September Bird Forecast

By Kristen Currie

Tailless Grackles – What Happened?

In August and into September our resident songbirds begin the process of molt to replace their feathers. As a result, they look pretty ratty for several weeks until their feathers grow back in. Perhaps you’ve done a double take at a tailless Great-tailed Grackle. It’s nothing to worry about. The birds are not sick, did not tangle with a predator or car, and the male grackles will be sporting their remarkably long tails soon.

Tailless Great-tailed Grackle – COURTESY: Jane Tillman

Amazing Migration

Birds of many species will be passing through central Texas in September, heading south. If you want to see what migration looks like check out BirdCast. It uses data from weather surveillance radar, and factors in wind, temperature, rainfall and barometric pressure to predict birds’ migration patterns. Scientists hope that by knowing when peaks will occur, humans can take actions to reduce the bird collisions that annually kill millions of birds. Targeted stoppage of wind turbines to allow hawks’ safe passage or turning off lights when peak migration is occurring have the potential to help stop the downward trend in migratory bird populations.

So, let’s look at some of the birds that will be passing through in September.

Wilson’s Warbler

A warbler that is a little smaller than the Yellow Warbler, and easily confused with Yellow, unless you get a good look, is the Wilson’s Warbler. Named for the father of American ornithology, Alexander Wilson, the male has a jaunty black cap on its otherwise yellow head. It has a somewhat olive-green back and bright yellow underparts. The adult female shows a variable amount of dark feathers on her crown. Young birds don’t have the black cap, but have a yellow eye ring and yellow eyebrow which set off their dark eyes. Wilson’s Warblers mainly breed in Canada and the western U.S. mountains, and have been recorded in every one of the lower 48 on their way to wintering grounds in Mexico and Central America. They tend to forage lower than other warblers, but are fast moving as they forage for insects. To increase your chances of seeing one, look in shrubby thickets along streams or pond edges.

Male Wilson’s Warbler – COURTESY: James Giroux

Bank and Tree Swallows

There are many swallow species in the Austin area, but two are more easily seen in fall migration, when they might join mixed flocks with the more ubiquitous Cliff, Cave and Barn Swallows. Swallows on the wing are challenging to identify. They eat insects so the best places to look for them are open fields or open water or marshy spots where they can course back and forth to catch insects on the wing. Once you’ve found their habitat, look for a place where they might be perching, on a utility wire, or in a shrub or tree close by. Then look down the row of swallows and focus on their size. The smallest one might be a Bank Swallow. Its most distinctive feature besides its diminutive size is its dark defined breast band contrasting well with its white throat and belly. If the Bank Swallow is in motion, listen for its electrical sounding call, like a buzzy zhritt.

Bank Swallow – COURTESY: Greg Lasley

The Tree Swallow is a striking swallow. The adult male has a blue-green back, set off by a bright white throat and underparts. Some females resemble males or have at least a few blue-green feathers. The young are drab brown above, but sport the same clean white underparts. Young Tree Swallows may be confused with young Banks due to their grayish (but blurrier) breast bands and similar brownish backs.

Tree Swallow – COURTESY: James Giroux

Both Bank and Tree Swallows are uncommon nesters in Texas, with the Tree Swallow the more expected of the two. Fun facts: The tiny Bank Swallow digs a burrow about 25 inches long for its nest in eroding river banks or even in road cuts and sand and gravel quarries. Tree Swallows have been noted “playing” by tossing and catching feathers.

Eyes to the Skies: Raptor Migration Underway

If COVID restrictions allow, consider taking a day trip to the Hazel Bazemore County Park hawk watch just north of Corpus Christi, during late September. While late August and the first week of September are known for Mississippi Kite migration, the last three weeks are famous for the number of Broad-winged Hawks passing through Texas en route to Central America and northern South America. Hawk migration is one of the great spectacles of nature, and catching migration on a good day at Hazel Bazemore when 50 to 100,000 raptors fly over is awe-inspiring. Hazel Bazemore’s location and topography act to funnel the raptors south since they typically avoid flying over large bodies of water like the Gulf. Plus you may see other migrating species, too, like Anhingas, American White Pelicans and endangered Wood Storks.

Migrating Broad-winged Hawks – COURTESY: Jane Tillman

Migrating Anhingas – COURTESY: Jane Tillman

But wait. Aren’t hawks migrating through Austin? Yes, they are, but it takes a little more effort to see them. The birds are flying high, and on a clear day with few clouds to provide contrast, they are difficult to see. Sometimes cloud cover will bring them down lower. Remember to look up periodically throughout the day especially from mid-morning to mid-afternoon.

Compiled by Jane Tillman, Travis Audubon Volunteer