Bicolored Hawk, Accipiter bicolor in Guayaquil city (Western Ecuador): new preys-species records and citizen science urban records

Accipiter bicolor is a widely distributed Neotropical raptor but knowledge about its ecology is poor, particularly in urban areas. In this work, we document the presence of A. bicolor in the city of Guayaquil and in nearby forested areas, in addition, we provide new records on its diet and discuss possible foraging strategies in synanthropic environments. Also, reports of this species are considered on citizen science platforms. Accipiter bicolor was observed consuming an individual of Columbina bluckeyi and another of Artibeus fraterculus; near a colony of this species of bat. Finally, we found 59 records of A. bicolor between 2007 and 2022 for Guayaquil and its surrounding areas, 14 records were in urban habitats. Observations in different urban and peri-urban habitats are discussed, as well as their feeding habits.

Accipiter bicolor es una rapaz Neotropical ampliamente distribuida pero el conocimiento sobre su ecología es escaso en particular en zonas urbanas. En este trabajo, documentamos la presencia de A. bicolor en la ciudad de Guayaquil y en áreas boscosas cercanas, además, proveemos nuevos registros sobre su dieta y discutimos posibles estrategias de forrajeo en ambientes sinantrópicas. También, se consideran reportes de esta especie en plataformas de ciencia ciudadana. Accipiter bicolor fue observada consumiendo un individuo de Columbina bluckeyi y otro de Artibeus fraterculus; cerca de una colonia de esta especie de murciélago. Finalmente, se encontraron 59 registros de A. bicolor entre el 2007 y 2022 para Guayaquil y sus áreas circundantes, 14 registros fueron en hábitat urbanos. Se discute las observaciones en diferentes hábitats urbanos y periurbanos, así como sus hábitos de alimenticios.

Is a diet of Planococcus citri nymphs and adults suitable for Chrysoperla externa for use in biological control?

ABSTRACT Several studies have shown that the survival and reproduction of lacewings varies depending on the type of prey they consumed, especially during the first instar. In this study, we evaluated the effect of a diet consisting of Ephestia kuehniella (EK) and/or Planococcus-citri (PC) eggs offered to first instar Chrysoperla externa on subsequent development and survival. Larvae supplied only with P. citri (PC) nymphs had extended immature development, low survival, adults with lower weight and longevity, low fecundity and egg viability, and lower net reproduction rate (R0). Larvae submitted to the treatment EK+PC responded positively to the diet, showing results similar to those obtained in the control-EK treatment. Therefore, this mealybug supports suitable development and reproduction of C. externa when it is provided to second instar larvae after they fed on E. kuehniella eggs as first instars. As far as we know, this is the first report that demonstrates the effect of natural prey and alternatives on different larval stages of lacewings. This information is valuable in developing protocols for use of C. externaas a pest control agent.

Trophic relationship between Chrysoperla externa (Neuroptera: Chrysopidae) and Planococcus citri (Hemiptera: Pseudococcidae) associated with rose bushes

ABSTRACT This study aimed to determine the consumption of Planococcus citri (Risso, 1813) (Hemiptera: Pseudococcidae) nymphs and the predator:prey ratio required for high predatory efficacy and survival of Chrysoperla externa (Hagen, 1861) (Neuroptera: Chrysopidae) larvae under different densities of prey, reared in rose bushes. Consumption by first-, second-, and third-instar larvae of C. externa was assessed. The predatory efficiency and survival of the predator were calculated for larvae in the second instar under densities of 20, 40, 80, 120, and 160 nymphs of P. citri and predator:prey ratios of 1:5, 1:10, and 1:20. The assessments were performed after 24 and 48 hours of exposure between species. There was increasing consumption throughout the larval development of C. externa. The predator:prey ratios 1:5 and 1:10 were the most efficient for P. citri population reduction, but the 1:5 ratio led to lower survival of larvae than the 1:10 and 1:20 ratios. There was a positive correlation between C. externa larval density and cannibalism (ρ = 0.45) and a negative correlation between predator density and P. citri population density (ρ = -0.81). Third-instar larvae consume more P. citri nymphs than second-instar larvae. Second-instar larvae of this lacewing released at a 1:20 ratio caused total mortality of mealybug nymphs within 48 hours, regardless the density of P. citri, with high larvae survival of C. externa.

Inter - and intraspecific relationships between Macrosiphum rosae (Hemiptera: Aphididae) and Chrysoperla externa (Neuroptera: Chrysopidae)

ABSTRACT The predator Chrysoperla externa (Hagen, 1861) (Neuroptera: Chrysopidae) is a polyphagous species that has, among its wide range of acceptable prey, the aphid Macrosiphum rosae (Linnaeus, 1758) (Hemiptera: Aphididae), an important pest of rose plants. We assessed the consumption of nymphs and adults of M. rosae by C. externa larvae, the predatory efficiency, and larval survival under different predator:prey ratios, densities of aphids, and ages of aphids. The bioassays were performed at 25 ± 1°C and 70 ± 10% RH under a 12-hour photoperiod, with aphids taken from roses of the cultivar Avalanche. Consumption was assessed by making young aphids (2nd and 3rd instars) and more developed aphids (4th instar and adult) available throughout the larval stage of the predator. The predatory efficiency and survival were studied for second-instar larvae offered M. rosae nymphs at densities of 20, 40, 80, 120, and 160 using predator:prey ratios of 1:5, 1:10, and 1:20. The assessments were performed 24, 48, and 72 hours after putting the species together. All of the C. externa instars consumed younger than older aphids. Larvae in the third instar consumed 80% of the young aphids and 77% of the older aphids. The higher the predator:prey ratio and larval density, the higher the predatory efficiency and the lower the larval survival. The ratios 1:5 and 1:10 led to the elimination of younger and older aphid populations 72 hours into the interaction between species.

Functional activation of the periaqueductal gray matter during conditioned and unconditioned fear in guinea pigs confronted with the Boa constrictor constrictor snake

The periaqueductal gray matter (PAG) is an essential structure involved in the elaboration of defensive responses, such as when facing predators and conspecific aggressors. Using a prey vs predator paradigm, we aimed to evaluate the PAG activation pattern evoked by unconditioned and conditioned fear situations. Adult male guinea pigs were confronted either by a Boa constrictor constrictor wild snake or by the aversive experimental context. After the behavioral test, the rodents were euthanized and the brain prepared for immunohistochemistry for Fos protein identification in different PAG columns. Although Fos-protein-labeled neurons were found in different PAG columns after both unconditioned and conditioned fear situations at the caudal level of the PAG, we found greater activation of the lateral column compared to the ventrolateral and dorsomedial columns after predator exposure. Moreover, the lateral column of the PAG showed higher Fos-labeled cells at the caudal level compared to the same area at the rostral level. The present results suggested that there are different activation patterns of PAG columns during unconditioned and conditioned fear in guinea pigs. It is possible to hypothesize that the recruitment of specific PAG columns depended on the nature of the threatening stimulus.

Voracity, reaction to stings, and survival of domestic hens when feeding on the yellow scorpion (Tityus serrulatus)

Scorpionism is a worldwide problem that has already made thousands of victims, and multi-disciplinary approaches for controlling their populations are to be more successful. Hens are often mentioned as tools for controlling scorpions; however, systematic/experimental behavioral studies are not available. Moreover, there is no systematic information on the effect of scorpion venoms on hens. Using the venomous yellow scorpion Tityus serrulatus, the present study aimed to clarify the following aspects: (1) voracity of hens, (2) how hens react when stung, (3) the effect of scorpion stings on hen behavior during attacks, and (4) hen survivorship after feeding on scorpions. Methods: We attracted hens with corn powder, offered them scorpions and then recorded the hen-scorpion interaction. To test the effects of the sting we manually removed the scorpion's telson. Results: We found that some hens ate up to six scorpions within minutes. By means of an ethogram and drawings, we showed that they exhibited several aversive behaviors when capturing scorpions. Removal of the scorpion telson stopped the aversive reactions, which was not observed in the control group. Finally, hens did not exhibit atypical behaviors after 1, 7 and 30 days and were all alive after 30 days. Conclusion: This is the first empirical and video recorded study providing evidence that hens are clearly affected by scorpion venom but do not die. Therefore, they may have potential to be used in biological control of these arthropods.(AU)

Voracity, reaction to stings, and survival of domestic hens when feeding on the yellow scorpion (Tityus serrulatus)

Abstract Background: Scorpionism is a worldwide problem that has already made thousands of victims, and multi-disciplinary approaches for controlling their populations are to be more successful. Hens are often mentioned as tools for controlling scorpions; however, systematic/experimental behavioral studies are not available. Moreover, there is no systematic information on the effect of scorpion venoms on hens. Using the venomous yellow scorpion Tityus serrulatus, the present study aimed to clarify the following aspects: (1) voracity of hens, (2) how hens react when stung, (3) the effect of scorpion stings on hen behavior during attacks, and (4) hen survivorship after feeding on scorpions. Methods: We attracted hens with corn powder, offered them scorpions and then recorded the hen-scorpion interaction. To test the effects of the sting we manually removed the scorpions telson. Results: We found that some hens ate up to six scorpions within minutes. By means of an ethogram and drawings, we showed that they exhibited several aversive behaviors when capturing scorpions. Removal of the scorpion telson stopped the aversive reactions, which was not observed in the control group. Finally, hens did not exhibit atypical behaviors after 1, 7 and 30 days and were all alive after 30 days. Conclusion: This is the first empirical and video recorded study providing evidence that hens are clearly affected by scorpion venom but do not die. Therefore, they may have potential to be used in biological control of these arthropods.

Helminth and ectoparasitic faunas of the Harris's hawk, Parabuteo unicinctus (Accipitriformes: Accipitridae), in Chile: new data on host-parasite associations for Neotropical raptors / Helmintos e ectoparasitas do gavião-asa-de-telha (Accipitriformes: Parabuteo unicinctus) no Chile: novas associações parasita-hospedeiro para os rapinantes neotropicais

Abstract Birds of prey harbor a wide spectrum of various parasites, mostly with a heteroxenous life cycle. However, most reports on their parasites come from Europe. Although the Harris's hawk (Parabuteo unicinctus) is a widespread species in America, parasitological surveys on this hawk are mostly focused on coprological findings and ectoparasites, with poor attention paid to helminths. The aim of this study was to gather new and additional data on host-parasite associations for the Harris's hawk. Twenty-nine birds from central and southern Chile were necropsied. Further, nine birds from a rehabilitation center and 22 museum specimens were inspected for ectoparasites. Sixty-eight percent of birds hosted at least one parasite species. Four lice species, one mite species and eight helminth species (five nematodes, two platyhelminthes and one acanthocephalan) were recorded. Parasitic lice Colpocephalum nanum and Nosopon chanabense, and a nematode Cyathostoma (Hovorkonema) americana were recorded for the first time in raptors from the Neotropics. A feather mite, Pseudalloptinus sp., nematodes, Physaloptera alata and Microtetrameres sp., and a trematode Neodiplostomim travassosi, were recorded for the first time in Chile. The presence of diverse heteroxenous helminths reported here in the Harris's hawk could be explained by the generalist diet of this raptor.

Resumo As aves de rapina representam uma fonte importante de parasitas heteroxenos. Porém, a maioria dos relatos são da Europa. O gavião-asa-de-telha (Parabuteo unicinctus) é uma espécie amplamente distribuída no continente Americano, porém estudos parasitológicos nessas aves têm documentado achados coprológicos e ectoparasitas, com poucos relatos sobre endoparasitas como helmintos. Por essa razão, o objetivo deste estudo foi descrever novas associações parasita-hospedeiro para o gavião-asa-de-telha e rapinantes neotropicais. Vinte nove aves provenientes do centro e sul do Chile foram submetidas à necropsia. Por outro lado, nove aves de um centro de reabilitação e 22 espécimes de museu foram inspecionados em busca de ectoparasitas. Do total de aves, 68,3% foram identificadas como portadoras de pelo menos uma espécie de parasita. Quatro espécies de piolhos, um ácaro e oito helmintos (cinco nematoides, dois platelmintos e um acantocéfalo) foram registrados. Os piolhos Colpocephalum nanum, Nosopon chanabense e o nematóide Cyathostoma (Hovorkonema) americana são reportados pela primeira vez em rapinantes neotropicais. Colpocephalum nanum, N. chanabense, Pseudalloptinus sp., Physaloptera alata, Microtetrameres sp., C. (H.) americana e Neodiplostomim travassosi, são reportados pela primeira vez no Chile. A diversidade de helmintos heteróxenos, identificados neste trabalho, poderia ser explicada devido à dieta geralista do gavião-asa-de-telha.

Water column use by reef fishes of different color patterns

Color in animals responds to selective pressures and mediates the relationship between organism and environment. Reef fishes have the amplest variety of pigment cell types. This color patterns' variety may function as camouflage and be related to spatial use. We tested the hypothesis that the coloration of reef fish relates to water column stratum occupation. We predicted that sedentary animals connected to the background take advantage of background matching or disruptive patterns; more mobile demersal species apply disruptive coloration or motion-dazzle; and that pelagic species tend to have silvery bodies. We classified color patterns and categorized the water column stratum use for the Brazilian reef fishes in FishBase. Our analyses confirmed that irregular contrasting contour breaks, suggestive of disruptive coloration, occurs in benthic species and that silvering color was more prevalent in the pelagic stratum. Our raw data suggested a higher frequency of contrasting regular stripes, typical of motion-dazzle, in demersal species. However, the considerable uncertainty around estimates did not confirm this pattern. Reef fishes coloration is correlated to occupation of different strata in the water column. This can be interpreted as fishes being adapted to these habitats and partially explaining the richness of color patterns among them.(AU)

A cor nos animais responde a pressões seletivas e media a relação entre organismo e ambiente. Peixes recifais têm a maior variedade de tipos de células de pigmento. Essa variedade de padrões de coloração pode funcionar como camuflagem e estar relacionada ao uso espacial. Nós testamos a hipótese de que a coloração dos peixes recifais está relacionada à ocupação do estrato da coluna d'água. Previmos que animais sedentários conectados ao fundo aproveitam a semelhança ao fundo ou padrões disruptivos; espécies demersais mais móveis aplicam coloração disruptiva ou deslumbramento de movimento; e que espécies pelágicas tendem a apresentar corpos prateados. Classificamos os padrões de coloração e categorizamos o uso do estrato da coluna d'água para os peixes recifais brasileiros no FishBase. Nossas análises confirmaram que quebras de contorno irregulares, sugerindo coloração disruptiva, ocorrem em espécies bentônicas e que a cor prateada prevaleceu no estrato pelágico. Nossos dados brutos sugeriram uma maior frequência de listras contrastantes, típicas do deslumbramento de movimento, em espécies demersais. Mas a considerável incerteza dessas estimativas não confirmou esse padrão. A coloração dos peixes recifais está correlacionada com a ocupação de diferentes estratos da coluna d'água. Isso pode ser interpretado como peixes sendo adaptados a estes habitats, explicando em parte a riqueza de padrões de coloração entre eles.(AU)

Simulación de la dinámica de la biomasa en plancton de un embalse colombiano tropical andino de alta montaña / Simulation of biomass dynamics in plankton of a high-altitude andean tropical reservoir in colombia

ABSTRACT The understanding of the relationships between the planktonic communities in a reservoir allows us to infer possible changes in the redistribution of matter and energy flows in these systems. This work proposes a dynamic model for the trophic network of the Riogrande II tropical reservoir, which integrates the planktonic trophic chains of detritus and grazing, limiting the prey-predator interactions by introducing the prey meeting factor (pmf). We built a dynamic model of mass balance supported by an extensive bibliographic search. The limitations of consumers and resources were represented simultaneously by means of the pmf. The data used to validate the model were compiled from previous investigations carried out in this reservoir from 2010 to 2013. The values of pmf that we found in each simulation suggest that the top predator can access its main prey in certain concentrations of total phosphorus, with a probability of encounter ranging from 9.3 % to 17.7 %. Our simulations indicate that most of the primary production is poorly used by the primary consumers in the photic zone, however, it enters in the flows of the detrital chain and supports the production of zooplankton almost entirely. According to this finding, the biomass densities obtained in the previous studies can be better explained by the causal relationships assumed in this model.

RESUMEN Entender las relaciones entre las comunidades planctónicas en un embalse nos permite inferir posibles cambios en la redistribución de los flujos de materia y energía en este sistema. Este trabajo propone un modelo dinámico para representar la red trófica del embalse tropical Riogrande II, donde se integran las cadenas tróficas de pastoreo y detritus y se limitan las interacciones entre predadores, presas y recursos al introducir un factor limitante de encuentro con la presa (pmf). El modelo dinámico se enfoca en el balance de masas sustentado en una amplia búsqueda bibliográfica. Los datos usados para validar el modelo se colectaron de datos previamente reportados para el embalse durante los años 2010 y 2013. Los valores de pmf obtenidos en cada simulación, sugieren que el predador dominante puede acceder a su presa principal a ciertas concentraciones de fósforo total, con una probabilidad de encuentro que va desde 9,3 % hasta 17,7 %. Nuestros resultados indican que la mayor parte de la producción primaria es poco aprovechada por los consumidores en la zona fótica, sin embargo, ingresa en el flujo de la cadena detrítica de manera que soporta la producción de zooplancton casi por completo. Las relaciones causales asumidas en este modelo explican en gran medida las densidades de biomasa reportadas en estudios previos.

Oral Iron Supplementation in Pregnancy: Current Recommendations and Evidence-Based Medicine Suplementação oral de ferro na gravidez: recomendações atuais e medicina baseada na evidência

Abstract Objective To review the evidence about universal iron supplementation in pregnancy to prevent maternal anemia. Methods Bibliographic research of randomized and controlled clinical trials, meta-analyses, systematic reviews, and clinical guidelines, published between August 2009 and August 2019, using the MeSH terms: iron; therapeutic use; pregnancy; anemia, prevention and control. Results We included six clinical guidelines, three meta-analyses and one randomized controlled clinical trial. Discussion Most articles point to the improvement of hematological parameters and reduction of maternal anemia risk, with supplementary iron. However, they do not correlate this improvement in pregnant women without previous anemia with the eventual improvement of clinical parameters. Conclusion Universal iron supplementation in pregnancy is controversial, so we attribute a SORT C recommendation strength.

Resumo Objetivo Rever a evidência sobre a necessidade de suplementação universal de ferro na gravidez para prevenção de anemia materna. Métodos Pesquisa bibliográfica de ensaios clínicos aleatorizados e controlados, metanálises, revisões sistemáticas e normas de orientação clínica, publicados entre agosto de 2009 e agosto de 2019, utilizando os termos MeSH: iron, terapêuticas use; pregnancy; anemia, preventivos and control. Resultados Incluímos seis normas de orientação clínica, três metanálises e um ensaio clínico randomizado e controlado. Discussão A maioria dos artigos aponta para a melhoria dos parâmetros hematológicos e redução do risco de anemia materna por meio da suplementação com ferro. Conclusões A suplementação universal com ferro na gravidez é controversa, pelo que atribuímos uma força de recomendação SORT C.

First report the role of benthic macroinvertebrates as preys for native fish in Toltén river (38° S, Araucania region Chile) / Primeiro relate o papel dos macroinvertebrados como presas de peixes nativos no rio Toltén (38° S, região da Araucanía, Chile)

Abstract The Toltén river is located in the 137 years old Araucania region, Chile (38° S), and is characterized by low alterations through human interference due agriculture and towns in its surrounding basin, the presence of native fishes and salmonids, and by its lake effluent regime originated from Villarrica lake. The aim of the present study was to make a review of ecological role of the benthic inland water macroinvertebrates as preys for native fishes of the River Toltén, in order to understand their importance in the ecosystem of the river. The literature revealed that the main prey for native fishes are Chironomidae larvae, nevertheless there are not specific reports for Tolten river. The exposed results are similar with similar native species for Patagonia, and these native species would have prey for introduced salmonids, or these species would have prey competition with introduced salmonids in according to the literature descriptions for Argentinean and Chilean Patagonia.

Resumo O rio Toltén está localizado na região da Araucanía, com 137 anos de idade, Chile (38° S), e é caracterizado por baixas alterações por interferência humana devido à agricultura e cidades da bacia circundante, pela presença de salmonídeos e pelo regime de efluentes dos lagos. do lago Villarrica. O objetivo do presente estudo foi fazer uma revisão do papel ecológico dos macroinvertebrados bentônicos de águas interiores do rio Toltén, a fim de entender sua importância no ecossistema do rio. A literatura revelou que as principais presas de peixes nativos são as larvas de Chironomidae, no entanto, não há relatos específicos para o rio Tolten. Os resultados expostos são semelhantes com espécies nativas semelhantes para a Patagônia, e essas espécies nativas teriam presa por salmonídeos introduzidos, ou essas espécies teriam competição de presas com salmonídeos introduzidos de acordo com as descrições da literatura para a Patagônia Argentina e Chilena.

PREDATORY INTERACTION BETWEEN TWO ANURAN SPECIES WITH Thamnodynastes chaquensis (COLUBRIDAE) IN THE BRAZILIAN CERRADO / Interacción depredatoria entre dos especies de anura con Thamnodynastes chaquensis (Colubridae) en el Cerrado brasileño

ABSTRACT Although predatory events are uncommon to be recorded in nature, these data are important tools for understanding prey-predator interaction of the involved species. Snakes of genus Thamnodynastes are known for having an anuran diet, including some species of hylid frogs in their diet. Despite this, this pattern does not include T. chaquensis since there are no records on predation or trophic interaction with hylid frogs. Here, we report the first predatory interaction between T. chaquensis and two hylid frogs in Brazilian Cerrado. The first predation event with treefrog Boana caiapo occurred with success but, the second with B. albopunctata did not. Connecting trophic links within an ecosystem requires in-depth knowledge of its species and their intraspecific interactions. In this context, records of the predation and predation attempts such as these may help to connect unknown trophic links, which helps to understand aspects of the natural history of the species involved.

RESUMEN Aunque los eventos depredatorios son poco comunes de registrar en la naturaleza, estos datos son herramientas importantes para comprender la interacción presa-depredador de las especies involucradas. Las serpientes del género Thamnodynastes son conocidas por su dieta basada en anuros y, aunque algunas especies incluyen ranas hílidas en su dieta, esto no ocurre en la especie T. chaquensis porque no hay registros de depredación o interacción trófica con los hílidos. Aquí informamos sobre la primera interacción depredatoria entre T. chaquensis y dos ranas hílidas del Cerrado brasileño. El primer evento de depredación con la rana Boana caiapo fue exitoso, pero el segundo con B. albopunctata no. Conectar los enlaces tróficos dentro de un ecosistema requiere conocer íntimamente sus especies y sus interacciones intraespecíficas. En este contexto, los registros de depredación y de intentos de depredación como estos pueden ayudar a conectar enlaces tróficos no conocidos, lo cual ayuda a comprender los aspectos de la historia natural de las especies involucradas.

The devil is coming: Feeding behavior of juvenile Munk's devil rays (Mobula munkiana) in very shallow waters of Punta Descartes, Costa Rica

Introduction: Identifying critical habitats for vulnerable elasmobranch species is crucial for effective conservation measures. The Munk's devil ray (Mobula munkiana) is endemic to the Eastern Pacific, but yet little is known about its biology, ecology, and habitat use. As filter feeders, it is assumed that this species concentrates at high-productive upwelling regions, such as the Costa Rican Dome. Like many elasmobranchs, its populations are highly depleted and require urgent information to inform better conservation measures. Objective: The study was conducted to gain information on a unique behavior observed in juvenile M. munkiana, so further information can be provided on early life stages of this vulnerable species. Methods: From June to September 2017 and in August 2018, the feeding behavior of juvenile Mobula munkiana was observed in two shallow bays located at Punta Descartes, North Pacific Costa Rica. Individuals were captured using a non-lethal method to obtain data on size, weight, and sex distribution. Plankton samples (n = 100) were taken at both bays throughout the months to infer diet composition. Results: Munk's devil rays showed a repetitive swimming movement parallel to the beach, feeding exclusively in the shallow breaking zone of the low tide waves at depth <50cm. A total of 12 M. munkiana (11 live and one found dead) indicated a juvenile feeding aggregation ranging from 490 - 610mm in disk width and 1400 - 2300gr in weight. The sex ratio (males to females) was 3:1. Zooplankton of the order Mysidacae was found in the highest abundance in the breaking zone. Conclusions: The specific behavior and seasonal occurrence of juvenile Munk's devil rays in this area seem to be driven by prey abundance. More research is needed to conclude the presence of reproductive adults at deeper depths and the year-round habitat use of Punta Descartes. The area is threatened by unsustainable development and requires realistic management strategies to guarantee the survival of vulnerable species and their critical habitats.

Introducción: La identificación de hábitats críticos para especies vulnerables de elasmobranquios es crucial para tomar medidas de conservación efectivas. La manta diablo o raya de Munk (Mobula munkiana) es endémica del Pacífico Oriental y se sabe poco sobre su biología, ecología y uso de hábitat. Como filtradores, se asume que se concentran en regiones de afloramiento con alta productividad; sus poblaciones se consideran en disminución y requieren información urgente para fundamentar medidas de conservación. Objetivo: El estudio se realizó para obtener información sobre un comportamiento de alimentación observado en juveniles de M. munkiana, con el fin de proporcionar más información sobre las primeras etapas de vida de esta especie considerada vulnerable a la extinción. Métodos: De junio a setiembre de 2017 y en agosto de 2018, se observó el comportamiento de alimentación de los juveniles de M. munkiana en dos bahías poco profundas de Punta Descartes, en el Pacífico norte de Costa Rica. Los individuos fueron capturados utilizando un método no letal para obtener datos sobre el tamaño, peso y sexo. Se tomaron 100 muestras de plancton en las bahías para inferir la composición de la dieta. Resultados: Las rayas mostraron un comportamiento de natación repetitivo paralelo a la playa, alimentándose exclusivamente en la zona de rompimiento de las olas en marea baja, a menos de 50 cm de profundidad. Un total de 12 rayas M. munkiana (11 vivas y una encontrada muerta) indicaron una agregación de juveniles para alimentarse. Los anchos de disco variaron de 490 a 610 mm y el peso entre 1400 a 2300 g. La proporción sexual (machos: hembras) fue de 3:1. En la zona donde rompían las olas se encontró principalmente el orden Mysidaceae. Conclusiones: El comportamiento específico y la ocurrencia estacional de M. munkiana en la zona de estudio parecen estar impulsados por la abundancia de presas. Se necesita más investigación para concluir la presencia de adultos reproductivos a mayor profundidad y sobre el uso de hábitat en los alrededores de Punta Descartes durante todo el año. Esta área se encuentra amenazada por un desarrollo insostenible y requiere estrategias de manejo realistas para garantizar la supervivencia de especies vulnerables y sus hábitats críticos.

Feeding habits of the Robber Frog Pristimantis paulodutrai (Bokermann, 1975) in northeastern Brazil / Hábitos alimentares da rã Pristimantis paulodutrai (Bokermann, 1975) no nordeste do Brasil

Abstract: Studying feeding habits is crucial to understand complex predator-prey interactions. Even though anurans play a fundamental role in the control of arthropods populations, the diet of several Neotropical species is poorly known. We describe the frequency and occurrence of prey items and their dry mass in stomach contents of the Robber Frog Pristimantis paulodutrai in the north east of the state of Bahia, Brazil. Based on the stomach contents of 30 individuals, Araneae, Isopoda, and Formicidae were found to be the most important food items. The generalist diet of this frog, which seems to be phylogenetically conserved among Pristimantis, is likely to be linked to its ecological dominance in the habitats surveyed. Our study corroborates the high trophic relevance of Robber Frogs in tropical forests as generalist predators.

Resumo: Estudar hábitos alimentares é crucial para entender as complexas interações predador-presa. Embora os anuros tenham papel fundamental no controle das populações de artrópodes, a dieta de várias espécies neotropicais é pouco conhecida. Descrevemos a frequência e a ocorrência de presas e sua massa seca no conteúdo estomacal da rã Pristimantis paulodutrai, no nordeste do estado da Bahia, Brasil. Com base no conteúdo estomacal de 30 indivíduos, Araneae, Isopoda e Formicidae foram os itens alimentares mais importantes. A dieta generalista desta rã, a qual parece ser conservada filogeneticamente entre os Pristimantis, provavelmente está ligada à sua dominância ecológica nos habitats pesquisados. Nosso estudo corrobora a alta relevância trófica dos Robber Frogs em florestas tropicais como predadores generalistas.

Network prediction of the potential molecular mechanisms in birds of prey exposed to organochlorine pesticides / Red de predicción de potenciales mecanismos moleculares en aves de presa expuestas a pesticidas organoclorados

Abstract In the 1960s, organochlorine compounds were responsible for the decline of birds of prey populations such as Haliaee- tus leucocephalus and Falco peregrinus. Pesticides similar to DDT cause bioaccumulation in birds, affecting their eggshell com- position and compromising their development. Using system biology tools, the goal of this study was to better comprehend how organochlorines act on birds. We performed a literature review, using the STITCH 5.0 platform, searching for the terms DDT and TCDD. The sub-networks were amplified in 100 interactions in STRING 10.5 and joined by the Cytoscape 3.4.0 Merge software, using the experimental animal model Gallus gallus. Clusterization, gene ontology, and centrality were the parameters evaluated in the resulting network. The resulting network had 1,417 interactions and 137 nodes. The clusterization indicated four clusters and the gene ontology pointed to biological processes related to cell signaling and morphological development. The centrality analysis indicated ESR1 and HSP90AB1 as hub/bottleneck proteins involved in the estrogen pathway and calcium transport. Therefore, it is possible that HSP90 proteins have increased expression in birds contaminated with organochlorine pesticides, favoring ESRI-organochlorines interaction and disturbing the calcium availability related to the eggshell formation. The presence or absence of heat shock proteins, such as HSP90, influences several aspects of reproduction in many species. Therefore, the relationship between the HSP90 protein expression and thin-shell syndrome was identified for the first time in this in silico study.

Resumen En los años 60, los organoclorados fueron responsables del declive de aves de rapiña como Haliaeetus leucocephalus y Falco peregrinus. Pesticidas como el DDT, causan biomagnificación en las aves, afectando las cáscaras de los huevos y dañando su desarrollo. El objetivo de este trabajo fue, a través de herramientas de biología de sistemas, comprender cómo los organoclorados actúan en el organismo de las aves. A través de una revisión bibliográfica se incluyeron dos compuestos, DDT y TCDD. Estos fue ron prospectos en la plataforma STITCH 5.0. Las subredes encontradas fueron aumentadas en 100 interacciones en la plataforma STRING 10.5 y unidas por la herramienta Merge del programa Cytoscape 3.4.0, usando el modelo experimental Gallus gallus. En la red resultante se analizaron la clusterización, la ontología génica y la centralidad. La red resultante presentó 137 nudos y 1.417 interacciones. El análisis de clusterización indicó 4 clusters, siendo que el análisis y ontología génica apuntó procesos biológicos ligados a la señalización y al desarrollo morfológico. El estudio de centralidad apuntó a ESR1 y HSP90AB1 como los hubs-bottle- neck proteínas que estaban involucradas en la vía de recepción de estrógeno y en el transporte de calcio. De acuerdo con los resultados podemos inferir que las proteínas HSP90 tienen su expresión aumentada, en aves contaminadas con pesticidas organoclo rados, favoreciendo la interacción entre ESRI y DDT / TCDD. Con ello, la interacción ESRI y la hormona estrógeno se compromete perjudicando el transporte de calcio y consecuentemente la formación de la cáscara del huevo en aves expuestas. La expresión de proteínas de choque térmico ha sido asociada a varios aspectos de la reproducción en muchas especies, sin embargo, una asociación entre HSP90 y el síndrome de la cáscara fina del huevo fue identificada por primera vez en este experimento in silico.

Fatal asphyxia due to laryngeal displacement by large-sized prey in a Guiana dolphin (Sotalia guianensis), Brazil / Asfixia por deslocamento laríngeo associado a consumo de presa de grande tamanho em boto-cinza (Sotalia guianensis), Brasil

ABSTRACT: The Guiana dolphin (Sotalia guianensis) is a small odontocete distributed from Santa Catarina state, Brazil, to Honduras. Although it is currently considered "near threatened" by the International Union for Conservation of Nature, considerable knowledge on health and disease aspects of this species has been gained over the last decade. The main threats for the species are represented by multiple anthropic factors. Guiana dolphins feed on a variety of taxa, primarily teleosts, crustaceans, and cephalopods. Herein, we reported a case of severe laryngeal displacement and esophageal impaction with ulceration associated with a deglutted adult leatherjacket (Oligoplites sp.). This fish species is not a common prey item of Guiana dolphins' diet. Severe upper aerodigestive compromise likely led to death by mechanical asphyxia (choke) in this dolphin. This report attested the occurrence of upper aerodigestive dysfunction due to overzealous feeding in Guiana dolphin and contributed to general knowledge on pathology of the species.

RESUMO: O boto-cinza (Sotalia guianensis) é um pequeno odontoceto que ocorre desde o estado de Santa Catarina, Brasil, até Honduras. Embora esta espécie seja considerada "quase ameaçada" pela União Internacional para a Conservação da Natureza, um considerável conhecimento sobre diversos aspectos de saúde e doença nesta espécie foi adquirido na última década. As principais ameaças para a espécie são representadas por múltiplos fatores antrópicos. Os botos-cinza se alimentam de uma variedade de táxons, incluindo principalmente teleósteos, crustáceos e cefalópodes. No presente estudo relatamos um caso de deslocamento laríngeo grave e impactação esofágica com ulceração pela deglutição de um peixe adulto do gênero Oligoplites. Esta espécie de peixe não é um elemento comum da dieta dos botos-cinza. É possível que o comprometimento aerodigestivo grave tenha levado o animal à morte por asfixia mecânica. Este relato atesta a ocorrência de disfunção aerodigestiva superior devido à alimentação de tamanho excessivo por um boto-cinza, e contribui para o conhecimento geral de patologias na espécie.

Stability analysis of a prey refuge predator–prey model with Allee effects

We constructed a discrete-time predator–prey model by adding prey refuge and Allee effects (predator saturation on preyand mate limitation on predator) to an earlier prey–predator model and examined its dynamics. We show the existence ofpositive fixed points and study the stability properties. The numerical simulations and bifurcation diagrams verify theimpact of refuge and the Allee mechanism on the system.

Escape o sea presa: nuevos registros y conocimiento actual sobre depredadores de ranas Pseudinae (Anura: Hylidae) en América del sur / Escape or be preyed: new records and current knowledge on predators of pseudinae frogs (anura: hylidae) in south america

ABSTRACT Neotropical amphibians play important roles as preys and predators in freshwater and terrestrial ecosystems. The subfamily Pseudinae includes small and medium-sized frogs within three genera representing 13 valid species. Most published records of predation on Pseudinae frogs are anecdotic and scarce. Herein, we provide five new reports of predation and presenting a detailed literature review on Pseudinae predation, with 15 studies published between 1983-2017. Pseudinae species were preyed at both day and night by a wide variety of predators, principally birds. Adults were preyed upon more frequently than juveniles and tadpoles. In the present study, most predators were diurnal, with birds accounting for most records. A variety of invertebrates prey on anurans, but water bugs and spiders are the most common ones. In the present study, water bugs comprised 75 % of the Pseudinae predation records by invertebrates. However, anuran predation by invertebrates remains poorly documented. Thus, the description of new cases of predation accompanied by a review of the data available in the literature is crucial to understanding Neotropical food webs.

RESUMEN Los anfibios neotropicales desempeñan papeles importantes como depredadores y presas en los ecosistemas dulce acuícolas y terrestres. La subfamilia Pseudinae incluye ranas pequeñas y medianas, distribuidas en tres géneros y representando 13 especies válidas. Los registros de depredación de Pseudinae son escasos y anecdóticos. Por lo tanto, el conocimiento de nuevos casos puede mejorar nuestra comprensión de las relaciones depredador-presa entre estas ranas y su papel en la cadena trófica. Presentamos cinco nuevos registros de depredación y revisamos los casos de depredación de la literatura, que incluyen 15 estudios publicados entre 1983 y 2017. Las especies de Pseudinae son depredadas, tanto durante el día como en la noche, por una gran variedad de depredadores, principalmente aves. Los adultos son más frecuentemente depredados que los juveniles y los renacuajos. En el presente estudio, las chinches de agua representan 75 % de los registros de depredación de Pseudinae por invertebrados. Sin embargo, depredación de anuros por invertebrados permanece poco documentada. Por lo tanto, la descripción de nuevos casos de depredación, junto a una revisión de los datos disponibles en la literatura es crucial para entender redes tróficas neotropicales.

Insights into the development of a juvenile harpy eagle's hunting skills / Considerações sobre o desenvolvimento da habilidade de caça de um gavião-real juvenil

The post-fledging period is of paramount importance for raptors, since this is when a juvenile develops its hunting skills and gains the abilities required in adulthood and independence through dispersal. Little is known however, about this stage in the lives of raptors such as harpy eagles, Harpia harpyja. Between March 2016 and July 2017, we recorded three predation attempts on groups of primates by a wild juvenile harpy eagle in southwestern Brazilian Amazonia, including the first predation of an adult squirrel monkey, Saimiri ustus. These sequential records give insights into the gradual development of hunting skills during the post-fledging period, similar to what has been reported for other birds of prey. We hypothesize that a link between developing flight skills, decreasing parental food provisioning and increasingly successful captures triggers adulthood and independence in harpy eagles. (AU)

O período pós-emplumagem é de suma importância para os rapinantes, pois é quando um jovem desenvolve a habilidade de caça necessária na idade adulta e a independência por meio da dispersão. Entretanto, pouco se sabe sobre esse estágio na vida de rapinantes como o gavião-real, Harpia harpyja. Entre março 2016 e julho 2017, três tentativas de predação sobre grupos de primatas por um gavião-real juvenil foram registradas no sudoeste da Amazônia brasileira, incluindo a primeira predação de um macaco-de-cheiro adulto, Saimiri ustus. Estes registros sequenciais indicam um desenvolvimento gradual da habilidade de caça ao longo do período de pós-emplumagem, de forma similar ao relatado para outros rapinantes. Hipotetizamos que a associação entre o desenvolvimento da habilidade de voo, diminuição do provisionamento pelos pais e aumento da taxa de capturas bem-sucedidas promove a maturidade e independência no gavião-real.(AU)