Life-history theory predicts a trade-off between current and future reproductive effort and, in this context, the terminal investment hypothesis proposes that reproductive investment, and consequently breeding success, should increase at older ages. We analyzed how relative minimum age related to breeding investment and success in Tachycineta leucopyga (Chilean Swallow) females across 6 breeding seasons in northwestern Argentine Patagonia. We also examined age associations between laying date and physical condition. Our results showed no evidence that reproductive investment increased with age. However, older females laid earlier and achieved higher breeding success than younger ones, which may be related to age-associated differences such as experience or skill. We propose that older females may refine foraging efficiency, increasing the quality or quantity of food delivered per visit, while maintaining self-care; physical condition slightly improved from 1- to 2-year-old females but remained similar in older females. Given that migratory aerial insectivores are particularly vulnerable to global climate change, understanding how reproductive investment and success vary with age provides essential life-history data to identify critical demographic constraints. Such information is particularly scarce in South America, where information on breeding costs and survival remains limited and hinders the development of effective conservation strategies. Reproduction is demanding for birds, especially females, so they must balance the effort between raising young now and maintaining their own survival to reproduce again in the future. We studied how reproductive effort and breeding success changed with age in female Tachycineta leucopyga (Chilean Swallow), a migratory bird that feeds on flying insects. Older females laid their eggs earlier and had greater breeding success, even though they did not lay more eggs or feed their chicks more often. We suggest that older swallows gain experience, for example, by migrating at the right time and becoming more efficient at finding food, which helps them feed their chicks with better or more food on each visit during the nestling period, leading to higher breeding success. These findings help us understand how birds adapt to changing environments and why protecting older, experienced birds may have important consequences for population persistence. La teor & iacute;a de historia de vida predice un compromiso entre el esfuerzo reproductivo presente y futuro. Dentro de este marco te & oacute;rico, la hip & oacute;tesis de inversi & oacute;n terminal propone que la inversi & oacute;n reproductiva y, en consecuencia, el & eacute;xito reproductivo, deber & iacute;a aumentar en clases de edad mayores. En este estudio, analizamos la relaci & oacute;n entre la edad m & iacute;nima relativa y la inversi & oacute;n y el & eacute;xito reproductivo de las hembras de Tachycineta leucopyga a lo largo de seis temporadas reproductivas en el noroeste de la Patagonia Argentina. Tambi & eacute;n analizamos la posible asociaci & oacute;n entre la edad y la fecha de puesta o la condici & oacute;n f & iacute;sica. Nuestros resultados no mostraron evidencia de que la inversi & oacute;n reproductiva aumente con la edad. Sin embargo, las hembras mayores pusieron huevos m & aacute;s temprano y lograron un mayor & eacute;xito reproductivo que las m & aacute;s j & oacute;venes, lo cual podr & iacute;a estar relacionado con diferencias dadas por la edad en experiencia o habilidades. Proponemos que las hembras mayores podr & iacute;an mejorar la eficiencia en la b & uacute;squeda y obtenci & oacute;n de alimentos, aumentando la calidad o la cantidad de alimento entregado en cada visita al nido, al mismo tiempo que mantienen su propia condici & oacute;n f & iacute;sica; de hecho, la condici & oacute;n f & iacute;sica fue levemente mejor en las hembras de dos a & ntilde;os con respecto a las de un a & ntilde;o, aunque se mantuvo similar en las hembras m & aacute;s viejas. Dado que las aves insect & iacute;voras migratorias son particularmente vulnerables al cambio clim & aacute;tico global, entender c & oacute;mo var & iacute;an la inversi & oacute;n y el & eacute;xito reproductivo con la edad proporciona datos esenciales de historia de vida para identificar limitaciones demogr & aacute;ficas cr & iacute;ticas. Esta informaci & oacute;n es particularmente escasa en Sudam & eacute;rica, donde los datos sobre los costos reproductivos y la supervivencia siguen siendo limitados, dificultando el desarrollo de estrategias efectivas de conservaci & oacute;n.

ABSTRACT Secondary poisoning with anticoagulant rodenticides (ARs) has been identified as an important threat for raptor conservation worldwide. In 2019, the California State Legislature passed Assembly Bill 1788 (made effective in 2020), which prohibits or limits the use of second-generation anticoagulant rodenticides (SGARs) in the state, as a follow-up to the California Department of Pesticide Regulation’s ban on SGARS implemented in 2014. Currently, the adherence to these recent restrictions on ARs in southern California is unknown. To assess whether these bans prevented exposure of raptors and other wildlife to ARs, we investigated (1) the prevalence of exposure to eight different ARs in the blood of Turkey Vultures (Cathartes aura) before and after the 2019 ban, and (2) the distribution of resighted (encountered) wing-tagged Turkey Vultures included in this study to assess where exposure might occur. Of 27 Turkey Vultures tested for eight ARs, one out of 11 sampled in 2017 had detectable (trace) but not quantifiable levels of difethialone, and two out of 16 (12.5%) sampled in 2021 had detectable levels of diphacinone (one had 8 ppb; another indicated as positive without quantification). Overall, the prevalence of exposure to ARs was 11.1% (3 of 27), 7.4% for diphacinone and 3.7% for difethialone. Based on 93 resightings of 20 of the wing-tagged Turkey Vultures, all but one remained within the areas of Los Angeles, San Bernardino, Orange, Riverside, and San Diego Counties of southern California. Our study suggests that the exposure risk of Turkey Vultures to ARs persisted despite recent restrictions. Our small sample size and reliance on blood in live vultures rather than liver tissue in dead ones may be underestimating true ARs exposure in our study population. We propose a continued and integrated monitoring approach that includes measurements of ARs in both free-ranging (blood samples) and deceased (liver samples) Turkey Vultures for effective large-scale monitoring. This approach will assess compliance with current and future bans and regulations regarding the use of these poisons in California.

Chilean swallows (Tachycineta leucopyga) are the southernmost swallows in the Tachycineta genus, breeding from central Chile to southern Chile and Argentina. Studies focused on a population breeding at 54 degrees S in Tierra del Fuego, revealed differences in life-history traits compared to their Northern Hemisphere congeners, such as smaller clutch size, and greater male nest attendance during the incubation period. To assess the consistency of these patterns for the species, we studied breeding biology and parental care of Chilean swallows in Northwestern Argentine Patagonia (41 degrees S). If austral population breeding traits reflect species traits, we predict smaller clutch size, higher female reproductive investment, and similar nest attendance by both sexes during incubation compared to Tachycineta species breeding at similar Northern Hemisphere latitudes. We also anticipate negative correlation between clutch size, egg size, and breeding success with laying date, as observed in Tachycineta species, including Chilean swallows. Surprisingly, clutch and egg sizes did not differ between northern and southern Patagonian populations. We did not find evidence of a negative relationship between clutch or egg size and laying date. Male nest attendance during incubation was variable and low, but their nestlings feeding rates equalled those of females. These findings suggest that Chilean swallows adopt diverse reproductive strategies across regions. This may help this species adapt to different environments and climates, ranging from the shorter breeding seasons and lower summer mean temperatures of Tierra del Fuego to the longer breeding seasons and higher seasonal and daily thermal amplitudes in continental north Andean Patagonia.

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn Email Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation Ulises Balza, Nicolás A. Lois, Valeria Ojeda; Mapping the Mountain Caracara (Phalcoboenus megalopterus)/White-throated Caracara (P. albogularis) Contact Zone and Possible Hybrid Zone in Northern Patagonia. Journal of Raptor Research 2024; doi: https://doi.org/10.3356/JRR-23-36 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest Search

En Argentina, el riesgo que los rodenticidas anticoagulantes podrían presentar para las aves rapaces locales fue reconocido inicialmente en la década de 1980. Lamentablemente, 40 años después de esta primera señal de alarma, los rodenticidas anticoagulantes siguen siendo ampliamente utilizados en el país y en toda Sudamérica, sin haberse estudiado el problema medioambiental que estos pueden suponer. Aquí presentamos una revisión práctica e integral sobre los rodenticidas anticoagulantes y la intoxicación por estos en aves rapaces. Discutimos su impacto, tanto sobre individuos como en sus poblaciones, como también los aspectos relacionados al manejo de animales intoxicados y a la necesidad de contar con capacidad diagnóstica en la región. La información aquí recopilada permitirá contar con contenidos relevantes, actualizados y accesibles necesarios para abordar el estudio de esta amenaza para la conservación de las aves rapaces de Argentina y de otros países de Sudamérica. Al mismo tiempo, esperamos que promueva investigaciones sobre el tema que permitan dar los pasos necesarios para evaluar y mitigar el riesgo que el uso de los rodenticidas anticoagulantes puede tener sobre las aves rapaces y otra fauna silvestre

ABSTRACT 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. How to Cite Soares, L., K. L. Cockle, E. Ruelas Inzunza, J. T. Ibarra, C. I. Miño, S. Zuluaga, E. Bonaccorso, J. C. Ríos-Orjuela, F. A. Montaño-Centellas, J. F. Freile, et al. (2023). Neotropical ornithology: Reckoning with historical assumptions, removing systemic barriers, and reimagining the future. Ornithological Applications 125:duac046. LAY SUMMARY Research conducted by ornithologists living and working in Latin America and the Caribbean has been historically and systemically excluded from global scientific paradigms, ultimately holding back ornithology as a discipline. To avoid replicating systems of exclusion in ornithology, authors, editors, reviewers, journals, scientific societies, and research institutions need to interrupt long-held assumptions, improve research practices, and change policies around funding and publication. To advance Neotropical ornithology and conserve birds across the Americas, institutions should invest directly in basic field biology research, reward collective leadership, and strengthen funding and professional development opportunities for people affected by current research policies. Resumen Una barrera importante para el avance de la ornitología es la exclusión sistémica de los profesionales del Sur Global. Una colección especial de artículos publicada recientemente, Advances in Neotropical Ornithology, incluye un análisis de deficiencias que involuntariamente sigue un largo patrón de destacar a las personas, el conocimiento y las opiniones de los EEUU y Europa (Norte Global) mientras que omite en gran medida las perspectivas de personas basadas en el Neotrópico. Aquí revisamos las fortalezas y oportunidades actuales en la práctica de la ornitología neotropical. Además, discutimos el problema de evaluar el estado de la ornitología neotropical a través de una visión del norte, incluida la propagación de narrativas de descubrimiento, una imagen incompleta (y sesgada) de su historia y avances, y la promoción de preguntas, herramientas y enfoques que, si bien son populares actualmente en el norte, no necesariamente encajan en la agenda y realidades de la investigación neotropical. Argumentamos que los avances futuros en la ornitología neotropical dependerán críticamente de identificar y abordar las deficiencias sistémicas que frenan a los ornitólogos que viven y trabajan en el Neotrópico: financiamiento limitado y poco confiable, exclusión del liderazgo de la investigación internacional, difusión restringida del conocimiento (por ejemplo, a través de la hegemonía del idioma y el sesgo de citación) y barreras logísticas. En el futuro, debemos examinar y reconocer las raíces coloniales de nuestra disciplina y promover agendas de investigación, capacitación y conservación que sean explícitamente anticoloniales. Invitamos a nuestros colegas dentro y fuera del Neotrópico a unirnos en la creación de nuevos modelos de gobernanza que establezcan prioridades de investigación con una participación vigorosa de ornitólogos y otras partes interesadas de la región neotropical. Para incluir una diversidad de perspectivas, debemos abordar sistémicamente la discriminación y el sesgo arraigados en el sistema de clases socioeconómicas, el racismo anti-negro, anti-mestizo y anti-indígena, la misoginia, la homofobia, la inclusión simbólica y el capacitismo. En lugar de buscar la excelencia individual y recompensar el liderazgo de arriba hacia abajo, las instituciones del norte y del sur pueden promover el liderazgo colectivo. Al adoptar estos enfoques, los ornitólogos nos uniremos a una comunidad de investigadores de toda la academia en la construcción de nuevos paradigmas que reconcilien nuestras relaciones y transformen la ciencia. Hay traducciones al español y al portugués en el material suplementario.

European starlings (Sturnus vulgaris) were introduced ca. 40 years ago to South America, where they naturalized to central and northern Argentina, now reaching some neighboring countries. While Patagonia (southern Argentina and Chile) has remained free of European starlings (ES) in the past, they are now present along its northern boundary. Our objectives were to 1) investigate the factors explaining this recent invasion, and 2) predict how starlings might expand across southernmost America based on niche modeling using landform, land cover, and climatic variables representing conditions that may limit ES. Based on records from community science, informants, and our own observations, we conclude that two parallel processes generated new population nodes in northern Patagonia: 1) a southwards expansion from their core areas near the Atlantic coast (generating an incipient population node in NE Patagonia), and 2) birds released or escaped from captivity (generating an isolated population node in north-central Patagonia). Community science data was most useful from 2018 onwards, while data from informants was key to understand previous events (e.g., first ES confiscated from illegal trade in 2008; first free ranging ES seen in 2014). The most parsimonious model confirmed our prediction that human transformed lands in several portions within the target area are suitable for ES establishment, both in Chile and Argentina. Null suitability was modeled for the lands in southernmost Patagonia (all cover types). Desert lands (Patagonian steppe, Monte Desert, High Andes) that skirt the Andean temperate forests on the north, and most of the Andean forests, turned out to be unsuitable (especially with increasing latitude). Conversely, most of coastal Argentine Patagonia and the human-transformed lands of south-central Chile emerged as moderately suitable habitat for ES. Because the riverine areas under current ES colonization in northern Patagonia are fovourable for ES (i.e., agricultural and urban lands with abundant nesting sites), without control actions, this species might soon spread over ca. 5000 km2 around the Colorado and Negro rivers, affecting their agricultural industry. These rivers, which run west-east through desert lands unsuitable for ES, now represent corridors into south-Andean ecosystems, as they are surrounded by treed land (willows and poplars introduced from Europe) not originally available, connecting formerly separate ecoregions. In case ES manage to reach the eastern slopes of the Andes, they might cross to Chile through low elevation passes (<1000 masl) available south of ca. 38°S. The valleys of south-central Chile are both suitable habitat for ES and valuable productive lands that may be threatened by the invasion. We present management suggestions, and advocate for the development of a bi-national strategy to retard, prevent and alleviate the far-reaching impacts ES may exert on America’s southernmost ecosystems and resources.

Maintenance of tree cavity supply is a global conservation priority for forest wildlife, which requires understanding the ecology and population dynamics of cavity-bearing trees. Explaining the occurrence of cavities in trees is particularly important in ecosystems where most secondary cavity-users (SCUs) are critically dependent on the slow formation of cavities by wood-decay processes. Our main objectives were (1) to explain the distribution of decay cavities in trees according to their individual attributes and, (2) to quantify the relative importance of each individual tree attribute to determine the presence of decay cavities. We focused on medium and large decay cavities (smallest entrance dimension >= 5 cm), which can limit populations of managementsensitive SCUs. We measured forest attributes and inspected cavities in trees (n = 860) and snags (n = 93) in six 0.5 ha plots from old- and second-growth Nothofagus dombeyi forest stands. We used generalised linear mixedeffects models (GLMM) to analyse the distribution of decay cavities in trees using data on their presence/absence, based on several tree individual attributes, across different sites. We applied an information-theoretical and multi-model inference approach to quantify the strength of alternative sets of hypotheses/models. We used model averaging, which allows estimating coefficients and making inferences that account for model and parameter uncertainty. Diameter at breast height (DBH), crown damage and decay, crown ratio (crown length center dot trunk length-1) and woodpecker foraging signs were important to explain the presence/absence of decay cavities in trees. Diameter at breast height, woodpecker foraging signs and a moderate-high crown damage and decay were positively related with decay cavity presence. The presence of medium and large decay cavities was also positively related with DBH, but trees with low crown ratios had relatively low probabilities of presenting these cavities, even with DBHs 150 cm. Trees with DBHs smaller than 50 cm had very low probabilities (<0.25-0.30) to present decay cavities, while the probability of trees presenting decay cavities of medium and large sizes was very low for trees with diameters < 100 cm, even for trees with high crown ratios. Our results point out that conservation of large diameter trees with high crown ratios is important to maintain the supply of decay cavities required by management-sensitive SCUs in these forests. As these keystone structures are globally threatened by climate change induced disturbances (e.g. fires, droughts), they should be maintained/restored through forest management (e.g. retention of keystone structures) to achieve cavity-using wildlife habitat conservation in the long-term.

An outbreak of avian botulism type C occurred at the Kelp Gull (Larus dominicanus) colonies located at the Nahuel Huapi National Park and lake area in Argentina, at the end of the breeding season, during austral summer 2020. While conducting fieldwork, birds were observed with paralysis of the lower and upper limbs, and dead birds were found in a sitting down position with no signs of having been attacked. We collected blood and tissue samples from eight Kelp Gulls and one Ashy-headed Goose (Chloephaga poliocephala) for toxicological analysis. One sample of Ashy-headed Goose resulted positive for botulinum toxin type C. Diseases like botulism are usually lethal for wildlife and have important effects on bird populations. Though the impact on the Kelp Gull colonies did not seem to be of great concern (~2.3% of the population affected), specific research into the source of the toxin and the initiating conditions are required to understand the potential threats to the environment and to different bird populations that live in this area. This would be key for aquatic bird species such as the Ashy-headed and the Upland Goose (C. picta), both considered threatened in Argentina.

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 degrees S to 55 degrees 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.

In temperate systems of the Northern Hemisphere, wood‐decay fungi are known to facilitate cavity excavation by woodpeckers. For South America, woodpecker–fungi interactions have not been explored. The aim of this work was to identify wood‐decay fungi associated with the process of cavity excavation by the Magellanic woodpecker ( Campephilus magellanicus ), a large South American picid that excavates on living trees. The survey was conducted in old‐growth Nothofagus pumilio forests of Patagonia. For freshly excavated cavities, wood condition was assessed, adjacent basidiocarps were collected, and fungal cultures were obtained from wood samples taken to the laboratory. All cavities exhibited softened wood. Four Agaricomycotina were isolated in cultures: Stereum hirsutum was the most frequent, followed by Postia pelliculosa, Nothophellinus andinopatagonicus and Aurantiporus albidus . Basidiocarps around cavities were of two species that did not develop in cultures: Laetiporus portentosus and Macrohyporia dictyopora . Excavations were slightly more frequent in white rot colonized than brown rot colonized wood, but this may be an artefact of differential success in fungal isolation and culturing, since several cavities that showed visual symptoms of brown wood rots did not yield mycelia of those wood‐decay fungi. As shown by research elsewhere, basidiocarps underestimated heart rot on cavity walls and revealed additional wood‐decay species living on the same trees; therefore, assessments of fungal diversity in substrates used for cavity excavation should be based on culturing and/or DNA extraction. Because fungal communities in the southern Andes are poorly known, decay fungi and their roles in ecosystem development should be studied across different forest areas, where samples from non‐cavity‐bearing (control) trees should also be taken in order to determine excavation‐site selection.

Capsule Breeding Chilean Swallows Tachycineta leucopyga in Argentina use visual and acoustic signals in response to potential threats from a predator, but these did not vary with brood age. Aims To study anti-predator behavioural responses in breeding Chilean Swallows from North Patagonia, Argentina, by using a nest-box experiment. Methods At days eight and 14 after the first nestlings hatched, Chilean Swallow breeding adults were exposed to a stuffed decoys of either a natural local predator, the Austral Pygmy-Owl Glaucidium nana, or a neutral decoy, a stuffed Rufous-Collared Sparrow Zonotrichia capensis. Results Anti-predator behavioural responses consisted of displaying dives, circling flights and group mobbing around the predator decoy, together with the emission of several vocalizations, among which a mobbing alarm call was the most frequent. We did not find significant differences in the intensity of parental nest defence behaviours at different nestling ages (8 and 14 days old). Conclusion Anti-predator behaviour of breeding Chilean Swallows consists of visual and acoustic signals, involving swallows other than the nest owners, and without variation during the nestling period. Our exploratory assessment on the anti-predator behaviour of Chilean Swallows is the first description of the southernmost Neotropical swallow defence behaviour and will therefore help delineate future research.

Aglaoctenus Tullgren, 1905 es un género de arañas sudamericanas perteneciente a la familia Lycosidae, del cual se conocen cinco especies. Se reporta por primera vez su presencia en Chile, donde en febrero de 2018 se registraron ejemplares de la especie Aglaoctenus puyen Piacentini, 2011 en un ambiente altoandino. Se observaron y fotografiaron un macho y una hembra cargando sus crías en el abdomen, en un faldeo occidental del cerro Tronador, dentro del Parque Nacional Vicente Pérez Rosales, en la Región de Los Lagos. Se aportan datos y fotos que revelan hábitos de esta especie recientemente descrita y poco conocida. Estos hallazgos resaltan la necesidad de realizar relevamientos en otras localidades al este y al oeste de los Andes, en busca de esta especie.

BACKGROUND:Parasites can exert selection pressure on their hosts through effects on survival, on reproductive success, on sexually selected ornament, with important ecological and evolutionary consequences, such as changes in population viability. Consequently, hemoparasites have become the focus of recent avian studies. Infection varies significantly among taxa. Various factors might explain the differences in infection among taxa, including habitat, climate, host density, the presence of vectors, life history and immune defence. Feeding behaviour can also be relevant both through increased exposure to vectors and consumption of secondary metabolites with preventative or therapeutic effects that can reduce parasite load. However, the latter has been little investigated. Psittaciformes (parrots and cockatoos) are a good model to investigate these topics, as they are known to use biological control against ectoparasites and to feed on toxic food. We investigated the presence of avian malaria parasites (Plasmodium), intracellular haemosporidians (Haemoproteus, Leucocytozoon), unicellular flagellate protozoans (Trypanosoma) and microfilariae in 19 Psittaciformes species from a range of habitats in the Indo-Malayan, Australasian and Neotropical regions. We gathered additional data on hemoparasites in wild Psittaciformes from the literature. We considered factors that may control the presence of hemoparasites in the Psittaciformes, compiling information on diet, habitat, and climate. Furthermore, we investigated the role of diet in providing antiparasitic secondary metabolites that could be used as self-medication to reduce parasite load.RESULTS:We found hemoparasites in only two of 19 species sampled. Among them, all species that consume at least one food item known for its secondary metabolites with antimalarial, trypanocidal or general antiparasitic properties, were free from hemoparasites. In contrast, the infected parrots do not consume food items with antimalarial or even general antiparasitic properties. We found that the two infected species in this study consumed omnivorous diets. When we combined our data with data from studies previously investigating blood parasites in wild parrots, the positive relationship between omnivorous diets and hemoparasite infestation was confirmed. Individuals from open habitats were less infected than those from forests.CONCLUSIONS:The consumption of food items known for their secondary metabolites with antimalarial, trypanocidal or general antiparasitic properties, as well as the higher proportion of infected species among omnivorous parrots, could explain the low prevalence of hemoparasites reported in many vertebrates.

We describe pathological aspects of an infection caused by parasitic nematodes in skeletal muscles of a Magellanic woodpecker (Campephilus magellanicus), providing the first description of any disease findings in this species. A weakened female with locomotory dysfunction was rescued near Bariloche city (Argentine Patagonia), which soon died. At the necropsy, unexpected masses of tissue were located at three joints (legs and tail). A dissection of these masses exposed numerous nematodes in the musculature surrounding the joints that were identified as Hamatospiculum flagellispiculosum (Nematoda: Diplotriaenidae), a species that was not previously found in Piciformes (woodpeckers, toucans, and allies) of the Neotropical Region. In this report, we complement the original parasite description from 1952 with SEM images, and extend the species range about 2000 km southwards. Histopathological analysis (tissues sectioned 4-6 microns, stained with hematoxylin and eosin) of the affected tissues revealed parasitic myositis with muscle fibrosis. Severe muscle degeneration and necrosis, fibrous tissue replacing muscle tissue, chronic inflammation with widespread diffuse mononuclear infiltration, and parasitic content (adult roundworms, eggs, and eggs with first-stage larvae) were present in all samples. The multifocal nature of these lesions was consistent with the locomotory dysfunction exhibited by the bird. Both the immune response (mononuclear infiltration without eosinophils, which normally fight helminth colonization) and the clinical severity of this case (a lethal, multifocal macroparasite infection) are noteworthy. The expected immune response may have been suppressed through immunomodulation by the parasite, as observed for filarial parasites. Based on their demography and life history traits (i.e., long-lived picids that produce a single nestling every 1-2 years, and live in sparse populations), Magellanic Woodpeckers do not seem to be obvious hosts of an obligately killing parasite, and other (more regular) hosts should be expected to occur in the same region.

Woody bamboos that undergo masting on a cyclic basis constitute large-scale endogenous disturbances in forests of America, Africa and Asia, driving long- and short-term effects on community structure and dynamics. Among the transient effects of these nonequilibrial phenomena are rodent outbreaks whose potential bottom-up consequences on top predators have never been explored. We investigated the effects of unpredictable rodent outbreaks on the assemblage of nocturnal raptors of the southern Andes after a large-scale (>140000ha), spatially heterogeneous, Chusquea culeou masting event in north Argentine Patagonia. We compared owl numbers and behaviours between pre-masting (2009) and post-masting (2011) at subsidized (outbreaking rodents) and unsubsidized (normal rodents) contiguous sites. Both generalist (opportunistic forest resident) and rodent-specialist (forest-facultative) owls were monitored, with emphasis on the resident territorial rufous-legged owl (Strix rufipes). The resident owls behaved as predicted, perceiving the rodent increases soon and gathering at subsidized sites, while apparently relaxing territoriality. Contrary to our predictions, later at the rodent outbreak phase, resident territorial owls turned inconspicuous, coinciding - causally or not - with an irruption of forest-facultative barn owls (Tyto alba tuidara), and influx of some open country short-eared owls (Asio flammeus suinda, some of which took a chance to breed in the woods). Considering the whole rodent outbreak period, besides significant changes in owls' numbers, we recorded a notable adjustment in owls' foraging modes in response to food surplus (consuming prey heads only), and null interference behaviours among all observed species. This study provides a first quantitative assessment of the effects of bamboo episodic masting on top carnivores globally, and contributes novel data on the indirect effects of these events in forests of South America.

Fil: Mathiasen, Paula. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina