Listening to Fire: Using Passive Acoustic Monitoring to Detect and Explain Prescribed Fire Effects on Avian Communities in Oak-Hickory Forests of the Central Hardwood Region

Author

• Wesley Petty, Southern Illinois University CarbondaleFollow

Date of Award

8-1-2026

Degree Name

Doctor of Philosophy

Department

Environmental Resources & Policy

First Advisor

Park, Logan

Abstract

Prescribed fire is an increasingly important tool for restoring oak-hickory forests in the Central Hardwood Region, yet its effects on avian communities remain poorly understood because traditional monitoring methods cannot easily capture wildlife responses across the large spatial and fine temporal scales at which fire effects unfold. This dissertation develops and tests a framework for using passive acoustic monitoring (PAM) to detect prescribed fire effects on avian communities and to explain the ecological mechanisms behind them. Acoustic data were collected at Giant City State Park and Touch of Nature Environmental Center in southern Illinois across six recording sites for seven months before and seven months after a November 2020 prescribed burn, using a Before-After-Control-Impact (BACI) design.The work progresses across three studies. The first tested whether the Acoustic Complexity Index (ACI) and Bioacoustic Index (BI) could detect fire effects across multiple seasons and daily time-periods, and found significant pulse-type and press-type responses, with the two indices sometimes responding in opposite directions. The second evaluated whether traditional biodiversity metrics derived from BirdNET presence/absence data—species richness, functional richness, and functional dispersion—could explain this acoustic variation, and found statistically significant but very weak associations, revealing a mismatch between metrics that weight all species equally and indices dominated by the most vocal species. The third introduced a detection-weighted, species-level framework that classifies species into acoustic dominance tiers and links individual species’ fire responses to index variation. This species-level analysis showed that fire increased total vocal activity while decreasing acoustic complexity, a divergence explained by compositional turnover: generalist species with simple calls, such as American Crow, increased, while complex-singing specialists, such as Eastern Whip-poor-will, Scarlet Tanager, and Summer Tanager, declined. The findings demonstrate that acoustic indices can serve as effective first-pass detection tools, and that species-level analysis is required to interpret them, supporting a detect-then-investigate approach to PAM in adaptive fire management.