Birds of Effigy Mounds: A Park Where Birds Are Faring Better Than the Region

About 66 percent of bird species in the region around Effigy Mounds National Monument in Iowa are in decline, some at alarming rates. Inside the monument, the picture is better. Comparing 14 years of park surveys with regional trends, the National Park Service found that Effigy Mounds' breeding bird community is faring better than the region's.

A Warbling Vireo. Credit: NPS.

Why birds

Birds eat pests, disperse seeds, pollinate plants and feed people, and birdwatching is a multi-billion-dollar industry. They are also an early warning system for environmental change. The Heartland Inventory and Monitoring Network surveys the park's birds each breeding season, along with the plant communities they live in, and compares park trends with the region's to guide how the park restores and maintains habitat.

The park's birds, 2009–2022

• 111 species recorded in 14 years of surveys; 96 could breed in the park.
• The number of species and how they were spread across the landscape stayed relatively unchanged.
• 38 species were common enough to track. The most abundant and widespread were the American Redstart, American Robin, Baltimore Oriole, Eastern Wood-Pewee and Red-eyed Vireo.
• Park trends from 2009 to 2019 mostly matched the region's — except the American Robin, Brown-headed Cowbird, Common Grackle and White-breasted Nuthatch, which were increasing in the park but declining in the region.

Eight breeding species of regional concern should guide habitat management: Bald Eagle, Black-billed Cuckoo, Blue-winged Warbler, Brown Thrasher, Cerulean Warbler, Dickcissel, Red-headed Woodpecker and Willow Flycatcher.

Habitat

Effigy Mounds lies in the Prairie Hardwood Transition Bird Conservation Region, once prairie to the west and south and beech-maple forest to the north and east, with oak savanna between. Glaciers left pothole wetlands, shallow lakes and Great Lakes estuaries, and the Mississippi River runs through it; about 133 breeding bird species live in the region, including dense populations of waterfowl. The park lacks the region's extensive prairie but has deciduous woods, shrubs, permanent and seasonally flooded areas and brushy openings.

Woodland and mounds at Effigy Mounds National Monument. Credit: NPS.

The White-breasted Nuthatch

A White-breasted Nuthatch. NPS.

This year-round resident of mature deciduous woods and edges gets its name from how it eats: it wedges seeds and nuts into tree crevices, hides them under bits of bark, lichen or moss, and later "hatches" — hammers — them out. Most of the year it eats spiders and insects, saving the stored food for winter, and it nests in natural cavities or old woodpecker holes. At Effigy Mounds it is increasing, even as it declines in the region.

Sources

Based on "Bird Community Monitoring at Effigy Mounds National Monument in Iowa, 2022" from the National Park Service's Heartland Inventory and Monitoring Network, a work of the United States government in the public domain. The full report is in the NPS DataStore. Pictures the first rewrite left out, filed by the Park Service as public domain in NPGallery, were restored on 2026-09-26.