Abstract – Bird song is crucial for attracting mates
and defending territories, but different types of song or different
singing behaviours may be involved in acquiring or maintaining each
resource. Furthermore, male songbirds may adjust when and where they
sing throughout the breeding season, depending on their breeding stage.
However, such relationships remain untested in several avian taxa. Here,
we studied male Bermuda White-eyed Vireos (Vireo griseus
bermudianus ), a passerine with two distinct song types (discrete and
rambling), to test the mate attraction, territory defence, and nesting
stage hypotheses. We compare song rate and song perch height among
different stages of the breeding season and during the non-breeding
season. We show that male vireos produce both song types during the
breeding and non-breeding seasons, suggesting dual roles in mate choice
and territorial defence. Singing rate did not differ between the two
seasons, but, within the breeding season, males without nesting duties
had significantly higher song rates than males with nesting duties. Song
rate was lowest during the nestling stage, which coincided with the
highest rate of nest predation. Song perch height was higher during the
breeding season versus non-breeding season, among males without nesting
duties compared to males with nesting duties, and when males produced
discrete versus rambling songs. Our findings suggest that male vireos
increase their conspicuousness to prospecting females by increasing
singing rate and song perch height, and that they sing during the
breeding and non-breeding seasons to defend year-round territories.
Collectively, our study supports the mate attraction and territory
defence hypotheses of bird song and suggests that Bermuda White-eyed
Vireos adjust their singing rate in response to nest predation risk.
Keywords: Bermuda White-eyed Vireo, breeding behaviour, daytime
singing, island songbirds, song perch selection, vireos,