As March begins each year, I take to the trails to look for spring.

Each year, I wonder if I'll see something new and unusual -- a stand of wildflowers peeking through the leaf litter, perhaps? Or tree leaves bursting out into green? Alas, it never happens.

I guess I'm just ready for the warm spring breezes and an end to winter's taupe and gray palette.

This year, like all the years past -- and despite the non-winter we just experienced -- spring is, for the most part, still waiting in the wings. I returned to my desk at work determined to be patient.

But then I was saved by a flash of yellow, and I knew that spring is ready to be sprung.

The little American goldfinch at the Hogback Ridge Park bird feeders did not have to sing for me to hear its "spring-is-coming" message. It had only to show off a few head and neck feathers as it helped itself to some thistle seed -- yellow head and neck feathers.

The olive-drab bird comes to the feeders all winter, quietly blending in with its surroundings. Then suddenly, one day, it is brilliant yellow -- having seemingly transformed while I was sleeping. In reality, the molt is gradual, and it will be some time before my favorite little finch is bright yellow. But the promise of yellow is there -- and with it, the promise of spring.

I'm starting to hear spring bird song, too -- especially from the northern cardinals, whose "cheer-cheer-cheer, birdie-birdie-birdie" melodies brighten up even the rainiest spring day. The cardinal's voice is the one I hear most often outside my window at work. But I can also hear the tufted titmouse sing "peter, peter, peter," and the chickadee is whistling "phoebe."

These are all winter birds, but the changing light triggers their new songs, which are welcome melodies that always take me by surprise as winter wanes.

I'm seeing other spring signs as well. The buds of tree leaves are swelling; especially evident are the maple trees whose bare branches are showing a reddish glow. It does seem early for tree buds, but I recently read that if we have a cold snap, and the leaf buds are damaged, the tree can grow new ones. (That's not true with flower buds on trees, but that's another story.)

I have not visited Gallant Woods Park for a while, but my fellow Preservation Parks staffers tell me the spring peepers and other frogs are starting to ramp up their springtime melodies. If you have never heard the sometimes-deafening din of a wetland filled with peepers and chorus frogs, I encourage you to pack up the kids and take a trip up to Gallant Woods, 2151 Buttermilk Hill Road in Delaware. It's a sound you will never forget, and one you'll find yourself looking forward to hearing each spring.

As the new season nears, Preservation Parks is bringing out a whole new crop of programs to introduce you and your family to the natural world.

Preschoolers and homeschoolers can experience free programs on frogs and baby farm animals. Staff member and bird lover Craig Flockerzie will lead three early-morning spring bird walks March 25, April 29 and May 27, and naturalist Liz Neroni will host a two-day "Save the Frogs" weekend at the end of April. Delaware County Master Gardeners will team up with Preservation Parks for a couple of garden programs, and we have Earth Day fun April 23 and an Arbor Day event April 28 at Gallant Farm.

Of course -- as we do each year -- we'll welcome back ospreys from their winter homes in South America and watch them nest on platforms in the northern section of Alum Creek Reservoir.

There is so much to celebrate in the spring -- the warmth, the surging life and the parks. You'll want be a part of it.

Sue Hagan is marketing and communications manager for Preservation Parks of Delaware County.