including negative results and articles on basic biology; (2) maintain or create options for free or low-cost publication; (3) offer the option of a submission and review process in Spanish (and possibly other languages in the future); (4) increase the representation of ornithologists based in the Neotropics (especially women and those belonging to other marginalized groups) in core editorial teams and on editorial boards; and (5) introduce structured reflexivity statements, in which authors declare how local scientists were involved in the research and how equity was promoted in the collaboration that resulted in the manuscript. For these changes to be broadly effective in the long term, ornithologists across the Global South, and Indigenous, Brown, and Black ornithologists globally, should play lead roles in designing, implementing, and assessing the effectiveness of journal policies and programs. Spanish and Portuguese translations are available in the supplementary material.

A major barrier to advancing ornithology is the systemic exclusion of professionals from the Global South. A recent special feature, Advances in Neotropical Ornithology, and a shortfalls analysis therein, unintentionally followed a long-standing pattern of highlighting individuals, knowledge, and views from the Global North, while largely omitting the perspectives of people based within the Neotropics. Here, we review current strengths and opportunities in the practice of Neotropical ornithology. Further, we discuss problems with assessing the state of Neotropical ornithology through a northern lens, including discovery narratives, incomplete (and biased) understanding of history and advances, and the promotion of agendas that, while currently popular in the north, may not fit the needs and realities of Neotropical research. We argue that future advances in Neotropical ornithology will critically depend on identifying and addressing the systemic barriers that hold back ornithologists who live and work in the Neotropics: unreliable and limited funding, exclusion from international research leadership, restricted dissemination of knowledge (e.g., through language hegemony and citation bias), and logistical barriers. Moving forward, we must examine and acknowledge the colonial roots of our discipline, and explicitly promote anti-colonial agendas for research, training, and conservation. We invite our colleagues within and beyond the Neotropics to join us in creating new models of governance that establish research priorities with vigorous participation of ornithologists and communities within the Neotropical region. To include a diversity of perspectives, we must systemically address discrimination and bias rooted in the socioeconomic class system, anti-Blackness, anti-Brownness, anti-Indigeneity, misogyny, homophobia, tokenism, and ableism. Instead of seeking individual excellence and rewarding top-down leadership, institutions in the North and South can promote collective leadership. In adopting these approaches, we, ornithologists, will join a community of researchers across academia building new paradigms that can reconcile our relationships and transform science. Spanish and Portuguese translations are available in the Supplementary Material.

The genus Nonnula (Galbuliformes: Bucconidae) includes 6 species of nunlets, understory insectivores of humid Neotropical forest. Like the rest of their lineage (Galbuliformes, Piciformes, Coraciiformes, Bucerotiformes, Trogoniformes, and Leptosomiformes), Nonnula were speculated to nest in cavities or burrows, either underground, in mounds of leaf litter, in trees, or in arboreal termitaria. From 2014 to 2020 we studied 17 nests of Rusty-breasted Nunlet (Nonnula rubecula) at Cruce Caballero Provincial Park in the Atlantic Forest of Misiones, Argentina. From the outside, nests looked like the burrows excavated by relatives in Malacoptila, but nunlets excavated only the floor, carpeted it with leaves, built a roof frame of twigs and rachises, and finally covered the whole structure with leaf litter from the surrounding area. A clutch of 4 (occasionally 3) white eggs with mean dimensions 20.1 (SD 0.8) × 16.8 (SD 0.3) mm (2.8 [SD 0.3] g; n = 5) was laid on alternate days, and incubated 17–18 d. The pink, naked hatchlings, with eyes sealed shut, scrambled around the nest chamber and came to the tunnel entrance by day 3, similar to other Bucconidae. Two secretive adults incubated, brooded, and fed nestlings. Fledglings hopped out of the nest at 17–19 d, sometimes returned before leaving definitively, and apparently could not fly. The probability of a nest surviving the 42 d from laying to fledging was 0.40, comparable to some tree-cavity-nesting birds in our study area (but 95% confidence intervals were large: 0.11–0.69). There is no evidence that any Nonnula use tree cavities or excavate burrows. We propose that Nonnula are unique in their lineage in building a dome-shaped nest at ground level. This habit may have evolved from relatives that excavate underground burrows, surround the entrance with a collar of twigs, and cover the excavation site with leaf litter.

Resumen ∙ Aunque el conocimiento de la distribución de la Lechucita Canela (Aegolius harrisii) se amplió notablemente en la última década, su biología permanece poco conocida. El conocimiento de la nidificación se basa en un solo nido confirmado, que no fue monitoreado, y una serie de observaciones de posibles nidos donde no fue comprobada la presencia de huevos o pichones. Entre diciembre de 2018 y enero de 2019, confirmamos y estudiamos un nido en una vieja cavidad excavada por una pareja de Carpintero Garganta Estriada (Dryocopus lineatus) a 9,6 m de altura en una grapia (Apuleia leiocarpa) muerta en selva Atlántica primaria del Parque Provincial Cruce Caballero, Misiones, Argentina. El nido contenía tres huevos blancos que eclosionaron en días alternos. Durante la incubación encontramos abundantes restos de escarabajos (Scarabaeidae: Coleoptera) debajo de la entrada del nido. Al nacer, los pichones tenían plumón natal gris oscuro muy ralo; a los 10 días empezaban a tener disco facial como el de los adultos; y a los 24 días se asemejaban a los adultos. Un adulto pasó todo el día dentro del nido desde la incubación hasta que el pichón mayor tenía 20–24 días de edad. Desde que nació el primer pichón hasta que voló el último los adultos trajeron por lo menos 32 roedores pequeños. Hubo un pico de aportes de alimentación justo después de la puesta del sol. Los tres pichones volaron exitosamente luego de 35–37 días, lo cual está en el límite superior del rango conocido para el Mochuelo Boreal (A. funereus) y el Mochuelo Cabezón (A. acadicus). No volvieron a utilizar la cavidad una vez que voló el último pichón. Aún es importante esclarecer el período de incubación, el rol de cada sexo en la reproducción y el rol de las cavidades (e.g., como dormidero) fuera del ciclo reproductivo. Abstract ∙ Nesting of the Buff-fronted Owl (Aegolius harrisii) in Misiones, Argentina Knowledge of the distribution of the Buff-fronted Owl (Aegolius harrisii) has increased notably in the last decade, but its biology remains poorly known. Knowledge of nesting is based on one confirmed nest, which was not monitored, and a series of observations of possible nests where the presence of eggs or nestlings was not confirmed. Between December 2018 and January 2019, we confirmed and studied a nest in an old cavity excavated by Lineated Woodpeckers (Dryocopus lineatus), 9.6 m above the ground in a dead garapa (Apuleia leiocarpa) tree, in primary Atlantic Forest at Parque Provincial Cruce Caballero, Misiones, Argentina. The nest contained three white eggs that hatched on alternate days. During incubation we found abundant beetle (Scarabaeidae: Coleoptera) remains below the nest entrance. On hatching, nestlings had sparse dark grey down; at 10 days old they began to have a facial disk like the adults; and by 24 days they looked similar to adults. One adult roosted in the nest all day from incubation until the oldest nestling reached 20–24 days of age. From when the first nestling hatched until the last nestling fledged, the adults brought at least 32 small rodents to the nest. There was a peak in prey delivery just after sunset. The three nestlings fledged successfully 35 to 37 days after hatching, which is at the high end of the range reported for Boreal (A. funereus) and Northern Saw-whet Owl (A. acadicus). They did not return to use the cavity once the last nestling had fledged. Further study is required to clarify the incubation period, the role of each sex in reproduction, and the role of cavities (e.g., for roosting) outside of the breeding cycle.

Cavity-nesting animals and their nest trees are linked in interspecific facilitation networks known as nest webs, which play key roles in forest function but vary across biomes and with human perturbation. We examined the composition, structure and function of nest webs between two endangered old-growth forests representing the last remnants of the ancient coniferous family Araucariaceae in South America: pewen (Araucaria araucana; Endangered) in temperate Chile (2010–2018), and Parana pine (Araucaria angustifolia; Critically Endangered) in subtropical Argentina (2006–2018). Pewen and Parana pine accounted for 30 and 9% of forest basal area, but only 2 and 5% of nesting cavities, respectively. Instead, cavity-nesting birds and mammals nested disproportionately in coexisting broadleaf trees. Species richness, interaction richness, and mean number of links per species were much higher in Parana pine forest than in pewen forest, but the two nest webs had similar levels of evenness and nestedness. Most secondary cavity-nesting species depended on cavities formed by decay in Nothofagus spp. (98% of nest cavities in pewen forest) or Apuleia leiocarpa (26% of nest cavities in Parana pine forest). An exception was the globally endangered Vinaceous Parrot, a Parana pine seed disperser, which made 50% of its nests in decay-formed cavities in Parana pine. To conserve the ecosystem functions of endangered Araucaria forests it is important to protect and recruit not only Araucaria trees but also a mix of broadleaf trees that can confer resilience to nest webs in the face of major disturbances.

Woodpeckers and other excavators create most of the holes used by secondary cavity nesters (SCNs) in North American temperate mixedwood forests, but the degree to which excavators release SCNs from nest-site limitation is debated. Our goal was to quantify how excavators maintain the diversity and abundance of secondary cavity nesters in a temperate forest through the creation of tree cavities. We examined the short- and long-term (legacy) effects of excavators (principally woodpeckers, but also red-breasted nuthatches and black-capped chickadees) on forest biodiversity using longitudinal monitoring data (1,732 nest cavities, 25 sites, 16 years) in British Columbia, Canada. Sites with higher densities of excavator nests had more cavities available, higher species richness of SCNs and higher nest density of SCNs, indicating the importance of a standing stock of cavities. Years with higher nesting densities of excavators were followed by years with higher SCN diversity, indicating that the creation of nesting opportunities through fresh excavation releases SCNs from community-wide nest-site limitation. We also show that excavators leave a 'legacy' of biodiversity (species richness and abundance) at a site by accumulating cavities at rates faster than they become unusable by decay or destruction. By quantifying site-level effects of cavity excavation on the SCN community, our study highlights the key role of excavators as ecosystem engineers that maintain forest wildlife biodiversity.Si, dans la forêt mixte tempérée d’Amérique du Nord, les pics et autres excavateurs créent la plupart des cavités utilisées par les cavernicoles secondaires (SCN), la question de savoir s'ils augmentent la disponibilité des sites de nidification des SCN reste ouverte. Notre objectif était d’évaluer et quantifier l'impact qu'ont les excavateurs lorsqu'ils creusent des cavités dans les arbres, sur la diversité et l'abondance de cavernicoles secondaires dans une forêt mixte tempérée. Nous avons examiné les effets des excavateurs (principalement les pics, mais aussi la sittelle à poitrine rousse et la mésange à tête noire) à court et à long terme (survivance), sur la biodiversité de la forêt en Colombie-Britannique, au Canada, en utilisant des données longitudinales de surveillance (1,732 cavités ressource, 25 sites, 16 ans). Les sites à plus fortes densités de nids d'excavateurs avaient une plus grande abondance en cavités disponibles, une richesse en espèce SCN plus élevée, et une plus forte densité de nids de SCN, ce qui montre l'importance des arbres à cavités utilisables, vivants ou morts sur pied. Les années à plus fortes densités de nids d'excavateurs étaient suivies par des années à plus fortes diversités d'espèces SCN, ce qui signifie que la disponibilité de sites de nidification à partir de nouveaux creusements augmente le potentiel de nidification des espèces SCN pour l'ensemble de la communauté qui en dépend. Nous démontrons aussi que, sur un site donné, les excavateurs laissent une ‘survivance’ de biodiversité (richesse en espèce et abondance) en formant des cavités à un taux plus élevé que le taux avec lequel ces dernières deviennent inutilisables suite à leur décomposition ou destruction. En quantifiant les effets du creusement de cavités au niveau de chaque site par rapport à la communauté des SCN, notre étude met en évidence le rôle clé des excavateurs comme ingénieurs de l’écosystème favorisant la diversité de la faune forestière.

In the Northern Hemisphere, several avian cavity excavators (e.g., woodpeckers) orient their cavities increasingly toward the equator as latitude increases (i.e. farther north), and it is proposed that they do so to take advantage of incident solar radiation at their nests. If latitude is a key driver of cavity orientations globally, this pattern should extend to the Southern Hemisphere. Here, we test the prediction that cavities are oriented increasingly northward at higher (i.e. colder) latitudes in the Southern Hemisphere and describe the preferred entrance direction(s) of 1,501 cavities excavated by 25 avian species (n = 22 Picidae, 2 Trogonidae, 1 Furnariidae) across 12 terrestrial ecoregions (15°S to 55°S) in South America. We used Bayesian projected normal mixed-effects models for circular data to examine the influence of latitude, and potential confounding factors, on cavity orientation. Also, a probability model-selection procedure was used to simultaneously examine multiple orientation hypotheses in each ecoregion to explore underlying cavity-orientation patterns. Contrary to predictions, and patterns from the Northern Hemisphere, birds did not orient their cavities more toward the equator with increasing latitude, suggesting that latitude may not be an important underlying selective force shaping excavation behavior in South America. Moreover, unimodal cavity-entrance orientations were not frequent among the ecoregions analyzed (only in 4 ecoregions), whereas bimodal (in 5 ecoregions) or uniform (in 3 ecoregions) orientations were also present, although many of these patterns were not very clear. Our results highlight the need to include data from under-studied biotas and regions to improve inferences at macroecological scales. Furthermore, we suggest a re-analysis of Northern Hemisphere cavity orientation patterns using a multi-model approach, and a more comprehensive assessment of the role of environmental factors as drivers of cavity orientation at different spatial scales in both hemispheres.

Understanding nest-site selection is critical to conserving tree-cavity-nesting wildlife, but nest-sites may vary across landscapes. We examine variation in the characteristics of trees and cavities used by cavity-nesting birds from globally-threatened primary Atlantic Forest to open farmland with isolated trees. We predicted that nests would occur in the largest trees available, but that secondary cavity nesters (non-excavators) would increase their use of bird-excavated cavities and dead and exotic trees in open farmlands. We used a stratified case-control design and 20 random plots to assess variation in characteristics of trees and cavities (used and available) across gradients of canopy cover and distance to forest edge in subtropical Argentina. For secondary cavity nesters, nest cavities were more likely to occur in larger-diameter trees across all stand conditions, but more likely to occur in dead trees as canopy cover declined (i.e., in open farmland; n=123 nest trees). For primary excavators, nest cavities were more likely to occur in dead (vs. live) trees, with larger diameter, regardless of stand conditions (n = 54 nest trees). Available cavities declined from 4/ha in primary forest to 0.4/ha in open farmland. Cavities were increasingly of excavated origin in open farmland, including both available cavities and those used by secondary cavity nesters, which indicates that avian excavation may partly compensate for the loss of decay-formed cavities when large trees are cleared. As forest landscapes shift toward a predominance of agroecosystems, dead trees and primary cavity nesters may take on important roles in conserving cavity-nesting communities and their ecosystem functions. However, nest cavities declined in height and depth, and increased in entrance size toward open farmland, raising the possibility that birds increasingly use suboptimal cavities as forest cover declines. Fil: Bonaparte, Eugenia Bianca. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; Argentina Fil: Ibarra Eliessetch, José Tomás. Pontificia Universidad Católica de Chile; Chile Fil: Cockle, Kristina Louise. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; Argentina. University Of British Columbia. Centre For Blood Research.; Canadá

Population size is a key predictor of extinction risk and is critical to listing species in IUCN threat categories. Assessing population size can be particularly difficult for gregarious species, such as parrots—one of the most threatened bird families—whose ecology and behavior generate multiple sources of uncertainty that need to be addressed in monitoring efforts. To improve estimates of abundance for the endangered Vinaceous-breasted Parrot (Amazona vinacea), we combined extensive roost counts over the global range of the species (Argentina, Paraguay, Brazil) with an intensive regional survey designed to address five sources of uncertainty about parrot abundance in western Santa Catarina state (WSC), Brazil, in 2016 and 2017. We estimated abundance at both regional and whole-range scales using N-mixture models of replicated count data, which account for imperfect detection. The regional-scale estimate was 1826 ± 236 and 1896 ± 105 individuals for 2016 and 2017, respectively; global abundance was estimated at 7789 ± 655 and 8483 ± 693 individuals for the same two years. We found no statistical evidence of population change at either scale of the analysis. Although our assessments of abundance and geographic range are larger than those currently reported by the IUCN, we suggest the Vinaceous-breasted Parrot should remain in the ‘Endangered’ IUCN threat category pending further investigation of population trends. We recommend that roost-monitoring programs for parrots consider and address sources of uncertainty through adequate field protocols and statistical analyses, to better inform assessments of population size, trends, and threat status. Fil: Zulian, Viviane. Universidade Federal do Rio Grande do Sul; Brasil Fil: Müller, Eliara Solange. Universidade Comunitária Da Região de Chapecó; Brasil Fil: Cockle, Kristina Louise. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; Argentina Fil: Lesterhuis, Arne. Guyra Paraguay; Paraguay Fil: Tomasi Júnior, Roberto. Associação Amigos Do Meio Ambiente; Brasil Fil: Prestes, Nêmora Pauletti. Associação Amigos Do Meio Ambiente; Brasil Fil: Martinez, Jaime. Associação Amigos Do Meio Ambiente; Brasil. Universidade de Passo Fundo; Brasil Fil: Kéry, Marc. Swiss Ornithological Institute; Suiza Fil: Ferraz, Gonçalo. Universidade Federal do Rio Grande do Sul; Brasil

The Atlantic Forest in southeastern South America is a biodiversity hotspot with high species richness and high forest loss. Three large to medium-sized woodpecker species (Robust Woodpecker Campephilus robustus, Lineated Woodpecker Dryocopus lineatus, and the globally threatened Helmeted Woodpecker Celeus galeatus) coexist in the south of the ecoregion, and show remarkable convergence in plumage patterns and colouration, possibly driven by interspecific interactions. We assessed differentiation in nest tree species, nest substrates, and timing of breeding and evaluated whether nesting ecology may be a factor explaining an association with mature forests in the Helmeted Woodpecker. Robust and Lineated Woodpeckers excavated cavities in nine and eight nest tree species, respectively, whereas Helmeted Woodpeckers specialized narrowly on laurel trees (88% of nest cavities in two species in genus Nectandra of 52 ± 14 cm DBH). Helmeted Woodpecker is further distinguished by a more frequent use of living, partially decayed trees and by more frequent re-use of nest cavities. When nesting in selectively logged forest (vs. old-growth), Robust and Lineated Woodpeckers used trees with smaller DBH and Robust Woodpeckers excavated lower in trees. Helmeted Woodpeckers selected nest trees with similar dimensions in both environments, indicating lesser flexibility. Helmeted Woodpeckers bred 20-23 days later in the year than Lineated and Robust Woodpeckers, potentially allowing them to avoid nesting near the two larger species. The narrow specialization of Helmeted Woodpecker on nesting in Nectandra trees of large sizes at the onset of decay is a possible factor in making it sensitive to selective logging effects. To stop declines of Helmeted Woodpecker we recommend (1) sparing large trees from selective logging (including Nectandra and tree species used for roosting), and (2) restoring more forested areas to mature forest conditions. Fil: Lammertink, J. Martjan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas; Argentina Fil: Fernández, Juan Manuel. Universidad Nacional del Nordeste; Argentina. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentina Fil: Cockle, Kristina Louise. University of British Columbia; Canadá. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas; Argentina

∙ The Silky‐tailed Nightjar (Antrostomus sericocaudatus) is traditionally considered rare, poorly known, and possibly threatened. It comprises two subspecies: A. s. mengeli in the Amazon basin and A. s. sericocaudatus in the Atlantic Forest – a rapidly disappearing biodiversity hotspot in southeastern Brazil, eastern Paraguay, and the province of Misiones in Argentina. The subspecies differ in vocalizations and morphology, but reproductive biology has been studied only for A. s. mengeli. We found A. s. sericocaudatus throughout remaining Atlantic Forest in Misiones, and studied 10 nests. During courtship, the male sang incessantly from a high branch above the future nest site; when the female landed on another branch, he doubled the pace of his song, flew to the female (who emitted soft barks), dropped his wings, fanned his tail, and mounted the female while emitting a low croak. Antrostomus s. sericocaudatus laid two immaculate white eggs, in contrast to A. s. mengeli and most other Antrostomus, which lay eggs with markings. The incubation period was 19 days, and hatchlings were covered in dense pinkish‐brown down (vs. “golden” in A. s. mengeli). During the day, incubation and brooding were mostly performed by the female, although the male was found incubating once during the day and brooding once at night. Both parents performed distraction displays from incubation until the chicks were 18–19 days old. Considering the restricted range of A. s. sericocaudatus, its dependence on remaining Atlantic Forest, and its differences with A. s. mengeli, it is important to study its population size, population trajectory, and tolerance of forest fragmentation, in order to determine its global conservation status.Resumen ∙ Biología reproductiva y distribución del Atajacaminos Oscuro (Antrostomus sericocaudatus sericocaudatus) en Misiones, Argentina El Atajacaminos Oscuro (Antrostomus sericocaudatus) fue tradicionalmente considerado raro, poco conocido, y posiblemente amenazado. Se conocen dos subespecies: A. s. mengeli en Amazonia y A. s. sericocaudatus en la Selva Atlántica ‐ un hotspot de biodiversidad en rápida desaparición en el sudeste de Brasil, este de Paraguay y la provincia de Misiones en Argentina. Las subespecies difieren en vocalizaciones y morfología pero la biología reproductiva ha sido estudiada sólo para A. s. mengeli. Encontramos a A. s. sericocaudatus en todos los remanentes de Selva Atlántica en Misiones, y estudiamos 10 nidos. Durante el despliegue el macho cantó incesantemente en una rama alta cerca o sobre el lugar del futuro nido; cuando la hembra llego a otra rama, el macho redobló el ritmo del canto, voló hacia la hembra (que emitió ladridos suaves), dejó caer sus alas, puso la cola en forma de abanico y montó a la hembra mientras emitía un “croar” bajo. Antrostomus s. sericocaudatus puso 2 huevos de color blanco inmaculado, en contraste con A. s. mengeli y la mayoría de las otras especies del genero Antrostomus, que ponen huevos con marcas. El período de incubación fue de 19 días, y las crías estaban cubiertas por un denso plumón natal color marrón rosado (vs. “dorado” en A. s. mengeli). Durante las horas diurnas la incubación de los huevos y pichones estuvo principalmente a cargo de la hembra, mientras que el macho fue encontrado incubando una vez durante el día y otra por la noche. Ambos padres realizaron despliegues de distracción desde la incubación hasta que los pichones tenían 18–19 días de edad. Considerando el rango restringido y la dependencia a la Selva Atlántica de A. s. sericocaudatus y las diferencias con A. s. mengeli, es clave estudiar el tamaño y trayectoria de la población, y la tolerancia a la fragmentación de la selva, con el objetivo de determinar su estado de conservación global.

Schiffornis (Aves: Tityridae) includes seven species of Neotropical forest birds whose breeding biology is poorly known. We studied three nests of Greenish Schiffornis ( Schiffornis virescens ) in the Atlantic Forest of Misiones, Argentina. Nests were bulky cups of dead leaves and other vegetative fibres, lined with Marasmius rhizomorphs and fine rootlets. They were attached laterally to tree fern ( Alsophila procera ) stems, supported from below, and camouflaged by abundant epiphytes and tree fern petioles. Each contained three eggs, which were creamy white speckled with chestnut. Only one adult was seen to incubate, with on-bouts of 65, 69 and 89 min, and off-bouts of 18, 25 and 28 min. Two nests were depredated at the incubation stage, and the third was not followed. Considering that no Schiffornis nest has been followed to fledging, we strongly encourage researchers and bird watchers to be alert to Schiffornis flushing in the understory, and to follow nests to completion whenever possible.

El Atajacaminos Ala Negra (Eleothreptus anomalus) es una especie amenazada cuya biología reproductiva es casi desconocida. En la Reserva Natural Rincón de Santa María (Corrientes, Argentina) capturamos adultos entre 2012 y 2019. Realizamos 47 capturas de hembras y 209 de machos, de los cuales 13 hembras y ningún macho tenían parche incubatorio. La temporada reproductiva comenzó en agosto con marcada actividad sonora (mecánica y vocal) por parte de los machos en reuniones de tipo leks. Adultos en estado reproductivo se encontraron entre octubre y enero cuando aún capturamos hembras con parches incubatorios y juveniles dependientes. Colocamos radiotransmisores a dos hembras con parche incubatorio. Una hembra con radiotransmisor hizo dos posturas con una diferencia de 12 días y 361 m de distancia entre sí, pero ambas fueron depredadas. Las posturas fueron de uno y dos huevos aunque es posible que la primera puesta haya sido depredada antes de completarse. Los huevos eran de color blanco cremoso con manchas y pintas marrones rojizas y manchas y placas grises de variable tamaño, en toda la superficie. La densidad y distribución de las marcas variaba entre los huevos, incluso en una misma nidada. Las medidas y pesos de los huevos fueron 27,3 x 21,9 mm, 7,2 g; 26,6 x 20,8 mm, 6,2 g; y 25,8 x 21,1 mm, 6,3 g. Los huevos fueron puestos directamente sobre (1) pasto seco aplastado, rodeado de pastizal nativo de 2,2 m de alto con algunas matas de Baccharis dracunculifolia y (2) en tierra desnuda arriba de un tacurú (nido viejo de hormiga carpintera, Camponotus sp.) de unos 50 cm de alto, rodeado de pastizal nativo inundado. Es importante confirmar el cuidado uniparental en Eleothreptus anomalus y poner a prueba la hipótesis de un sistema de apareamiento tipo lek como se ha propuesto para su único congénere el Atajacaminos Ala Blanca (Eleothreptus candicans)., The Sickle-winged Nightjar (Eleothreptus anomalus) is a threatened species whose reproductive biology is almost unknown. At Reserva Natural Rincón de Santa María (Corrientes, Argentina), we captured adults between 2012 and 2019. We made 47 captures of females and 209 of males, of which 13 females and no males had brood patches. The reproductive period began in August with marked production of sounds (mechanical and vocal) by males in lek-like groupings. Adults in reproductive condition were found between October and January when we still captured females with brood patches and dependent juveniles. We attached radio transmitters to two females with brood patches. One radio-tagged female laid two clutches with a difference of 12 days and separated by 361 m, but both were depredated. The clutches contained one and two eggs, respectively, although it is possible that the first clutch was depredated before it was completed. The eggs were creamy white with reddish-brown patches and spots, and grey patches of variable size, all over the surface. The density and distribution of markings varied among eggs, even within the same clutch. Egg measurements and weights were 27.3 x 21.9 mm, 7.2 g; 26.6 x 20.8 mm, 6.2 g; and 25.8 x 21.1 mm, 6.3 g. Eggs were laid directly on (1) crushed dry grass, surrounded by native grassland, c. 2.2 m tall, with some Baccharis dracunculifolia shrubs and (2) on bare earth atop an old nest of Camponotus sp. ants, about 50 cm high, surrounded by flooded native grassland. It is important to confirm uniparental care in the Sickle-winged Nightjar and test the hypothesis of a lek-mating system as proposed for its only congener, the White-winged Nightjar (Eleothreptus candicans)., Facultad de Ciencias Naturales y Museo

Woodpeckers (Picidae) are broadly associated with forests but vary in sensitivity to habitat alteration, with some species restricted to mature and old-growth forests, usually because of their foraging or nesting requirements. Roosting sites have rarely been considered a critical resource for woodpecker conservation because nearly all woodpecker species roost year-round in excavated cavities similar to their nest sites. A possible exception is the globally vulnerable Helmeted Woodpecker (Celeus galeatus) of the Atlantic Forest of South America. To determine whether roosting ecology may explain their association with mature forest, we radio-tracked 12 Helmeted Woodpeckers in old-growth and selectively logged forests in Argentina, monitored roost cavities, and provided 9 roost boxes. Unlike other woodpeckers, Helmeted Woodpeckers roosted year-round in decay-formed cavities (n = 21), with perching space above the entrance, in the living trunks of large trees. Adults usually roosted alone, but after nesting (in excavated cavities), each adult roosted with one juvenile in a shared, decay-formed cavity for up to 67 days, implying that cavities need enough space for 2 birds. We did not observe use of roost boxes. Helmeted Woodpeckers travelled up to 1,482 m between nests and roosts, reused roost cavities over multiple years (sometimes changing ownership), and interacted aggressively with other cavity-nesting birds at roost cavities, indicating that suitable cavities are a scarce resource. Because logging is likely to have a strong negative impact on the availability of this resource, we urge managers in the Atlantic Forest region to retain large living trees with decay-formed cavities and to allow more selectively logged areas to become old growth. Los pájaros carpinteros (Picidae, Aves) están ampliamente asociados a los bosques, pero varían en su sensibilidad a la alteración del hábitat, con algunas especies restrictas a bosques maduros en buen estado de conservación, usualmente debido a sus requerimientos de forrajeo y nidificación. Los sitios dormidero rara vez han sido considerados un recurso crítico para la conservación de los pájaros carpinteros, debido a que casi todas las especies pernoctan todo el año en cavidades similares a sus sitios de nidificación. Una posible excepción es Celeus galeatus, del Bosque Atlántico de Sudamérica, vulnerable a nivel mundial. Para determinar si la ecología de los dormideros puede explicar su asociación a bosques maduros, colocamos radio-transmisores a 12 C. galeatus en bosques maduros y bajo tala selectiva en Argentina, monitoreamos cavidades-dormidero, y colocamos 9 cajas-dormidero. A diferencia de otros carpinteros, C. galeatus pernoctó todo el año en cavidades formadas por degradación de la madera (n = 21), con espacio para perchar por encima de la entrada, en troncos vivos de árboles grandes. Los adultos usualmente pernoctaron solos, sin embargo, después de nidificar (en cavidades excavadas), cada adulto pernoctó con un juvenil en una cavidad formada por degradación por hasta 67 días, implicando que las cavidades deben tener suficiente espacio para dos carpinteros. Individuos de C. galeatus hicieron movimientos hasta 1,482 m entre nidos y cavidades-dormideros, reutilizaron cavidades-dormidero a lo largo de varios años (y por parte de individuos sucesivos), y tenían interacciones agresivas con otras especies de aves en las cavidades-dormidero, indicando que las cavidades adecuadas son un recurso escaso. Es probable que la tala tenga un fuerte impacto negativo en la disponibilidad de este recurso. Instamos a los gestores en la región del Bosque Atlántico a retener árboles grandes, vivos, con cavidades formadas por descomposición, y recuperar más áreas con explotación selectiva. Fil: Lammertink, J. Martjan. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentina. Cornell University; Estados Unidos Fil: Fernández, Juan Manuel. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura; Argentina Fil: Cockle, Kristina Louise. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Universidad Nacional de Misiones. Instituto de Biología Subtropical; Argentina. University of British Columbia; Canadá

Tree cavities are a critical multi-annual resource that can limit populations and structure communities of cavity-nesting vertebrates. We examined the regional and local factors influencing lifetime productivity (number and richness of occupants) of individual tree cavities across two divergent forest ecosystems: temperate mixed forest in Canada and subtropical Atlantic Forest, Argentina. We predicted that (1) species would accumulate more rapidly within cavities in the species-rich system (Argentina: 76 species) than the poorer system (Canada: 31 species), (2) cavity characteristics associated with nest-site selection in short-term studies would predict lifetime cavity productivity, and (3) species would accumulate more rapidly across highly used cavities than across cavities used only once, and in Argentina than in Canada. We monitored and measured nesting cavities used by birds and mammals over 22 breeding seasons (1995–2016) in Canada and 12 breeding seasons (2006–2017) in Argentina. Cavities were used an average of 3.1 times by 1.7 species in Canada and 2.2 times by 1.4 species in Argentina. Species richness within cavities increased with number of nesting events at similar rates in Canada and Argentina, in both cases much slower than expected if within-cavity species assemblages were random, suggesting that lifetime richness of individual cavities is more strongly influenced by local ecological factors (nest site fidelity, nest niche) than by the regional species pool. The major determinant of lifetime cavity productivity was the cavity’s life span. We found only weak or inconsistent relationships with cavity characteristics selected by individuals in short-term nest-site selection studies. Turnover among (vs. within) cavities was the primary driver of diversity at the landscape scale. In Canada, as predicted, species accumulation was fastest when sampling across high-use cavities. In Argentina, the rates of species accumulation were similar across high- and low-use cavities, and fastest when both high- and low-use cavities were pooled. These findings imply that biodiversity of cavity nesters is maintained by a mix of long-lived (highly productive, legacy trees) and many high-turnover (singleuse, fast decaying) tree cavities. Conservation of both long-lasting and single-use cavities should be incorporated into decisions about stand-level forest management, regional land use policies, and reserve networks. Fil: Cockle, Kristina Louise. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; Argentina. University of British Columbia; Canadá Fil: Trzcinski, Mark Kurtis. University of British Columbia; Canadá Fil: Wiebe, Karen L.. University of Saskatchewan; Canadá Fil: Edworthy, Amanda B.. University of British Columbia; Canadá Fil: Martin, Kathy. Environment and Climate Change Canadá. Science & Technology Branch; Canadá. University of British Columbia; Canadá

Para conservar una superficie representativa de los bosques subtropicales de Misiones (Argentina), ecosistema amenazado a nivel mundial, es necesario encontrar una solución económicamente viable a las superficies que actualmente y de acuerdo a la ley 26331 pueden destinarse exclusivamente al manejo sostenible del bosque nativo, así como disminuir la deforestación en las áreas pasibles de ser reemplazadas (901617 ha y 477858 ha, respectivamente, de acuerdo al último ordenamiento territorial llevado a cabo por la Provincia de Misiones). La deforestación, que ocurre desde mediados del siglo pasado, ha sido fomentada por políticas públicas de incentivos a actividades de producción intensivas como las plantaciones forestales u otros cultivos. Los bosques remanentes se encuentran degradados por la explotación de las principales especies nativas comerciales en ciclos de corta menores a 20 años, y la productividad maderera es más baja de lo necesario para sostener económicamente la actividad. La productividad podría recuperarse en algunos casos con manejos post-extracción (por ejemplo, el corte de bambúes y lianas), mientras que en situaciones de mayor degradación se necesitan acciones de manejo más intensivas como la escarificación de los suelos o la plantación de renovales de especies de alto valor comercial y rápido crecimiento que permitan turnos de corta de 30 años e incrementos de al menos 3 m3 ha-1 año-1. Asimismo, se necesita una política de control del comercio ilegal de madera nativa, la cual disminuye los precios y reduce la rentabilidad de productores responsables. Por otra parte, la obtención de madera debería complementarse con disminuciones impositivas, por ejemplo, a través de la compensación por provisión de servicios ecosistémicos, o mediante otros tipos de usos como el aprovechamiento de recursos no madereros. En el caso de pequeños y medianos productores, el gobierno y organizaciones no gubernamentales deberían estimular la conservación del bosque por el uso de sus recursos y servicios ambientales, incentivar activamente la diversificación de la producción, y brindar las herramientas que les permitan a los productores independizarse del cultivo intensivo de tabaco. Es necesario mayor financiamiento directo a los productores para el manejo, así como a organismos dedicados a generar conocimiento que permita avances concretos en el manejo sostenible del bosque. To conserve a representative area of the subtropical forests of Misiones, a globally endangered ecosystem, it is necessary to find a viable economic solution for the areas destined under Law 26331 exclusively for sustainable management of native forest, and to reduce deforestation in the areas where replacement of native forest is permi�ed (901617 ha and 477858 ha, respectively, according to the latest land use planning by the Province of Misiones). Since the middle of the last century, public policies have provided incentives for plantations of trees and other crops, promoting deforestation. Remnant forests are degraded from exploitation of the principal commercial species in cu�ing cycles shorter than 20 years, and productivity of wood is now too low to be economically useful. Productivity can be improved through post-harvest management (e.g., cu�ing of bamboo and lianas), but on highly degraded sites more intensive management is needed, such as scarifying of soils or planting seedlings of high-value, fast-growing species to allow cu�ing cycles of around 30 years and increments greater than 3 m3 .ha-1.year-1. Action is also needed to control illegal trade in native wood, which diminishes the prices and reduces the viability of socially and environmentally responsible enterprises. Moreover, sustainable management of the native forest should be accompanied by reductions in taxes, for example through payment for ecosystem services, or by other types of use, such as harvesting of non-timber forest products. In the case of small and medium property owners, governments and organizations should stimulate conservation of forest through forest resources and services use, actively encourage diversification of production, and offer tools that promote independence from intensive tobacco cultivation. Funding is needed both directly to producers (through laws) and to institutions that generate knowledge that permits concrete advances in sustainable forest management. Fil: Campanello, Paula Inés. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco"; Argentina Fil: Von Below, Jonathan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Universidad Nacional de Misiones. Instituto de Biología Subtropical; Argentina. Universidad Nacional de Misiones. Facultad de Ciencias Forestales; Argentina Fil: Hilgert, Norma Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Universidad Nacional de Misiones. Instituto de Biología Subtropical; Argentina. Universidad Nacional de Misiones. Facultad de Ciencias Forestales; Argentina Fil: Cockle, Kristina Louise. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Universidad Nacional de Misiones. Instituto de Biología Subtropical; Argentina Fil: Villagra, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Universidad Nacional de Misiones. Instituto de Biología Subtropical; Argentina Fil: Di Francescantonio, Débora. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Universidad Nacional de Misiones. Instituto de Biología Subtropical; Argentina Fil: García, Daily Sofía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Universidad Nacional de Misiones. Instituto de Biología Subtropical; Argentina. Universidad Nacional de Misiones. Facultad de Ciencias Forestales; Argentina Fil: Jaramillo, Manuel. Fundacion Vida Silvestre; Argentina Fil: Gauto, Oscar Arturo. Universidad Nacional de Misiones. Facultad de Ciencias Forestales; Argentina Fil: Goldstein, Guillermo Hernan. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina

Los integrantes del género Dendrocincla (Furnariidae: Dendrocolaptinae) son conocidos por sus asociaciones mientras forrajean con correcciones de hormigas y grupos de mamíferos, y por sus machos emancipados, que no proporcionan cuidado parental. Poco se sabe de la historia natural de Dendrocincla turdina, una especie endémica de la Selva Atlántica. En Paraguay (2000–2002) y Argentina (2000–2016), a menudo encontramos Dendrocincla turdina forrajeando en asociación con monos capuchinos negros (Sapajus nigritus), a menos que estuviesen en un nido, cuando se alimentaban solos, a menudo con vuelos hasta la superficie de ramas, troncos e incluso hojas. En nuestra principal área de estudio, Parque Provincial Cruce Caballero, las tasas de encuentro de monos y Dendrocincla turdina aumentaron drásticamente despues de 2012. Encontramos dos nidos, uno con dos huevos y el otro con dos pichones, ambos en cavidades profundas, no excavadas, en sotobosque sombrío. Un adulto sigiloso asistió a cada nido; no hubo evidencia de un vínculo de pareja con otro adulto. Durante la incubación, la atención del nido fue de 62 %, con turnos de 35 6 5 min (promedio 6 EE; rango: 3–83; n¼ 21) y recesos de 16 6 1 min (rango: 8–28; n¼ 24). El adulto trajo líquenes y otros materiales al nido a lo largo del período de incubación, y a veces los utilizó para cubrir los huevos cuando salía del nido. Una vez que los huevos eclosionaron, la atención del nido disminuyó rápidamente, aunque el adulto durmió con los pichones hasta que tenían 14 días de edad. La dieta de los pichones incluyo artrópodos (especialmente Orthoptera, Lepidoptera, Hemiptera y Coleoptera) y vertebrados (murciélago y rana), pero difirió entre los dos nidos, lo que sugiere oportunismo. El adulto trajo alimento mucho más frecuentemente al amanecer (7,93 6 0,69 visitas/h) y al atardecer (8,03 6 1,19 visitas/h) que durante el resto del día (3,26 6 0,22 visitas/h). El desarrollo de los pichones fue más lento que en Dendrocolaptinae coexistentes que exhiben cuidado biparental, y los pichones abandonaron el nido a los 26–27 días de edad. El cuidado uniparental es inusual en insectívoros de bosque pero ha surgido por lo menos dos veces en Dendrocolaptinae y parece estar asociado con comportamientos crípticos, el encubrimiento de los huevos, y el crecimiento lento de los pichones. Dendrocincla woodcreepers (Furnariidae: Dendrocolaptinae) are known for their foraging associations with army ants and mammals and for their emancipated males, which provide no parental care. Little is known of the natural history of the Plain-winged Woodcreeper (Dendrocincla turdina), an Atlantic Forest endemic. In Paraguay (2000–2002) and Argentina (2000–2016), we nearly always found Plain-winged Woodcreepers foraging in association with black capuchin monkeys (Sapajus nigritus), unless they were attending a nest, when they foraged alone, often by sally-gleaning. In our main study area, Parque Provincial Cruce Caballero, encounter rates of both monkeys and Plain-winged Woodcreepers increased dramatically after 2012. We found 2 nests, 1 with 2 eggs and the other with 2 nestlings, both in deep, nonexcavated tree cavities in shady forest understory. One secretive adult attended each nest; there was no evidence of a pair bond with another adult. During incubation, nest attentiveness was 62%, on-bouts were mean 35 (SE 5) min (range 3–83; n ¼ 21) and off-bouts averaged 16 (SE 1) min (range 8–28; n ¼ 24). The adult brought lichens and a few other nesting materials throughout the incubation period and sometimes used them to cover the eggs when it left the nest. Once the eggs hatched, nest attentiveness declined rapidly, although the adult roosted with the nestlings until they were 14 days old. Nestling diet included arthropods (especially Orthoptera, Lepidoptera, Hemiptera, and Coleoptera) and vertebrates (bat and frog) but differed between the 2 nests, suggesting opportunism. The adult brought food much more frequently around sunrise (7.93 [SE 0.69] visits/h) and sunset (8.03 [1.19] visits/h) than during the rest of the day (3.26 [0.22] visits/h). Nestling development was slower than for coexisting Dendrocolaptinae with biparental care, and the nestlings fledged when 26–27 days old. Uniparental care is unusual in forest insectivores but has arisen at least twice in Dendrocolaptinae and seems to be associated with hiding of eggs, secretive behavior, and slow nestling growth. Fil: Bodrati, Alejandro. Proyecto Selva de Pino Paraná; Argentina Fil: Cockle, Kristina Louise. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; Argentina Fil: Di Sallo, Facundo Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; Argentina

Population size is a key predictor of extinction risk and is critical to listing species in IUCN threat categories. The population size of parrots—one of the most threatened bird families—is often assessed using roost counts, which suffer from multiple sources of uncertainty that need to be addressed in monitoring efforts. To improve estimates of abundance for endangered Vinaceous-breasted Parrot (Amazona vinacea), we compared extensive roost counts over the whole range of the species (Argentina, Paraguay, Brazil) with an intensive regional survey designed to address five sources of uncertainty about parrot abundance in western Santa Catarina state (WSC), Brazil, in 2016 and 2017. We estimated regional-scale abundance using a sampling design that minimizes double counting and an N-mixture model of replicated count data, which accounts for imperfect detection, implemented in a Bayesian framework. The whole-range counts amounted to 3,888 and 4,084 individuals in 2016 and 2017, respectively; regional estimates were 945 ± 50 and 1,393 ± 40 individuals, for the same two years. We found no evidence of population growth because the increase in numbers matched an increase in observation effort on both spatial scales. When extrapolating the WSC abundance estimate to three hypothetical geographical range areas of the species, under the simplifying assumption of homogenous density, we obtained values above the whole-range counts, but within the same order of magnitude, putting the global population size of Vinaceous-breasted Parrot in the thousands of individuals. Although our estimates of abundance and geographic range are larger than those currently reported by the IUCN, we suggest that Vinaceous-breasted Parrot remain in the ‘Endangered’ IUCN threat category pending further investigation of population trends. We recommend that roost-monitoring programs for parrots consider and address sources of uncertainty through field protocols and statistical analysis, to better inform assessments of population size, trends, and threat status.

Reproductive biology of the Red-billed Scythebill (Campylorhamphus trochilirostris) and Black-billed Scythebill (C. falcularius) in Argentina. – The genus Campylorhamphus (Furnariidae: Dendrocolaptinae) is poorly known in terms of natural history and reproduction. Here we describe aspects of reproduction from three nests of the Red-billed Scythebill (Campylorhamphus trochilirostris) in the Chaco of Argentina, and from one nest of the Black-billed Scythebill (C. falcularius) in the Atlantic Forest of Argentina. One of the nests of C. trochilirostris was in a cavity excavated by a woodpecker. The remaining nests were in cavities formed by natural decay. Both species had a clutch size of two. Two adults participated in incubation at each nest, bringing pieces of bark when they entered the cavity. Incubation bouts were 50 ± 3 min (mean ± SE) for C. trochilirostris (n = 3) and 57 ± 13 min for C. falcularius (n = 8). The nest of C. falcularius was depredated during the incubation period. In C. trochilirostris both adults delivered arthropods to nestlings and removed fecal sacs. They brought food on average 5.8 times/h and removed fecal sacs 2.5 times/h when the nestlings were feathered. Campylorhamphus should be included among the genera of Dendrocolaptinae with biparental care, along with Dendrocolaptes, Xiphocolaptes, Dendroplex, and Lepidocolaptes, but in contrast to Dendrocincla, Xiphorhynchus, and Sittasomus.

Cavity-nesting vertebrates are an important component of biodiversity in tropical and subtropical forests, but their persistence will increasingly depend on remnant trees in logged forest and agricultural areas. To identify key habitat features for conservation, we examined the factors that influenced daily nest survival for a community of cavity-nesting birds along a gradient of human impact, from primary Atlantic Forest through logged forest to farms. We used logistic-exposure models to determine how characteristics of the habitat, nest tree, cavity, and timing influenced daily nest survival. Overall, predation and/or usurpation caused 92% of nest failures. Daily survival rates ranged 0.961-0.992 for five species of birds that could be studied best, giving probabilities of 0.19-0.62 of survival from laying to fledging. The top models predicting nest survival included cavity and tree characteristics but no habitat variables (canopy cover, forest condition, or distance to forest edge). Small birds (12-128. g) experienced higher nest survival in cavities with smaller entrance diameters, higher above the ground. Large birds (141-400. g) experienced higher nest survival in living trees than in dead trees. Birds experienced similar nest survival in primary forest, logged forest, and farms. Our results highlight the conservation value of cavity-bearing trees in anthropogenic habitats. A pressing policy issue for tropical and subtropical forests is to move beyond minimum diameter cutting limits and instead focus on retention of large old trees. Fil: Cockle, Kristina Louise. Provincia de Misiones. Proyecto Selva de Pino Paraná; Argentina. University of British Columbia; Canadá. State University of Louisiana; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Bodrati, Alejandro. Provincia de Misiones. Proyecto Selva de Pino Paraná; Argentina Fil: Lammertink, J. Martjan. Provincia de Misiones. Proyecto Selva de Pino Paraná; Argentina. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentina. Cornell University; Estados Unidos Fil: Martin, Kathy. University of British Columbia; Canadá

The Neotropical ovenbirds (Furnariidae) are an adaptive radiation of suboscines renowned for the diversity of their nests. Like most altricial insectivores, they generally exhibit biparental care. One tribe, Philydorini, includes 46 species thought to nest in either underground burrows or tree cavities, nest types traditionally treated as equivalent in phylogenetic studies. Their parental care systems are poorly known, but could help illuminate how uniparental care – typically associated with frugivory – can arise in insectivores. We examined the extent to which nest placement, parental care, and associated reproductive traits map onto two major clades of Philydorini identified by genetic hypotheses. We review published literature and present new information from the Atlantic Forest of Argentina, including the first nest descriptions for Ochre-breasted Foliage-gleaners (Anabacerthia lichtensteini) and Sharp-billed Treehunters (Heliobletus contaminatus). In the Automolus-Thripadectes-Clibanornis clade (including Philydor rufum), 134 of 138 reported nests were in underground burrows. In the Syndactyla-Anabacerthia-Anabazenops clade (including Heliobletus, Philydor atricapillus, and Philydor erythrocercum), 44 of 48 nests were in tree cavities. Remaining nests were in buildings or species-level identification was unclear. At least eight species in the first clade, but none in the second clade, excavated their nest sites. Biparental care was confirmed for nine species in the first clade and one species in the second clade. In contrast, nests of A. lichtensteini and H. contaminatus were attended by a single secretive adult. We propose that species in the Automolus-Thripadectes-Clibanornis clade are underground burrow excavators, and those in the Syndactyla-Anabacerthia-Anabazenops clade are secondary tree-cavity nesters (nonexcavators). We also note that parental care strategies in Furnariidae vary with nest complexity and conspicuousness – from uniparental care in secretive tree-cavity nesters to cooperative breeding in highly vocal builders of elaborate nests – suggesting evolutionary links among nest-building, concealment, and parental care strategies. Fil: Cockle, Kristina Louise. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; Argentina Fil: Bodrati, Alejandro. Proyecto Selva de Pino Paraná; Argentina

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

We report on the breeding biology of the White-throated Woodcreeper (Xiphocolaptes albicollis), a species endemic to the Atlantic forest of South America, based on 16 nesting attempts in 11 cavities (9 natural tree cavities and 2 nest boxes) in Misiones, northeastern Argentina. Natural cavities were 3.3–8.3 cm in diameter and 46–103 cm in depth, and generated by decay processes (not woodpeckers) at heights of 3–17 m in live trees 29–106 cm in diameter at breast height. White-throated Woodcreepers laid 2–4 eggs on alternate days, on a bed comprised of bark flakes, leaf fragments and seed pods. Incubation bouts (n = 3) were more than 1 hr 40 mins. Incubation lasted 17 days and the nestling period 18–22 days, shorter than the congeneric Great Rufous Woodcreeper (Xiphocolaptes major). Both adults brought nest material, incubated the eggs, fed the nestlings, and removed fecal sacs; however, we suspect that the male contributed more to fecal sac removal. Both adults roosted in the cavity a few nights...

Many forest bird species require tree cavities for nesting, and share this resource with a diverse community of animals. When cavities are limited, niche overlap can result in interspecific competition, with negative consequences for threatened populations. Vinaceous-breasted Parrots (Amazona vinacea) are endangered cavity nesters endemic to the subtropical Atlantic Forest, where cavities are scarce. We examined nest niche overlap among Vinaceous-breasted Parrots and 9 potential competitors (birds and mammals >140 g, and social insects) in Argentina, considering (1) timing of breeding, (2) characteristics of cavities (depth, entrance diameter, height), trees (diameter at breast height DBH, species, condition), and habitat (surrounding land use, distance to edge), and (3) interspecific cavity reuse. During 10 breeding seasons we studied nests and roosts, measured their characteristics, and monitored cavities to detect reuse. We used multinomial logistic regression to determine whether the 6 most abundant taxa differed in nest and roost site characteristics. Timing of breeding overlapped for all bird species except the White-eyed Parakeet (Psittacara leucophthalmus). No combination of cavity, tree, and habitat characteristics predicted the taxa that utilized cavities. Moreover, 8 of the 10 taxa reused cavities interspecifically. The high level of overlap in realized nest niche, combined with previous evidence that cavities could limit bird density in our study area, suggest the possibility of interspecific competition for cavities among multiple taxa. Although models did not perform well at classifying cavities by taxon, some characteristics of cavities, trees, and habitat were selected more by Vinaceous-breasted Parrots than by other taxa, and we recommend targeting conservation efforts toward cavities and trees with these characteristics (7-40 cm entrance diameter, >10 m high, DBH >55 cm). We found 62% of Vinaceous-breasted Parrot nests on farms (vs. ≤50% for other taxa), highlighting the importance of working with local farmers to conserve cavities in anthropogenic habitats as well as in protected areas. Fil: Bonaparte, Eugenia Bianca. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; Argentina. Universidad Nacional de Córdoba; Argentina Fil: Cockle, Kristina Louise. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; Argentina. University of British Columbia; Canadá

An important goal for the conservation of tropical forest biodiversity is to maintain adequate supplies of tree cavities to support diverse communities of cavity-nesting and roosting vertebrates over the long term, especially in human-modified landscapes. The conservation and replacement of nesting cavities depend critically on cavity persistence, which is predicted to decline with increasing anthropogenic impact to the habitat, and to vary according to characteristics of trees and excavators. We used Cox proportional-hazards models to study the factors influencing persistence of 277 cavities used by 43 species of nesting birds in 38 species of trees, across a gradient of human impact in the subtropical Atlantic Forest of Argentina, 2004–2016. Median cavity persistence was 6 years, with 79% of cavity losses caused by the collapse of either the whole tree or the section of the tree holding the cavity. Contrary to predictions, cavity persistence did not vary across habitats (primary forest, degraded forest, farm) or excavator types (true woodpecker vs. weak excavator). Persistence was highest (median > 10 years) for non-excavated cavities in live trunks of healthy trees, and increased with tree size and species-specific wood density. Thus, although logging and conversion to farmland remove most cavities, the cavities that remain in these human-modified habitats provide high quality, multi-annual nest sites for forest birds. Preserving and restoring these cavities should be a priority for conservation of forest vertebrates. The positive effect of species-specific wood density on cavity persistence suggests a trade-off in rates of cavity turnover, whereby cavities are produced early but lost quickly in fast-growing (low wood density) pioneer tree species, and produced late but persist much longer in slow-growing (high wood density) climax species. Fil: Cockle, Kristina Louise. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; Argentina. University of British Columbia; Canadá. Proyecto Selva de Pino Paraná; Argentina Fil: Martin, Kathy. University of British Columbia; Canadá. Proyecto Selva de Pino Paraná; Argentina Fil: Bodrati, Alejandro. Proyecto Selva de Pino Paraná; Argentina

Logging often reduces taxonomic diversity in forest communities, but little is known about how this biodiversity loss affects the resilience of ecosystem functions. We examined how partial logging and clearcutting of temperate forests influenced functional diversity of birds that nest in tree cavities. We used point-counts in a before-after-control-impact design to examine the effects of logging on the value, range, and density of functional traits in bird communities in Canada (21 species) and Chile (16 species). Clearcutting, but not partial logging, reduced diversity in both systems. The effect was much more pronounced in Chile, where logging operations removed critical nesting resources (large decaying trees), than in Canada, where decaying aspen Populus tremuloides were retained on site. In Chile, logging was accompanied by declines in species richness, functional richness (amount of functional niche occupied by species), community-weighted body mass (average mass, weighted by species densities), and functional divergence (degree of maximization of divergence in occupied functional niche). In Canada, clearcutting did not affect species richness but nevertheless reduced functional richness and community-weighted body mass. Although some cavity-nesting birds can persist under intensive logging operations, their ecosystem functions may be severely compromised unless future nest trees can be retained on logged sites. Fil: Ibarra, José Tomás. University of British Columbia; Canadá. Pontificia Universidad Católica de Chile; Chile Fil: Martin, Michaela. University of British Columbia; Canadá Fil: Cockle, Kristina Louise. University of British Columbia; Canadá. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; Argentina Fil: Martin, Kathy. University of British Columbia; Canadá

Predation is the major cause of avian nest failure, and an important source of natural selection on life history traits and reproductive behavior. However, little is known about the identity of nest predators in much of the world, including the Neotropics. To identify some of the nest predators exerting selection pressure on birds of the subtropical Atlantic forest, we present observations of animals depredating bird nests in Argentina and Paraguay. We recorded depredations (destruction or removal of eggs or nestlings) at 33 nests of 25 species of birds, confirming as predators ten species of birds (Squirrel Cuckoo Piaya cayana, White-eared Puffbird Nystalus chacuru, Toco Toucan Ramphastos toco, Red-breasted Toucan Ramphastos dicolorus, Saffron Toucanet Pteroglossus baillonii, Chestnut-eared Aracari Pteroglossus castanotis, Planalto Woodcreeper Dendrocolaptes platyrostris, White-throated Woodcreeper Xiphocolaptes albicollis, Buff-browed Foliage-gleaner Syndactyla rufosuperciliata, and Plush-crested Jay Cyanocorax chrysops) and two species of medium-sized mammals (White-eared Opossum Didelphis albiventris and Crab-eating Fox Cerdocyon thous), and inferring two additional mammal species (Black Capuchin Monkey Sapajus nigritus and Southern Tigrina Leopardus guttulus). Fifty-five percent of these nests were depredated by toucans or aracaris (Ramphastidae), which destroyed eggs and nestlings at cup-, closed- and cavity-nests. Red-breasted Toucans destroyed nests 1.6?22 m high, in habitats ranging from primary forest to a backyard. Mammals and jays depredated nests from ground-level to midstory, whereas woodcreepers and aracaris depredated nests from the midstory to canopy. We did not record snakes at any bird nests, in strong contrast to studies from other Neotropical forests. Further studies should examine trade-offs among nest concealment, physical protection, and parental defense behavior as means of reducing nest predation, and use camera traps to quantify nest predation rates by predator species. Fil: Cockle, Kristina Louise. Proyecto Selva de Pino Paraná; Argentina. University of British Columbia; Canadá. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; Argentina. State University of Louisiana; Estados Unidos Fil: Bodrati, Alejandro. Proyecto Selva de Pino Paraná; Argentina Fil: Lammertink, J. Martjan. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentina. Cornell University; Estados Unidos. Proyecto Selva de Pino Paraná; Argentina Fil: Bonaparte, Eugenia Bianca. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Proyecto Selva de Pino Paraná; Argentina Fil: Ferreyra, Carlos. Proyecto Selva de Pino Paraná; Argentina Fil: Di Sallo, Facundo Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Proyecto Selva de Pino Paraná; Argentina

As ornithologists working with birds in South America, we were intrigued by the title of a recent paper in Climatic Change, ‘Are bird populations in tropical and subtropical forests of South America affected by climate change?’ (Nores 2009). The author claims that vast areas of South American forests have become ‘practically ornithological deserts,’ presumably due to some unspecified effect of climate change. However, the bird data reported grossly underestimate current bird diversity in these forests. Moreover, the methods employed are unacceptable in modern ornithology, and the conclusions of the Climatic Change (2011) 108:383–386 DOI 10.1007/s10584-011-0162-1

In forests worldwide, tree-cavity supply can limit populations of the 10-40% of bird and mammal species that require cavities for nesting or roosting. Conservation efforts aimed at cavity-using communities have often focused on woodpeckers because, as cavity excavators, they are presumed to control cavity supply. We show that avian excavators are the primary cavity producers in North America (77% of nesting cavities), but not elsewhere (26% in Eurasia and South America; 0% in Australasia). We studied survivorship of 2805 nest cavities and found similar persistence of cavities created by woodpeckers and those created by decay in Canada, but low persistence of woodpecker-excavated cavities in Poland and Argentina. Outside of North America, the ephemeral nature of many woodpecker cavities may render most cavity-using vertebrates critically dependent on the slow formation of cavities by damage and decay. The future of most cavity-using communities will therefore be highly dependent on changing forest policies to stem the current loss of old trees. Fil: Cockle, Kristina Louise. University of British Columbia; Canadá. Universidad Maimónides; Argentina. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentina Fil: Martin, Kathy. University of British Columbia; Canadá. Environment Canada; Canadá Fil: Wesołowski, Tomasz. Wrocław University; Polonia

Cavity-nesting birds may frequently compete for a limited supply of nest and roost cavities in trees, but interspecific sharing of these cavities has rarely been reported. The globally vulnerable Helmeted Woodpecker (Dryocopus galeatus), a little-known Atlantic Forest endemic, is believed to be threatened by nest-site competition; however, little is known about its ecology or natural history. I report an observation of a female Helmeted Woodpecker roosting with two White-eyed Parakeets (Aratinga leucophthalma) in their non-excavated (natural) nest cavity at Cruce Caballero Provincial Park, Argentina, and discuss possible implications for ecology and conservation of this rare woodpecker.

Tree cavities are proposed to limit populations and structure communities of cavity-nesting birds. Although the greatest diversity of cavity-nesting birds is found in tropical and subtropical moist forests, little is known about how tropical logging affects the abundance of cavities or cavity-nesting birds. We compared the abundance of cavities and cavity nests between primary and selectively-logged subtropical moist Atlantic forest in Argentina, and conducted the first before-after controlled nest-box addition experiment to determine whether nest sites limit the breeding density of cavity-nesting birds in tropical or subtropical moist forest. Visual inspection of 86 cavities identified through ground-surveys revealed that only 19% were suitable for nesting birds, suggesting that cavity abundance may be overestimated in the literature on tropical forests. Suitable cavities were found in fewer than 1% of 1156 trees 100 cm dbh. Logged forest had half the basal area of primary forest, one third the density of large trees, nine times fewer cavities suitable for nesting birds, and 17 times fewer active nests. When we added nest boxes, nesting density increased on treatment plots but not on control plots in both logged and primary forest, suggesting that cavity supply can limit nest density even in relatively undisturbed forest. This is the first experiment to show how reduced cavity supply in logged tropical forest can limit breeding density of cavity-nesting birds. International initiatives such as forest certification should promote tropical timber management strategies that conserve large live cavity-bearing trees.

Avian hosts may either resist the negative effects of nestling ectoparasites by minimizing the number of parasites, or tolerate parasitism by increasing their fecundity via the reproductive compensation hypothesis. Little is known about the interactions between ectoparasites and their avian hosts in the tropics. We (1) examined nestling development rates, and tested whether (2) parasitism by a subcutaneous ectoparasitic botfly (Philornissp.) had negative effects on the condition of nestlings, and (3) these negative effects were minimized in larger broods in a tropical cavity-nesting bird, the planalto woodcreeper (Dendrocolaptes platyrostris), in primary and secondary Atlantic forests in the northern province of Misiones, Argentina. Nestling mass and ectoparasite load per nestling reached maxima when nestlings (n = 50) were between 10 and 14 d old. General linear mixed models predicted that mass at fledging declined with increasing nestling parasite load, suggesting that botflies had a negative influence on fledging condition. Parasite load per nestling declined with increasing brood size indicating that woodcreepers that increase their reproductive output minimize the negative effects of parasitism. Overall we found evidence to support the tolerance via reproductive compensation hypothesis. Future tests of the reproductive compensation hypothesis may help determine the underlying mechanism of the observed negative correlation between parasite load of nestlings and brood size.

One of the five most important global biodiversity hotspots, the Neotropical Atlantic forest supports a diverse community of birds that nest in tree cavities. Cavitynesting birds may be particularly sensitive to forestry and agricultural practices that remove potential nest trees; however, there have been few efforts to determine what constitutes a potential nest tree in Neotropical forests. We aimed to determine the characteristics of trees and cavities used in nesting by excavators (species that excavate their own nest cavity) and secondary cavity-nesters (species that rely on existing cavities), and to identify the characteristics of trees most likely to contain suitable cavities in the Atlantic forest of Argentina. We used univariate analyses and conditional logistic regression models to compare characteristics of nest trees paired with unused trees found over three breeding seasons (2006‐2008). Excavators selected dead or unhealthy trees. Secondary cavity-nesters primarily selected cavities that were deep and high on the tree, using live and dead cavity-bearing trees in proportion to their availability. Nonexcavated cavities suitable for birds occurred primarily in live trees. They were most likely to develop in large-diameter trees, especially grapiaApuleia leiocarpaand trees in co-dominant or suppressed crown classes. To conserve cavity-nesting birds of the Atlantic forest, we recommend a combination of policies, economic assistance, environmental education, and technical support for forest managers and small-scale farmers, to maintain large healthy and unhealthy trees in commercial logging operations and on farms.

We provide the first description of the nest, eggs, and nestlings of the Planalto Woodcreeper (Dendrocolaptes platyrostris), a secondary cavity-nester, based on three nests in natural cavities and 14 in nest boxes. Nests were found from October to January in 1997, 2006, and 2007 in the humid Chaco and Atlantic Forest of Argentina. Planalto Woodcreepers used natural cavities and nest boxes 40–60 cm deep with entrance diameters of 5–12 cm. They selected the deepest nest boxes available. Three or four white eggs were laid on a bed of bark flakes and incubated for 14–16 days. Newly hatched nestlings had pink skin with gray down, yellow mouth linings, and large whitish gape flanges. They opened their eyes when 6–7 days of age and fledged at 16–18 days. Nearly all nestlings were infested with botflies (Philornis sp.). Both adults contributed to nest building, incubation, nestling-rearing, and nest sanitation.

Most bamboos are semelparous. Their synchronous masting events occur on a cycle of 3–120 yr and represent an extremely pulsed resource for granivorous birds. Although many bird species feed occasionally on bamboo seeds, there are constraints to specializing on such a fluctuating resource and few bird species are known to specialize on bamboo seeds. Three of these bird species are endemic to the Atlantic forest of South America: the purple-winged ground-dove Claravis godefrida, buff-fronted seedeater Sporophila frontalis, and Temminck's seedeater Sporophila falcirostris. All three species are irregularly recorded in the province of Misiones, Argentina. We compared the temporal and spatial patterns of records of these birds in Misiones to masting events of the five common bamboos: yatevoGuadua trinii, takuaruzuGuadua chacoensis, takuapiMerostachys claussenii, pitinga Chusquea tenella, and takuaremboChusquea ramosissima. All bird records coincided with times and places where Guadua bamboos (G. trinii and G. chacoensis) were known or estimated to have seeds. None of the bird species occurred during masting events of Merostachys or Chusquea, unless Guadua was also masting. We discuss relevant ecological and morphological features of the birds that might bear on their association with Guadua bamboos and that might be key to their conservation. RESUMEN Especializacion en semillas de Guadua por tres especies de aves en la Selva Atlantica Interior de Argentina. – La mayoria de los bambues son semelparos. Sus eventos de floracion masiva ocurren en ciclos que tardan entre 3 y 120 anos, y representan un recurso extremadamente pulsado para las aves granivoras. Aunque muchas especies de aves se alimentan ocasionalmente de semillas de bambu, existen restricciones que dificultan la especializacion en un recurso tan fluctuante, y se conocen unas pocas especies de aves especialistas en semillas de bambu. Tres de estas aves son endemicas de la Selva Atlantica de Sudamerica: la Palomita de Ala Morada (Claravis godefrida), el Corbatita Olivaceo (Sporophila frontalis), y el Corbatita Picudo (Sporophila falcirostris). Estas tres especies son registradas irregularmente en la provincia de Misiones, Argentina. Comparamos los patrones de distribucion espacial y temporal de estas aves en Misiones con los eventos de floraciones masivas de los cinco bambues comunes: Yatevo (Guadua trinii), Takuaruzu (Guadua chacoensis), Takuapi (Merostachys claussenii), Pitinga (Chusquea tenella), y Takuarembo (Chusquea ramosissima). Todos los registros de las aves coincidieron con sitios y en momentos en que las Guadua (G. trinii y G. chacoensis) tenian semillas o estimamos que habrian tenido semillas. Ninguna de las especies de aves fue registrada durante eventos de floracion de Merostachys o Chusquea, a menos que alguna Guadua tambien estuviera floreciendo. Discutimos caracteristicas ecologicas y morfologicas que pueden estar relacionadas con la asociacion de las aves con las Guadua y que pueden ser clave para su conservacion.

Network analysis offers insight into the structure and function of ecological communities, but little is known about how empirical networks change over time during perturbations. ?Nest webs? are commensal networks that link secondary cavity-nesting vertebrates (e.g., bluebirds, ducks, and squirrels, which depend on tree cavities for nesting) with the excavators (e.g., woodpeckers) that produce cavities. In central British Columbia (Canada), Northern Flicker (Colaptes auratus) is considered a keystone excavator, providing most cavities for secondary cavity-nesters. However, roles of species in the network, and overall network architecture, are expected to vary with population fluctuations. Many excavator species increased in abundance in association with a pulse of food (adult and larval beetles) during an outbreak of mountain pine beetle (Dendroctonus ponderosae), which peaked in 2003?2004. We studied nest web dynamics from 1998 to 2011 to determine how network architecture changed during this resource pulse. Cavity availability increased at the onset of the beetle outbreak and peaked in 2005. During and after the outbreak, secondary cavity-nesters increased their use of cavities made by five species of beetle-eating excavators, and decreased their use of flicker cavities. We found low link turnover, with 74% of links conserved from year to year. Nevertheless, the network increased in evenness and diversity of interactions, and declined slightly in nestedness and niche overlap. These patterns remained evident 7 years after the beetle outbreak, suggesting a legacy effect. In contrast to previous ?snapshot? studies of nest webs, our dynamic approach reveals how the role of each cavity producer, and thus quantitative network architecture, can vary over time. The increase in interaction diversity with the beetle outbreak adds to growing evidence that insect outbreaks can increase components of biodiversity in forest ecosystems at various temporal scales. The observed changes in (quantitative) network architecture contrast with the relatively stable (qualitative) architecture of empirical mutualistic networks that have been studied to date. However, they are consistent with recent theory on the importance of population fluctuations in driving network architecture. Our results support the view that models should allow for the possibility of rewiring (species switching partners) to avoid overestimation of secondary extinction risk. Fil: Cockle, Kristina Louise. University Of British Columbia; Canadá. State University Of Louisiana; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Bio y Geociencias del Noroeste Argentino; Argentina Fil: Martin, Kathy. University Of British Columbia; Canadá. Environment Canada; Canadá

In the Atlantic forest region, there is a need to develop economic activities that can be carried out in buffer zones around parks, with minimal impact on forest bird species. One such possibility is the farming of yerba mate, Ilex paraguariensis, under native trees. We compared bird speciesȁ9 presence and abundance between a forest reserve and an adjacent plantation of shade-grown yerba mate, to determine which species might use such plantations. Of the 145 species that were regularly recorded in the forest, 66%, including five globally threatened species, were also regularly recorded in the plantation. Most canopy species and tree trunk insectivores showed similar abundance in both habitats, but forest floor and understory species were absent from the plantation. Within the plantation, higher tree density did not lead to a greater abundance of forest birds. Yerba mate grown under native trees could be used to rehabilitate cleared land and allow recolonization by some Atlantic forest bird species.

We assessed the impact of clearcutting on small mammals in riparian areas and evaluated riparian buffer strips as a tool for conserving small mammals in managed forests. Over two summers, we trapped small mammals of seven species in riparian areas in southwestern British Columbia, Canada. Communities of small mammals were compared across three different habitat types: (1) clearcut to the stream bank, (2) clearcut with a 30 m riparian buffer strip, and (3) control (no logging). Species richness was significantly lower in clearcuts than in controls and buffers. On clearcut sites, creeping voles were more abundant, but red-backed voles and dusky shrews were less abundant than at the control sites. At sites with riparian buffer strips, both voles were present in numbers similar to those found in controls, but dusky shrews were less common. Significantly more deer mice and creeping voles were infested with bot flies at clearcut sites than at buffer sites, and no animals were infested at any of the control sites. Riparian reserves appear to be useful in reducing the short-term impacts of clearcutting on small mammal communities, though they do not eliminate these impacts altogether.

There are a large number of ornithological societies in North America, some dating back to the 1880s. Although they differ in part by history, region, scientific approach and taxonomic focus, many of the memberships overlap and the societies are increasingly holding joint meetings. The largest of