Alberta study examines why birds sing first thing in the morning

The Adelaide’s warbler is seen in an undated photo from the University of Lethbridge.

New research from the University of Lethbridge is offering a possible explanation as to why songbirds seem to sing so intensely first thing in the morning.

The study, published in Behavioral Ecology, looked into the Adelaide’s warbler dawn chorus.

It suggests the birds aren’t just singing their hearts out to welcome you to the day, but are instead warming up their voices just like humans would before a big performance.

"Our study was to look at how well they sing their songs using some performance measures, and then how their performance changes throughout the morning," said PhD student Juleyska Vazquez Cardona.

The Adelaide’s warbler is a small songbird found in a dry forest in southwestern Puerto Rico.

The group started recording them before sunrise and continued recording them throughout the dawn chorus, where the birds sing for about 20 to 25 minutes.

The recording then continues for another hour or so after.

Using the information they gathered, the team was able to identify performance changes in the warblers as they progressed through their warm-up.

These measures include recovery time, voiced frequency modulation and unvoiced frequency modulation.

"The measures of performance are basically about how fast the bird can sing," explaimed David Logue from the Department of Psychology.

"You can hear these notes in rapid succession, and we have three different ways of measuring how fast they sing."

Researchers believe the warm-up helps the warblers maximize its performance.

"We found that singing at a high rate through the dawn chorus increased the birds’ performance in both recovery time and unvoiced frequency modulation," said Vazquez Cardona.

"Now, we want to take this further and look at the function of a strong vocal performance. One thing we’ll be looking at is how they use their vocal performance relative to the time of an aggressive encounter with a neighbour bird who is trying to get into that territory. We also need to figure out whether the females prefer high performance songs."

The study, called Vocal performance increases rapidly during the dawn chorus in Adelaide’s warbler, can be read online here.