While many of the shorebirds are not as vibrant as the songbirds of the forests, they make up for the lack of colorful hues in their behaviors.
Many species will flash their wings in display or may sound up a chattery alarm call when alerted. Not all shorebirds are dull in coloration, but those covered this month are perhaps on the less striking side.
The yellowlegs are aptly named. Two species, the Greater and Lesser, belong to the genus Tringa. Two other members of the genus, Willet and Solitary Sandpiper, also share shallow Iowa waters during spring and fall migration.
The yellowlegs have long, slender yellow legs. Lesser Yellowlegs is smaller in overall proportions compared to Greater, with a shorter bill and legs. Both species are mostly grayish above with a white belly and undertail. Primary feathers are darker with dark mottling and banding observed on the backside closer to breeding season. The bill of Greater Yellowlegs generally appears slightly upturned. One common rule is if you imagine flipping the bill 180 degrees on either species in its anatomical position, the bill of Greater Yellowlegs will significantly pop out the back of the head, whereas for Lesser it will barely poke out.
Yellowlegs are among the first shorebirds to return to Iowa during the spring migration. Sightings of both species will pick up during the second half of March, usually waning out by the end of May. The migration window in the fall if more spread out. When they are southbound, expect seeing the yellowlegs from July to as late as November.
Many shorebirds can be identified by sound.
The yellowlegs certainly are no exception. Greater Yellowlegs tend to give a quick burst of three “tu” sounds, e.g. “tututu.” The Lesser has a slower “too too” call. While these calls can be difficult to discern in a large flock of either species, they can generally be helpful with single birds flying over or flocks of less than a handful.
Shallow water near mud flats is generally the type of habitat yellowlegs prefer. Each yellowlegs species typically walks through shallow water on the hunt for aquatic invertebrates and small fish. Greater Yellowlegs, since they have longer legs, can wade out in deeper water with larger shorebird species, such as Willet, stilts, avocets and godwits. Although less commonly seen, yellowlegs can inhabit wet, grassy areas, especially those interspersed with pockets of shallow water.
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The additional Iowa Tringa members, Willet and Solitary Sandpiper, bookend the sizes of all four species. Solitary Sandpiper resembles a small yellowlegs with a shorter, sometimes darker bill. It also has shorter, light-green legs and unique white spotting along the backside out to the tips of the flight feathers. Willet is similar in size to Greater Yellowlegs, but is stockier, has a thicker bill and gray legs. In flight or during a wing flash, the best field mark to identify Willet, especially at distance, is a broad white wing stripe in the middle of its black wings. The stripe is more pronounced on the underwing, but is clearly seen on the upperwing as well.
OTHER BIRDS TO LOOK FOR IN AUGUST
— Shorebirds. The peak of shorebird migration will usually occur sometime in August. Note the Iowa City Bird Club trip below, specifically catered to finding shorebirds. This is a prime opportunity to see them up close and personal with the aid of good guides and optics.
— American Goldfinch will be active raising young. Listen for their wide array of squeaky, bubbly sounds.
— American White Pelican already have increased in numbers at Hawkeye Wildlife Management Area in Johnson County. Their numbers should continue to increase, peaking in September when the pelican festival occurs. Last year the festival was canceled because of high water. This year, however, looks like water levels should be perfect by the time of the festival.
— Great Blue Heron and Great Egret numbers will start to increase at Hawkeye WMA. Keep eyes out for the more rare Snowy Egret and Little Blue Heron. Green Heron should be around as well.
— Grasshopper Sparrow and Lark Sparrow will be the first breeding sparrow species to migrate back south, fully waning out by late August.
— August 7, 8 a.m. — Kent Park Bird Walk with leader Rick Hollis. Meet at the Kent Park CEC.
— August 18, 8 a.m. — Hawkeye Wildlife Area for shorebirds and other early fall migrants. Meet leader Chris Caster at the HWA parking lot on Swan Lake Road, across from Swan Lake. (GPS coordinates, 41.776081,-91.675009). The group will carpool around HWA, finishing around noon. Expect moderate hiking at some viewing areas. Dress for the weather and wet and muddy trails. Bring a spotting scope if you have one, however, a top-level scope will be provided for those who want closer looks at shorebirds.
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— August 21, 8 a.m. — Kent Park Bird Walk with leader Rick Hollis. Meet at the Kent Park CEC.
— August 23-25 — Iowa Ornithologists’ Union Fall Meeting in Pella, with trips around the Lake Red Rock area. See iowabirds.org in the upcoming weeks for more details. You do not need to be a member of the IOU to attend the meeting. New birders or even those with moderate interests in birds are especially welcome and can expect great guides to help with any bird ID at hand. The meeting is for birders of all skill levels. There will be several lodging options for those who wish to stay the weekend. A book auction also will be held, which is a great opportunity to cheaply purchase all kinds of birding-related/bird identification-related material. There is usually historical material as well.
Brandon Caswell has undergraduate degrees in biology, anthropology and geology. His graduate degree centered on dating continental collisions within the Precambrian Canada Shield. Bird-watching and nature photography are among his favorite hobbies. He lives with his wife and son in Marion. Email firstname.lastname@example.org with birding-related questions, including questions about activities.