ABSTRACT
We present new aspects of breeding biology of Gray-fronted Dove Leptotila rufaxilla, from five nests found between 2012 and 2014 in a lowland forest fragment in southwestern Brazil. The nests simple/platform shape were built at a mean height of 1.90 m above ground. The clutch size was two eggs white and elliptic, incubated for 15 days (based on three nests). We recorded predation in two nests still in incubation phase. Minimum hatch weight of nestlings was 10 g and young fledged with a mean mass of 56 g. The constant growth rate (K) of nestlings was 0.40 with a growth asymptote of 60.7 g. Daily survival rate, Mayfield and apparent nesting success in the incubation period was 90, 20 and 56%, respectively, while in the nestling period were all 100%. Our data and the contribution of citizen science showed that L. rufaxilla breeds over the year, mainly in the rainy season, both in southwestern Amazonia and in other regions of occurrence.
Presentamos nuevos aspectos de la biología reproductiva de la Yerutí Colorada Leptotila rufaxilla, de cinco nidos encontrados entre 2012 y 2014 en un fragmento de bosque de tierras bajas en el suroeste de Brasil. Los nidos con forma simple / plataforma se construyeron a una altura media de 1.90 m sobre el suelo. El tamaño de la puesta fue de dos huevos blancos y elípticos, incubados durante 15 días (basado en tres nidos). Registramos depredación en dos nidos aún en fase de incubación. El peso mínimo al nacer de los pichones fue de 10 g y los polluelos dejaron el nido con una masa media de 56 g. La tasa de crecimiento constante (K) de los pichones fue de 0.40 con una asíntota de crecimiento de 60.7 g. La tasa de supervivencia diaria, Mayfield y el éxito aparente de anidación en el período de incubación fue de 90, 20 y 56%, respectivamente, mientras que en el período de cría fueron todos de 100%. Nuestros datos y el aporte de la ciencia ciudadana mostraron que L. rufaxilla se reproduce durante el año, principalmente en la época de lluvias, tanto en el suroeste de la Amazonia como en otras regiones de ocurrencia.
ABSTRACT
Our study provides information on the breeding and biometrics of Rusty-Margined Flycatcher Myiozetetes cayanensis in southwest Brazilian Amazonia. M. cayanensis is distributed from Central America until north of South America. We made observations on reproduction and captures of this species in a terra firme forest fragment in the state of Acre, between 1999 and 2020 and we evaluated the breeding season in Brazil through citizen science data. We monitored nine nests between 2012 and 2020, built at a mean height of 1.8 m above ground. Clutch size was two, three or four eggs, incubated for 15 days. We monitored the development of six nestlings: minimum hatch weight was 2 g and young fledged with a mean mass of ca. 25.5 g. The constant growth rate (K) of nestlings was 0.18 with a growth asymptote of 22.8 g. Daily survival rate was 90% and 100% during the incubation and nestling periods, respectively. The Mayfield success in the incubation and nestling periods was 20 and 100%, respectively. Apparent nesting success in the incubation and nestling periods was 46 and 100%, respectively. We recorded a minimum longevity of 2 years, nine months and 26 days. The subspecies M. c. cayanensis start to nest mainly between the dry and rainy season in Brazil, overlapping with the molt period in southwest Amazonia.
Nuestro estudio proporciona información sobre la reproducción y la biometría del bienteveo alicastaño Myiozetetes cayanensis en el suroeste de la Amazonia brasileña. M. cayanensis se distribuye desde América Central hasta el norte de América del Sur. Realizamos observaciones sobre la reproducción y captura de esta especie en un fragmento de bosque de tierra firme en el estado de Acre, entre 1999 y 2020 y evaluamos la época de reproducción en Brasil mediante datos de ciencia ciudadana. Monitoreamos nueve nidos entre 2012 y 2020, construidos a una altura promedio de 1.8 m sobre el suelo. El tamaño de la puesta fue de dos, tres o cuatro huevos, incubados durante 15 días. Monitoreamos el desarrollo de seis polluelos: el peso mínimo al nacer fue de 2 g y los polluelos con una masa media de ca. 25.5 g. La tasa de crecimiento constante (K) de los polluelos fue de 0.18 con una asíntota de crecimiento de 22.8 g. La tasa de supervivencia diaria fue del 90% y 100% durante los períodos de incubación y cría, respectivamente. El éxito de Mayfield en los períodos de incubación y cría fue de 20 y 100%, respectivamente. El éxito aparente de anidación en los períodos de incubación y polluelo fue de 46 y 100%, respectivamente. Registramos una longevidad mínima de 2 años, nueve meses y 26 días. La subespecie M. c. cayanensis comienzan a anidar principalmente entre la estación seca y lluviosa en Brasil, superponiéndose con el período de muda en el suroeste de la Amazonia.
ABSTRACT
The feeding habits, the sexual dimorphism in size and sexual maturity of the actively foraging lizard Cnemidophorusocellifer were analysed in an area of a reforested Restinga habitat located in the municipality of Mataraca, along the northern-most coast of Paraíba State, Brazil. Seventy-five specimens of C. ocellifer were examined (46 males and 29Â females). Of this total, only 23 specimens had prey in their stomachs. The most frequent prey consumed items were orthopterans (50 percent), coleopterans (23.9 percent) and arachnids (10.9 percent); termites and insect larvae were less consumed (both with 2.2 percent). There were no significant differences observed between the numbers of prey consumed by either males or females. There were significant differences in SVL (snout-vent length) between the sexes, with males attaining larger SVL values. When the influence of SVL was removed from the analyses, sexual dimorphism in the form was still reflected in the head size of these lizards. Sexual maturity in females and males was attained with SVL of 42.2 and 49.0 mm respectively. Although no significant difference was observed between the SVL of the females and the number of eggs produced, there was a clear tendency for larger females to produce more eggs. The low structural complexity of the vegetation and the poor soil quality in the reforested restinga area examined does not furnish favourable habitat for insect and termite larvae, contributing to the marked differences in the diet of the population of C. ocellifer observed in the present study in relation to the diet of their conspecifics in undisturbed areas of restinga, cerrado and caatinga.
O hábito alimentar, dimorfismo sexual e tamanho na maturidade sexual do lagarto forrageador ativo Cnemidophorus ocellifer foram analisados em um habitat de restinga reflorestada, situado no município de Mataraca, extremo norte do litoral do Estado da Paraíba, Brasil. Foram examinados 75 espécimes de C. ocellifer, sendo 46 machos e 29 fêmeas. Deste total, apenas 23 espécimes continham presas em seus estômagos. As mais frequentes presas consumidas foram os ortópteros (50 por cento), coleópteros (23,9 por cento) e aracnídeos (10,9 por cento); enquanto térmitas e larvas de insetos foram os itens menos consumidos (ambos com 2,2 por cento). Não houve diferença significativa no número de presas consumidas por machos e fêmeas. Houve diferença significativa do SVL (comprimento rostro-cloacal) entre os sexos, com machos alcançando valores máximos de SVL. Removido o efeito do SVL das análises, o dimorfismo sexual na forma foi evidenciado pelo tamanho da cabeça dos lagartos. A maturidade sexual das fêmeas e machos foi alcançada com SVL de 42,2 e 49,0 mm, respectivamente. Embora não tenha havido uma diferença significativa entre o SVL da fêmea e o tamanho de sua desova, foi observada uma clara tendência de fêmeas maiores produzirem desovas maiores. Na área de restinga reflorestada, a baixa complexidade da estrutura da vegetação e inadequada qualidade do solo, provavelmente, não propiciam condições favoráveis de habitat para larvas de insetos e térmitas, desse modo, contribuindo para a marcante diferença na dieta da população de C. ocellifer observada no presente estudo em relação a outras áreas de restinga não perturbadas, cerrado e caatinga.
Subject(s)
Animals , Female , Male , Feeding Behavior/physiology , Gastrointestinal Contents , Lizards/physiology , Sexual Maturation/physiology , Body Mass Index , Brazil , Diet , Ecosystem , Lizards/anatomy & histology , Oviposition/physiology , Sex CharacteristicsABSTRACT
The breeding success of a double-brooding colony of Boat-billed Herons Cochlearius cochlearius was studied in pasturelands of Costa Rica. Mean clutch size in the first clutches (2.9 eggs/nest) was higher than in second and repeat clutches (2.3 eggs/nest). Breeding success was similar in the first attempt and second attempts (20.7% and 21.7%, respectively). In both attempts earlier nests enjoyed a higher breeding success. Starvation of the youngest chicks within the nest and destruction of nests by bad weather conditions were the main factors related to nestling death. No effects of human activity on the reproduction of the breeding colony were observed.
Estudiamos el éxito reproductivo de una colonia del ave Cochlearius cochlearius en una zona ganadera de Costa Rica. El promedio de huevos por nido fue mayor durante el periodo de primeras puestas (2.9 huevos/nido) que durante el periodo de segundas puestas y reposiciones (2.3 huevos/nido). El éxito reproductor de los dos periodos fue similar (20.7 % y 21.7 %, respectivamente). En ambos tuvieron más éxito las parejas que comenzaron la puesta antes. Las principales causas de mortandad fueron inanición de los pollos más jóvenes del nido y la destrucción de los nidos debido a condiciones climáticas adversas. No notamos efectos adversos por la actividad humana.