The heat of a late summer afternoon begs for a nap, and people aren’t the only ones feeling drowsy. Some mammals have already checked out for a summer nap, and they have every intention of rolling the snooze right on through to next spring. The Belding’s ground squirrels of the Klamath Basin are gone except for maybe a few young still trying to pack on a few more ounces before the long sleep. Marmots, too, are settling down for an eight-month slumber. What a life.
These are the masters, the true hibernators that sleep so soundly they barely breathe. Their hearts beat ever so slowly, and their body temperature falls to within a few degrees of the surrounding air. Poke them with a stick (please don’t), and they won’t respond. Chipmunks and black bears are not considered true hibernators. They don’t sleep quite so soundly, and their metabolic rate doesn’t sink so low, and they will respond when poked with a stick.
Of the more than 10,000 species of birds in the world, only one hibernates, as far as we know. This bird is the common poorwill, and they can be heard in the evenings here in Jackson County. Notice I said “heard,” because they are very shy. Poorwills are the smaller counterpart of the whip-poor-will of the eastern United States. They roost and nest on the ground and are nearly perfectly camouflaged. If you want to see one, the best strategy is to drive slowly along the back roads where they nest and watch for the bright-red eye shine on or alongside the road. They patiently wait for insects to fly by and then flutter up to pluck them out of the air.
If you are wondering about the name, it’s the call. Their call is a rich, but soft “poor-will-ip.” The “ip” portion is so soft it is seldom heard.
Poorwills are more common in the drier portions of the state along rimrock-lined streams and open Ponderosa pine forests. Only in Jackson Country can you reliably find them west of the Cascades in Oregon. It’s been known for years that poorwills can be found at a few specific locations in Jackson County. Salt Creek Road off Highway 140 is one, along with the slopes of Roxy Ann Peak.
This spring, I discovered that they are more common in the county than previously understood. I found them at several relatively high-elevation sites, including Shale City Road off Dead Indian Memorial Road, Hobart Bluff, and at several locations in the vicinity of Mount Ashland. I discovered several accidentally as faint background sounds when recording warblers for my research.
So, do they hibernate in our area? This is where our knowledge of poorwills is lacking. Hibernating birds have only been found in the arid portions of Southern California and Arizona. No one knows whether they hibernate farther north. Fall sightings in our area are often outside their normal breeding habitat. This suggests they are birds on the move, probably heading south. Do they migrate and then hibernate in more southerly areas? Do the birds that migrate from farther north remain active in the winter and only individuals from more southerly populations hibernate? There is so much we don’t know about the natural world. There is plenty of room for young naturalists to enter the field and make important contributions.
Stewart Janes is a biology professor at Southern Oregon University. He can be reached at email@example.com.