Mild winter buoys Iowa pheasant population

A lack of snowfall this past winter was likely a boon for Iowa pheasants, which were seen in roughly equal numbers as last year by state officers for their recent annual population survey.

That survey portends a similar pheasant harvest for the upcoming hunting season as 2021, when hunters felled about 375,000 of the birds. That was the highest number since 2008.

“If hunters enjoyed last year, they should enjoy this year,” said Todd Bogenschutz, upland wildlife research biologist for the Iowa Department of Natural Resources.

The state’s pheasant population has declined significantly in the past century. There was a time, Bogenschutz said, when the birds were so abundant that the state allowed hunters to shoot hens. That’s illegal now because they are more essential than roosters to increase their numbers. One rooster can fertilize the eggs of a dozen hens.

The highest harvest on record was about 2 million pheasants, Bogenschutz said.

Pheasant habit has plummeted

In the past 30 years, potential pheasant habitat acres that are tracked by the U.S. Department of Agriculture have plummeted. That includes land that is used for hay, small grains such as wheat and rye, and land that is set aside in the federal Conservation Reserve Program. In 2020, they totaled about 2.9 million acres, a 36 percent decrease from 1990.

A recent DNR report described the decrease as equal to a 9-mile-wide strip of land that stretches across the entire state.

A decline in hay acres accounted for most of that habitat loss, but land that is used to grow small grains also has dwindled. Pheasant counts now are less than half of what they were in 1990 and about a quarter of what they were in the early 1960s, when the state began tracking population trends and harvest numbers.

Mild winters boost bird populations

Weather has a more acute effect on pheasant populations year to year. The birds are more likely to survive winters with less snowfall, and warm and dry springs increase the viability of eggs, Bogenschutz said.

This past winter was mild in terms of snowfall, with an average of about 15 inches statewide. That’s nearly 10 inches below what is typically expected. The spring was about 3 degrees cooler than normal, and there were some heavy rainfalls in certain parts of the state that might have affected nesting.

Each August, DNR staff record the number of pheasants they see along roadways to track their populations. The sightings averaged about 20 birds per 30-mile route — a slight decrease from last year — but dry conditions might have caused an undercount.

“Many staff reported they felt the survey did not capture the birds they’ve been seeing, likely related to lack of good dew during the survey on many routes,” according to a recent report that summarized the survey results.

Heavy morning dew pushes pheasants to drier areas, such as roadways.

While the current pheasant population for Iowa is relatively low compared with decades ago, the number of pheasants noted in the DNR survey this year is triple what it recorded 10 years ago. That population nadir was likely influenced by five straight winters with a statewide average of more than 30 inches of snowfall.

The largest concentrations of pheasants in the state are in northwest Iowa. The smallest concentrations are in the southwest.

The first day of the regular pheasant hunting season is Oct. 29.

This article was first published in the Iowa Capital Dispatch.