Another Armadillo

You might recall that I offered an article in the January 2016 issue of Heritage, Bur Oak Land Trust’s environmental journal, about a roadkill armadillo in Johnson County (see “The Armadillo is Here”) And it seemed so improbable that I saved the frozen carcass for show-and-tell at Prairie Preview 2016. Today’s blog is to mention that another armadillo is alive and well today on the south edge of Iowa City.

My son’s colleague Rusty was preparing to launch his boat at the landing at Sturgis Ferry Park, which is located a half mile south of Bur Oak Land Trust’s headquarters. Another fisherman brought his attention to an armadillo in the weeds, and Rusty captured an unmistakable photo of the critter.

Armadillo’s make their living mainly by digging for ants, termites, and other subterranean insects. The Sturgis Ferry site is probably ideal in that the entire block is a former gravel pit along the river, which then became a non-burning landfill from around WWII to 1964, and was later capped with scrap concrete slabs, then dirt.

Between 1968 and 1974, graduate students Harry Taylor and Roger Gerhardt, plus myself, studied the whole chain of former gravel pits that run along the river and were then converted to landfills, including the Bur Oak Land Trust block, the City Busbarn block, and the Mesquakie Park block. We were mainly focused on their effect upon the local groundwater, but also noted that large cavities had formed beneath the Busbarn concrete slabs due to decay and settling of the garbage below. In one drill hole through the concrete cover, thousands of small black beetles came pouring out and started crawling up our pant legs. We abandoned that site and sealed it off with bentonite.

But this might be exactly what an armadillo needs – plenty of ant nests and beetle nests sheltered beneath concrete, with a huge food supply for them below. These spaces could also become hibernation dens below frost line in winter and places to rear young armadillos.
The river corridor contains a lot of easy-digging sandy soils and extends southward from town to create a route northward for armadillos to migrate. The rocky bluffs of Iowa City/Coralville, plus the city traffic and dogs, are perhaps a barrier to their northward migration further along this corridor. This would make Sturgis Ferry the last hospitable site along their northward migration route, and perhaps they will build up a population there.

So keep your eyes open, especially around the south edge of Iowa City, and you might witness an invasion of a southern species.