Examining the role of management, forest structure, and prey abundance in driving Eastern Whip-poor-will habitat use in Southern Illinois and the Missouri Ozarks

With its song once-familiar as the sound of summer nights in the rural Eastern United States, the Eastern Whip-poor-will (Antrostomus vociferus) is now experiencing steep population declines. An aerial insectivore reliant upon forests in all stages of their life history, reduced forest quantity and quality across their range is suspected to play a large role and may also affect their primary prey: large moths. Given widespread cultural interest in restoring whip-poor-will populations, I surveyed 17 sites across southern Illinois and the Missouri Ozarks during the 2023 and 2024 field seasons. I assessed whip-poor-will occupancy and abundance across a diverse range of forests, sampling both entirely unmanaged habitats and a wide range of areas subjected to different management and silvicultural treatments. I paired these data with management histories, vegetation survey structural measurements, and abundances of large arthropods. I found that whip-poor-will habitat selection is largely driven by structural measurements rather than prey abundance, with habitat selection positively associated with reduced tree counts, increased understory density, high variability in canopy cover, reduced overall canopy cover, reduced herbaceous ground cover, high litter depth, and younger forest stands. Occupancy and abundance were lower in unmanaged than in managed forests, particularly in Illinois, where management produced a larger shift in use patterns than in Missouri. Overall high occupancy and abundance suggested high-quality habitat within our study regions, consistent with published regional trends models. Prey abundances were not strong predictors of habitat use, possibly due to the overall high prey abundances in comparison to other regions. Higher moth counts in unmanaged parcels, however, may suggest a mismatch between prey abundance and accessibility for foraging birds. These results offer practical guidance for land managers seeking to provide whip-poor-will habitat and underscore the complex relationship between forest structure and prey dynamics shaping whip-poor-will habitat selection.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Natural Res & Env Sciences

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• Coates, Holly Christine

Contributors dc:contributor

• Benson, Thomas J.
• Ward, Michael P.
• O'Keefe, Joy

• Whip-poor-will
• Abundance
• Occupancy
• Forestry
• Habitat
• Conservation
• Forest Management
• Conservation Biology
• Moth
• Nightjar
• Ornithology
• Ecology
• Illinois
• Missouri

Statement dc:rights

• Copyright 2025 Holly Coates

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/129983

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F129983