02027nas a2200145   4500008004100000022001400041245007900055210006900134260001600203490000700219520155800226100002101784700002101805856005501826       2018                        eng d  a0340-544300aConspecific challenges provoke female canyon wrens to sing but not to duet0 aConspecific challenges provoke female canyon wrens to sing but n  cJan-12-20180 v723 a<p>Song by female birds is rare in some species, particularly at north-temperate latitudes. Nevertheless, female song can carry important signal content and may be used in functional ways, both when sung solo and when combined into partner duets. Evidence supports the idea that duets reflect elevated threat levels because they indicate partner cooperation, but this comes from species with frequent female song and duetting. Here we asked the following questions about infrequently given female song in canyon wrens (Catherpes mexicanus) in Western North America. Do female birds use song in a context that implies functional significance? Do canyon wren mates combine their songs to form duets? Are duets a more threatening signal than non- overlapping dual-sex solo songs? To address these questions, we challenged canyon wrens with paired simulated intruders singing alternating solo songs or duets formed by overlapping male and female songs with consistent timing. Results indicated that female canyon wrens approached and sang in response to conspecific song playback as quickly as males did and increased their song rates significantly. Partners did not overlap their songs to create duets more often than expected by chance, and neither sex responded more strongly to duets than to solo songs. Outcomes match the prediction that duets only carry different signal content from solo song in species that frequently duet, and suggest that canyon wren female song is highly functional despite being rarely used outside of contest situations.</p>
1 aHathcock, T., J.1 aBenedict, Lauryn  uhttp://link.springer.com/10.1007/s00265-018-2625-0