What to watch for in August: Miscellaneous Migrants

It’s hard to believe, but several bird species have already started migrating south from their breeding grounds to their wintering grounds. August is the month when many returning shorebirds drop in around Austin. Judging from late July sightings, they are right on schedule. The best places to look for shorebirds are the Hornsby Bend Biosolids Management Plant ponds and Bob Wentz Windy Point Park on Lake Travis. Three of the more common species to look for are Western, Semipalmated and Least Sandpipers. There are subtle differences between these three species and identification can be challenging, especially since they are often seen at a distance. It’s okay to just call them peeps.

Western Sandpiper. COURTESY: Jeff Osborne

Western Sandpipers are one of the most abundant shorebirds, with an estimated population of 3.5 million worldwide. They are small birds, about 6.5 inches in length, with a 14 inch wingspan. Long distance migrants, they breed only along the coastal tundra of western Alaska and far eastern Siberia. The fact that they concentrate in such a small area, putting all their eggs in one basket so to speak, is cause for conservation concern, as one disaster or disease could jeopardize the species. They winter across a broad range of the U.S. Pacific, Atlantic and Gulf Coasts and down into Central and South America primarily along the coasts. In winter they can also be found in smaller numbers along inland lakes, where they can find aquatic invertebrates along muddy shorelines. Females are often larger than males, and have longer bills. Females also appear to winter further south than the males do. It is hypothesized that this gives the males an advantage in staking out a breeding territory before the females arrive. Adults leave the breeding grounds before the young of the year do, which is fairly common in shorebirds.

Western Sandpipers have been well-studied at a stopover site in Kansas called Cheyenne Bottoms/Quivira National Wildlife Refuge. Adult migration there runs from early July to late September, peaking in mid-August. Juveniles start arriving in late July, and continue through early October. Adult birds stay longer at fall stopover sites than at spring sites. This allows them to molt their flight feathers so they can more easily complete their journeys. If you are wondering how you can tell juveniles from adults, juveniles don’t have the heavy spotting of the adults’ breasts in breeding plumage, and their faces are pale with no rufous on their crowns.

Semipalmated Sandpiper. COURTESY: Jeff Osborne

An interesting fact about the Semipalmated Sandpiper is that this species totally vacates the U.S. in the winter months. Contrast that with the Western and Least, in which at least part of the population can be found in U.S. inland and coastal habitats in winter. Semipalmated Sandpipers summer in the high Arctic all across Canada and Alaska. They are long distance migrants, wintering in northern and central South America on the coasts. A part of the population makes a 2,000-mile nonstop trans-oceanic hop from New England to northern South America. Unfortunately this sandpiper has had recent population declines and numbers about 2.3 million individuals worldwide.

Least Sandpiper. COURTESY: Jeff Osborne

The Least Sandpiper, which is the world’s smallest sandpiper, has a larger summer range across Canada and Alaska than the other two species, and can easily be found during winter in inland and coastal mudflats in Texas and other states from California to the Carolinas. Least Sandpipers are also considered long-distance migrants, with some of the eastern population flying nonstop to South America in the fall. The worldwide population is estimated at 700,000. The Least Sandpiper is more difficult to count than the Western and Semipalmated Sandpipers because it does not gather in huge flocks at key migratory stopover points like the others do.

The Least Sandpiper has yellowish green legs, not always easy to see, while the Western and Semipalmated legs are black. It is the brownest of the three in breeding and non-breeding plumage. The Least Sandpiper has short legs which give it a crouching look. It does not typically wade, preferring drier grassy and weedy vegetation near mudflats.

Drought conditions like Austin and much of Texas have been experiencing make migration more difficult for these and other migrants, as stopover wetlands and ponds dry up. If you make an effort to see these birds, such as on the Hornsby monthly bird walk mentioned below, give them a wide berth so that they can live to fly another day.

Other August Migrants

Mississippi Kites, Broad-winged Hawks, and Peregrine Falcons are raptors moving through Texas in August. Expect migrating Ruby-throated Hummingbirds to vie with Black-chinned Hummingbirds at your feeder and Yellow Warblers, an early migrant, might pop up at your bird bath.

Juvenile Mississippi Kite. COURTESY: Jeff Osborne

Compiled by Travis Audubon Volunteer Jane Tillman for KXAN.

Featured image: Yellow Warbler, courtesy: James Giroux.