Nesting information for Tropeiro Seedeater (Sporophila beltoni), an endemic songbird from southern Brazil

We present the first nesting information for the Tropeiro Seedeater (Sporophila beltoni), a newly described and poorly known Neotropical passerine endemic to southern Brazil. We observed a novel male biased behavior for nest site selection in the Tropeiro Seedeater based on seven events of pre-nesting display courtship. We describe the nest, eggs, nestlings, and fledglings based on 133 nests found over four breeding seasons (2007 to 2011). The nest is a cup-shaped structure made with dry grass inflorescences and spider webs. It is placed in low, forked branches of substrate shrubs and contains multiple attachment points. The eggs are typically white with dark spots or stripes, and are pyriform in shape. Average egg dimensions are 18.2 × 13.2 mm. Nestlings fledge after 10 days. We provide the key information for distinguishing the nest, eggs, nestlings and fledglings of S. beltoni from other sympatric Sporophila species.