Up until last week, my birding friend Paul Markson and I had been feeling very guilty. Fellow bird enthusiast Ed Grew had told us about hearing whippoorwills in Bangor’s Walden Parke Preserve, as well as provided detailed instructions on the best times to hear them.

But for one reason or another, we couldn’t coordinate our schedules to make a trip out there. Finally, Paul managed to go but had no luck. The next morning he reported his unsuccessful venture to Ed.

“He was so disappointed,” Paul said to me later. “It was as if he had left a treasure out there and felt it was his fault I didn’t find it.”

We both resolved to get out there, both to save face as birders and to make Ed feel better.

We headed out there at dusk on a warm, humid evening and had great success. We heard three of the birds calling as soon as we got out of the car.

It’d been quite awhile since I’d heard whippoorwills, almost 11 years since I’d moved to Maine. I was living in Blue Hill at the time. Coming down Blue Hill Mountain at twilight, this little nightjar’s signature song kept me company going down the trail. I had always wondered why I hadn’t heard them more often.

According to The Birds of North America, certain populations of this bird are in decline, due to outright habitat loss, predation, and, ironically, maturation of forests. The birds do not seem to like a forest that is too closed in and dense, preferring a more open canopy with sparse ground cover. As ground nesters, they require some shade-providing shelter but need open spaces through which they can hunt for insects.

Like other members of this family, whippoorwills do not construct a nest but lay their two cryptically colored eggs amongst the leaf litter of the forest floor. Once the eggs hatch and the chicks go through their first molt at about eight days of age, the female leaves them in the care of her mate while she lays a second brood.

Amazingly, the hatching of the eggs seems to be timed to periods of a full moon; as these birds rely on sight (with eyes adapted to low-light conditions) to capture insects, the additional nocturnal brightness enables them to meet the extra demands of feeding their chicks. Otherwise, whippoorwills forage only at dusk and dawn.

It is also then that the birds do most of their vocalizing. Again, the fullness of the moon will increase the tempo of their song and cause them to continue longer into the night.

As Paul and I hiked a little way into the preserve along a wide trail, we heard the birds calling “whip-poor-will” from the forest floor over and over again in the gathering twilight. Overhead, we heard the familiar flight call of its cousin, the common nighthawk. This wonderful night music seemed to be amplified by the soft, muggy air. As it grew darker, the birds called less and heat lightning flashed intermittently, lending a surrealistic quality to the place.

It may not have been a brilliant night with a full moon, but this was the next best thing.

BDN bird columnist Chris Corio can be reached at bdnsports@bangordailynews.net