By the time you read this column I will be back to school. All of the harbingers of this event have been present for some time now, though I will admit that I have tried to ignore them to the best of my ability. The first hint of this change of season came in the form of cicadas singing in the warm afternoon hours. Next came the songs of katydids in the warm hours of summer evenings. The disappearance of certain flowers, and the emergence of others (notably the blooming of turtlehead flowers in my meadow) have also given me plenty of warning. It is the beginning of the end of another summer vacation.
As bittersweet as this all is, I think that I shall attempt to focus on the sweetness of the season. The meadow that I spend so much of my time observing from the comfortable support of my Thinking Chair is simply bustling with activity. Crickets sing out with such volume that they appear as a hazy band of noise on the sonograms that I record while searching for birdsong. There is a huge family of blue jays that seem to arrive every morning at about 7 a.m. with the full expectation that I will have and endless supply of peanuts for them to collect and hide. Butterflies flit among the Joe-Pye weed flowers and I even saw a weasel cross the path through the meadow; more on that topic another time.
All of this is delightful, but an even stronger piece of evidence to suggest the change in season was the appearance of a juvenile chestnut-sided warbler (Setophaga pensylvanica) last week. When I saw that bright little face suspiciously peering at me from the underbrush I knew that things were starting to happen. I then went onto a website called “BirdCast,” which is run cooperatively by The University of Massachusetts Amherst, The Cornell Lab of Ornithology, and Colorado State University. I clicked on “Live Migration Maps” and there I found all of the evidence I needed. Starting at sunset, a huge wave of migratory birds came flooding out of Canada and into New England. The birds up north are already packing it in for the winter.
Here in Massachusetts we tend to see chestnut-sided warblers in two distinct waves. In the spring, when adult birds ready for the breeding season begin to appear in May, the birds are easy to identify. The males (seen on the left) are impossible to confuse with any other warbler species. The bright yellow cap, the black mask on the eyes and the namesake chestnut sides make this a spectacular bird to observe. Adult females have the same basic color scheme, but slightly more reserved. The black mask is not as full and the chestnut feathers on the side are more of a smudge than the bold stroke seen on the males. I also happen to find the pattern of black, white, gray and yellow on the backs of adult males to be gorgeous.
Chestnut-sided warblers are denizens of disturbed hardwood forest. They breed from Maine to Pennsylvania, with a thin line of habitat extending southward through the Appalachians. The breeding range then extends northwestward through Michigan, Wisconsin, Minnesota, southern Ontario, southern Manitoba and south central Saskatchewan. Throughout this range, the warblers will look for areas that have been recently disturbed and I have found that the areas under power lines are often extremely attractive to them. My own yard seems like it should be decent habitat, but the birds don’t
seem to agree. Thus, I see adults in the spring and then juvenile birds in the fall.
The juvenile (first-year) birds don’t look much like their parents. As seen in the right panel of today’s photo array, the young birds have a mustard-yellow cap that washes down the back. There is a suggestion of the pattern seen on the backs of adults, but there is no hint of any sort of black mask, nor are their any chestnut-colored swaths down the flanks. Instead, the face, chin, breast and belly are a light gray. It wouldn’t be unreasonable for a novice birder to think that these birds belonged to an entirely different species.
By mid September, the chestnut-sided warbler is identified as being uncommon and by the end of September they are typically gone from Massachusetts. Birds from the east spend their winters in the Caribbean, while birds from the western portion of the range will head for southern Mexico, most of Central America and the northern portions of Colombia and Venezuela. They will return in May, fanning out across their breeding range in search of recently-disturbed hardwood forests. Human activity, such as logging, can actually create wonderful habitat for these birds as long as the forests are allowed to regenerate from the disturbance. New forest is good, while parking lots are bad.
So, it is with great anticipation that I prepare myself for the fall migration. At this time of year the world will be full of juvenile birds that tend to be extremely curious about all of the new things that they see, including me! The scrutiny of a juvenile passerine is something wondrous and delightful to feel aimed in your direction and there are even times when young wrens and catbirds will commence with an energetic scolding; as if to see if whatever I am is dangerous or not. The constant presence of the chickadees will eventually reassure almost everyone that I am “safe” and then the photos start to pile up. I can’t wait.
Bill Danielson has been a professional writer and nature photographer for 28 years. He has worked for the National Park Service, the US Forest Service, the Nature Conservancy and the Massachusetts State Parks and he currently teaches high school biology and physics. For more information visit his website at www.speakingofnature.com, or go to Speaking of Nature on Facebook.