12/1/24: Clock-work

Transcript

“There are cuckoos in Maine?” This is often the question that follows any mention of these birds.  

I can understand the confusion, however. Despite spending every chance I could in my family’s woodlot beside the Kennebec, I cannot recall ever having seen or heard a cuckoo during my childhood. In my mind, Maine’s cuckoos were confined to living room clocks. However, an offhand comment from an old-time birder about spotting a Black-billed cuckoo in the Belgrades piqued my curiosity, incidentally serving as one of the catalysts for my interest in studying Maine’s birdlife.

I would soon after learn that there were two cuckoo species to be found within the state: the aforementioned Black-billed Cuckoo and the Yellow-billed Cuckoo, both of which are secretive songbirds. Black-billed Cuckoos are a more widespread species and can be found statewide in Maine. Suited to a range of forest types, they are easily overlooked in the dappled light of the forest canopy in their gray-brown plumage. Those who have the pleasure of viewing these birds well will note a striking ring of crimson about its eye, a long tail, and a black decurved bill.

Dubbed the “raincrow” due to their habit of singing on cloudy days often ahead of storms, Yellow-billed Cuckoos don’t nest quite so far north in Maine, breeding within forests just a hundred miles or so from the coastline. Although somewhat similar in appearance to their Black-billed relatives, they sport a spotted tail, cinnamon flight feathers, and the bright yellow bill which earned this bird its name. 

Both birds are caterpillar connoisseurs, eating many species often characterized as pests. Webbed caterpillar nests marked with holes are a good indicator of cuckoos nearby. Some of the caterpillars selected do not exactly appear like choice forage, especially those bearing spiny, indigestible hairs. In order to make use of this sometimes plentiful albeit prickly food source, cuckoos have adapted the unusual yet useful ability to regurgitate their entire hair-riddled stomach lining. Years when the caterpillars are particularly numerous, these birds sometimes lay additional eggs in the nests of other birds in addition to incubating and brooding the young in their own nests.

On a late spring morning, I had trudged into a scrubby wetland within a utility corridor a few miles from home. Standing on a bare knoll, I scanned the surrounding scrub, cattails, and adjacent forest for birdlife. Swamp Sparrows, Alder Flycatchers, and Red-winged Blackbirds abounded within the marsh while a Red-tailed Hawk spiraled above. Suddenly, a song was taken up within the adjacent forest: “cu-cu-cu-cu, cu-cu-cu-cu, cu-cu-cu-cu” [recording]. My first Black-billed Cuckoo of the year. Seconds later, two additional Black-billed cuckoos glided over the clearing towards the singing bird. Observing a single cuckoo is a treat. The peak of Black-billed Cuckoo migration had spoiled me with three.

I would encounter another cuckoo in midsummer while encamped along a stretch of the Androscoggin just south of where the Western Mountains enter the state. Massive silver maples flanked the river on both shores, allowing only scattered sunlight to percolate through their foliage to dance on the amber water’s surface. The day was oppressively humid and hot. Standing knee deep in the cool water, I tried for better looks of the riparian birdlife within the shade along the river. A soft, slow refrain- “coo-coo-coo-coo-co-co” [recording] arose from the opposite bank. A Yellow-billed Cuckoo this close to the mountains? As I cupped my ear to listen, another bird vocalization caught my attention. “kikikikikikik” [recording] – another Yellow-billed cuckoo responding. This second bird was just a few trees distant from my position. Settling in on the bank, I observed the bird on the opposing shore silently cross downstream before slowly making its way to meet the second in the maple bower overhead, singing all the while. Hunched forward, it puffed its throat and bowed its body with every note. For a time, it sang unhindered with a caterpillar clasped within the tip of its bill. Although this riverine forest certainly had the trappings of suitable habitat for Yellow-billed cuckoos, the location was notably on the northern edge of their known breeding range within the state. 

Cuckoo vocalizations taper off in the late days of summer, around the time when the last of their young fledge. At the conclusion of the nesting season, however, young cuckoos tend to wander and during this dispersal period, cuckoo songs can be heard once more for a time. Both species will remain near their breeding grounds until early Autumn before commencing with long journeys to their non-breeding grounds. Black-billed Cuckoos leave sooner- bound for the scrublands and tropical forests of western South America. Yellow-billed Cuckoos linger a short while longer before departing for riparian woodlands East of the Andes. Until their return in spring, we’re left to content ourselves with clock songs or else no cuckoos at all.