M. Martin-vivaldi et al., Song strophe-length and reproductive success in a non-passerine bird, the Hoopoe Upupa epops, IBIS, 141(4), 1999, pp. 670-679
Hoopoe Upupa epops males produce a very simple song, with a repertoire size
of one, in which the main difference between different strophes of a male
and between the songs of different males is the number of elements they inc
lude (strophe-length). In several passerine species it has been shown that
strophe-length is a sexually selected trait that reflects male quality and
correlates with reproductive success. Here we analyse whether in a non-pass
erine, the Hoopoe, strophe-length of males is correlated with several varia
bles of their reproductive success. Females paired with males singing long
strophes laid their first clutch earlier, produced larger first clutches an
d laid second clutches after a successful first one more frequently than th
ose paired with males singing short strophes. Moreover, males with long str
ophes produced more fledglings in their first clutches and in the whole sea
son, partly because they brought more food for the brood than males with sh
ort strophes. The relationships found are not mediated by age effects. Prev
iously we have shown that Hoopoe females in the early spring are attracted
preferentially to songs with long strophes. Here we show that males singing
long strophes also obtain postpairing benefits in terms of reproductive su
ccess, and that females paired with these males obtain direct benefits beca
use these males provide greater feeding effort in the second half of the ne
stling period. These findings support the hypothesis that in the Hoopoe, st
rophe-length is a sexually selected cue under direct selection.