Fall Migration on the Upper Texas Coast
Analysis by Don Verser
by Cin-Ty Lee
Houston's position on the Central Flyway makes it a hotspot for fall migration. The Upper Texas Coast witnesses a steady flow of migratory birds beginning as early as July and lasting through November. Many species hug the coastline on their way to South and Central America for the winter. Read more on the Migratory Flyways of North America on the Texas Parks and Wildlife web site.
Excerpt from "A Birdwalk at Bolivar Flats" by Cin-Ty Lee of Rice University.
By the first week of July fall migration has commenced as southbound dowitchers, Western and Semipalmated Sandpipers, Piping Plovers, and Black-bellied Plovers start to arrive. All of these will be adults in full breeding plumage. However, their breeding plumages will be duller and more worn-out than when we last saw them in April. This is because their plumage has had to weather two long-distance trips. Now some of these fall arrivals will actually stay to winter and some will continue on to more southerly locations. The former will molt into their winter plumages and the latter will just keep on going. In August, the major influx of juvenile birds will finally arrive. These will be characterized by beautiful, crisp clean plumages. The passage of juvenile birds will continue through September with some bleeding into October. By November, most of the southbound shorebird migration has stopped and the composition of shorebirds at Bolivar stabilizes.
Hawk migration begins in August. Within the city limits, in August Mississippi Kites soaring overhead are a common sight. Later in the season kettles of Broad-winged Hawks may sometimes be spotted. To fully appreciate hawk migration, though, visit Smith Point on the Bolivar Peninsula, site of one of the best hawk watches in the country. Hawks and many other species are naturally funneled to the tip of the peninsula where Smith Point is located. The Smith Point Hawk Watch is sponsored by the Gulf Coast Bird Observatory, which has built a 40 foot hawk tower. Counters and volunteers are at the Hawk Watch daily August 1 through November 15. More information about the Smith Point Hawk Watch can be found on the Gulf Coast Bird Observatory web site.
Migration begins in July and lasts through October; peak numbers are in September.
Swifts and Swallows
Peak numbers for Purple Martins are in July and August. The largest congregations of Chimney Swifts are in September and October. Not as well known are the spectacular numbers of swallows, particularly Barn and Tree, which may be seen along the coast August through October.
Fall Landbird Migration on the Coast
Birding is most often an adventure to observe migration. But migration is not one way and most all spring migrants can also be found in the fall. Some landbirds such as Chuck-will's-widow, Olive-sided Flycatcher, Yellow-bellied Flycatcher, Nashville Warbler, Prairie Warbler, Mourning Warbler and Canada Warbler are actually more common on the coast is the fall than in the spring. To fully appreciate the migration of landbirds try birding the coast in the fall starting in August or even July!
In early July the Black-and-white Warbler reappears and is suddenly very common on the coast and for me this marks the start of the fall landbird migration. The Blue-gray Gnatcatcher appears on the coast in late July and quickly becomes abundant in the first week of August. It is also interesting how Least Flycatchers become common at the end of July. And Louisiana Waterthrush is a very early migrant and the time to see it as a fall migrant is July and early August.
Empidonax flycatchers are especially common in August so this is a good time to study this particularly difficult group and attempt to learn their call notes. You may find that at times Yellow-bellied Flycatchers are abundant in the woods and that Alder is more common than Willow.
View the full article and Don Verser's spreadsheet of Fall Migration Data linked above. The data is presented as graphs and allows for species comparison.