When restoration began in Somme Woods, the ground under the trees was bare. This preserve supported few birds, butterflies, snakes, or animals of any kind.
Our hypothesis from the beginning was that restoring health and natural diversity to the plant community would also be good for the whole ecosystem, including its animals.
But that was a hypothesis. Little such experiment has been done. Less has been tested scientifically.
We spend most of our time as stewards working to bring back the herbs (herbaceous plants: grasses and "forbs") ("forbs" is a technical name for wildflowers). In a few mere decades we could show that basic restoration techniques could, at least for the foreseeable future, conserve large numbers of rare or uncommon plant species and gene pools that would otherwise have been lost. Most of plant diversity, even in woodlands, is among the grasses, sedges, and forbs.
This post was inspired by the impressive abundance of migrating birds feeding down in the herbs on September 24, 2024. A brief study on one day proves little. But it encouraged me to hypothesize yet more.
This year I'd been noticing large numbers of warblers flitting among the uncommon asters, goldenrods, and grasses that now grace increasingly large areas of the Somme woodland fall understory. This seemed new. When the brush is first cut, there follow seasons of bare ground and then aggressive "weedy" forb species. In the past these "weed patches" had attracted migrating sparrows, to eat seeds, but not warblers.
Few people perhaps would notice these little insect-eating migrants. Even when I found time to study them with binoculars, they were largely obscured by vegetation, or moving so fast, flitting from flower to flower and stem to stem that I failed to identify most of them. But in a few minutes I counted twenty migrating warblers of five species, and they carried a message.
The most abundant was the Nashville warbler with eleven individuals. Like many warblers, they're mostly coming from Canada and heading for Central America or the Caribbean or the Amazon to spend the winter.
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| Nashville Warbler |
Second most common were the black-throated green warblers (4 individuals identified) and the western palm warblers (3 individuals) - two species which typically spend their migration hunting time in very different habitats.
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| Black-throated Green Warbler |
In the past I mostly remember seeing the black-throated green high in mature trees. But on this warm and pretty day, hungry for insect fuel to power their long flights, they seemed to be going where the food was. I saw none feeding up in the trees. They hovered in front of flowers or jumped from stem to stem.
Western palm warblers spend their summers in open bogs and their migration in prairies, fields, and dunes. Here they were in the herb understory of the woods, where I also saw one yellow-rumped warbler.
The other migrating warbler I saw today was an ovenbird. These handsome stripey-breasted characters hunt mostly on the ground in mature forest under thick shrubs. Or herbs? I've wondered if they might even return to nest here, as the habitat improves.
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| Ovenbird |
The wildflowers and grasses these birds flitted among included elm-leaved goldenrod, Short's aster, wood reed, silky rye, and woodland thistle. I saw these birds mostly in areas of improving diversity and quality.
Summer nesting birds had responded more quickly. In summers, the birds we see feeding in the herbs include the indigo bunting, yellowthroat, blue-gray gnatcatcher, hummingbird, and bluebird. Actually the bluebird perches on a low tree branch and watches like a hawk, until it sees a tasty bug and plunges down into the herbs to catch it. Once I was surprised to see a pair of scarlet tanagers foraging from flower to grass to flower, feeding on insects, leaving their expected high-in-the-trees habitat behind. This is not a common site, but then neither is an oak woods with abundant summer flora.
Also impressive in the breeding season are the flycatchers and woodpeckers. Dramatically more common than before restoration, the flycatchers we see (and hear) most often the great crested, the eastern pewee, and from time to time the kingbird, a flycatcher that nests across Waukegan Road in the savannas of Somme Prairie Grove, but finds food in the open areas of this woodland too. Flycatchers hunt from the trees, but the flying insects they feed on may mostly get their substance eating herbs. That's probably why there were few of them when this preserve was just trees.
Woodpeckers are actually close relatives of flycatchers, and they're a major Somme success story. It's easy to see the link in red-headed woodpeckers, which also often sally out from a perch to catch flying insects. They also eat the acorns and boring beetles that feed on wood. Long described as one of the fastest-declining birds on the continent, the red-headed was absent from the Sommes before restoration but now are represented by five or more breeding pairs every year.
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| Red-headed woodpecker feeding young |
The flicker is a woodpecker that mostly feeds on the ground. Eating insects living there, it was absent from Somme Woods when restoration started but now may be the most common summer woodpecker.
The pileated woodpecker also feeds on the ground a surprising amount of the time. Often they tear apart rotting logs for the delicious treasures within. But they like room to fly and have come back to Somme only recently.
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| Pileated woodpecker |
No habitat works for every bird. But restoring plant communities at Somme seems to work well for many species of conservation concern - including migrating fall warblers. More study of varying approaches to restoring habitats would help conservation prioritizing.
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If you might like to help Somme's fall seed gathering or winter brush cutting with bonfires, check the schedule here.
For other Somme Woods bird posts, see
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Acknowledgements
Mourning warbler photo from A-Z Animals
Red-headed woodpecker photo from Birds and Blooms
Pileated woodpecker photo from American Bird Conservancy
Other photo credits: All About Birds (Cornel Lab or Ornithology)
How wonderful. Isn't it just flabbergasting how organisms we think we know something about start violating our assumptions when we provide them with quality habitat that provides them choices?! We can learn a lot from literature and historical review and scientific data, but we still know very little, and how can we even ask the right questions if we aren't out in these places through the seasons simply seeing stuff!
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