This page is actively being updated by Holly Coates as of November 2025. Please excuse the mess.
Overview
Despite being a familiar sound of rural summer nights across eastern North America—and a fixture in American folk music and media—the Eastern Whip-poor-will has long eluded scientific understanding. Their rapid disappearance from forests, with populations declining by more than 70% since the 1970s (Rosenberg et al. 2019; Sauer et al. 2019), has sparked both scientific inquiry and public concern, as many lament the fading chorus that once defined their summer evenings.
In 2019, the Ward Lab, in collaboration with the Benson Lab at the Illinois Natural History Survey, launched a large-scale research effort to uncover the causes of these declines and identify pathways for conservation. What began as a focused project has now expanded to include five graduate students (Ian Souza-Cole, Sarah Stewart, Grant Witynski, Holly Coates, and Dave Edlund), dozens of field technicians, and collaborators such as Dr. Chris Tonra and Dr. Roberto Sosa. Together, we study whip-poor-wills across six U.S. states (IL, MO, WI, MI, OH, FL) and two states in Mexico (Oaxaca and Chiapas), including research on diet, forest structures, effects of pesticides, nesting ecology, survival, migration, physiology, and wintering ecology.
Projects:
Central Illinois habitat and prey associations
Publication: Souza-Cole et al. 2023
Ian Souza-Cole monitored whip-poor-wills and prey abundances in forest parcels across Central Illinois. He found that whip-poor-wills strongly avoided urbanization and were much more abundant in high moth abundance areas, and that 92% of whip-poor-will diet samples contained moths.
Central Illinois activity patterns
M.S. thesis: Souza-Cole 2021
Ian Souza-Cole tracked birds at Sand Ridge State Forest using VHF tags and a system of automated telemetry towers. He found that whip-poor-wills face are much less active than diurnal birds over the course of a 24-hour period–meaning that whip-poor-wills have narrow windows each day to fulfill their nutritional needs.
Central Illinois egg, chick, and juvenile bird survival and nesting behaviors
M.S. thesis: Stewart 2023
Sarah Stewart led the 2021-2023 effort to monitor whip-poor-will nests in Illinois. She found that while eggs and chicks have relatively low survival (51% – 54%), fledglings had high survival (96%). Whip-poor-wills have only 1-2 eggs per nest and 1-2 nests per pair per breeding season.
Central Illinois prey distributions
M.S. thesis: Witynski 2023
Grant Witynski trapped nocturnal insects in Central Illinois from 2021-2023, to understand distributions of prey species. He found that large moths were more abundant in forest interiors over edges (which contrasts with whip-poor-wills’ preference for foraging on edges), and that moth abundance have complex relationships with weather and habitat.
Southern Illinois and Missouri Ozarks habitat and prey associations
M.S. thesis: Coates 2025
Holly Coates monitored whip-poor-wills and prey abundance across different forest management treatments, in southern Illinois and the Missouri Ozarks, 2023-2024. She found that forest management increased whip-poor-will use and that they strongly avoid dense, closed-canopy forests. In contrast to Ian’s work above, whip-poor-wills did not pick habitats based on prey abundances, suggesting there might be different conservation strategies for whip-poor-wills in dominantly forested regions (like southern IL) vs dominantly agricultural regions (like central IL).
Midwestern migration and winter range tracking
Publications: Skinner et al. 2022, Skinner et al. 2023, and Skinner et al. 2025
Oaxaca and Chiapas winter habitat associations
Several projects (including the above) have tagged whip-poor-wills to find out where they go during the winter season, and all (100+) have gone to southern Mexico and Central America. We collaborated with Dr. Roberto Sosa at CIIDIR Oaxaca to search for and study Eastern Whip-poor-wills on their wintering grounds. They have been extremely challenging to find, but have sparked great collaborations and several future research directions (see Dave Edlund’s Florida work and Holly Coates’ Latin America range modeling work).
Illinois pesticide prevalence in natural areas
Report: Benson and Zaya 2024
Completed by collaborator Benson Lab, with big implications for the direction of our Eastern Whip-poor-will research. Pesticides have trespassed into much of the natural areas of Illinois.
Central Illinois long-term survival analysis
At Sand Ridge State Forest in Central Illinois, Ph.D. student Grant Witynski is leading a long-term banding project to learn about whip-poor-will survival. This banding work started in 2019 with M.S. student Ian Souza-Cole and will be completed in 2026.
Midwestern (five states) causes for declines
Collaboration with Dr. Chris Tonra, in progress!
Florida wintering habitat and prey associations
Dave Edlund’s M.S. work, in progress!
Central Illinois prey selection
Grant Witynski’s Ph.D. work, in progress!
Illinois pesticide effects on lab-reared prey species
Grant Witynski’s Ph.D. work, in progress!
Southern Illinois and Missouri Ozarks activity patterns
Holly Coates’ Ph.D. work, in progress!
Florida migration and summer range tracking
Dave Edlund’s M.S. work, in progress!
Latin America habitat associations, nightjar species range overlaps, and conservation planning
Holly Coates’ Ph.D. work, in progress!
Missouri, Wisconsin, and Illinois nutrition
Holly Coates’ Ph.D. work, in progress!