Breeding biology of the Arundinicola leucocephala (Tyrannidae) in the state of Espírito Santo, Brazil

The White-headed Marsh Tyrant, Arundinicola leucocephala, is a tyrannid bird with a wide distribution in South America. It inhabits humid and wet areas. It is the only species of the genus and presents sexual dimorphism. Available information on the reproductive biology of this species is punctual and has a theoretical-evolutionary relevance as for its conservation. The purpose of this research is to describe its reproductive biology. The study of reproductive biology is being carried out in the town of Jaguaré-ES, Brazil (18°54’23″S/48°04’31″O). Nests (n=16) from 14 couples were found by active search and monitored at intervals of 2-4 days. The breeding season lasted from September 17, 2016, (first nest found) until April 23, 2017 (last nestling left the nest). The species presented a closed, oval shape nest with a lateral aperture, made by the female using vegetal fibers, feathers, mosses and cobwebs. The nests had a mean size of 134.15mm in height, 87.46mm in width, 97.57mm in length and an aperture of 47.19 x 43.34mm. The eggs were uniformly white with an average size of 19.22 x 13.77mm length x width. Incubation was performed by the female with a duration of 14 to 16 days (n=12) and the nestling period ranged from 14 to 16 days (n=15). The care of the nestlings was carried out by the pair. The fledglings resemble the female and remain in the territory of the parents between 30 and 90 days. The observed reproductive pattern resembles that presented by other species of Tyrannidae family.