Spring birdsongs carry a message

Whatever else you say about winter, it's a quiet and fairly monochromatic season, leaving us hungry for color and sound.

But all that is about to change, and in a big way. As the sun swings higher in the sky, birds begin to undergo dramatic changes, and suddenly the world is more vibrant. The first thing we notice is birdsong, so welcome after the silence of winter.

Cardinals have been singing from the tops of trees since February, every "wha-cheer" announcing the red bird's ownership of a territory and his attempts to appeal to a female cardinal. He is essentially weaving a sound fence to ward off encroachers and encircle a mate.

Chickadees start singing in late winter, too, and many of us mark their sweet "fee-bee" songs as a promise that spring isn't far behind. However, to other chickadees, that song sounds either like an announcement of a male's readiness to pair up or a warning to other males to move on.

Both chickadees and cardinals spent the winter among flocks of their own kind, but now, with daylight increasing, hormone levels are on the rise. As they begin singing, flocks break up, with individual birds becoming territorial and aggressively defending their space.

Woodpeckers are drumming on resonant surfaces, their version of a springtime attract/repel song. Nuthatches sneeze a rapid, nasal "wha, wha, wha" sound, very different from their "yank, yank" contact calls. And all-winter-silent juncos, just before leaving to head north to breed, string out a series of loud trills.

Many birds sing from a visible perch, such as those cardinals at the tops of trees, or goldfinches on a branch. Such perches offer an unobstructed view for the singer, with few obstacles in the way to absorb their sounds.

Birds change their appearance for springtime, as part of their courtship and breeding rituals. Migrants trade in their winter plumage for brighter feathers to catch the eye of females of their species, then begin the trek northward.

Male goldfinches trade their gray-brown winter look for bright yellow feathers in spring, in a slow and highly visible molting process. Suddenly we'll notice a finch at the feeder sporting a bright yellow throat, and in the weeks to come the little bird shows more and more color until finally it lives up to its name again.

Spring in the bird world starts slowly, but then the floodgates open: We spot a flash of blue and hear a whispered song, signals that Eastern bluebirds are getting ready to mate. One of the prettiest songsters, both in appearance and voice, is the returning rose-breasted grosbeak — some describe its rich song as sounding like a robin that's had singing lessons.

Yellow warblers add flash and dash to spring, with their "sweet, sweet, sweet, I'm so sweet" song, and catbirds lurk in the newly leafed-out shrubbery, issuing soft "meow" sounds. Scarlet tanagers sing from high trees in the forest, and are hard to spot among the leaves, even with their fluorescent red-orange plumage.

Yes, our sensory starvation is coming to an end, with birds providing a welcome feast for the eyes and ears.