I have learned that a walk in the woods at this time of year is best done very slowly. Each day there are changes in the forest flora from the day before.

The abundance of trilliums and bellworts are lingering, but the violets, spring beauties and trout-lilies are fading. Taking their place are growths of starflower, baneberry, wild lily-of-the valley and blue-bead lily. They add colors to the shading scene, but also lots of greenery.

But when it comes to growth in the woods of early June, it is the ferns that prevail. Many were a bit late this year to unroll from their fiddleheads, rising from the underground stems. These fern leaves (fronds) quickly reached up from the start and within a couple of weeks ostrich, interrupted and lady ferns stand 2-3 feet tall.

But as I wander here at the end of May, I am seeking movement in the trees. Wild plum, juneberry and cherries hold white blossoms while others are opening new leaves. All of these attract insects and the numerous little critters are met by a new crop of birds, many just back from migration. Their sights and sounds cause me to stop often and look up for these avian songsters.

In the treetops are vireos, flycatchers, orioles, grosbeaks and tanagers while various thrushes remain low. Nearly all are quick to sing when returning from wintering in the south. But the most abundant migrants now in the Northland are the warblers.

This group of small songbirds; only about 5 inches long, is very diverse and find Minnesota as a good place to nest or to pass through. More than 30 kinds can be found within the state and 26 of these are regular in our region during spring. Their small size and quick movements among the tree branches can make them a challenge to observe clearly, yet they add much to the season.

Flitting among the newly forming leaves, they find insect meals. Like many, I try to see all these species each spring. This may mean having patience, good binoculars and willing to search among the branches.

Despite the name of warbler, which refers to songs, most do little singing when first returning. They frequently travel with several kinds together in what has been called a wave. Often, we wander about to see them, and sometimes they come to us.

Such was the case during a recent May day. I went to a lakeshore site in mid-morning. The day was clear following rains of the previous day. Sitting on a lawn chair, I was treated to a warbler movement around me that continued for a couple of hours. When finally subsiding at noon, I had seen 13 kinds without getting up from my viewing site. The close views of these tiny flitting birds included ovenbird, redstart, yellowthroat, yellow-rumped, chestnut-sided, orange-crowned, black and white, parula, yellow, palm, Nashville, Tennessee and Cape May.

None of these are rare or unexpected, but seeing this many together was unexpected. Most of them will remain in the region for the breeding season while the others go further north. Seeing half of the 26 species at one place was great, but it did not end. Four more greeted me in my yard: pine, Blackburnian, black-throated green and black-throated blue.

I've seen all before, but it's delightful to see them again. The warbler migration of spring that we are fortunate enough to host in the Northland is one of nature's annual events worth observing regularly.