116 3rd St SE
Cedar Rapids, Iowa 52401
A warbler’s world
Yellow-rumped will hang around Iowa all month
By the time October rolls around only a handful of warbler species still are expected on the Iowa landscape.
While palm, Nashville, and orange-crowned warblers still are observed through the first third of October, it is the yellow-rumped warbler that will not diminish until the end of the month. In fact, the species is known to overwinter in Iowa as evidenced by increasing detection on Christmas Bird Counts since the early 1970s.
As yellow-rumped warbler is the “last warbler standing” at the end of the year, the same is true on the opposite end. Most individuals are migratory, being the first warbler species seen each year in Iowa, typically around mid-March to early April. Its ability to eat berries, as well as insects, is what gives some yellow-rumpeds the option to hunker down in the cold Iowa winters.
The yellow-rumped warbler probably is the most abundant warbler species in Iowa during migration. It is the only species that typically forms large flocks. A flock of about 500 was recorded by on May 2, 1992 at Dudgeon Lake WMA. I recorded about 400 at Swan Lake, Hawkeye WMA on April 24, 2019.
There are two subspecies of yellow-rumped warbler in the United States. The Western subspecies is known as Audubon’s warbler, which has only been recorded a handful of times in Iowa. The eastern subspecies is called myrtle. Another subspecies is Goldman’s. They are a sedentary species restricted to the Guatemalan highlands and are absolutely stunning. These subspecies may be given full species status in the future.
Iowa is purely a migrational stop for the myrtle, aside the few that stick around in the fall and decide to overwinter. The species’ breeding range is from most of Alaska and east all the way across Canada. Some can be found year-round in the Pacific Northwest. Breeders in the west prefer mountainous terrain, such as in the Rocky Mountains and the southeast Arizona “sky islands.” They also breed in northern parts of Minnesota, Wisconsin and Michigan and throughout several states in the northeast.
Wintering occurs in many states in the southeast and southern U.S. and into Central America and the West Indies.
A breeding male myrtle has a dark lores and auriculars, forming a black mask on the face. A white lower eye arc and white supercilium also are characteristic. The top of the head down the backside are a grayish coloration accented by dark streaks. The throat is white. The breast is largely dark with dark streaks that taper off down the flanks. Two large yellow patches are located on the sides of the breast.
The crown (top) of the head has a yellow spot and the rump, which gives the bird its namesake, is yellow. Females appear similar to males, but are more light brownish than grayish overall.
BIRDS OF OCTOBER
- Sparrows, sparrows, sparrows. Sparrow numbers and diversity should peak in October. Try “pishing” some sparrows in their habitat. Nobody really knows why birds, especially sparrows, respond to pishing. There is no vowel sound when doing a pish, just “Pshhhhhhh.” Repeat it three or four times quickly. Did it work? If you come across a bush or hedgerow with sparrows, first position yourself where you can get a good look. If doing photography, set yourself in a position with some good lighting. Then try to pish. Often, sparrow will pop up and sit on a bare branch just long enough to get a good look or photo.
- About 17 species of sparrows migrate through Eastern Iowa in October. Grasshopper, lark, and Henslow’s sparrows already have headed south by the start of the month. Dark-eyed Junco, American tree and fox sparrows will first arrive in late September or early October, with numbers ramping up as the month progresses. Sparrow species found in low numbers include clay-colored, vesper, LeConte’s and Nelson’s. Look for LeConte’s on the perimeter of marshy areas or in damp prairie. Look for Nelson’s in marshy areas. Swamp sparrows usually will be the most abundant sparrow species while looking for Nelson’s.
- Some of the best places to look for fall sparrows are at Hawkeye WMA in Johnson County. Hedgerows, brushy spots, wet prairies and large wood piles can be some of the best habitat to find large congregations of sparrows. Some productive roads to cruise include hedgerows along James Avenue NW north of its intersection with Swan Lake Rd NW, grassy to brushy ditches along Swan Lake Rd NW west of its intersection with Half Moon Ave NW, marshy areas along Greencastle Ave NW north of its intersection with Swan Lake Rd NW, and wet prairie areas along Swan Lake Rd NW where the road runs north/south and just to the southeast of Matson Pond.
OCTOBER BIRDING CALENDAR
- Oct. 6 and 20, 8 to 10 a.m. — Kent Park Bird Walk with Rick Hollis. Meet at Kent Park in the parking lot at Conservation Education Center. Walk with Rick along his patch of mulched and mowed trails. We’ll spend about two hours observing breeding and migrant birds throughout the seasons. Group size is limited to 10 people who are COVID vaccinated. Sign up here or contact Rick through Facebook.
- Oct 10, 7 a.m. to noon — The Big Sit at Sugar Bottom Recreation Area Day Use Area, 2192 Mehaffey Bridge Rd NE, Solon. Drop in at any time to count birds and enjoy the camaraderie, free coffee and doughnuts. The objective of this worldwide, semi-competitive birding event is to tally as many bird species as can be seen or heard from within a 17-foot circle. Join team hosts Terri Macey and Linda Quinn near the parking lot at the Day Use Area, near the beach and restrooms. Bring a chair and binoculars.
Brandon Caswell has a keen interest in natural and social sciences. He enjoys bird-watching and nature photography in his spare time. He resides with his wife and two young children in Marion.
A breeding male myrtle yellow-rumped warbler clings to a vertical stalk at Pleasant Creek SRA in April of 2018. (Brandon Caswell/correspondent)
A fall myrtle yellow-rumped Warbler at Cedar Lake in October of 2019. (Brandon Caswell/correspondent)
A breeding male Audubon’s yellow-rumped warbler in late May of 2015 at Elkhorn Hot Springs, Mont. The yellow throat on the Audubon makes them a particularly dapper warbler subspecies. (Brandon Caswell/correspondent)
An adult LeConte’s sparrow at Hawkeye WMA in early October 2020. Last year there was a large concentration of this species along Swan Lake Rd NW, just southeast of Matson Pond. (Brandon Caswell/correspondent)
An immature Harris’s sparrow near the intersection of Swan Lake Rd NW and Babcock Access, Hawkeye WMA in early November 2019. More common in the western half of the state, finding a Harris’s in the fall in Eastern Iowa is always a treat. (Brandon Caswell/correspondent)
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