Gelett Burgess may have avoided purple cows*, but a Purple Sandpiper is a different matter. During the last week of 2016, I was one of hundreds of birders who flocked to Dillon Reservoir, in the Colorado Rockies, for a glimpse of this misplaced bird. For a species that winters along the Atlantic coast and summers in far northern Canada and Greenland, an individual spending the holidays in Colorado was a bit out of the ordinary. Perhaps it was fooled by the unseasonable weather we had a month or so ago—or perhaps it simply got lost.

Finding the bird was easy—just look for the birders, identifiable by their scopes and cameras. We followed the nicely compacted trail leading through the snowy field to the inlet where a stream fed into the mostly frozen reservoir. And there the bird was, feeding in the running water along the bank.

Wary of getting too close—I didn’t want to flush a bird who was working hard to survive in a less-than-hospitable location—I hung back, hoping my long lens would make up for the added distance. Others weren’t so careful, and approached for a closer shot. Happily, the bird was too busy probing for something to eat to be distracted by the paparazzi.

As I studied the sandpiper, noting its dark head, bill with an orange base, and bright legs, I was struck by how similar it was to a Rock Sandpiper.My photo of the Purple Sandpiper is on the left, while a Rock Sandpiper** is on the right:

Of course, that species isn’t normally found in Colorado either, preferring the rocky shores of the Pacific coast. Still, I wondered. How was this bird identified? If I hadn’t already seen all the news articles and posts by expert birders, I wouldn’t have confidently made the distinction.

 

Usually, it’s easy to tell these two species apart. If you’re on the west coast, you’re looking at a Rock Sandpiper. If you’re on the east coast, it’s a Purple Sandpiper. But what about a bird in Colorado? The Cornell Lab of Ornithology points out that “Breeding Rock Sandpiper has dark patch on belly; Purple Sandpiper’s belly is white.” Nice, but breeding birds are on the arctic tundra, and this was December.

They helpfully add that “Non-breeding Purple Sandpiper is darker than Rock Sandpiper, with brighter bill base and legs.” But “darker” and “brighter” are relative terms. This is where the internet can be a real help. While the illustrations in my field guides were very similar, I was able to go online, and study numerous pictures of both species. I now have a feel for “darker” and “brighter” as the terms apply to these two species. If I ever see either again, I’ll know which is which.

I’m not normally one to chase rarities, especially if I’ve already seen the species elsewhere. However, this was a lifer for me—the last one of 2016—and probably the only opportunity I’ll have to see it. (I have no plans to visit the Atlantic seaboard in winter, and the arctic tundra is pretty inaccessible.) Plus, this individual had been hanging around for a couple of week already, and was very likely to be there when we finally arrived. After all, where else could it go?

One of the families we met had stopped to see what all the fuss was about. They weren’t birders (the mom first through I’d said “sandwiper”!). When I explained how lost this bird was, she asked why we didn’t simply catch it and take it “home.” Why not, indeed?

I tried to explain that we observed nature, rather than  interfering with it. It’s tempting to try and rescue an individual, but we aren’t really doing the species any favors. In a sense, this bird is an experiment. If it survives, it may add this behavior to the gene pool, supporting a new migration route and increasing the species’ versatility. If it dies, at least it won’t influence other Purple Sandpipers to opt for a winter vacation in Colorado.

Whether or not the bird makes it to spring remains to be seen. It may hang around, or it may decide to take its chances elsewhere. When I saw it, it seemed active and healthy—but the cold season is just beginning, and weathering a Colorado winter at 9.000 feet is always a challenge. In either case, delighting hundreds of birders is a worthy accomplishment!
_____
* You may recall the poem by Gelett Burgess:

I never saw a Purple Cow,
I never hope to see one,
But I can tell you, anyhow,
I’d rather see than be one!

** Rock Sandpiper photo by Greg Schechter from San Francisco, USA (Rock Sandpiper) [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)%5D, via Wikimedia Commons