Although Memorial Day weekend in Baxter State Park began with cool temperatures and gloomy, overcast skies, it still produced great birding opportunities.

There were many great bird sightings throughout the weekend, but on Monday the sun finally came out in all its glory, bringing warmth and voracious crops of black flies. It also encouraged the warblers, which became much more vocal and conspicuous, making it easier to see and observe them.

I opted out of another hike and went canoeing on South Branch Pond instead. Afterward I went birding around the campground, trying to ignore the black flies as best I could. I soon noticed two American redstarts singing nearby.

At first I thought one was a female, because it lacked the gorgeous orange-red and black coloring of an adult male. Instead, its upper body and head was grayish-olive; its under-body was white. Instead of the male’s flashy orange patches on wings and tail, this bird had pale yellow counterparts.

Once I had arrived home and done some research, I realized this bird was actually a “first- year” male. Unlike most warblers, redstart males don’t acquire “adult” plumage until their second summer. In other words, the summer when they’re born is their “hatching year.” They migrate to wintering grounds in Mexico, Central and South America, returning the following spring for their first summer. They are sexually mature despite their appearance.

These first-year males will attempt to establish territories and attract mates, but are rarely successful. They sing a repetitive song with an accented ending, as the one I observed was doing. In fact, its song sounded a bit similar to a chestnut-sided warbler’s, but not quite right. American redstarts are notorious for being difficult to identify by voice, as they have many song variations.

The other redstart was in a clump of birch trees surrounding a small grassy glade, located on the other side of the campground parking lot. This bird had acquired his full adult plumage, and sang a song very different from the younger male; his was more varied and less repetitive. Both seemed to be singing in response to the other. I wasn’t sure if the older male had acquired a mate yet, and I wondered if the young one had a chance. If he doesn’t attract a female soon, he’ll move to another area within a few weeks, stake out a territory, and try again. If he remains unsuccessful, he’ll depart for his wintering grounds much earlier than older birds that have mated and produced offspring.

Plumage in these warblers serves a function other than reproductive status. If you observe a redstart, you may notice the bird flicking its wings and flaring its tail, “flashing” their brightly colored patches. This flushes their insect prey out of hiding.

And it has earned them some endearing nicknames. In French, it is called “Petit du Feu,” which I believe translates into “little flame,” or “little fire.”

I could think of nothing more fitting for such a striking, endearing bird.

Chris Corio, a volunteer at Fields Pond Audubon Center in Holden, can be reached at fieldspond@juno.com