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This work describes a specimen of Chimango Caracara (Milvago chimango - Vieillot, 1816), from southern Brazil, as a new natural host for Trichomonas gallinae (Rivolta, 1878). Caseous oral lesions were observed in a young bird, and the parasite was isolated in modified Diamond’s media. Morphology of the parasite was evaluated through microscopy and subsequently, sequencing of the internal transcribed spacer 1 (ITS1) of ribosomal DNA was performed to confirm T. gallinae identification. As far as authors are concerned, this is the first report of Milvago chimango as a natural host for T. gallinae. Keywords: Raptors, Falcons, Trichomonosis, Avian diseases

Capsule: Studies of nest predation using artificial nests need to consider the effect of egg size on the types of predator that are detected. Aims: To estimate the nest predation rate in the Patagonian temperate forest and evaluate the influence of egg size on predator guild. Methods: On different plant species, we placed 108 nests each containing eggs of either Atlantic Canary Serinus canaria or Common Quail Coturnix coturnix, and a model clay egg of equal size to the real egg. Nest predators were identified from the marks left on the clay eggs or by videos recorded using camera traps. Results: 86% of the nests were predated. Birds, mainly Chimango Caracara Milvago chimango, were the main nest predators. A marsupial, the Monito del Monte Dromiciops gliroides, and rodents also contributed to nest predation. Nest predation rates were similar for both egg sizes but the nest predator guild was different. Birds and rodents preyed on both eggs but the Monito del Monte consumed mainly small eggs. Conclusion: Egg size did not influence the rate of nest predation but, instead, affected the nest predator guild. Consequently, in order to avoid underestimating the impacts of small predators, egg size should be considered in studies of nest predation. Fil: Vazquez, Miriam Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico 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 Fil: Rodriguez Cabal, Mariano Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico 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 Fil: Gonzalez, Daniela Vanesa. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche; Argentina Fil: Pacheco, Gabriel S.. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche; Argentina Fil: Amico, Guillermo Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico 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

Las prácticas recreativas al aire libre reflejan diversos modos de convivir con la biodiversidad. Una de ellas, la observación de aves, ha ganado popularidad mundial pues, a través de las aves, las personas socializan entre sí y con la naturaleza. Esta actividad también puede fomentar el cultivo de una relación ética con las aves, la gente y sus culturas. En este trabajo se presenta al “pajareo biocultural” como una propuesta teórico-práctica para enriquecer la ética del turismo relacionado a las aves mediante la integración de narrativas ecológicas y culturales de las aves en un ciclo de observación–reflexión. Se integró investigación ornitológica interdisciplinaria con la creación de metáforas y el diseño de actividades de observación de aves en Puerto Williams, Chile. El Chimango (Milvago chimango) es capaz de unir los sistemas ecológicos y sociales del Cono Sur americano a través de sus funciones biológicas y significados culturales. Éstos fueron socializados a través de las metáforas “vínculo marino-terrestre” y “cara-a-cara con el caracara”, confeccionados desde la ecología y la extensión de la expresión “cara-a-cara” de Emmanuel Lévinas. Utilizando criterios de adecuación referencial, social, ambiental y de sustentabilidad, se evaluó la capacidad de estas metáforas para acercar a los participantes a las aves, sus ecosistemas y las culturas en que participan. Se recomienda adaptar esta propuesta con otras aves y contextos, para diversificar las relaciones y valoraciones actuales de la avifauna y la gente en los sistemas socio-ecológicos. Outdoor recreational practices reflect the diverse ways of living together with bio-diversity. One of these practices, birdwatching or birding, has gained world-wide popularity, favouring the socializing of people and nature through birds. Birding also can promote an ethical relationship with birds, people and their culture. In this work, we present “biocultural birding” as a theoretical–practical proposal to enrich birding ethics using ecological and cultural narra- tives associated with birds in an observation–reflection cycle. We integrate interdisciplinary research with metaphor composition and guided birdwatching activities in Puerto Williams, Chile. The Chimango Caracara (Milvago chimango) is capable of linking ecological and social systems in the Southern Cone. We communicate these findings using the metaphors “marine-terrestrial link” and “face-to-face with the caracara”, which we constructed based on ecological research and Emmanuel Lévinas’ expression “face-to-face”. Using the criteria of referential, social, environmental and sustainability adequacy, we evaluated how these metaphors bring together participants and birds, their ecosystems and the cultures in which they participate. We recommend to adapt this proposal with other birds and contexts, as a way to diversify human–nature relationships and promote respect for birds and cultures in socio-ecological systems.

We evaluated the species composition, relative abundance, habitat use, and seasonal variability of raptor assemblages in the Flooding Pampas of Argentina, which represents the southeastern part of the biome known as the Rio de la Plata Grasslands. We conducted seasonal roadside surveys to detect raptors in modified and natural habitats over a 3-yr period from spring 2006 through autumn 2009. We classified raptor species according to their relative abundances and occurrence frequencies, and compared the assemblage composition among land-cover types (croplands, grazing fields, periurban areas, and grasslands) and seasons. The raptor assemblage in the Flooding Pampas comprised 16 species, representing approximately 43% of all raptor species in the biome. The Chimango Caracara (Milvago chimango) was the dominant species in all land-cover types and seasons. The Southern Caracara (Caracara plancus), American Kestrel (Falco sparverius), and Roadside Hawk (Rupornis magnirostris) were all abundant and very frequently observed species, whereas Burrowing Owl (Athene cunicularia), White-tailed Kite (Elanus leucurus), and Long-winged Harrier (Circus buffoni) were less abundant but recorded during most surveys. The remaining raptors (Aplomado Falcon [Falco femoralis], Cinereous Harrier [Circus cinereus], Short-eared Owl [Asio flammeus], Sharp-shinned Hawk [Accipiter striatus], and Snail Kite [Rostrhamus sociabilis]) were much less abundant in the study area. We also recorded four other raptor species (Variable Hawk [Geranoaetus polyosoma], Black-chested Buzzard-Eagle [G. melanoleucus], Striped Owl [Asio clamator], and Barn Owl [Tyto alba]), but only outside of the standard transect surveys. Species composition differed among land-cover types, but we detected no distinct overall seasonal patterns except that species diversity indices were lower in autumn and especially, spring. Milvago chimango was important to determine similarity in assemblage composition within land-cover types, but other less abundant species, such as C. plancus, A. cunicularia, and R. magnirostris, were more important to differentiate land-cover types based on raptor composition. Species diversity was highest in grazing fields and grasslands, and lowest in periurban areas. Our results suggest that although some raptor species appear to benefit from land-cover patterns in the study area, many other species may be threatened by the expansion of urban areas and agriculture in the Pampas region. Fil: Baladron Felix, Alejandro Victor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Bó, Maria Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Bechard, Marc J.. Boise State University; Estados Unidos Fil: Malizia, Ana Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina

The breeding parameters of the Black-faced Ibis (Theristicus melanopis) in pastures of southern Chile between 5 July and 30 November 2014 were evaluated. Thirty active nests were monitored in an area of 31 km2, using a mirror mounted on a 13-m retractable aluminum pole. Each nest was visited once a week. The Black-faced Ibis presented an asynchronous posture period, with a maximum of three egg clutches. The first eggs were laid on 6 August 2014, and the mean incubation period was 28.66 (± 4.41) days. Mean clutch size during the first posture was 2.23 (± 0.73) with a range of one to three eggs per nest. None of the structural parameters of the nesting site evaluated were related to clutch size. The nests were oriented with a mean angle of 218° SW. Hatching of the chicks began on 25 September 2014, and the mean period of parental care lasted 36.67 (± 14.49) days. The apparent hatching success was 0.54, the fledging success was 0.40, and the total breeding cycle success was 0.23 independent young per nest. Predation explained the 56.7% nest loss. Chimango Caracara (Milvago chimango) was the main predator of eggs and chicks. The Mayfield estimator indicated a daily survival probability of 4.4% for the incubation cycle, 26.2% for the fledglings and 11.3% for the total breeding cycle.

Summary The goal of the present survey was to improve the scarce knowledge regard the endoparasites of raptors in Chile and South America. Thus, necropsy was performed on 14 chimango caracara Milvago chimango temucoensis from Los Ríos Region, Chile. From all examined birds, 78.6% were positive to helminths. The species identified were Capillaria tenuissima, Pterothominx sp., Baruscapillaria falconis, Cosmocephalus obvelatus, Skrjabinoclava sp., Synhimantus (Dispharynx) nasuta, Synhimantus (D.) sp., Synhimantus (Synhimantus) sp., Paracuaria adunca, Procyrnea spinosa, Porrocaecum depressum, Contracaecum rudolphii sensu lato, Stephanoprora sp. and Polymorphus mutabilis. All species listed, with the exception of C. tenuissima, P. spinosa and P. depressum, are new records for the chimango caracara. Furthermore C. obvelatus, Skrjabinoclava sp., S. (D.) nasuta, S. (D.) sp., P. adunca, C. rudolphii s. l., Stephanoprora sp. and P. mutabilis all are new records for Neotropical raptors.

The study of traits that enable species to thrive in urban habitats is critical to a better understanding the evolution of urban ecosystems. Here, we examined variation in boldness, neophobia, and exploratory behavior in a generalist raptor, the Chimango Caracara, Milvago chimango, occurring in areas with different urbanization level. We also focused on the relationship between object exploration and neophobia in rural and urban population of this species. The results showed that birds from more urbanized habitats showed more tolerance to humans than rural raptors, without any effect of age and sex in this trait. Rural birds were also more neophobic and were slower to explore than urban raptors, though they dedicated a similar amount of time to exploring novel objects, indicating a non-correspondence between the speed to approach and contact these objects and the amount of exploration performed. Finally, we found a correlation between exploration speed and neophobia in rural birds, whereas for urban raptors this correlation was not observed. Our results show that urbanization not only influences the expression of risk-taking behaviors and novelty responses in the chimango, but can also modify the relationship between exploration and neophobia.

Chimango (Milvago chimango) enredado en aparejos de pesca en el sudeste de la provincia de Buenos Aires, Argentina Las artes y aparejos de pesca abandonados, perdidos o descartados, incluidas las líneas de nylon o monofilamento, a menudo tienen un impacto negativo en una variedad de aves. Sin embargo, es escasa la información disponible para aves rapaces en América del Sur. Presentamos tres casos de aves enredadas o mutiladas en el sudeste bonaerense, Argentina; todos pertenecientes al Chimango (Milvago chimango). Los avistamientos incluyen una hembra mutilada (2015) y un macho y dos hembras enredadas en líneas de nylon o monofilamento (2017). Todos los hallazgos incluyeron individuos vivos durante la temporada reproductiva de la especie. Abandoned, lost, or discarded fishing tackle, including monofilament lines, often result in negative impacts on a variety of birds. However, scarce information is available for South American raptors. Here we report three instances of raptor entanglements or injured birds in southeastern Buenos Aires, Argentina, all belonging to the Chimango Caracara (Milvago chimango). The sightings include one injured female (2015), and one male and two females entangles in nylon monofilament lines (2017). All observations referred to live individuals during the species breeding season. Fil: Seco Pon, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Bó, Maria Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Block, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Galván, Federico Emilio. Mar del Plata; Argentina Fil: García, Germán Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina

Natural environments have been greatly transformed by human populations and activities and the responses of species to these changes vary. In human-dominated environments, birds may adopt behaviours that enable them to adjust to these novel habitats. We analysed the reproductive ecology of a common and human-tolerant bird of prey, the Chimango Caracara (Milvago chimango), in a peri-urban zone in central Argentina in response to different levels of human presence. A total of 34 nests were monitored. Nests were in dense colonies with a random distribution of nests within the colony. The reproductive output of Chimango Caracaras was not affected by levels of human presence at either the local scale (colony site) or within colonies (distance to neighbouring nests). However, the lower reproductive success in our study compared with that observed in natural habitats suggests that this species may be negatively affected by anthropogenic factors at a very local scale (i.e. a breeding colony in a peri-urban area) despite its behavioural plasticity and apparent tolerance to human presence.

En muchos estudios sobre aves rapaces se requiere la captura de los individuos y la selección de la técnica de trampeo más efectiva puede ser crucial para alcanzar los objetivos del estudio. Se evaluó la efectividad de las trampas de tipo “walk-in” para capturar a un ave rapaz neotropical muy común pero pobremente estudiada, el Chimango (Milvago chimango), en diferentes ambientes y se evaluaron los efectos de variables ambientales y metodológicas sobre el éxito y el número de individuos capturados. Entre 2009–2013 se capturó un total de 1452 individuos (en 188 días y 2178 horas de trampeo efectivo) con al menos 423 aves recapturadas más de una vez durante el estudio. La tasa promedio de captura diaria fue de 0.90 ind/h, con un máximo de 11 ind/h. El número de individuos capturados y el éxito de captura fueron mayores durante el período reproductivo y en colonias de mayor tamaño, pero fueron más bajos cuando se registraron períodos largos sin trampeo; además, estas variables fueron independientes de cualquier otro factor metodológico o del tipo de ambiente. El éxito, pero no el número de individuos capturados, se incrementó durante la mañana al ser comparado con las horas de la tarde. El éxito y el número de individuos capturados no estuvieron sesgados hacia ningún sexo o grupo etario. Los resultados muestran que las trampas de tipo “walk-in” constituyen una técnica de trampeo útil y altamente efectiva para capturar al Chimango durante todo el año, tanto en términos de éxito como de número de capturas. Many raptor studies require the capture of individuals and selection of the most effective trapping techniques may be crucial to achieving research goals. We assessed the effectiveness of walk-in traps to capture a very common, but poorly studied Neotropical raptor bird, the Chimango Caracara (Milvago chimango) in different environments and we evaluated the effects of environmental and methodological variables on trapping success and number of individuals captured. During 2009–2013 we captured a total of 1452 individuals (188 days and 2178 hours of effective trapping) with at least 423 birds being recaptured at least once during the study. The mean daily capture rate was 0.90 ind/h, with a maximum of 11 ind/h. Number of individuals captured and trapping success were higher during the breeding season and in larger colonies but were lower when longer lapse of non-trapping periods were recorded, then these variables were independent of any other methodological factor and environment type. Trapping success, but not number of individuals captured, increased during the morning when compared with afternoon hours. Trapping success and number of individuals captured were not biased towards any sex, or age group. Our results show that the walk-in trap is a useful and highly effective trapping technique for the Chimango Caracara measured both in terms of number of captures and trapping success throughout the year.

Many raptor studies require the capture of individuals and selection of the most effective trapping techniques may be crucial to achieving research goals. We assessed the effectiveness of walk-in traps to capture a very common, but poorly studied Neotropical raptor bird, the Chimango Caracara (Milvago chimango) in different environments and we evaluated the effects of environmental and methodological variables on trapping success and number of individuals captured. During 2009-2013 we captured a total of 1452 individuals (188 days and 2178 hours of effective trapping) with at least 423 birds being recaptured at least once during the study. The mean daily capture rate was 0.90 ind/h, with a maximum of 11 ind/h. Number of individuals captured and trapping success were higher during the breeding season and in larger colonies but were lower when longer lapse of non-trapping periods were recorded, then these variables were independent of any other methodological factor and environment type. Trapping success, but not number of individuals captured, increased during the morning when compared with afternoon hours. Trapping success and number of individuals captured were not biased towards any sex, or age group. Our results show that the walk-in trap is a useful and highly effective trapping technique for the Chimango Caracara measured both in terms of number of captures and trapping success throughout the year. En muchos estudios sobre aves rapaces se requiere la captura de los individuos y la selección de la técnica de trampeo más efectiva puede ser crucial para alcanzar los objetivos del estudio. Se evaluó la efectividad de las trampas de tipo "walk-in" para capturar a un ave rapaz neotropical muy común pero pobremente estudiada, el Chimango (Milvago chimango), en diferentes ambientes y se evaluaron los efectos de variables ambientales y metodológicas sobre el éxito y el número de individuos capturados. Entre 2009-2013 se capturó un total de 1452 individuos (en 188 días y 2178 horas de trampeo efectivo) con al menos 423 aves recapturadas más de una vez durante el estudio. La tasa promedio de captura diaria fue de 0.90 ind/h, con un máximo de 11 ind/h. El número de individuos capturados y el éxito de captura fueron mayores durante el período reproductivo y en colonias de mayor tamaño, pero fueron más bajos cuando se registraron períodos largos sin trampeo; además, estas variables fueron independientes de cualquier otro factor metodológico o del tipo de ambiente. El éxito, pero no el número de individuos capturados, se incrementó durante la mañana al ser comparado con las horas de la tarde. El éxito y el número de individuos capturados no estuvieron sesgados hacia ningún sexo o grupo etario. Los resultados muestran que las trampas de tipo "walk-in" constituyen una técnica de trampeo útil y altamente efectiva para capturar al Chimango durante todo el año, tanto en términos de éxito como de número de capturas.

We assessed the ability of southern house wrens (Troglodytes aedon musculus) to recognize and discriminate different birds of prey. We exposed nesting birds to stuffed specimens of two sympatric predator species, the chimango caracara (Milvago chimango, a nest predator) and the roadside hawk (Buteo magnirostris, a predator of adults and nests), and to a dummy of a non-sympatric predator, the double-toothed kite (Harpagus bidentatus, a predator of adults). Nesting wrens avoided going into their nest or took a longer time to resume their parental duties when exposed to the predators than when they were exposed to a control dummy (Chrysomus ruficapillus, a sympatric blackbird). Nest avoidance was higher when birds were exposed to the roadside hawk but no differences were detected when exposed to the chimango caracara or the double-toothed kite. The results indicate that southern house wrens are able to recognize a predator, responding in a graded manner. Our findings support the hypothesis that southern house wrens exhibit a threat-sensitive response during breeding. Also, individuals were able to recognize the unknown predator but failed to correctly assess the threat level represented by it. We propose that correct assessment of threat level by house wrens requires direct experience with the predator, which might mediate in the modulation of the response. Fil: Duré Ruiz, Natalia Mabel. 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 Fil: Fasanella, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico 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 Fil: Fernandez, Gustavo Javier. 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

Natal dispersal is a process whereby birds move from their birthplace to the site of their first attempt at reproduction. This process has strong implications for the dynamics and genetic structure of populations. However, studies on the dispersal of neotropical birds of prey are scarce. Here we investigated the post-fledgling and natal dispersal and philopatry of a common but poorly studied raptor, the Chimango Caracara (Milvago chimango) through band recovery and resighting data analysis across human modified and natural environments. During 10 years of study we banded 1738 individuals, with 793 banded as nestlings or fledglings in suburban, rural and natural habitats of central Argentina. We determined the dispersal distance for 94 individuals, 80 of which were recaptured at their natal site. Nine individuals moved between 5 and 120 km during the post-fledgling period (i.e. prior to their first breeding attempt) and five had natal dispersal distances (i.e. from natal to definitive breeding sites as adults) that varied between 10 and 800 km. Throughout band re-sighting we determined that Chimango Caracaras were able to breed at an age of 2 years old. Individuals tended to disperse to similar colonies and habitats as their natal sites (i.e. similar type of colony and degree of anthropogenic disturbance). Although most Chimango Caracaras exhibited short-distance dispersal (

Exploration represents an important way by which organisms evaluate environment information. The decision of whether or not an animal should investigate environmental changes may influence the extent to which animals learn about their surroundings and cope with habitat modifications. We analysed exploration behaviour in a suburban population of a raptor species, the Chimango Caracara, Milvago chimango, by examining how age, previous experience and object complexity influence novel object exploration. Our findings showed that object complexity did not influence caracaras initial approach and contact with objects, but did influence the degree of engagement during exploratory activities, as measured by total exploration time and number of exploration events. These variables were higher for complex objects than for simple objects. Experience resulted in less exploration of simple objects. It is likely that, for caracaras, simple objects are easier to encode and recall than complex objects, so additional exploration of such objects would not provide further information. Results suggest that exploratory behaviour in this raptor was guided more by the benefits of a greater quantity of information obtained by exploring complex objects, than by the risks associated to this activity. We can conclude that caracaras cope with novel features in their surroundings with a novelty-seeking strategy, characteristic for generalist species in discovering early new resources opportunities, and which might be a determining factor for adaptive responses to environment modification. Fil: Biondi, Laura Marina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Guido, Jorgelina María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Bó, María Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Muzio, Ruben Nestor. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); Argentina. Universidad Atlantida Argentina. Facultad de Psicologia; Argentina Fil: Vassallo, Aldo Ivan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras; Argentina

A combination of infrared cameras and plasticine eggs were used to identify potential nest predators of Flightless Steamer-Ducks (Tachyeres pteneres) and Flying Steamer-Ducks (T. patachonicus) and to evaluate the relative efficacy of these methods for identifying predators. Cameras were set up at 31 artificial nests with plasticine eggs and at four Flightless and two Flying steamer-duck nests. Two avian predators, Chimango Caracara (Milvago chimango) and Southern Crested Caracara (Caracara plancus), and two mammalian predators, Fuegian Culpeo fox (Pseudalopex culpaeus lycoides) and American mink (Neovison vison), were identified as depredating artificial nests from photos. Active Flightless and Flying steamer-duck nests were found only on islets, and from the photos the Chimango and Southern Crested caracaras were identified as nest predators. Mammalian predators were not photographed on islets (neither on artificial nor natural nests). Though the potential predator community at Lapataia Bay was small, there were considerable similarities in physical evidence and marks left at nests, especially within avian predators. Also, depredated nests were sometimes revisited by other predators and these multi-predator visits sometimes caused changes to the appearance of the depredated nest following departure of the initial predator. The cameras provided an objective method for definitive identification of nest predators. Fil: Liljesthrom, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Fasola, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Valenzuela, Alejandro Eduardo Jorge. Administración de Parques Nacionales. Delegación Regional Patagonia; Argentina Fil: Raya Rey, Andrea Nélida. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Schiavini, Adrian Carlos Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina

Behaviour is expected to be one of the most important factors driving urban living of bird species because it largely determines how animals interact with their environments. The contribution of different behavioural traits as facilitators of contemporary process of bird colonization of urban environments, however, is still unclear. Here we examined the differences in three behavioural traits: neophobia (avoidance of a new object) and solving success and solving latency of a problem solving test related to obtain food, in rural and urban living individuals of a common diurnal Neotropical raptor, the chimango caracara (Phalcoboenus chimango). Moreover, for solving success and solving latency behaviours, we tested the plasticity (i.e., habituation) in birds. Urban and rural chimangos showed similar neophobia of a new object. All chimangos showed an improvement in their output in problem-solving test as the five-day testing passed but urban chimangos showed higher solving capabilities than rural conspecifics as they were more successful in solving the problem test. More, urban birds shown lower solving latency than rural, as they were able to improve their test performance by opening doors in less time as the day passed; in rural birds this relation was not so abrupt. In addition, those individuals that opened more doors, opened these faster too. Lastly, both solving success and latency showed very low individual consistency (repeatability < 0.275). Our results provide evidence of plasticity in solving capabilities of chimango caracaras which reveal that a habituation process in these behavioural traits could be associated to establishment of birds in urban environments. Fil: Solaro, Claudina. Universidad Nacional de La Pampa. Facultad de Ciencia Exactas y Naturales. Departamento de Recursos Naturales. Centro para el Estudio y Conservación de Aves Rapaces; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentina Fil: Sarasola, José Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentina. Universidad Nacional de La Pampa. Facultad de Ciencia Exactas y Naturales. Departamento de Recursos Naturales. Centro para el Estudio y Conservación de Aves Rapaces; Argentina

The Polyborinae is the most diverse subfamily of the Falconidae in terms of both morphology and behaviour, and includes falconet-shaped birds (Spiziapteryx), arboreal omnivores (Daptrius, Ibycter), as well as terrestrial generalists and scavengers (Caracara, Milvago and Phalcoboenus). The Polyborinae are endemic to the New World, with all but one species (Caracara cheriway) being restricted to Central and South America. Using over 7300 bp of mitochondrial and nuclear sequence data, we aim to clarify the taxonomy and biogeography of the Polyborinae. The genus Milvago was unexpectedly found to be polyphyletic, with Chimango Caracara Milvago chimango being related to the genus Phalcoboenus and Yellow-headed Caracara Milvago chimachima being sister to Daptrius. Furthermore, very low genetic divergence was found among the four species of the genus Phalcoboenus, with the lowest divergence being between White-throated Caracara Phalcoboenus albogularis and Mountain Caracara Phalcoboenus megalopterus. Our divergence time analyses revealed that the Polyborinae started to diversify in the Miocene, at about 14 Ma, and that the generalist ⁄scavenger behaviour in the Falconidae appeared between 14 and 6.6 Ma. All speciation events within the caracaras occurred during the Pleistocene. This situation differs from the general pattern described for forest birds, in which most diversification events are older, occurring primarily in the Pliocene and Miocene.

Chimango caracara (Milvago chimango) is a southern Neotropical species and the most common raptorial bird in the Pampean region of Argentina, where natural grasslands were completely transformed by agriculture and urbanization. We determined whether this species responds to the intensity of these human disturbances through changes in its abundance. To examine the response to agricultural intensity, both birds and land use were surveyed along 18 transects covering the regional agricultural gradient from pure arable to pure pastoral farming landscapes. To explore the effects of urbanization, birds were surveyed at 19 points along an urban—rural gradient. Results showed that chimango caracara did not respond to changes in agricultural intensity. No land use type was associated, either positively or negatively, with abundance in the arable or pastoral farming scenarios. In contrast, we observed a negative response to increasing urbanization, where a higher abundance was recorded in rural than in commercial or...

The uropygial glands of birds are sebaceous organs that contribute to the water-repellent properties of the feather coat. We studied the histological and histochemical characteristics of the uropygial gland of chimango caracara using hematoxylin and eosin (H & E), Gomorís trichrome, orcein, Gomorís reticulin, periodic acid-Schiff (PAS), Alcian blue (AB) and a variety of lectins. The gland is composed of two lobes and a papilla with 20 downy feathers. It is surrounded by a capsule of dense connective tissue that contains elastic, reticular and smooth muscle fibers. The papilla is delicate and has two excretory ducts. The gland mass relative to body mass was 0.143%. Both adenomer cells and their secretions were stained with Sudan IV, PAS and AB, and were positive for numerous lectins that indicated the presence of lipids and carbohydrates. Immunohistochemical techniques to detect PCNA confirmed cell proliferation in the basal stratum of the adenomer cells. The lipids and glycoconjugates secreted by the uropygial gland serve numerous functions including protection against microorganisms. Fil: Chiale, Maria Cecilia. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Montalti, Diego. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Flamini, Mirta Alicia. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina Fil: Fernández, P.. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina Fil: Gimeno, Eduardo Juan. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Barbeito, Claudio Gustavo. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

We studied the nesting ecology of the Chimango Caracara (Milvago chimango), a common yet poorly known raptor on Chiloe Island, southern Chile, during two breeding seasons. Deforestation and land clearing in this landscape may be benefiting this raptor, which is tolerant of open and disturbed habitats and human activity. Chimangos nested at different heights in a variety of trees and shrubs, but nests were always well concealed because they were placed centrally and in dense vegetation within the substrate. Egg laying occurred in most nests in October during both years; the most common clutch sizes were 2 or 3 eggs. The incubation and nestling periods were approximately 5 (2 nests) and 6 (1 nest) weeks, respectively. Nest success (Mayfield) for 72 nests averaged 57% for the two years. Productivity averaged 1.22 ± 0.11 fledglings per active nest and did not differ between years. For nests located during both years (n = 15), productivity was slightly higher in 1997–1998 and more nests failed in 1998–1999. Two pairs attempted to renest after nest failure but were not successful. Habitat and landscape features associated with high productivity of chimango nests included exotic trees and shrubs, tidal flats, linear forest strips, and occupied houses or barns. Successful nesting was associated with exotic trees and shrubs. Nesting density was highest along beaches, although not all pairs that built nests along beaches laid eggs. Successful nests along beaches fledged twice as many young as inland nests. Continued clearing of the rainforest in this region may provide increased foraging opportunities for this raptor but may also result in fewer nest sites.

Milvago chimango (Falconidae, Caracarinae) es una rapaz común con una extensa área de distribución geográfica en América del Sur. Esta especie se caracteriza por un comportamiento gregario y se puede observar en grupos mientras forrajea y descansa. Observamos dormideros de M. chimango en un humedal en la provincia de Buenos Aires, Argentina. En este sitio realizamos conteos mensuales de M. chimango durante tres años. Se utilizó un análisis de varianza (ANAVA) para explorar las variaciones estacionales y anuales en el dormidero, y se exploró la relación entre la abundancia de aves y la precipitación mensual. Se registró un promedio mensual de 1.004 ± 689 individuos de M. chimango en el dormidero. Se encontraron diferencias en la abundancia entre el invierno y el verano, el invierno y la primavera, y el otoño y el verano, y no se observó asociación entre la abundancia de aves y la precipitación mensual. La variación en el número podría reflejar variaciones en los comportamientos de alimentación de cada temporada, que están vinculados a las prácticas agrícolas y su dieta. Estas actividades agrícolas se llevan a cabo principalmente durante el invierno, cuando varias especies de aves se congregan. La disminución durante el verano podría estar asociada con el inicio del período reproductivo de la especie, y no con el régimen de precipitación. Este sitio dormidero también podría funcionar como un “centro de información,” donde jóvenes y adultos de M. chimango adquieren información sobre buenos sitios de alimentación o aprenden habilidades de forrajeo. Sin embargo, se necesitan más estudios para comprender la combinación de factores físicos y biológicos en la conducta de descanso comunal en esta especie. Fil: Josens, Maria Laura. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Pretelli, Matías Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Escalante, Alicia Haydee. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina

We studied object exploration and manipulative behavior in wild-caught Chimango Caracaras (Milvago chimango), an opportunistic and generalist raptor species, in relation to age and sex differences. Each bird was presented with six objects. We then recorded the latencies to approach and first contact with the objects, the number of objects explored, and the number of exploration events performed on each object. Age influenced the tendency to explore in M. chimango. Compared with adults, juveniles were more likely to explore the objects, approaching and contacting them more quickly. The number of objects explored was also higher in young than adult birds. Both age classes used a variety of manipulative behaviors to explore the objects, some of which have been described as play in others studies. Sex did not affect an individual’s likelihood to explore or the number and frequency of manipulative behaviors used during object exploration. The tendency for both young and adult birds to explore and manipulate objects that not resemble prey is likely to be a distinct advantage for a generalist species like M. chimango which must cope with a high diversity of modified environments. Fil: Biondi, Laura Marina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Guido, Jorgelina María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Madrid, Enrique Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Bó, Maria Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Vassallo, Aldo Iván. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina

Many of the mechanisms involved in visual signalling in birds are based on pigment-based plumage ornamentation and colouration rather than the expression of other, non-plumage-based displays. We have analysed the colouration of the tarsi and ceres of free-ranging Chimango Caracaras Milvago chimango, a controversial morphological trait for this species, and examined the proximal causes related to the expression of colour in these featherless body parts. The tarsi-ceres of 81 Chimango Caracaras captured in central Argentina between 2005 and 2008 were either yellow-yellow or bluish-pink coloured. Differences in colour were not linked with plasma carotenoid levels and did not vary seasonally. Rather, expression of the two colours was affected by the gender and age of individuals. Yellow-coloured tarsi and ceres were recorded only in adult males, while the remaining age and gender groups showed pinkish- and bluish-coloured bare parts, which is the suspected neutral developmental stage under low hormonal levels. These results support sexual rather than natural selection forces acting on the expression of yellow colouration in the bare parts of adult males. However, an exaggeration of yellowish colour during mating periods in accordance with an increase of circulating carotenoid levels may be expected due to the sexually-related nature of this trait. This documented partitioning of colour variation among sexes and ages that is unrelated to melanin-dependent plumages is unusual and contrary to the most widely observed types of sexual dichromatism in birds. © 2010 Dt. Ornithologen-Gesellschaft e.V.

The Caracarini falcons are among the most versatile birds of prey, and their variable diet includes fishes, which may be taken as carrion. However, fishing behaviour is described for two species. Here we describe the Chimango Caracara (Milvago chimango) fishing at an estuary in Chile, Pacific coast of South America. The caracara flew and glided close to water surface, hovering on occasions. After such a hovering, the bird plunged and attempted to snatch a prey with its talons. If successful, the caracara carried the fish in its talons and landed on an adjacent beach where the prey was torn apart and eaten. The 'glide-hover' technique of the Chimango Caracara differs slightly from the fishing recorded for the closely related Yellow-headed Caracara (Milvago chimachima), which plunges to the prey from a nearby perch ('perch to water'). The Black Caracara (Daptrius ater) picks up fish individually with its bill or talons while staying on a river bank ('ground foraging'). Thus, at least three fishing techniques are used by the Caracarini falcons, a group already known for its varied foraging techniques. Os falcões da tribo Caracarini estão entre as aves de rapina mais versáteis e sua variada dieta inclui peixes, que podem ser apanhados mortos. Todavia, comportamento de pesca está descrito para duas espécies. Descrevemos aqui o chimango (Milvago chimango) pescando num estuário no Chile, costa pacífica da América do Sul. A ave voava e planava próximo à superfície da água, pairando de quando em vez. Após este pairar, o chimango baixava rapidamente e tentava apanhar uma presa com suas garras. Se bem sucedido, o chimango carregava o peixe em suas garras e pousava numa praia próxima, onde a presa era dilacerada e consumida. A tática de 'planar-pairar' do chimango difere ligeiramente da tática de pesca adotada pelo pinhé (Milvago chimachima), espécie relacionada, que se lança sobre a presa a partir de um poleiro. O gavião-de-anta (Daptrius ater) apanha peixes individualmente com o bico ou garras, enquanto pousado na margem de um rio. Portanto, pelo menos três táticas de pesca são usadas pelos falcões Caracarini, um grupo conhecido pelas suas variadas táticas de forrageio.

Animal innovations have far-reaching ecological and evolutionary consequences. The occurrence and persistence of an innovation require several processes, including exploration, social and asocial learning, and low neophobia. In addition, the identity of the innovator may determine how these new behaviours are socially transmitted. Taking into account inter-individual and age differences, we investigated three correlates of animal innovation: object exploration, neophobia level and novel problem-solving ability in an opportunistic generalist raptor, the Chimango Caracara (Milvago chimango). Eighteen individuals (7 adults and 11 juveniles) were caught during the non-breeding period and housed in individual cages in outdoor aviaries. Each bird was given three tests: exploration, neophobia and problem-solving. Individuals differed in their response to novel situations both within and between age groups. Most of the juveniles were more explorative and had a lower neophobic response to a strange object than adult birds, but both age groups were able to solve a novel problem when given a food reward. In juveniles, neophobia level and problem-solving performance were inversely related; however, we found no relationship between these behaviours in adults. Exploration did not correlate with neophobia or problem-solving ability for either age group. This research is one of the few studies exploring the inter-individual and age differences in behavioural innovation and their correlates in a bird of prey. The explorative tendency, low neophobia and ability to innovate showed by M. chimango may be advantageous for this generalist and opportunistic raptor and might be some of the factors underlying its ecological success.

Forty-two larvae of Argas keiransi (Acari: Argasidae) were collected from the Chimango Caracara, Milvago chimango (Falconiformes: Falconidae), at three localities in La Pampa Province, Argentina. Ticks were determined by a combination of palpal segment IV as long as or longer than the other palpal segments, absence of a trumpet-shaped sensillum extending from the capsule of Haller´s organ into the lumen of the tarsus, length of dorsal plate between 180 and 240 μm, length of hypostome between 180 and 205 μm, dental formula 2/2 in the basal third, 2/2 or 3/3 apically, and length of posterolateral setae between 45 and 50 μm. Morphological determination was confirmed by analysis of sequences of the mitochondrial 16S rRNA gene. The results of this work constitute the first Argentinean record of A. keiransi, which has previously been reported only from Chile.

We studied the use of European hare (Lepus europaeus) carcasses by avian scavengers in Argentinean Patagonia. A total of 16 hare carcasses were placed in locations that could be observed without disturbing birds feeding on them. Six avian species fed on these carcasses: chimango caracara (Milvago chimango), crested caracara (Polyborus plancus), black vulture (Coragyps atratus), grey eagle-buzzard (Geranoaetus melanoleucus), red-backed hawk (Buteo polyosoma) and cinereous harrier (Circus cinereus). Turkey vultures (Cathartes aura), although abundant, never fed on the hare carcasses. The Andean condor also did not feed on the carcasses. Mammals visited hare carcasses on only two occasions. Of the hare carcasses, 69% were fully consumed during the first day of exposure and 25% in two days. There was no difference in the time elapsed from the placement of the carcass and its detection by crested and chimango caracaras. There were similar time periods from detection to first arrival, and time elapsed from first arrival to the start of feeding at the carcass by crested and chimango caracaras. Hare body parts were consumed in different proportions by crested and chimango caracaras whereas black vultures consumed the whole carcass. Interspecific hierarchies at the carcass in a decreasing sequence of dominance were crested caracara > black vulture > chimango caracara, coinciding with that expected from a body mass perspective. The scavenging species that consume hare carcasses did not show a clear pattern denoting they were a highly interdependent assemblage in the way described for scavengers in Africa

Two species of blood protozoans were identified from blood smears collected from 15 specimens of the Chimango caracara (Milvago chimango) on Isla Grande de Chiloé in southern Chile. These included Leucocytozoon toddi in 13 birds, including all 5 of the 4-6 week old nestlings examined, and 8 of the subadults or adults. One of the nestlings also had a dual infection of L. toddi and Haemoproteus tinnunculi. These are the first reports of blood parasites from M. chimango.

The topographic distribution of retinal ganglion cells and their cell body size have been studied in five Falconiform species, including predatory (chilean eagle Buteo fuscenses australis, and sparrow hawk Falco sparverius) and carrion-eating (chimango caracara Milvago chimango; condor Vultur gryphus, and black vulture Coragyps atratus) birds. All these species had a well defined nasal fovea and a horizontal streak. Instead of a temporal fovea as in eagles and hawks, an afoveate temporal area is present in chimango, condor, and vulture. The highest ganglion cell density was found in the nasal fovea of Falco and Buteo with 65,000 and 62,000 cells/mm2, respectively. A negative correlation between ganglion cell density and cell body size was found in all the species studied. The specializations of the temporal retina showed a rather homogenous population of medium sized neurons, while the nasal foveas showed a homogeneous population of smaller ganglion cells. Finally, the peripheral retina showed a heterogeneous population of large, medium, and small ganglion cells. Predatory behavior appears to be closely related to foveal specializations, and is best exemplified in the eagle and hawk and to a lesser extent in the chimango.

We observed six species of raptors: Black-chested Buzzard-eagle (Geranoaetus melanoleucus), Cinereous Harrier (Circus cinereus), Red-backed Hawk (Buteo polyosoma), Chimango Caracara (Milvago chimango), Crested Caracara (Polyborus plancus), and Peregrine Falcon (Falco peregrinus), nesting at Buff-necked Ibis (Theristicus caudatus) colonies in northern Argentinean Patagonia. Four out of these six species preyed upon Buff-necked Ibis nestlings and eggs. Ibis breeding success was not different when raptor species were present or absent from colonies. The association between raptors and ibises could be a consequence of generally low availability of colony sites where raptors are absent.