When nature calls, swamp rabbit experts want to know

Eric Schauber knows the concept draws snickers -- researchers setting out fake-log latrines for reclusive swamp rabbits.

But the Southern Illinois University wildlife ecologist says the federally funded study involving where bunnies do their business is serious stuff. It may help sort out whether state and federal programs, including those that pay farmers to return some of their agricultural land to wetlands or wilderness, will help the rabbits’ numbers bounce back in Illinois.

“The real question is how quickly do they start using habitat that’s taken out of agricultural production and allowed to grow back into natural vegetation?” Schauber said. “How quickly does it become suitable habitat?”

Cousins of the cottontail, swamp rabbits have longer legs and coarser fur. They favor bottomland hardwood forests and are most abundant in the southeastern United States. The rabbits are excellent swimmers, and to escape predators, they can dive under water and remain submerged with just their noses breaking the surface.

Because the rabbits are so reclusive, gauging their population is difficult. But in southern Illinois, the northernmost edge of their range, experts believe the animals’ numbers have become fragmented as their moist, nutrient-rich turf -- in many cases, flood plain -- was converted over time into farmland.

With the help of a four-year $200,000-plus federal grant that also covers their research of mourning doves and quail, Schauber and others at SIU’s Cooperative Wildlife Research Laboratory are conducting the rabbit study with a simple baseline: Knowing where the bunnies have been requires knowing what they left behind.

Enter rabbit restrooms.

For reasons still unclear to wildlife specialists, swamp rabbits prefer mossy, rotting fallen logs or stumps when nature calls. Because onetime farmland lacks fallen timber, SIU researchers created 400 rabbit restrooms late last fall and placed them on 30 sites, mostly in four of the state’s southernmost counties.

Costing about $2 apiece, the long, narrow privies were framed of plywood and covered with unsupported carpeting, mimicking the spongy give of a rotting log or stump. Live traps were set near the fake logs, allowing researchers to authenticate the users as swamp rabbits.

The rabbits took to the carpeted commodes.

“We immediately saw signs at a few of the sites,” says Paul Scharine, the SIU graduate research assistant from Wisconsin whose job included routinely checking the privies and logging how much the rabbits had deposited.

Within a month of the carpeted logs’ appearance, he said, two of the 30 sites showed swamp rabbit droppings. Not much later, eight sites showed proof that swamp rabbits had been there.

“Every latrine log was used, with upwards of 400 to 500 pellets on a log,” Scharine said. “It was very promising.”

The traps caught more than two dozen rabbits, each of which was released.

To Schauber, an assistant professor in Southern Illinois’ zoology department, the findings illustrate that the rabbits use the onetime farmland at a relatively early stage of regrowth, and that if the land were restored to wilderness, the animals would fill in those areas where they’ve been less common, making their populations more contiguous.

“The populations that are left seem to be fragmented, separated by quite a distance,” Schauber says. “We’re thinking of possible ways to connect those up.”