Tanagers are a family of brightly colored songbirds found in North and South America. There are roughly 240 species of tanagers, characterized by their vibrant plumage in shades of red, yellow, blue, green, and orange. Tanagers are omnivorous, feeding on fruit, insects, and occasionally small vertebrates. They prefer tropical and subtropical forests and woodlands.
Both male and female tanagers sing, though their songs and singing behaviors differ between the sexes. Understanding the singing patterns of male and female tanagers can provide insight into their social structures, breeding strategies, and evolution.
Purpose of Bird Song
Bird songs serve several important purposes:
- Defending territories – Songs establish boundaries between neighboring birds.
- Attracting mates – Songs advertise a male’s fitness to potential partners.
- Strengthening social bonds – Duets and coordinated songs facilitate pair bonding.
- Signaling identity – Songs announce a bird’s species, sex, and individual identity.
In most temperate bird species, only male birds sing. But in the tropics, female birds commonly sing as well. Female tanager songs help identify territory ownership, signal readiness for breeding, and coordinate breeding activities with a mate.
Sex Differences in Tanager Song
Both male and female tanagers sing, but their singing patterns differ in several ways:
Singing Frequency
Males sing much more frequently and persistently than females. Males may sing for hours each day, broadcasting their presence. Females sing less often, such as occasional duets with a mate.
Song Complexity
Male tanager songs tend to be more complex than female songs. Males have larger song repertoires with more variable notes, tones, and phrases. This allows males to signal their individual identity. Female songs are simpler, mainly used for breeding coordination.
Seasonality
Male tanagers sing year-round, defending territories even in the non-breeding season. Females primarily sing during the breeding season when courting, nesting, and raising young.
Duets
Paired males and females perform coordinated duets to strengthen their pair bond. Males initiate duets, and females respond with a complementary tune at a specific time delay.
Examples of Male and Female Tanager Songs
Here are some examples of common tanager species and differences between male and female songs:
| Species | Male Song | Female Song |
|---|---|---|
| Summer tanager | Musical warbling and buzzy phrases | Lower-pitched hoarse notes |
| Scarlet tanager | Rapid staccato notes and trills | Croaking sounds |
| Western tanager | Melodic whistles and sharp chatters | Softer hoots and chirps |
These differences reflect the distinct roles and selective pressures shaping male and female tanager song evolution.
Why Do Female Tanagers Sing?
There are several hypotheses for why female tanagers sing, despite lower song production than males:
Territory Defense
Females help establish territory ownership and boundaries through song. Unmated females may claim a nesting territory through singing.
Mate Attraction
Female song may help attract a high quality mate. Shared song repertoires indicate mate compatibility.
Pair Coordination
Duets and coordinated songs help pairs stay in contact and synchronize breeding activities.
Shared Parenting Duties
In tanagers, both sexes incubate eggs and feed nestlings. Female song may stimulate equal parental investment from males.
Evolution of Female Bird Song
Why do females sing in tropical species like tanagers, but not in most temperate species? Several theories propose evolutionary drivers of female bird song:
Year-round Territories
In tropical regions, territories are maintained year-round rather than just the breeding season. This selects for female defense through song.
Increased Social Competition
Higher population densities in the tropics lead to greater social competition between females, favoring female territorial signals.
Lower Mate Certainty
In tropical birds, females can’t be certain of male parental investment. Female song may help evaluate mates.
Higher Predation
More predators in the tropics select for stronger pair bonds. Duets and coordinated songs facilitate pair bonding.
Polygyny
In tropical birds like tanagers, males often mate with multiple females. Female song likely evolved to compete over high quality males.
Conclusion
In summary, both male and female tanagers sing. But male songs are used mainly for mate attraction and territory defense. Female tanager songs are simpler and sung less frequently, primarily serving to strengthen pair bonds, signal territory ownership, and coordinate breeding activities.
The evolution of complex song in male tanagers but simpler song in females reflects differences in their reproductive strategies and priorities. Understanding the context and patterns of male and female tanager songs provides insight into their unique social and evolutionary pressures.
