A nighttime stakeout for the western screech-owls of Big Bend National Park
Gary Clark, Correspondent
Aug. 3, 2023
During a recent stay in the mountains of Big Bend National Park, my wife, Kathy, and I drove to the historic desert oasis called Dugout Wells one evening.
We needed to get there before nightfall to see and photograph the Milky Way arching across the clear night sky. An old windmill churned and creaked along the edge of a dense growth of cottonwood and mesquite trees rising out of a brushy understory. Long gone was the schoolhouse that once stood at the location to educate children of early 20th-century settlers, as was the local community center.
While sitting on a picnic table along the wooded edge, waiting for nightfall, we heard the eerie songs of western screech owls deep in the woods. Their vocalizations are often described as sounding like a bouncing ball — an inadequate description.
Instead, the vocalizations are like basal tremolo tones from an old wooden flute, played at rising and falling pitches to create an echoing sound. A family of owls will utter vocalizations in a call-and-response pattern, with one set of vocalizations followed by another.
We walked quietly along the dirt trails through the woods and thickets to get a glimpse of the owls. Muted hues of their brownish-gray feathers refract scant light, making them difficult to see at eventide. We listened to locate owls by their voices.
But owls have hearing far superior to humans, and they had already located us.
Western screech owls are cousins and near look-alikes to eastern screech owls, which are common in local neighborhoods and parks.
Western and eastern screech owls were once considered the same species until studies showed the distinct difference in vocalizations between the two species.
Western screech owls inhabit West Texas, western North America and parts of Latin America. They live in various habitats that include mesquite trees in deserts, mountain canyons, tree-lined streams and even in urban and suburban communities.
They have round heads with small ear tufts, yellow eyes, a pale facial disk bordered in black and large prickly feathered feet.
Folk names include ghost owls, death owls and Guadalupe owls
I turned to see an owl perched 12 feet from me on a dead tree. Its burly body, with short tail and outsized feet, stood about 10 inches tall, about the size of a roll of paper towels. The bird moved its head up, down and sideways while pinpointing my position with its cone-like eyeballs for night vision; its large ear drums directed toward the slightest sounds of my rustling clothes.
Then it began vocalizing, and members of its group in other trees responded with their own vocalizations, creating an owl chorus that resounded through the dense woods. Their voices would often come from different directions, after they flew silently from one perch to another.
As the sky turned dark, the owls flew over the desert for their nocturnal hunt. They were looking for a bounty of nighttime prey — cottontail rabbits, rats, gophers, crickets and flying insects.
A nighttime stakeout for the western screech-owls of Big Bend National (houstonchronicle.com)
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