The pre-dawn chorus of songbirds is a delight to wake up to these early spring mornings. The smell of newly awakening earth reaches deep into the most primitive parts of our brains to announce the season's arrival.

Among spring's delights is the bounding flight of a male American goldfinch (Carduelis tristis).

It was April 24, 1993, when I saw my first American goldfinch. A male and a female were at the thistle feeder I had set up behind our old house.

It is 15 years later and the goldfinches are still coming to our backyard, 5 miles from the U.S. Capitol.

In April, male goldfinches are in their breeding plumage, a striking pattern of yellow and black with distinctive white wing bars.

Goldfinches exhibit "sexually dimorphic plumage"-the ornithologist's way of saying that the males and females have different colors. Like most species that have gender-specific coloration, the male goldfinches show the brighter color and distinctive patterns. The brilliant yellow of his back, head and breast is in sharp contrast to his jet black forehead and wings.

The female pattern is similar, but the colors are a muted olive green and yellow wash, and the forehead splash of black is missing entirely. Goldfinches have pink bills and feet.

The goldfinches have become regulars, and a second thistle feeder has been added to accommodate their growing numbers. This is happening across the United States. Goldfinches are gregarious birds, and they populate backyards from coast-to-coast. Here in the mid-Atlantic, they are often year-round residents.

The goldfinches I am watching have recently gone through a molt, giving rise to their especially vibrant colors. Typically, birds add their most vibrant colors as a prelude to breeding. These goldfinches won't breed until midsummer, though. They are almost exclusively seed eaters, and will need to wait until their food is more abundant before they undertake the arduous task of breeding and rearing a brood.

Because of their relatively late start, they produce a single brood annually.

By the end of summer, the birds will be ready to molt again. This time, the males exchange their trademark lemon yellow feathers for a more subdued hue. The vibrant colors give way to browns and grays with the males clinging to just a hint of the striking color that gives them their name.

Goldfinches are alone in their North American family of finches to exhibit this seasonal variation. Their cousins such as the house finch, purple finch and redpoll maintain their basic color scheme year-round, although the intensity changes with feather wear and molting.

There is something about that vibrant yellow. To the birds themselves it is a key to reproductive success.

But to this human, it is also powerfully alluring. Every April, I look forward to that spring triptych of yellows: daffodils, forsythia and goldfinches. It lifts my heart - I can't help but be cheered by that familiar hue.

I need these moments of color. So much of what we do is the routine stuff of life. Work and routine are essential, to be sure, but they are not typically filled with the exuberance that gives special joy and meaning to our lives.

That lemony yellow of the goldfinch, perfectly set off by the stark blackness of his cap and wings, is a visual demand. It makes my eyes immediately lock in on these handsome birds as they fly across the yard with their bounding flight. It says, "Stop now, and look at me. Feast your eyes for a moment on the beauty of a finch in flight."

At a certain biological level, this desire for color seems to be hard-wired. Medical research shows that patients who can see the vibrant colors of the natural world heal faster than those who can see nothing but the institutional beiges of most hospitals.

These moments transport me out of my daily routine and remind me of the need for color in my own life. Striking photographs grace my office walls. My eyes delight in the Amish quilt hanging over a chair in the bedroom. These bold colors touch something primitive in me, and they invariably leave me wanting more.

Today's backyard goldfinches are re-enacting a ritual as old the species itself. And for the last 15 years they have helped to usher in spring for me. Their bouncing flight carries them from feeder to tree and back again.

And with each winged bound, they lift my spirit a bit more. Welcome, spring.