Researchers are accusing ornithologists of gender inequality because of their use of the image of a bright colored male birdsong singing furiously to make known his breeding territory. Nearby is a dull colored female attending to the nest.
That image is not applicable to most of the world's birds. They cited a 2016 survey which found that 64 percent of the time, the female sings when the male also sings. The new study pointed out that the female birdsong is critically underrepresented in scientific literature and biological sound recordings, Cosmos Magazine reported.
Unappreciated songs
If there is a better understanding of the unappreciated songs of the female songbird, it could lead to advances in many aspects of bird biology, Karan Odom, from Cornell University, and Lauryn Benedict, from the University of Northern Colorado, said. Their findings were published in The Auk: Ornithological Advances journal.
Benedict recalled that she began studying California towhees 17 years ago. She was fascinated by the vocalization by the female and male songbirds. However, when she began searching for the female song in other North American bird species, she was surprised to learn that it was more common than her expectations. She noted that the reports of the female song are buried in hidden corners of the literature. However, when it is placed together, it shows some interesting patterns.
She explained the source of the male bias to most birdsong studies coming from North America and Europe, temperate regions of the world. In these places, the male birdsong is used to proclaim its breeding territories upon arrival from wintering grounds. But Benedict pointed out that even in the temperate region, when a closer look is made at the behavior of the female songbird, it would reveal that 42 percent of the resident songbird species have females that sing.
And in 43 percent of European songbirds, females were reported to have the same amount of song. They added that many female nonpasserine species use complex vocal signals during breeding and in other contexts which suggested that this interesting female vocal behavior could be pervasive across all birds.
The female lyrebird
To improve the world's understanding of the comparative physiology, neurobiology, behavioral ecology, and evolution, or everything studied about avians, Odom and Benedict believe that the study of the female song is essential.
They cited the superb lyrebird in Australia which is a classic case of the male species overshadowing the female. But it has been detrimental to the understanding of the behavioral ecology of the species. The male is depicted as heavily decorated with elaborate plumes in its tail that are shaped like a lyre. On a carefully created stage, he performs spectacular songs of mimicry.
The male bird of the lyrebird species has been studied extensively for hundreds of year. It was only in 2016 that scientists published a study on the song of the female lyrebird which is also an accomplished mimic.
The study, authored by Anastasia Dalziel, from Cornell University, and Justin Welbergen, from Western Sydney University in Australia, said that their research throws out past portrayal of vocalizations by female lyrebirds as rare and functionless by-products of sexual selection on males. The study suggested that the bird's song plays a role in nest defense and female-female competition for breeding territories.
Cosmos Magazine pointed out that there is on more reason to highlight the female birdsong. There is the risk of having an inaccurate picture of population size if ecologists would survey a threatened bird species based on a wrong assumption that all the singers are only male birds.
Odom's online platform
To encourage more scientific studies, notes from naturalists, and recordings of female birds, Odom created an online platform. The other objective of the platform is to raise awareness that female birds sing. She stressed that if bird observers hear an avian sing, they should not assume right away that it is a male bird. However, Odom said if they observe a female bird singing, she urged them to document it by uploading field notes, audio, or video to the collections on the website. She reminded the bird observers to ensure that they should also indicate how they recognized the bird is female.
Odom and Benedict pointed out that the goal of their commentary includes recruiting researchers from diverse fields to play a crucial role in documenting female songs. They shared that a roundtable discussion on the topics was held at the 2016 North American Ornithological Conference in Washington DC. There was a follow-up discussion at the 2017 Animal Behavior Society meeting in Toronto, Ontario, Canada.
At least in Australia, bird lovers would find that many of the species listed on Odom's website are widespread and often encountered. The list includes the spotted pardalote, rufous whistler, scarlet robin, satin flycatcher, and the olive-backed oriole. About 80 percent of the bird families listed on Odom's website – where very little is known about the female song – are endemic to Australia.
[researchpaper 리서치페이퍼= Vittorio Hernandez 기자]