State bird, other grassland species, decline in area, study finds

JAMESTOWN — Declines in grassland bird species could be attributed to increases in acres of corn and soybeans, according to a recent study by wildlife biologists.

The study was authored by Max Post van der Burg, research ecologist at the U.S. Geological Service’s Northern Prairie Wildlife Research Center in Jamestown, and looked at the bobolink, grasshopper sparrow, Savannah sparrow and western meadowlark in North Dakota from 1998 to 2021.

“Wildlife managers in this part of the world have been talking about the decline of grassland birds that’s been going on for decades,” he said. “We looked at a more recent period of time and a shift in crops that has incentivized crops like corn and soybeans.”

The same period has seen a reduction in acres of the more traditional small-grain crops of wheat, oats and barley and a reduction in native grassland acres.

“Meadowlarks and grasshopper sparrow seem to be the most affected,” Post van der Burg said. “They seem to be indicators of what is going on.”

The decline in grassland birds is also an indicator of possible declines in other species that rely on grasslands such as certain species of bees and butterflies, he said.

Post van der Burg said the changing crop patterns in the region are reducing the nesting habitat for the grassland birds and their ability to feed on bugs and seeds that would be more plentiful in their normal habitat.

The study indicated the biggest declines in grassland birds were in areas where corn and soybeans are prevalent. The species are affected less by small-grain farming and the oil and gas production found in western North Dakota, Post van der Burg said.

“While oil and gas infrastructure and associated human activity and noise can negatively affect birds, these effects may be more localized,” he said.

None of the grassland bird species are currently listed by the federal government as an endangered species.

However, the North Dakota Game and Fish Department has listed the meadowlark, the state bird of North Dakota, as a Level II species of conservation priority since 2015, according to Bruce Kreft, conservation supervisor for the North Dakota Game and Fish Department.

“The state is part of the meadowlark initiative,” he said. “We are hoping to work with private landowners to promote grassland restoration.”

Kreft said the program’s intent is to stop the decline of grassland species such as the meadowlark.

“It is in the best interest of everybody to keep species from being federally listed as threatened or endangered,” he said.

Post van der Burg said the increase in corn and soybean acres has been driven by demand created by the production of biofuels like ethanol and biodiesel.

“I think it is pretty clear as we move forward we are trying to grapple with the idea of where we get energy from,” he said.

Dana Hager, executive director of the North Dakota ethanol council, said the study had not been discussed at any of its meetings.

Post van der Burg said he believed the decline in grassland birds and other species can be reversed, if there are habitat changes.

“It just requires a financial and time investment,” he said.