Northland Nature: Yellow warblers sing 'sweet' melody
Retired teacher Larry Weber, a Barnum resident, is the author of several books, including “Butterflies of the North Woods,” “Spiders of the North Woods,” “Webwood” and “In a Patch of Goldenrods.” Contact him via Katie Rohman at firstname.lastname@example.org.
May has lived up to one of its names as “the greening month,” beginning as bare woods and ending fully green. Shrubs and small trees began this change, with larger trees being late. Once foliated, the woods that were so open and filled with sunlight became shaded.
Another attribute to this time, spring wildflowers, have waned. Though there are several species that are tolerant of shade and continue to flower, the time of spring beauties, trout-lilies and trillium is a memory.
And the forest floor now holds an abundance of ferns. Not only do these plants thrive in shade, they also grow quickly in June’s moisture.
At the woods’ edge, small trees are blooming. The trio of plum, juneberry and pin cherry that began with white flowers was followed by elderberry, crab apple and chokecherry with apple and lilac in our yards. May’s flowering has moved, but it's still here in June.
Another happening that is so much part of May is the migration of songbirds into the Northland from southern wintering. Migrants began arriving in earlier months with flights of raptors followed by many water birds. In April, some songbirds began to return. During 31 days of May, we saw the arrival of many more: thrushes, flycatchers, vireos, orioles, grosbeaks, tanagers, wrens and hummingbirds. But the most diverse group of spring migrants are warblers.
Each May, 26 species of these small birds move through the Northland. They arrive at about the same time as the emergence of insects and caterpillars among the newly formed leaves. They feed wherever they appear. Not with much singing, but with plenty of movement, they flit through the branches. As long as the trees are not filled with new leaves, we are able to see them. With a pair of binoculars (and patience), we can discern many. (Warbler identification can be difficult, but just watching their activity in the trees is a fine way to get acquainted with these migrants.)
About half of this group will remain to nest while others continue to journey farther north, where they breed in boreal forests. One that I look for each year not only as a migrant, but also a resident, is the yellow warbler.
While May is the month of migrant songbirds, June is the month of breeding songbirds. Yellow warblers are both. These small birds are not the only warbler to have this color. Plenty of yellow can be seen in about a dozen others. A few of these also have “yellow” in their names, like the yellow-rumped warbler and yellowthroat (not to be confused with a yellow-throated warbler, farther south). Others, such as Wilson’s, Nashville and mourning warblers have bodies that are largely yellow. Yellow warblers continue to add color and song to the scene.
Yellow warblers are about 5 inches long. The males have yellow feathers, but also red streaks on the undersides, while females are completely yellow.
They seek areas of small trees and shrubs for nests. During my walks in June, I regularly pass a swamp that has a growth of alders and willows along the edge. As I search for their bright yellow bodies, I also hear males sing territorial songs at these nesting sites. The song has been given the memory phrase of “sweet, sweet, I am so sweet.” Like many other local breeding songbirds, the song is repeated daily through June and early July, and is best heard in the early morning.
Singing and raising young will continue until the fledglings have moved on. But in June, they add a lot of color and melodies to the days.