Contributions to the knowledge of the reproductive biology of the ‘salinas monjita’ (Xolmis salinarum, Passeriformes: Tyrannidae)

Abstract

The ‘salinas monjita’ is an endemic bird of the saline environments from central Argentina and there is little information about its biology and reproduction. We report new records on the reproductive biology of the species, particularly on a nesting site, posture parameters and chicks. The records resulted from surveys at sites in Salinas Grandes salt flats in the province of Córdoba, of which we were successful in only one. We observed flocks of between 20 and 40 individuals in autumn and winter, respectively, while in spring only a few scattered pairs and three individuals, performing possible courtship displays. In the summer, a nest with two chicks was located on the ground at the base of a jume. The chicks were covered with pearl grey down, the beak was pale yellow and the legs were yellowish. After seven days, both had grown and molted much of their down, but one was weak and the other lifeless. This may have been due to the high temperatures of 45oC in the previous days. After monitoring, a 90 mm rain shower flooded the site and the nest with the chicks had disappeared the next day. For the first time, we reported a behavior that could be linked to competition between males to court a female, description of a nest and data on the nestlings first molt. It is hoped that future studies can provide greater knowledge about the reproductive biology of the salinas monjita.