How listening to birdsong may help scientists conserve at-risk species
New research from an Edmonton-based wildlife biologist suggests much can be learned about at-risk songbirds by listening to the rate of their songs.
Birds' song rates, or the number of songs they sing in a given time period, change throughout their breeding season and researchers from the University of Alberta found they could predict breeding status by analyzing those song rates.
Their findings, published in the journal Ecosphere in January, offer a new way to monitor at-risk birds that could potentially aid future conservation efforts.
Determining breeding status by monitoring nests is expensive and challenging, like finding a needle in a haystack, wildlife biologist and lead author Emily Upham-Mills told CBC's Radio Active on Friday.
"If we can just listen to a bird and determine its status, then we can take that information and expand across the landscape and look at habitats where there are lots of birds that are successful at breeding," she said.
Researchers can also use this method to determine habitats where birds are not reproducing as much. These insights could potentially help scientists better understand why certain populations are in decline and how to protect them.
As part of her master's thesis, which she successfully defended in 2018, Upham-Mills studied the song rates of 28 male olive-sided flycatchers in northern Alberta (north of Fort McMurray) and in parts of the Northwest Territories.
The olive-sided flycatcher, a medium-sized songbird, was designated as "threatened" by the Committee on the Status of Endangered Wildlife in Canada in 2007. According to the conservation network Partners in Flight, its population was estimated to be 900,000 in 2013.
Scientists don't know why the population has decreased, but possible reasons include deforestation, forest harvesting, fewer available insects and more commercial and residential development.
Upham-Mills and a crew of field technicians gathered more than 500 five-minute audio segments of the birds and used automatic recognition software to monitor a much larger volume of data. Future work will analyze these recordings further.
The research, conducted in Dr. Erin Bayne's lab at the university's biological sciences department, received significant funding from Environment and Climate Change Canada.
What we learn from song rates
One of the reasons male songbirds sing is to attract female mates, but once they settle down, they are less likely to keep singing as frequently. Songs could alert predators to the birds' nests, Upham-Mills said.
The songbird in the above recording, observed late in the season, has a relatively fast song rate.
"That guy might have been single, still looking for a mate," Upham-Mills said.
Upham-Mills, now working as an environmental scientist for Spencer Environmental Management Services Ltd., said she hopes to publish more research from the data she gathered for her thesis.
Building on her work, scientists potentially use similar methods to monitor other species, she said, perhaps even going beyond birds.
"A lot of animals use vocalizations and the vocalizations mean something," she said.
"As soon as we understand the link between their status and the noises they're making, then we can just listen to them and start to learn way more about them."
