By James Reddoch
“Where are all the birds,” a friend asked recently? “I know fall migration is underway, but I’m not seeing anything like I saw back in the early spring. Have I missed it?”
You too may have noticed that things are much quieter in the woods at this time of year, but don’t be fooled. There are still plenty of birds to be found as fall migration continues. It just might take a little more work. Fall migration is very different than the frantic days in mid-May when birds were pouring into our region from further south. Why the difference? Here are a few possible explanations.
First, remember in both spring and fall most song birds are migrating at night. In addition to those adult birds who flew through this past spring, they are now joined by the young that are the product of this nesting season. Between the adults and juveniles, it means that thousands of birds, even more than in the spring, may have been flying over your house at night starting in September. This activity will continue through the month waning toward the end and heading into November. A helpful resource for seeing what is happening in our area on a given night is Birdcast. Birdcast uses ground-based weather radar stations to estimate the number of birds moving across a particular area. It turns out that weather radar that can detect clouds, rain drops, and snowflakes is just as good at detecting birds. Checking Birdcast on the last night of September, close to 3.5 million birds were estimated to have traveled over Oxford County Maine in one night alone. Obviously, we will only be lucky enough to see a tiny fraction of these migrating birds. But rest assured, they are out there. The question remains, why are things so quiet with all those birds out there?
A second reason might relate to those youngsters making their first migratory trip. Like females of most songbird species, these youngsters have drab plumage to help them stay hidden. I have learned to check small flocks of sparrows or chickadees moving around my yard. Some surprises might be found!
A third reason why you may not notice as many birds this time of year is because we often do not realize how much we rely on sound to zero in on birds. In the spring, birds arrive looking to establish the best breading territories. Song is one of the most obvious tools they have for claiming a territory and attracting a mate. In the fall, with breeding season over, birds are much quieter. At this time of year, the hormones that triggered all those territorial behaviors in the spring have dissipated and so has the almost frantic singing we heard back then. As an example, as I sit writing on my porch, a small flock of juncos feed quietly in front of me in the grass. Mixed in are a couple of white-throated sparrows. The birds are almost invisible in the grass and leaves. Occasionally one gives a chip-call, but otherwise they seem content to feed quietly in close proximity to each other. None of them are defending a breeding territory. As a result, they would be easy to miss without a little time and patience.
Migrating at night, drab patterns that blend in, and no singing are just a few explanations for why you might not be noticing as many birds during their fall migration, but rest assured there is still plenty to see. For example, when I first came out on the porch today, four birds flushed silently from the tall grass in the field. They were the size of blue jays but I saw no blue. What stood out instead was a bold, white patch on the rump of each of the four birds – northern flickers. These are normally noisy woodpeckers that nest in holes they have drilled into standing snags around my field edges. These four are probably just moving through. They were in the high grass searching for their favorite food, ants, to fuel the next leg of their journey south.
I now hear a blue-headed vireo in the tree line. It occasionally sings one stanza of its song, “Cheerio.” It is soft, almost calm, “Cheerio, see-ya.” Vireos are real jabber-mouths. They, especially the red-eyed vireo, can be heard in almost any forest at any time of day throughout the summer. Now, even vireos are quiet as they move south.
I catch sight of a larger, robin-sized bird skulking in the limbs of a big pine. It’s a yellow-bellied sapsucker. I hear the chip-call of a common yellow-throat deep in the high grass in the field. All of these birds are much noisier in the spring and therefore much easier for us to detect and see. Now they are calm, casual, and quiet.
Nevertheless, this time of transition provides opportunities. Get out there. The weather is beautiful. The bugs aren’t bad. Pause and listen for quiet chip-calls coming from your yard or along your walk. Sit for a few minutes. You may be rewarded with a surprising variety of birds as well as interesting behavior as these spring and summer visitors head home with youngsters in tow.
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