…and why feather evidence isn’t always reliable.
In July of 2018, I had the opportunity to go birding in Big Bend National Park, an ecological gem situated in the big bend (how fitting!) of southwestern Texas. The trip involved a road-trip tour from Atlanta with my very patient father, seeking birds and their feathers all the while.
That brings me to an unexpected sighting. In a parking lot in Sweetwater, Texas, I found this feather:
It is unmistakably a Ruffed Grouse (Bonansa umbellus) tail feather. The squared tip and thick terminal band are diagnostic (unique) traits of this species’ tail feathers–see the Feather Atlas scan here.
This is probably one of my more unexpected finds because the Ruffed Grouse’s normal range is nowhere near Texas, instead ranging in the northeastern United States and throughout Canada–see the Cornell Lab’s range map here. Additionally, the habitat in which it was found reveals another inconsistency. It was found in a parking lot adjoining a large grassy expanse, but Ruffed Grouse usually inhabit wooded areas with ample cover. I’ve considered a few explanations for the presence of a Ruffed Grouse all the way in Texas; perhaps a nearby hunting lodge stocks them for hunters, it stuck to a traveling car after a nasty roadkill incident in grouse territory, or it came from a rare vagrant. As you can see, these explanations range from mundane to extraordinary.
Let this be a cautionary tale that feather evidence can be an inadequate and confusing indicator of recent, natural activity of a species. There is no reliable way to systematically quantify how long ago a feather was shed, nor whether it traveled via wind, car grille, or even international importation, so any feather evidence should be combined with more definite signs such as recent calls or sightings in the vicinity to prove a species’s presence. It is important not to let emotions or expectations interfere with the identification process.