Though heavy rains have fallen this spring and early summer in parts of southern and especially southwest Minnesota, hope still exists the state pheasant population will continue the upswing it began two years ago.

Working to the birds' advantage was the recent mild winter. Additionally, relatively warm temperatures during the nesting and hatching seasons this spring and summer should aid production.

Most pheasant hens laid their eggs in late April or early May, with first clutches typically numbering 10 to 12 eggs. Once the eggs were laid, hens remained on their nests for up to 23 hours a day.

Peak hatching date was June 10. Hens who lost their nests and eggs before hatching will attempt to re-nest. But hens that lose their chicks after hatching won't re-nest.

Nicole Davros, upland game project leader with the state Department of Natural Resources (DNR) stationed in Madelia, believes a significant portion of the heavy rains this spring and summer occurred before pheasant hatching, thus increasing the likelihood of re-nesting attempts.

"The upside of the heavy rains is that a lot of lush vegetation and a lot of bugs are produced," Davros said Thursday. "Both are good for adult pheasants and chicks."

Dull-colored pheasant hens blend well with the grasslands in which they typically nest. This camouflage conceals them from predators. And by remaining on the nest for such prolonged periods, they limit their scent exposure to predators.

Again this year, Davros and her colleagues are using tiny radio transmitters to track pheasant hens and chicks. Their goal is to determine the types of habitat the birds select and the birds' corresponding survival rates.

"We started the nesting season tracking 36 hens, and we're down to 24," she said.

The 33 percent loss so far is similar to the proportion of transmitter-toting hens lost last year, Davros said. Counter-intuitively, perhaps, the majority of birds weren't killed by predators. Instead they were lost to mowers — sometimes those operating in alfalfa fields, but more often those used for cutting hay (or grass) in roadsides.

Attempts to encourage private landowners and government workers — whether township, county or state — to delay unnecessary mowing until Aug. 1 have been made continually since 1982, when Pheasants Forever was founded.

"Don't Mow Ditches!" was one of the group's first bumper stickers.

"Roadsides are especially important to pheasant production in wet years, when we're likely to have second nesting attempts," Davros said.

Hens still on their nests in late June or early July often won't leave even as a mower approaches, she said. "And chicks usually have to be at least three weeks old to fly away from a mower."

Songbirds, Hungarian partridge, rabbits and ducks also nest in roadsides, and early mowing kills some of these, too. Also, monarch butterflies and pollinators are put at risk. In all, the DNR says 40 wildlife species use roadsides for nesting in Minnesota's pheasant range.

By law, for safety reasons, Minnesota road authorities can make one mowing pass along road edges before Aug. 1, a swath that can range in width from 6 to 12 feet, depending on the type of equipment used.

Along more rural roads, such as those managed by townships or counties, restrictions are less clear-cut. In some instances, farmers are allowed to cut grass or mow hay whenever they want. In other instances, they do it without permission.

Attempts to develop and enforce uniform roadside management and mowing restrictions across the state have been frustrated for decades by non-compliance, inattention and indifference.

The issue has grown critical as Minnesota acres enrolled in the federal Conservation Reserve Program have declined dramatically, leaving roadsides one of the state's primary wildlife incubators.

The DNR estimates that some 500,000 acres of grass reside in roadsides in the state's pheasant range.

Last month, the DNR appointed Scott Roemhildt to lead the agency's Roadsides for Wildlife program in a further attempt to expand acceptance of delayed mowing programs. The effort is part of the state's pheasant restoration initiative.

In a perfect world — or at least a less imperfect one — Roemhildt will convince landowners and governments to delay roadside mowing whenever possible to Aug. 1, and convince them as well to plant more roadsides with native grasses and flowers, thereby reducing maintenance costs, increasing water filtration and improving aesthetics.

Wish him luck. He'll need it.

Dennis Anderson • danderson@startribune.com