News in Brief Animals

Warm-up benefit could explain morning birdsong

Dawn tune-up may improve sound for attracting mates

Adelaide’s warbler

WARBLER WARMUP  Even in the highly musical species of Adelaide’s warblers, singers aren’t at their best with the first trill of the morning.

Ron Knight/Flickr (CC BY 2.0)

By Susan Milius

WASHINGTON — Vocally warming up puts more dazzle into a bird’s singing for the day, a new test shows, perhaps helping to explain widespread outbursts of birdsong at dawn.

Males of Puerto Rico’s Adelaide’s warblers (Setophaga adelaidae) start trilling through their repertoires of 30 or so songs while it’s still pitch black.