They are relatively small with stubby, conical bills adapted for feeding on seeds and alike. Most species are strongly sexually dimorphic, and while "typical" adult males often are distinctive, female and immatures of both sexes can be very difficult (in some species virtually impossible) to identify to exact species. Females of at least some of these species have different ultraviolet colours, which can be seen by birds, but not humans. Female-like (paedomorphic) males apparently also occur, at least in some species.
^Ridgely, R. S., & G. Tudor (1989). The Birds of South America. Vol. 1. Univ. Texas Press, Austin
^Benites, P., Eaton, M. D., Lijtmaer, D. A., Lougheed, S. C. & Tubaro, P. L. (2010). Analysis from avian visual perspective reveals plumage colour differences among females of capuchino seedeaters (Sporophila). J. Avian Biology. 41: 597–602.
^Areta, J. I. (2009). Paedomorphosis in Sporophila seedeaters. Bull. B.O.C. 2009 129(2): 98-103.
Lijtmaer, D. A., N. M. Sharpe, P. L. Tubaro & S. C. Lougheed. 2004. Molecular phylogenetics and diversification of the genus Sporophila (Aves: Passeriformes). Mol. Philo. Evol. 33:562-579.
Robbins, M. B., M. J. Braun, C. J. Huddleston, D. W. Finch, & C. M. Milensky (2005). First Guyana records, natural history, and systematics of the White-winged Seedeater (Dolospingus fringilloides). Ibis 147:334-341.