Thursday, November 5, 2015

A Different Thrasher in North Carolina

For the second time in two months I made a chase for an ultra-rare bird. Last Wednesday I was off at 4:45 AM for Swannanoa, between Black mountain and Asheville, to look for a sage thrasher that had been found on the campus of Warren Wilson College.

There are only two previous records for sage thrasher in North Carolina, and none since 1975. This is a super-rarity anywhere in the eastern United States. The specie’s normal winter range is south and west Texas west to Arizona. They nest in the sagebrush of the western United States. As thrashers go they are very small, about eight and a half inches long. For comparison our local thrasher, the brown thrasher, is eleven and a half inches long. But all other marks clearly identify the bird as a thrasher; the streaked breast, yellow eye, long tail, and slightly drooped bill.

We arrived at the site, a weedy hedgerow with scatted shrubs and abundant multiflora rose and poke weed fruits, before 7:30 AM. Already there were four other birders from Winston-Salem present and as we approached they indicated the bird was in view and feeding intently. I raised my binoculars and ticked off state bird number 412. So easy it was almost embarrassing. Some birders had missed seeing the bird despite hours of looking, while others were catching intermittent brief glimpses during extended searches. Sage thrashers are skulkers, prone to disappearing into thick brush for much of the time.

The sage thrasher is an olive gray on the back instead of the bright reddish-brown seen on our familiar brown thrasher. Thrashers are first cousins to mockingbirds, and from the back this bird looked remarkably like a Northern mocker; just not as clear gay as that species.

As is often the case with these rarities, the number of birders who will make the trip to Swannanoa to see the thrasher will approach or even surpass 100. At least one birder came in from New York. It’s been forty years since the last occurrence in North Carolina so it is a new state bird for virtually every birder in the state.

Below is the actual sage thrasher currently being seen in Swannanoa, NC. Note the olive-gray upperparts of the sage thrasher in comparison to the bright reddish-brown of the brown thrasher pictured below the sage thrasher.

Sage Thrasher by Rob Van Epps

Brown thrasher by Lee Weber
Otherwise, the profiles and other markings are similar. The brown thrasher is much larger than the sage, by about 40%. The mantle color of the sage thrasher is actually closer to that of Northern mockingbirds. though the general shape of the closely related species is similar, with a good view it is easy to see the overall differences between the two. With only a rear view, an inexperienced birder could overlook the sage thrasher i suppose.

Northern Mockingbird by Cathy Miller