Biology and reproductive behavior of Ammodramus humeralis

Abstract

This study on the biology and reproductive behavior of Ammodramus humeralis (Bose, 1792) was carried out in a coffee-plantation near Campinas, Brazil. A blind was used for observations near the nests. These were built on the ground, under small tufts of grass, and were made of dry grass leaves. The nest is slightly domed with an opening diameter of S cm. Other average dimensions are: internal diameter 6 cm (n=4), depth 5 cm (n=4). externe diameter 8,4 cm (n=3). The clutch varíes from 2 to 3 eggs. incubated only by the female. The male sings in open spaces nearby. Only one nest presented signals of predation. Both male and female feed the nestlings with insects such as grasshoppers, beetles and leaf -hoppers, carried across their bill. They also may bring small seeds found on the ground. The nestlings produced two kinds of calls, one slower and weak when parents were absent. and another higher and quick when parents arrived to feed them. Male and female showed distraction displays. In one case only the female took care of the nestlings.