National Park Service


Date of this Version



Natural Resource Report NPS/HTLN/NRR 2019/1874 / NPS 394/150618, February 2019: vi, 29 pages

Editing and design by Tani Hubbard

Published by United States Department of the Interior, National Park Service, Natural Resource Stewardship and Science, Fort Collins, Colorado

Also available at:

Please cite this publication as: Peitz, D. G., L. W. Morrison, and K. L. Mecke. 2019. Bird monitoring at Effigy Mounds National Monument, Iowa: Status report 2009–2017. Natural Resource Report NPS/HTLN/NRR—2019/1874. National Park Service, Fort Collins, Colorado.


United States government work. Public domain material.


Executive Summary

In 2009, the Heartland Inventory and Monitoring (I&M) Network) initiated breeding bird surveys on Effigy Mounds National Monument (NM), Iowa, to address two objectives: (1) to monitor changes in bird community composition and abundance, and (2) to improve our understanding of relationships between breeding birds and habitat and the effects of management actions on such relationships. This report evaluates trends in the park’s breeding bird populations in the context of trends observed within the North American Bird Conservation Initiative’s (NABCI) Prairie Hardwood Transition Bird Conservation Region, the bird conservation region in which the park is located. By doing so, we can assess the influence of habitat management by the park on bird populations with an understanding of regional population trends that are outside the influence of natural resource management activities at Effigy Mounds NM.

One hundred and two species of birds were recorded during May and June site visits in the nine years since initiating monitoring. Ninety of the species are considered breeding species because they are permanent or summer residents. Eight of the breeding species recorded on Effigy Mounds NM are species of concern for the Prairie Hardwood Transition Bird Conservation Region. Twenty-three species were observed during the survey period in sufficient numbers to calculate annual abundances and trends with some degree of statistical confidence.

The American Redstart (Setophaga ruticilla), American Robin (Turdus migratorius), Baltimore Oriole (Icterus galbula), and Blue-gray Gnatcatcher (Polioptila caerulea) were the most abundant and widespread species on the park. However, American Redstart was the only species that had a strong increase in population size over the nine years of monitoring. The Brown-headed Cowbird (Molothrus ater), Common Yellowthroat (Geothlypis trichas), Red-winged Blackbird (Agelaius phoeniceus), and Rose-breasted Grosbeak (Pheucticus ludovicianus) had moderate increases in population size. One species, Eastern Wood-pewee (Contopus virens), had a stable population. For 14 species we were unable to detect with certainty either positive or negative population trends, and three other species had unreliable trend estimates.

Regional trends reported for the Prairie Hardwood Transition Bird Conservation Region were uncertain for 11 of the 23 species, including the Rose-breasted Grosbeak. Seven species, including the American Redstart, had populations that were increasing within the region. Five species, including three with positive trends on the park (Brown-headed Cowbird, Common Yellowthroat, and Red-winged Blackbird), had populations that were declining within the region.

This report provides current regional and local trends for breeding birds for future comparisons with bird data collected as part of the long-term monitoring efforts at Effigy Mounds NM. This information will help park staff plan management objectives, and assess the effectiveness of management alternatives. These monitoring data also provide park staff with additional information for interpreting natural resources.