When invasive species and development overtake prairies, forests, and marshlands in the Detroit area, biodiversity is threatened. But conservation groups are fighting, project by project, to restore some of the region’s natural biodiversity. It’s an effort that requires constant vigilance and takes decades.

“Without these projects, we are losing that habitat where these creatures exist,” says Ava Landgraf, research coordinator for Detroit Audubon. “And without that habitat, they’re going to slowly disappear if we don’t do something about it.”

Sally Petrella, president of the Friends of Rouge Park, says Rouge Park has some of the best biodiversity in Detroit. At 1,184 acres, it is also the city’s largest park. 

“It has such a nice variety of habitats, with four and a half miles of the Rouge River going through it, 40 acres of restored prairie, miles of floodplain forest, old growth trees, and many rare plants and animals,”  Petrella says.

The Friends of Rouge Park has spearheaded projects over the years to fight invasive species and prevent development that would endanger native species. 

“Various entities look at this park as sort of a blank slate,” Petrella says. “I try to steer development towards areas that are already just mowed turf grass.” 

In 2005, a mountain bike group wanted to put a trail in an area of the park with rare plants and salamanders. The Friends of Rouge Park worked with them to find another area of the park for the trail. In 2006, the organization, along with the Far West Detroit Civic Association, prevented the sale of 115 acres of the park for residential development.

Help document biodiversity in your neighborhood

Since she helped found the Friends of Rouge Park in 2002, Petrella has seen increased biodiversity in the park, especially through the return of animal species such as wild turkeys, coyotes, common and hooded mergansers, and deer. Great blue herons build giant stick nests in treetops and have expanded their rookery along the Rouge River to as many as 50 nests. Pileated woodpeckers are seen in the Lahser Marsh, and bald eagles have been sighted for two years in a row.

Despite these gains, invasive plant species are a serious problem, including garlic mustard, buckthorn, honeysuckle, and porcelain berry, a vine that smothers plants. The Friends of Rouge Park combats invasive species through volunteer days to remove them and steers the city and groups seeking to plant trees and green stormwater infrastructure toward natives. 

The group has also worked with partners on grant-funded projects for prescribed burns to maintain the prairie. The Huron-Clinton Metroparks is assisting with managing the prairie. 

One beneficiary of the renewed native prairie in Rouge Park is the eastern meadowlark, a grassland bird with a declining population in Michigan. It nests on the ground in June and July. The Friends of Rouge Park has worked with the city to ensure it will not mow areas where the meadowlark nest until after they have hatched their first clutch of eggs. 

Detroit Bird City

Detroit Audubon’s Detroit Bird City program plans to restore whole grassland habitats for birds in Detroit city parks. Landgraf says that restoring grassland habitats not only brings back a wide range of bird species, but it also creates a more complex ecosystem and increases biodiversity. In Spring 2019, Detroit Audubon planted 39 types of native flowers and 6 types of native grasses in Callahan Park in Poletown.

National Geographic, the National Audubon Society, and Michigan State University provided grant money for the Detroit Bird City program, and the U.S. Fish and Wildlife Service supplied the seeds. Detroit Audubon asked the local community for input and worked with the Fish and Wildlife Service to pick native plants that would serve native birds while also appealing to residents. Landgraf says, “We want it to benefit people just as much as it benefits the animals.”

Not all the plants and grasses in the park have bloomed, because it takes two or three years for them to fully grow, according to Landgraf. But the first year was a success.

“Since that was the first year, there are only a couple species blooming, but it was still really beautiful,”  Landgraf says.

Detroit Audubon is working with Michigan State University to measure the biodiversity of the plants and birds at Callahan Park. “Those studies will actually function to see if there’s a correlation between an increase in biodiversity and an increase in human activity around the parks or in human health around the parks,” Landgraf says.

It will take time for the birds to return, but Landgraf has seen an increase in the insects in the park, including monarch butterflies. More native insects can help songbirds like warblers and swallows which primarily eat insects. It’s hard for them to find food because of the heavy use of pesticides and lack of native plants in human-built environments.

Landgraf says native plants at Callahan Park are important even though some may look more like weeds than the garden plants people are used to growing. 

“It’s just really important that in this space, even if it is a little bit more wild and unkempt looking, that we have signs and benches to show that this is a kept space—that the space is being taken care of.”