Territorialidade e ecologia reprodutiva de Formicivora littoralis (Thamnophilidae) na Restinga da Massambaba, RJ

• Autor(a) principal: Chaves, Flávia Guimarães
• Data de Publicação: 2014
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/4935
• topic: Aves; Restinga Antwren; Spatial distribution; Life history; Paternity; Aves; Formigueiro-do-litoral; Distribuição espacial; História de vida; Paternidade; Ave - Rio de Janeiro (RJ); Ave - Reprodução; Ave - Comportamento; CNPQ::CIENCIAS BIOLOGICAS::ECOLOGIA

The spatial distribution of individuals results from the presence and absence of suitable microhabitats and individuals that settle in the best patches of habitat are favored by natural selection. Territory acquisition allows individuduals to survive and reproduce. Reproduction has a high energetic cost because resources are shifted towards maintaining offspring instead of being incorporated into individual growth. However, investing in an offspring does not mean achieving reproductive success. Reproductive success can be affected by predation events, food availability and parental care. The latter can be performed by both members of the breeding pair or by only one of them. Parental desertion by one sex may be a response to extra-pair copulations. Formicivora littoralis has a very limited distribution and is the only bird species considered endemic of the Restinga ecosystem. Although it is locally abundant, this species is threatened by extinction. Between 2010-2013, this study aimed to: 1) estimate territory sizes and compare these between breeding and non-breeding seasons, 2) test the influence of individual size and number of neighbors on territory size, 3) describe nest, eggs, and nestlings and determine reproductive success, 4) quantify parental care, and 5) develop microsatellite molecular markers to determine paternity. Blood samples, morphometric measurements (tarsus, wing, tail, total length) and body mass were obtained from individuals that were captured and marked. Territory size was estimated by the minimum convex polygon method (joined points where males were recorded singing). Density was estimated based on the size of the territories. Aspects of reproduction were evaluated through monthly nest searches and monitoring for two consecutive days. Predation rates and parental care were quantified. Paternity was determined by seven microsatellite markers developed for this purpose. Formicivora littoralis has a small territory (from 0.008 to 0.32ha), which varies according to the season (smaller in the breeding season). Territory size was not related to individual bird size but it was associated with the number of neighboring territories. Density of this species was high (0.53 to 1.15 individuals/km2). Regarding reproduction, nests had an open cup format with a maximum of two eggs. Nestlings were born without feathers, and sex ratio in the nest was similar. Predation rate was higher during incubation than during the nestling stage. Parental care (incubation and nestling) was performed by both sexes with no differences in the proportion of investment. Among the nine nests analyzed, all contained at least one nestling from extra-pair fertilization. A total of 81.2% nestlings (13 in 16) were not the biological offspring of the male that performed parental care and was socially paired with the female. This rate is the highest among studies in the Neotropics