Vermilion-crowned Flycatchers (Myiozetetes similis, formerly called Social Flycatchers) remain paired the year around (Skutch 1960). I was watching the members of a pair foraging in close association along the bank of a pond (near Escuintla in the Pacific lowlands of Guatemala) on 29 December 1976, when the two came to a patch of relatively bare earth 1-2 m in extent. This was late in the morning of a hot, sunny day. One of them immediately sprawled belly to the earth, with wings and tail widely spread and head back in the sunbathing posture of a passerine (Hauser 1957). When the second flycatcher tried to do likewise, it was driven away. After about a minute, the first bird left and the second one took its place. It too was intolerant, repulsing an attempt of the first flycatcher to sunbathe again. These sequences of alternate sunbathing with attacks on the nonsunbathing partner were repeated five times. I saw no signs of anting, and neither bird preened or scratched in association with the sunbathing.
Kilham, Lawrence, "Sunbathing Vermilion-crowned Flycatchers Repulse Mates" (1981). Open Dartmouth: Peer-reviewed articles by Dartmouth faculty. 3910.