116 3rd St SE
Cedar Rapids, Iowa 52401
While much is known about birds and why they do the things they do, it is undeniable that much more has yet to be discovered concerning their behaviors.
Birds always will have a mystical component about them no matter how much is actually learned or thought to be understood.
New “phenomena” may pop up every so often concerning new trends in bird adaptations or other witnessed behaviors. My past column on Swainson’s hawk revealed how this species has only recently swung or expanded its spring migration eastward.
Something even more fascinating has been in the works for several years and it now has an Iowa connection. This concerns the recent spread of the limpkin into novel areas of the United States.
The limpkin is an odd bird, looking like the mix between a rail, crane and heron. They have long, dark legs and huge feet, like a rail. Their upright posture is like that of a small crane.
They sound reminiscent of a red-shouldered hawk. This call, usually heard at night, is a loud, unmistakable wailing-like sound.
Limpkin are mostly brown-bodied, but also have white spotting on the wings, back, breast and neck. The bill is long and yellowish. The juvenile yellow-crowned night heron is the only other regular Iowa bird species it could probably get mixed up with.
Limpkin have been seen outside of Florida before, but not in the same way as they are now. A May 1956 record in northeast Mississippi and a June 1971 record in Maryland are two of the earlier “oddball” type vagrancy records. Several of the states in the southeast had limpkins records before the turn of the 21st century.
From 2014 to 2016, limpkin started to hop over the border from Florida to Georgia more readily. Many of these accounts noted birds were eating apple snails. By 2017, there was a nice pulse of expansion with multiple records dotting the southeastern states. Louisiana got its first record of a group of four on Dec. 30.
In 2019, limpkin demonstrated they wanted to expand well beyond the southeast. Ohio and Illinois recorded their first records. In 2020, a year when there was an incredible amount of local to regional bird-watching going on, vagrant limpkin sightings were surprisingly few. Sightings picked back up again in 2021 with Minnesota getting a mind-blowing record on May 30, just northeast of Minneapolis.
This year has seen an even larger number of birds disperse, with many Midwestern states adding limpkin to their “all-time” bird species lists.
Not surprisingly, the Iowa bird-watching community had been anticipating a limpkin sighting. On June 23, it happened in Lucas County. Jay Gilliam, an expert bird-watcher, was actually documenting dragonflies when a limpkin flew out from under a nearby bridge crossing the Charito River. This was right on the heels of Nebraska’s first record, which was found in Omaha earlier that day.
Access to the bird was tough and the discovery came right before a rainy weekend. Only a handful of people got to see and photograph this very special first Iowa record.
Fast forward to July 16. An excellent local bird-watcher named Dana Siefer found Iowa’s second record at Little Storm Lake in Buena Vista County. This limpkin was found in an area with better access and still is present as of the evening of Wednesday. The bird undoubtedly found this spot and decided to stay due to a preponderance of large snail prey, possibly the invasive and firmly established Chinese mystery snail. The snail species it is feeding on will soon be verified by a professor at Iowa State University.
One neat adaptation of the limpkin is at the tip of its bill. The tip is slightly bent and twisted, which allows it to snip a snail from the inner shell anchoring point and easily pull out the soft parts. The Little Storm Lake limpkin was eating well as evidence of a large snail shell midden at the edge of the cattails it occupied.
The limpkin is considered a non-migratory species, so what is the possible driver? The theory is related to the spread of an invasive species of apple snail. The native Florida apple snail, which makes up a significant portion of a limpkin’s diet, is likely why they even exist in Florida.
The invasive island apple snail, native to South America, is now supplanting the native Florida species. Likely introduced via the pet trade at least two decades ago, it has spread very quickly. It can decimate native aquatic vegetation via its feeding habits and also is a disease vector. Its spread throughout the southeast United States has undoubtedly facilitated the spread of limpkin.
It is interesting that the spread of a snail species, via human behavior, has changed the behavior of a bird species once firmly established in Florida only.
There are many fun questions to ponder in the future. Will this limpkin dispersal phenomenon keep occurring every year? Will the limpkin become an annual part of Iowa’s avifauna? Is there now a new population of migratory limpkin? Is limpkin nesting in Iowa going to be possible?
Only time will give us more answers.
BIRDS OF AUGUST
- August is when bird-watching in Eastern Iowa starts to really get good again. Fall shorebird diversity in Eastern Iowa generally peaks in August. To find shorebirds you must find their habitat. Most wading shorebirds in Eastern Iowa prefer muddy to sandy flats along floodplains or ponds and lakes. One rare shorebird to look for is the western sandpiper, a peep, which mostly shows up as fall juveniles. They are similar to the semipalmated sandpiper, but with a much longer bill that droops at the end.
- The very end of the month has produced some great warbler diversity over the past couple of years. This is a little surprising and possibly alarming given the typical peak of fall warbler diversity is usually around mid-September.
- Hit the woods, marshes and grasslands for early bird activity. Then go for shorebirds in the late morning onward. Shorebirds are active throughout the day, feeding so they can store energy for their next leg of migration. Heat rising off water and land surfaces can be a problem when viewing shorebirds on a hot day.
- Sod farms will continue to be the place to look for more terrestrially adapted shorebirds, such as pectoral, upland, buff-breasted and baird’s sandpipers. Linn and Johnson counties have a fair amount of sod farming to search.
- Look for the rare, but always possible least tern. Adults and juveniles should be on the radar. Least terns are slightly larger than a purple martin.
- Field trip to Hawkeye Wildlife Management Area, Aug. 14 (8 a.m.) — For shorebirds and other early fall migrants. Meet leader Chris Caster at the HWMA parking lot on Swan Lake Road, across from Swan Lake. Groups will be carpooling (only those vaccinated for COVID) our way around Hawkeye WMA. 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, at least one will be provided by the group leader. Finishing time around noon.
Brandon Caswell has a keen interest in natural and social sciences. He enjoys bird-watching and nature photography in his spare time. He and his wife live in Marion with their two children.