Predicting breeding status of birds using their song rates? It’s possible, according to research from Edmonton biologist Emily Upham-Mills. 

It took Upham-Mills and her research team three years to track olive-sided flycatchers, visiting their breeding territories on a weekly basis. Many hours were spent in olive-sided flycatcher territory, searching for nests and observing behaviour. 

“Each time we visited a male’s territory, we would have to locate him and count how many songs he sang in five minutes,” says Upham-Mills. 

Olive-sided flycatchers were listed as “threatened” under the federal Species at Risk Act in 2007 in Canada. Possible reasons for the decline of the species include forest harvesting and development projects. When re-evaluated in 2018, they were designated to be of “special concern.”

Monitoring via camera or live isn’t feasible

Upham-Mills says it’s challenging to monitor nests via camera — and live — because the species is a “cryptic nester.” That’s why using song to monitor breeding status was at the root of her research, recently published in Ecosphere.

“[The birds] have evolved approaches to stay hidden to avoid predation,” says Upham-Mills. “The olive-sided flycatcher often places its nest high up in tall coniferous trees. They also have large territories, meaning even if you know where a male is generally singing from in a patch of forest, his nest could still be 500 metres or more away from there. It often took a month of weekly site visits lasting many hours until there was some evidence to suggest where the nest was located.”