Islands of Refuge

By: Olivia Bautch

On the night of International Migratory Bird Day 2023, more than 757,000 birds were approximated to have passed through Marion County, Indiana, by way of BirdCast’s radar technology. While “lights out” movements in large cities aim to reclaim starlight for nighttime travelers, and increasing attention is being turned towards tropical wintering grounds, researchers indicate that there is still a neglected piece of the conservation puzzle.

When birds like the Golden-winged Warbler, a federal focal species, are making their way to the Boreal forests, quality stopover sites allow them to refuel before continuing northward. Birders are quick to scout out larger city parks- such as Fort Harrison State Park or Eagle Creek Park in Indianapolis- as traditional hotbeds for migrant species. Recent research, however, has noted that collections of small urban parks tend to see more turnover and a greater number of species than large urban parks. This means that those unassuming neighborhood parks, greenways, residential yards, and other plots altogether may just as well be small havens to birds who are making the tiring journey from wintering grounds to breeding grounds and back.

We spoke to urban planners and birders in the heart of our local metropolis about their work in the array of parks around Indianapolis, migratory trends, and what citizens might do to further unveil the untapped possibility of our urban ecology.

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They call them “islands of refuge”. The 33 parks totaling over 1,600 acres of managed green space spread across Marion County. In Indianapolis, a Land Stewardship department heads up the conservation of these green spaces, namely through invasive species removal and native planting. In some cases, specific state or federally endangered species are designed for. So far, this has resulted in management of over 70 invasive species and protection for over 20 species of concern, like the Henslow’s Sparrow.

For this reason, some habitats being restored in small parks are considered to be “state significant”. Adjacent the hip nightlife in Broad Ripple, Cerulean, Hooded, and Worm-eating Warblers take refuge in the old-growth forests of Marott Park. The edge habitat between swing-sets and sycamores make Clermont’s Robey Park a reliable viewing location for American Woodcock, thrushes and Broad-winged Hawk. And restored sedge meadow on far-southeast side Raymond Park hosts winter-migrant ducks and a variety of flycatchers.

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But in the eyes of a migratory bird, how do these parks compare to larger area parks? Researchers at Princeton University used radar technology to map stopover sites of the eastern United States. While somewhat random, their findings, published in 2023, saw that migrant passerines had a slight bias toward forested areas; even finding the sole forest fragment in deforested areas.

Don Gorney has been birding in Indianapolis for the past 25 years and noted the local result of this phenomenon: “I think the biggest change has been a decrease in breeding forest specialists. The number of individuals for species such as Wood Thrush, Cerulean Warbler, and Ovenbird – each a forest specialist – has declined based on my birding experience.” And what is a loss in forest habitat for breeding species is a loss for migrants as well.
A project of US Forest Service partner American Forests reports “tree equity scores” or native canopy for cities. Indianapolis has an overall score of 81 out of 100, not surprisingly with more affluent neighborhoods ranking higher, and less affluent neighborhoods ranking lower than the median. However, ranking even lower than the latter are outskirt communities such as Westfield and Whitestown, where patches of forest, farmland, and wetland are bulldozed by the day, paving the way for subdivisions and sparse ornamental plantings of no ecological value.

The restorative work of the Land Stewardship team places a priority on forested woodlands and tree canopy, which currently comprise around 75% of the native park habitats, although current plans give greater focus to Indiana’s disappearing wetlands. But scattered plots of green space in and of themselves aren’t seen to be the greater benefit for migrant species, rather, the collective effect or lack of fragmentation between plots. Specially designed greenways, designated conservation corridors, and rain gardens in street medians are native plant patches that serve as small connections between parks.

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A 2015 study of Chicago neighborhoods quantified the biggest way to fill in the gaps in the green and attract birds to dwell in the city or just stop by: yards! Doug Tallamy, entomologist of “The Nature of Oaks” fame, started a grassroots program called Homegrown National Park, with a mission to mobilize homeowners as a collective in invasive plant removal and native plant installation. This collaborative portal is just one way to map and visualize the habitats in your neighborhood. Taking it a step further, the National Wildlife Federation and its state affiliates can help you certify your patch as wildlife habitat.

Even without a stereotypical “patch”, an apartment balcony with a native plant container garden can host seeds, fruit, nectar and bugs that worn-out warblers and hummingbirds will gladly gobble up. In fact, most birds would prefer this to a birdfeeder. Small parks in Indianapolis can use your help too. Removing all those detrimental invasive plants takes a lot of time and effort, due to their rapid-spreading and highly-resistant nature. Volunteering with your city parks department or with local nonprofits like Amos Butler

Audubon Society for “work day” outings makes sure even the littlest parks are cared for, for years to come.

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Whatever the weather, our restored urban parks are islands of refuge for migratory birds in a bustling sea of buildings. But they don’t have to be. Just like turning out lights and stickering your windows, doing what you can to make your neighborhood, yard, or patio more natural is increasing the acreage of stopover habitat.

And head to the parks to get inspired. Recalling his experience with an eight-acre patch on the southeast side, Don Gorney shares, “I visited Gray Park for the first time in 2012…the variety of warblers, sparrows, and other species that are seen at the park was quite the pleasant surprise to me.”

“Gray Park is not unique,” he adds, “birders should visit a small park during the migration season to see what they can find.”

This May, it’s our challenge to you to choose a small park you have never visited before, and embark on a new adventure. Pay close attention to the little things: the plants and the insects that feed on them; and learn how to differentiate between the native and invasive species. And keep a close eye out for any special birds that land mid-journey, remembering how immensely grateful they are for this little green patch.

Photo Courtesy of Steve Bradley

References
https://cpree.princeton.edu/news/2023/princeton-research-reveals-secret-sites-where-
https://dashboard.birdcast.info/region/US-IN-097?night=2023-05-13
https://nextcity.org/urbanist-news/design-city-backyards-for-city-birds
https://royalsocietypublishing.org/doi/abs/10.1098/rspb.2023.1424
https://www.nwf.org/CERTIFY
https://www.treeequityscore.org/map#8.86/39.7174/-86.0735