Understanding the diel activity patterns and determinants of abundance of the eastern whip-poor-will

The eastern whip-poor-will (Antrostromus vociferus) is a species of nightjar, a group of aerially insectivorous birds that exhibit unique adaptations to take advantage of crepuscular and nocturnal periods when few other birds are principally active. Native to eastern North America, the whip-poor-will is also a species of conservation concern, having experienced population declines across much of its range. I investigated eastern whip-poor-wills to better understand the constraints placed on them by their crepuscular and nocturnal habits and the degree to which they match their activity to the lunar cycle. To do this, I tagged 43 adult birds with VHF transmitters in 2019 and 2020 and monitored them using an automated radio telemetry system to quantify their rates of activity. I found that both male and female whip-poor-wills increase their rates of activity when there is more moonlight available at night. I also found that whip-poor-wills were much less active than diurnal birds over the course of a 24-hour period. Furthermore, I found some evidence to suggest that chicks were more likely to survive if their pre-fledging period coincided with nights of greater moonlight availability. I also researched the role of land-cover characteristics and food availability as determinants of whip-poor-will distribution by estimating their abundance at twenty-three sites across central Illinois. I conducted nocturnal point counts to estimate abundance in 2019 and 2020. I also collected nocturnal insects using UV-light traps at these sites to sample their food resources. Results of this analysis determined that the number of large moths has a positive effect on the abundance of whip-poor-wills whereas the proportion of the landscape covered by medium- to high-intensity human development had a negative effect. Taken as a whole, this research shows how whip-poor-wills may be susceptible to declines in their prey populations and this sensitivity may be exacerbated by the constrained temporal niche in which they operate.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Natural Res & Env Sciences

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2022

Author dc:creator

• Souza-Cole, Ian Francis

Contributors dc:contributor

• Ward, Michael P
• Benson, Thomas J
• Hoover, Jeffrey P

• whip-poor-will
• abundance
• activity
• behavior
• landscape
• diet

Statement dc:rights

• Copyright 2021 Ian Souza-Cole

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/112998

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F112998