In the weeks surrounding the emergence of leaves on the shrubs and trees in the Adirondacks a rich variety of sounds, unlike that which is heard during any other time of the year, occurs in our forests. Some participants in this natural symphony bellow out a perky series of melodious notes, like the winter wren and red-eyed vireo, while others such as the robin and white-throated sparrow have a more stately quality to their voice.
A few, like the ovenbird and chestnut-sided warbler, contribute an intense and serious refrain to the mix, and then there is the soulful music of the hermit thrush, which frequently opts to perform solo after most of the other voices have subsided for the evening.
The hermit thrush, a common forest dweller, is slightly smaller than its distant cousin the robin and is more of a challenge to see. The rusty-tan plumage that covers the head, back, sides and tail of this thrush allows it to effectively blend into the shadows of the lower canopy and places of dense underbrush on the forest floor. Its white breast is heavily spotted, which matches the pattern of spots of light that filter down through the lattice of developing foliage and further increases the difficulty in seeing this handsome bird near the forest floor.
This hardy thrush is a seasonal resident of northern forests and returns to the Adirondacks in mid spring, just as the snow is finally disappearing from most wooded settings. Like the robin, the hermit thrush forages on the ground; however, it almost never strays onto lawns or into open fields to search for edibles. Rather, this bird remains among the underbrush scratching at the leaf litter with its feet and probing nooks and crannies among dead sticks and rotting wood with its bill for any morsel that can be ingested. Small soil bugs are its primary prey in spring as the nesting season arrives, although it will readily consume most small seeds that it finds.
Once a male establishes a pair bond with a female in mid to late April, the process of nesting quickly begins. The female hermit thrush constructs her cup-shaped nest directly on the ground in some sheltered spot, rather than in a tree or tall shrub. Beneath a small conifer in a patch of young evergreens, near the center of a thick cluster of witchhobble, or in the midst of an entangled mass of fallen trees are places known to harbor the nest of the hermit thrush.
It takes about a week for the female to complete the nest, which has an outer framework of strands of grass and weeds woven between small twigs. This grapefruit size outer structure is lined with hairs and feathers and eventually is reduced to the size of a tennis ball cut in half.
Should an intruder invade the personal space of the pair and get too close to the nest, one of the parents quickly signals an alarm. Initially, an upset adult produces a squawking mew-like cry resembling a call made by a catbird. If the creature gets too close to the nest, or is lingering in the immediate area for too long a period of time, an excited parent produces a brief whistling note. Both of these sounds indicate that a nest is close by and the parents are stressed.
Because of the limited visibility of the settings containing a hermit thrush nest, it is nearly impossible to spot one of these structures on the ground without causing an excess amount of grief for the parents. Should you happen to hear either of these sounds when hiking through a wooded thicket, it is always best to continue along your way and allow the parents to calm down and return to their duties of incubating their eggs and caring for the nestlings.
Listening to the soulful series of flute-like notes sung by the hermit thrush is just as delightful as enjoying the wailing cry of a loon. Whenever I encounter a male proclaiming ownership to a section of forest, I never fail to stop for a minute or two and enjoy the serenade. Because the male sings from a perch in the lower canopy, usually a safe distance from its nest, there is no need for concern that your presence may temporarily interrupt the nesting process. All thrush species have unique vocal talents and listening to any one of them is a treat; however I have a preference for the voice of the hermit thrush, which is one of the prime reasons I go for a stroll in a wooded area near dusk at this time of year here in the Adirondacks.
Photo courtesy Wikimedia user D. Gordon E. Robertson.