Saturday, March 22, 2014

ID: Western, Cassin's, and Tropical Kingbird

Western Kingbird
Western Kingbird. Hines, Oregon. May 24, 2009. Greg Gillson.
The identification of yellow-bellied kingbirds in the western United States is fairly straight-forward. The differences, though, can be hard to remember if you are only use to seeing one of the species regularly. Here I discuss Western, Cassin's, and Tropical kingbirds. A fourth, the Couch's Kingbird is only found in Texas and is almost identical to Tropical in plumage, but has a different call, and is not considered here.

The Western Kingbird is the summertime kingbird likely most familiar to birders in the western United States and the extreme southern parts of western Canada, wintering in Middle America. It is found in open rural agricultural areas and similar grassland habitats with scattered trees.

I found a tree with 4 migrant Western Kingbirds, here in San Diego County, on the last day of September, last year. That was immediately after moving here, and that was the first and last for me (in the county), so far. I expect them to arrive in April and stay common into August.

The main identifying marks of this large flycatcher are the pale gray head, breast, and back, the pale yellow belly, and the black tail with obvious white outer tail feathers. The common calls of Western Kingbird are a series of harsh "kit" notes often running into a chatter.

Cassin's Kingbird
Cassin's Kingbird. Dairy Mart Pond, San Ysidro, California. March 2, 2014. Greg Gillson
Cassin's Kingbirds are found in summer in the Southwestern US, even to eastern Wyoming. They are also year-round residents in southern coastal California, and south mainly in Mexico. They like open woods and the wilder edges of residential areas with tall trees and open spaces.

Cassin's Kingbirds have expanded their range in southern California in recent decades. In the early 1980's I recorded them only twice in 5 years of living in Ventura County. Now, here in San Diego County, they are common everyday birds year-round in tall trees, especially eucalyptus.

Compared with Western Kingbird, Cassin's has a darker gray head and chest, and clearly defined white throat. The blackish tail often shows a pale tip, suggesting the white tail tip on the Eastern Kingbird, but not nearly as broad, white, or obvious. The call of Cassin's Kingbird is a loud, hoarse "chi-KEER."

Tropical Kingbird
Tropical Kingbird. Dairy Mart Pond, San Ysidro, California. March 2, 2014. Greg Gillson
Tropical Kingbirds have a wide range from South America to Mexico. They barely reach SE Arizona and southern Texas as breeders. However, in the fall a few birds of this species undertake an unusual post-breeding dispersal to the north. Individuals show up on the immediate California coast northward to British Columbia. By "immediate coast" I mean residential areas and golf courses within a mile of the beach. They generally arrive in Oregon in late October and rarely remain to December--it seems a long ways to travel for such a brief period and no obvious reason we humans can determine. But since they are so rare when they venture northward in the fall, they are fun to find! Some birds are found in winter in southern California and Baja, Mexico.

Such was the case 3 weeks ago with the bird above. I was taking photos of the Cassin's Kingbird (two photos above) when I noted something different. This new bird (above) had a browner tail--not black--and it was notched, not straight across the end. Looking more closely I noted a longer, heavier bill. The yellow breast comes all the way up to the white throat. There is no gray across the breast, though the yellow does darken to greenish-yellow. The back is also greenish, not gray as the other two kingbirds we discussed. I've never heard the calls of Tropical Kingbird on their northward journeys. Evidently, though, they have a high-pitched chittering, very different from the calls of the other two kingbirds.

Hurray! Another new bird for the county. This was County Bird #225 and County Year Bird #182.