ABSTRACT Congeneric species have similarities in phenotypic and ecological traits. The sympatry of congeneric species constitutes an opportunity for studies on coexistence. Two bird species of Mimidae, the native Tropical mockingbird, Mimus gilvus Oberholser, 1919, and the restinga invader Chalk-browed mockingbird, Mimus saturninus (Lichtenstein, 1823), currently occur in sympatry across the sandy-coastal ecosystem (restinga) of Espírito Santo state, Southeastern Brazil. We studied the spatial distribution of Tropical mockingbird and Chalk-browed mockingbird to understand the degree of competition across a preserved and urban gradient. We sampled 1,451 sampling units across a preserved and urban landscape in a coastal area of southeastern Brazil. The best-fitting model for abundance (Punctual Abundance Index) included urbanization index, distance from the coast, and distance from the closest protected area, which explained 63% and 97% of the abundance of Tropical mockingbird and Chalk-browed mockingbird, respectively. The species exhibited a segregated spatial pattern at small scale, indicating that both species are avoiding one another. Chalk-browed mockingbird showed ecological plasticity in modified environments, whereas Tropical mockingbird was more sensitive to urbanization. We suggested that the coexistence of these species is associated with resource partitioning. Monitoring Tropical mockingbird populations may be a proxy for the assessment of habitat quality and restoration success in the highly threatened restinga ecosystem.

Los parásitos de las aves pueden ejercer una presión selectiva importante en las poblaciones de sus hospedadores, aunque su impacto puede variar dependiendo de las condiciones ambientales. Las moscas Neotropicales del género Philornis incluyen especies cuyas larvas son parásitas de los pichones de diversas especies de aves. En este estudio se analiza la prevalencia de moscas parásitas en especies de paseriformes que nidifican en una zona semiárida del Monte central de Argentina, durante cuatro temporadas reproductivas con condiciones climáticas contrastadas. Específicamente se cuantifica la prevalencia en los distintos hospedadores, su variación anual y estacional, la influencia de las precipitaciones, de la disponibilidad de hospedadores y el efecto del parasitismo en la mortalidad de los pichones. Se observó parasitismo por estas moscas en 8 de las 21 especies de paseriformes en las que se pudo seguir el desarrollo de los pichones. La prevalencia para estas especies fue, en promedio, del 15%, afectando principalmente a especies de Thraupidae (21%), Mimidae (14%) y Tyrannidae (7%). Las moscas parasitaron pichones al final de la temporada reproductiva en dos de las cuatro temporadas analizadas, que coincidieron con mayores precipitaciones al final de la primavera. Las condiciones ambientales también favorecieron una mayor disponibilidad de hospedadores. La mortalidad de pichones por causa del parasitismo de las larvas ocurrió en el 10% de los nidos parasitados. Los resultados indican que la prevalencia de este parasitismo es relativamente baja en el Monte central, y que está asociada a condiciones húmedas al final de la primavera, afectando principalmente a las especies que nidifican más tarde dentro de la temporada reproductiva. Sin embargo, los escenarios futuros de cambio global podrían incrementar el efecto negativo de estos parásitos, especialmente en aves hospedadoras con problemas de conservación.

Avian parasites may exert an important selective pressure on host populations, although their impact may vary depending on environmental conditions. The Neotropical flies of the genus Philornis include species whose larvae parasitize the nestlings of several bird species. Here, I analyze the prevalence of parasitic flies in passerine species nesting in a semiarid area in the central Monte of Argentina, during four breeding seasons with contrasting weather conditions. Specifically, I quantify the prevalence in different avian hosts, its inter-annual and seasonal variation, the influence of precipitation and host availability, and the effect of parasitism on nestling mortality. Botfly parasitism was observed in 8 of the 21 passerine species for which nestling development could be followed. Prevalence for parasitized species was, on average, 15%, mainly affecting species in Thraupidae (21%), Mimidae (14%), and Tyrannidae (7%). Botfly parasitism occurred at the end of the breeding season in two of the four years studied, coinciding with increased late spring precipitations. Environmental conditions also favored greater host availability. Nestling mortality due to botfly parasitism was found in 10% of parasitized nests. Results indicate that the prevalence of botfly parasitism is relatively low in the central Monte, and it is positively related to wet conditions during late spring, mainly affecting avian species that breed later in the season. However, future global change scenarios could increase the negative effect of this parasite, particularly in host species of conservation concern.

ABSTRACT This study describes aspects of the life history of the Tropical Mockingbird Mimus gilvus (Vieillot, 1808), including the breeding period, clutch size, nestlings and a list of plants used for nesting. Nests were monitored in an area of Restinga (sand-coastal plain) habitat in a protected area in southeastern Brazil. The data from 181 nests during five breeding seasons (2010-2014) showed that the Tropical Mockingbird has a long breeding season (26.1 ± 2.6 weeks) with up to two peaks of active nests from August to March. The breeding pairs made up to four nesting attempts in the same breeding season. The mean (± SD) clutch size was 2.4 ± 0.6 eggs (n = 169). The mean (± SD) incubation period was 14 ± 0.6 days, and the nestling remained in the nest for 14.5 ± 2.2 days. The nests were built on thirty plant species, and Protium icicariba (DC.) Marchand. was the plant species most commonly used for nesting. The breeding parameters of the Tropical Mockingbird are similar to those of other Mimidae species. The knowledge gained from this study makes the Tropical Mockingbird a good choice for future studies, particularly for testing ecological and evolutionary hypotheses regarding life history attributes, habitat selection and parental investment.

Resumen En el presente estudio reportamos características morfométricas y reproductivas del dzibabán, Melanoptila glabrirostris, algunas de ellas descritas por primera vez. El dzibabán es un mímido tropical endémico de la península de Yucatán muy poco estudiado. El estudio lo realizamos en la costa norte de la Reserva de la Biosfera de Sian Ka’an, México, entre febrero y agosto de 2008. Presentamos medidas de culmen, tarso y masa corporal. Proponemos un método de sexado válido durante la temporada no reproductiva, ya que los machos presentaron longitud de cuerda alar mayor que las hembras. La coloración del ojo puede ser un criterio suplementario para determinar la edad, puesto que los individuos de segundo año presentaron frecuentemente coloración ocular marrón, similar a los individuos de primer año. La temporada reproductiva inicia en abril y termina a mediados de agosto. El ciclo del nido es de 27 y 32 días y el tamaño de nidada es de dos a tres huevos. El macho construye la mayor parte del nido y la hembra incuba los huevos. La mayoría de los nidos se construyó en la palma Thrinax radiata y el arbusto Pithecellobium keyense. En conclusión, el dzibabán comparte características similares con Dumetella carolinensis y las principales diferencias son debidas a su distribución tropical.

Abstract In the present study, we report morphometric and reproductive characteristics of the Black Catbird, Melanoptila glabrirostris, some of them shown here for the first time. The Black Catbird is a tropical mimid endemic to the Yucatán Peninsula that is not well studied. Fieldwork was conducted in the North coast of the Sian Ka’an Biosphere Reserve, México, from February to August 2008. We present measurements of bill, tarsus, and body mass. We propose a method for sexing outside the breeding season because males had longer wing chords than females. We demonstrate that eye color can be an extra criterion for age determination because second-year birds more frequently had brown eyes, similar to the eye color of hatch-year birds. Breeding season lasted from April until at least the middle of August. The nest cycle was 27 to 32 days long, and clutch size was from two to three eggs. Mostly males built nests and females incubated the eggs. Most of the nests were built on Thrinax radiata palm and Pithecellobium keyense bush. In conclusion, the Black Catbird shares characteristics with Gray Catbird, and the main differences are due to its tropical distribution.

Foi estudada a guilda de aves que consomem frutos de Miconia albicans (Melastomataceae), bem como a fenologia dessa planta, em fragmento de cerrado no sudeste do Brasil. O período de frutificação ocorreu entre outubro e janeiro, coincidindo com a estação chuvosa. Dezenove espécies de aves, a maioria com dieta generalista, foram registradas consumindo frutos em 96 horas de observações. Espécies das famílias Emberizidae, Thraupidae e Tyrannidae apresentaram o maior número de visitas, enquanto aquelas das famílias Mimidae e Columbidae, de maior massa corporal, sobressaíram-se pelo número de frutos consumidos. Foi encontrada correlação entre massa corporal e consumo médio de frutos por visita. A altura das árvores foi um fator relevante na atração de aves. Os resultados sugerem que M. albicans pode ser útil na recuperação de áreas degradadas.

The avian guild that consumes Miconia albicans (Melastomataceae) fruits and its phenophases were studied in a fragment of cerrado vegetation located in southeastern Brazil. The fruiting period ocurred between October and January, coinciding with the wet season. Nineteen bird species, mainly of generalistic diets, were registered consuming fruits in 96 observational hours. Species of the families Emberizidae, Thraupidae and Tyrannidae showed the largest number of visits, while those of the families Mimidae and Columbidae, with higher body mass, were responsible for a considerable number of consumed fruits. A correlation was found between body mass and average fruit consumption per visit. Tree height was a relevant factor for bird attraction. Results suggest that M. albicans may be useful in the recovery of degraded areas.

Se realizó un inventario de enemigos naturales del chapulín (Orthoptera: Acridoidea) como resultado de observaciones hechas a través de la exploración, muestreos de ootecas, ninfas y adultos que se llevaron a cabo de 2002 a 2007 en 11,242 ha de 101 comunidades de 11 municipios del sur del Estado. Se examinaron 1620 ootecas y 8122 chapulines identificando tres especies de hongos entomopatógenos, un parasitoide y cinco depredadores. Se encontraron larvas de Epicauta spp. (Coleoptera: Meloidae) depredando ootecas de Melanoplus differentialis Thomas (Orthoptera: Acridoidea) y dos aves, Mimus polyglottos L. y Toxostoma curvirostre Swainson (Passeriformes: Mimidae) alimentándose de estadios ninfales o adultos de especies pequeñas. Se observaron estadios ninfales en la telaraña de Neoscona spp. (Araneae: Araneidae). Un depredador muy activo de ninfas pequeñas en las horas mas calientes del día fue el "moscón" Efferia spp. (Diptera: Asilidae). Se encontró a Sarcophaga spp. (Diptera: Sarcophagidae) en M. differentialis como huésped. Se observaron tres especies de hongos, Beauveria bassiana Balsamo (Hypocreales: Cordycipitaceae), Metharizium anisopliae Metschnikoff (Hypocreales: Clavicipitaceae) en todos los estadios y Entomophaga grylli Fresenius (Entomophthorales: Entomophthoraceae) en adultos de M. differentialis como hospedero, ocasionando epizootias con un buen nivel de infección.

We performed an inventory of natural enemies of grasshopper (Orthoptera: Acridoidea) as a result of observations made through exploration, sampling of egg pods, nymphs and adults were conducted from 2002 to 2007 in 11,242 ha of 101 communities in 11 municipalities of Southern Queretaro. 1620 egg pods were reviewed and 8122 grasshoppers; three species of entomophatogenis were identified, a parasitoid and five predators. Epicauta spp. (Coleoptera: Meloidae) larvae were found preying egg pods of Melanoplus differentialis Thomas (Orthoptera: Acridoidea) and two birds, Mimus polyglottos L. and Toxostoma curvirostre Swainson (Passeriformes: Mimidae) feeding nymphs or adults of small species. Nymphs were observed in the web of Neoscona spp. (Araneae: Araneidae). A very active predator of small nymphs during the hottest hours of the day was the blowfly Efferia spp. (Diptera: Asilidae). We found Sarcophaga spp. (Diptera: Sarcophagidae) in M. differentialis as a host. There were three species of fungus, Beauveria bassiana Balsamo (Hypocreales: Cordycipitaceae), Metharizium anisopliae Metschnikoff (Hypocreales: Clavicipitaceae) in all stages and Entomophaga grylli Fresenius (Entomophthorales: Entomophthoraceae) in adults of M. differentialis as a host, causing epizooties with a good level of infection.

Reportamos, por primera vez en México, la presencia de un individuo adulto de cuitlacohe pico curvo (Toxostoma curvirostre) con leucismo parcial. El individuo lo observamos del 2007 al 2010 en el campus principal de la Universidad Autónoma del Estado de Hidalgo, en la ciudad de Pachuca, Hidalgo.

We present the first report for Mexico of partial leucism in Curve-billed Thrasher (Toxostoma curvirostre). We observed the individual from 2007 to 2010 in the main campus of Universidad Autonóma del Estado de Hidalgo, in the city of Pachuca, Hidalgo.

En el presente estudio se describen los parámetros hematológicos para la especie Mimus gilvus en cautiverio. Se tomaron 45 muestras de sangre a 12 aves (6 hembras y 6 machos), durante cuatro periodos con intervalos de 21 días, dos de ellos en la temporada de lluvias y los otros dos en la temporada de calor; con el fin de determinar las diferencias existentes según las variables sexo, y estados climáticos. Se estableció que no hay diferencias hematológicas según el sexo de las aves, pero se encontró que existe una diferencia significativa entre los periodos climáticos en las medias muestrales de los indicadores: hematocrito, hemoglobina, concentración de hemoglobina corpuscular media, hemoglobina corpuscular media, volumen corpuscular medio y recuento total de plaquetas. No se encontró diferencia en el recuento total de eritrocitos, ni en el recuento total de leucocitos mostró cambios. Se encontró diferencia significativa en el recuento diferencial de leucocitos en estos dos periodos en las medias de los basófilos y eosinófilos. Son aportados valores de referencia para valores hematológicos en esta especie.

The present study describes hematologic parameters for the Mimus gilvus species in captivity. 45 blood samples of 12 birds (6 male and 6 female) were taken, during four periods with intervals of 21 days, two of them during the rainy season and the other two during the dry season, in order to determine the existing differences depending on the sex variables and the weather conditions. It was established that there are no hematological differences regarding the birds' sex, but it was found that there is a significant difference between the weather periods in the sample media of the indicators: hematocrit, hemoglobin, mean corpuscular hemoglobin concentration, mean corpuscular volume and total platelet count. Neither the difference in the total erythrocyte count was found nor the total leukocyte count showed changes. A significant difference was found in the differential count of leukocytes in these two periods in the basophils and eosinophils media. Reference values are provided for hematological values in this species.

Four pairs of the poorly understood tropical mockingbird Mimus gilvus were captured and color banded at a grassland in Maracaibo, Venezuela in June 1997. Throughout the following 8 months, individuals were observed two days per week for 4 hours each. We recorded courtship behaviour, nest construction, incubation, parental care, territory defense and timing of reproductive cycle. Pairs lived in defined territories defended primarily by the male. Both sexes participated in nest building which began at the start of two rainy seasons: April and October. Between April and June, 80 % of nests were parasited by the shiny cowbird (Molothrus bonariensis). No parasitism was recorded in the later nesting season. Consequently, breeding success for the April and October seasons was 20 % and 83 % respectively. Only the female incubated and the mean clutch size was 2.2 eggs

Se estudiaron aspectos básicos de la reproducción de la paraulata llanera Mimus gilvus en el campus de la Universidad del Zulia, en Maracaibo, Venezuela. Se capturaron y marcaron cuatro paraulatas con anillos de colores (junio 1997). Estas aves fueron observadas dos veces por semana en dos períodos de observación de dos horas cada uno. Se registró el comportamiento de cortejo, construcción de nidos, incubación y cuidado parental, frecuencia de la defensa territorial y la duración del ciclo reproductivo. Se buscaron nidos semanalmente de los cuales se registró la altura (del nido y árbol), la especie de árbol y tamaño de la nidada. Se determinó el tamaño medio y el éxito de la nidada. Las paraulatas iniciaron la construcción de nidos en concordancia con los períodos de lluvia (abril y octubre). El 80 % de los nidos fueron parasitados por el tordo mirlo Molothrus bonariensis en el período reproductivo de abril-junio, mas no en octubre-noviembre. Las paraulatas fueron observadas en parejas en territorios definidos. Ambos sexos construían el nido, pero solo la hembra incubaba y era principalmente el macho el que defendía el territorio. El tamaño medio de la nidada fue de 2.2 huevos. El éxito reproductivo en los periodos de abril y octubre fue de 20 % y 83 % respectivamente

Hortia brasiliana Vand. (Rutaceae) é um arbusto comum em áreas de cerrado na região de Uberlândia, MG. Os indivíduos atingem de 0,5 a 2,0 m de altura e possuem flores de cor rósea e consistência coriácea, reunidas em densas inflorescências umbeliformes, terminais, com eixos resistentes. A antese ocorre ao longo do dia ou da noite e pode durar de 25 minutos a 3 horas, dependendo da temperatura. A flor é protândrica e produz ca. de 60 µl de néctar, cuja concentração de açúcares varia de 24 a 32%. A espécie é autocompatível. As flores são visitadas por seis espécies de aves Passeriformes das famílias Fringillidae, Thraupidae e Mimidae, que foram consideradas polinizadores efetivos. Este tipo de polinização por pássaros pousadores é inédita para o cerrado. Os pássaros visitavam as flores receptivas de 04:30h até 08:30 h, em busca de néctar, e após este horário eram expulsos pelas abelhas Trigona spinipes (Apidae). Os pássaros utilizavam a inflorescência como plataforma de pouso, visitando de 15 a 25 flores sem incursionar vôo, sendo que o tempo de permanência em dada planta dependia da chegada de outros indivíduos. Todas as espécies de aves apresentaram comportamento agonístico quando outros pássaros pousavam na mesma planta. Efetuavam a polinização ao contactarem o estigma com as partes do corpo em que estava aderido o pólen pegajoso. Entre as abelhas, Trigona spinipes, a mais freqüente, iniciava suas visitas às 08:30 h, permanecendo até 17:00 h. Estas abelhas permaneciam muito tempo numa inflorescência possibilitando, principalmente geitonogamia. Xylocopa aff. hirsutissima foi menos freqüente que Trigona spinipes, mas em razão do seu comportamento ao visitar a flor, contactando o estigma e a antera, e ao seu maior tamanho em relação a Trigona, foi considerada como polinizador adicional. Os demais grupos de visitantes (vespas, borboletas, moscas e formigas) foram considerados como pilhadores de néctar ou pólen, podendo ocasionalmente efetuar polinizações.

Hortia brasiliana Vand. (Rutaceae) is a common shrub found in cerrado areas of Uberlândia, MG, Brazil. Individuals are 0.5 to 2.0 m high, with rose-coloured and coriaceous flowers, displayed in dense inflorescences. The anthesis occurs along the day or night and can take from 25 min. to 3 hours to complete, according to the temperature. The flower is protandrous and produces an average of 60 µl of nectar, with sugar concentrations ranging from 24 to 32%. The species is self-compatible. Flowers are visited by six Passeriform birds belonging to the Fringillidae, Thraupidae and Mimidae families, considered effective pollinators. This pollination type is new for cerrado vegetation. Birds were observed visiting the flowers to obtain nectar from 4:30 a.m. to 8:30 a.m., when they were sent away by Trigona spinipes bees (Apidae). In order to visit the plant, the birds use the inflorescence as a landing platform, probing 15 to 25 flowers per visit without flight incursion. The permanence period of a bird in a particular plant depended on the arrival of other individuals, and all bird species showed agonistic behaviour when other birds landed on the same plant. Pollination was carried out when the stigma got in contact with body parts in which sticky pollen was adhered to. Among the bees, Trigona spinipes was the most regular visitor, its activity taking place from 8:30 a.m. to 5 p.m. Bees remained in the same inflorescense for a long time performing selfing and geitonogamous pollination. Xylocopa aff. hirsutissima was less common than Trigona spinipes, but due to its behaviour on inflorescences, contacting the stigma and the anther, and its larger size as compared to Trigona, it was considered an additional pollinator. Other visitors (wasps, butterflies, flies, and ants) were considered nectar robbers, occasionally able to perform pollination.