For birds, this time of year, it's all about the music.
But some birds have a different take on song. Rather than singers, they're percussionists.
Every spring, like clockwork, I wake up to an insistent, rhythmic sound. It's a woodpecker tapping a tree with its beak. It sounds to me like a big bird. But every time I gaze up, I can't find it.
Ornithologist Don Kroodsma, a retired UMass biology professor, says it's probably a Downy woodpecker, the smallest around here.
"[If] you stretch the bird out it's, at the most, five or six inches," Kroodsma said.
Kroodsma and other experts say it could also be the Hairy woodpecker, which sounds similar. Both are black and white, with a distinctive white patch on the back.
Unlike songbirds, which use vibrating membranes -- kind of like vocal chords -- to sing, woodpeckers pound their beaks. It's called drumming.
Woodpeckers also use their beaks to search for food or to make a cavity for a nest.
Most songbirds learn their species' song by imitating adults. Each woodpecker species has its own drum and, it's believed, woodpeckers just know how to do it. It's innate.
"They pick a certain spot on a dead branch on a tree, right at the base," Kroodsma explains. "And they can find that resonant spot, where the sound just booms and radiates out."
In late winter, males drum to claim a territory. Both males and females can drum to attract a mate or to tell each other their location. Kroodsma describes a woodpecker "working" a tree:
"He finds a sweet spot and it's a magnificent drum," Kroodsma says. "He moves over just a little bit, hits a soft spot. It doesn't sound quite right and he moves back to the strong spot. So they know what they are listening for -- I'm quite sure."
Some species of woodpeckers drum on gutters and other found objects.
"My favorite, ever, was a [Northern] flicker who was drumming on a wooden fence post with the fence wire going through a metal staple," recalls Kroodsma. "And every time he drummed on the wooden post there was this beautiful ringing sound of the metal wire through the metal staple. They are tool-using woodpeckers, truly."
Kroodsma recorded two Hairy woodpeckers in 2008 at the Prescott Peninsula on the Quabbin Reservoir, in a kind of call and response. Kroodsma believes these are two males because they were far apart, as if calling from neighboring territories.
Woodpeckers' drumming can be heard until about the end of June.