The common perception of a singing bird often brings to mind a male. However, female birds sing, and their vocalizations are far more widespread and complex than previously understood. Ornithologists recognize that the assumption of male-only singing has skewed research for decades, largely due to historical biases towards studying temperate zone birds where female song is less pronounced.
The Reality: Female Birds Do Sing
Female bird song is a widespread behavior, with studies indicating that females sing in approximately 64% to 70% of songbird species globally. This challenges the long-held assumption that song was primarily a male trait. While some female singing might be subtle, it is a regular occurrence in many species, particularly in tropical regions.
In North America, female singing is well-documented in species like the Northern Cardinal, where females sing regularly, and the Red-winged Blackbird, whose females produce a rapid-fire call. Female Bullock’s and Baltimore Orioles also sing during nest building, with Bullock’s Oriole females sometimes singing more than males. Other species known to have singing females include Wilson’s, Yellow, Hooded, Chestnut-sided, and Prothonotary Warblers, along with Common Yellowthroats.
Why Female Birds Sing
Female birds sing for various reasons, often overlapping with male singing behaviors but also distinct. A primary function of female song is territory defense, both against other females and as a joint effort with their mate to defend shared resources. This is common for species where pairs maintain a territory year-round.
Female song also plays a role in pair bonding and communication within a mated pair, sometimes involving duets with their male partners. This coordinated singing reinforces the pair bond and signals their presence, communicating that a territory is claimed. Female song can also influence male behavior, such as a nesting female cardinal’s song prompting her mate to visit the nest more frequently. While male birds commonly use song for mate attraction, female song generally does not serve this purpose as widely. Instead, it can be involved in female-female competition, particularly in socially monogamous species where a female may sing to ensure her mate’s fidelity.
Nuances in Female and Male Song
The vocalizations of female and male birds exhibit both similarities and differences. In some species, such as the Venezuelan Troupial, females sing more frequently during the day than males, and their songs can have similar syllable numbers and syntax.
However, in other species, like Orchard Orioles, female songs may be acoustically distinct from male songs, differing in variables such as frequency range and inter-note intervals. While some temperate species may have quieter female songs, this is not a universal rule. The contexts for female singing can also vary, often occurring during the breeding season, in response to territorial threats, or as part of coordinated duets with their mates.