Yesterday, a hike through a peaceful ridgetop woods in the Furnace Hills of southern Lebanon County resulted in an interesting discovery. It was extraordinarily quiet for a mid-April afternoon. Bird life was sparse—just a pair of nesting White-breasted Nuthatches and a drumming Hairy Woodpecker. A few deer scurried down the hillside. There was little else to see or hear. But if one were to have a look below the forest floor, they’d find out where the action is.
2021 is an emergence year for Brood X, the “Great Eastern Brood”—the largest of the 15 surviving broods of Periodical Cicadas. After seventeen years as subterranean larvae, the nymphs are presently positioned just below ground level, and they’re ready to see sunlight. After tunneling upward from the deciduous tree roots from which they fed on small amounts of sap since 2004, they’re awaiting a steady ground temperature of about 64 degrees Fahrenheit before surfacing to climb a tree, shrub, or other object and undergo one last molt into an imago—a flying adult.
The woodlots of the Lower Susquehanna River Watershed won’t be quiet for long. Loud choruses of male Periodical Cicadas will soon roar through forest and verdant suburbia. They’re looking for love, and they’re gonna die trying to find it. And dozens and dozens of animal species will take advantage of the swarms to feed themselves and their young. Yep, the woods are gonna be a lively place real soon.
It’s that time of year when one may expect to find migratory Neotropical songbirds feeding among the foliage of trees and shrubs in the forests, woodlots, and thickets of the lower Susquehanna valley.
During a late afternoon stroll through a headwaters forest east of Conewago Falls outside Mount Gretna, I was pleased to finally come upon a noisy gathering of about two dozen birds. It had, previous to that, been a quiet two hours of walking, only the rumble of an approaching thunderstorm punctuated the silence. Among this little flock were some chickadees, robins, Gray Catbirds, an Eastern Towhee (Pipilo erythrophthalmus), and a Hairy Woodpecker (Dryobates villosus). Besides the catbirds, there were two other species of Neotropical migrants; both were warblers. No less than six Black-throated Blue Warblers (Setophaga caerulescens) were vying for positions in the trees from which they could investigate the stranger on the footpath below. And among the understory shrubs there were at least as many Ovenbirds (Seiurus aurocapilla) satisfying a similar curiosity.
When they depart the Susquehanna valley, these two warbler species will be southbound for wintering ranges that include Florida, many of the Caribbean Islands, Central America, and, for the Ovenbirds, northern South America. Their flights occur at night. During the breeding season and while migrating, both feed primarily on insects and other arthropods . On the wintering grounds, they will consume some fruit. It is during their time in the tropics that the Black-throated Blue Warbler sometimes visits feeding stations that offer grape jelly, much to the delight of bird enthusiasts.
Black-throated Blue Warblers and Ovenbirds commonly winter on the Florida peninsula and in the Bahamas. With the major tropical cyclone Hurricane Dorian presently ripping through the region, these birds are better off taking their time getting there. There’s no need to hurry. The longer they and the other Neotropical migrants hang around, the more we get to enjoy them anyway. So get out there to see them before they go—and remember to look up.