If you ever see a small brown mouse climbing up a tree and then fly away, you might at first think you are hallucinating. Perhaps you were half in your cups, tired from too much work, suffering from seasonal affect disorder or severe cabin fever? But that might not be the case. You may have just spotted the little known and unobtrusive brown creeper or Certhia americana.

Brown creepers have evolved to escape your detection while they peacefully pry insects from the bark of trees. At only four inches long, these mottled brown birds look very much like little mice as they climb. When they remain still, they all but disappear by blending in with the heavy grooved bark upon which they prefer to feed.

With their brown backs, streaked heads and white bellies, they blend in with the timber, and you might think they are the rarest birds around. Although they breed in dense stands of mature mixed hardwood forests at higher elevations of the Appalachians and Rocky Mountains, during the winter brown creepers disperse into the suburbs wherever large trees grow. So now is the time to find these birds in local woodlots, yards and parks.

In fact, New London County is a good place to spot these birds because there are many areas with these older and bigger trees. This is especially true along the I-95 corridor, where there are some massive red and white oaks. Devil’s Hopyard State Park is known to yield a few brown creeper sightings each year, too.

Many devoted birders have yet to see a brown creeper. Finding one gives you the thrill of a rare bird sighting, though it truly isn’t. Yet, in all my time trapesing through the woods, I have only seen 20 or so. Needless to say, it is always a thrill and more than that an intrigue. You stand there and wonder how many times you might have walked right past one.

Strange little birds they truly are. I remember the first time I saw one and how I was so puzzled at what seemed an illusion. Just a kid, I ran home, looked it up and learned all I could. To this day, I remain fascinated with the species. They build their semi-enclosed oriole-like nests, which sometimes have an entrance and exit hole, behind a piece of bark.

Not long ago, a (hysterical) soccer mom came running down my street to confess she was concerned about her son, who had just told her he had seen a “rabid brown leaf ” floating up and down a tree trunk in my woodlot. It took me a while, but I soon figured he had seen a brown creeper. I quickly retrieved my field guide from the back seat of my car and had her read the description, lest she consider sending her son for an unnecessary psych evaluation.

Perhaps it is a good thing we don’t see this unusual little woodland denizen often — otherwise we might have a whole bunch of people doubting their senses. But before you do go crazy from cabin fever, be sure to get out in the wonderful winter woods and maybe spot that ever-elusive brown creeper while they’re here.

Robert Tougias is a birding author living in Colchester. You can ask him birding questions at rtougias@snet.net.