From field to fecal: informing conservation of Chuck-will's-widows through habitat, abundance, & diet analysis

Chuck-will’s-widows (Antrostomus carolinensis; CWWI) are a crepuscular nightjar and species of conservation concern that breeds across eastern North America. Most research on this species has been conducted alongside the Eastern Whip-poor-will (Antrostomus vociferous; EWPW), leading to clumping of both species’ preferences and knowledge gaps in our understanding of the species-specific ecology of CWWI. By analyzing patterns in CWWI abundance, habitat use, insect abundance, and diet across three populations within its breeding range (Texas, Illinois, and Missouri), my thesis aims to determine whether CWWI exhibits specific habitat or dietary preferences that will inform conservation strategies for this declining species. Point count surveys suggest larger populations in Texas than in Illinois or Missouri, and that CWWI abundance, within all three populations, is positively correlated with increased insect abundance, low to moderate canopy cover, and greater amounts of edge within forests. Metabarcoding analysis of CWWI fecal samples collected across these sites also revealed that CWWI are more opportunistic feeders than other North American nightjars with diets composed of moths, beetles, cockroaches, and vertebrates. In addition, I conducted a methodological study evaluating potential biases in fecal metabarcoding caused by insect morphological traits. The results suggest that insect morphology—particularly exoskeleton type—influences detection probability and DNA yield in avian fecal samples. Specifically, DNA from insects with hard exoskeletons are more likely to be detected and exhibit higher copy numbers. This work contributes to the growing literature on metabarcoding and its applications for diet analysis across taxa, helping to improve the interpretation and reliability of dietary studies.

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

• Tomczyk, Sonia

Contributors dc:contributor

• Ward, Michael P
• Sperry, Jinelle H.
• Benson, Thomas J

• Avian
• Fecal Metabardocing
• Conservation
• Ornithology

Statement dc:rights

• Copyright 2025 Sonia Tomczyk

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/129986

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F129986