Semester

Spring

Date of Graduation

2023

Document Type

Thesis

Degree Type

MS

College

Davis College of Agriculture, Natural Resources and Design

Department

Wildlife and Fisheries Resources

Committee Chair

Christopher Lituma

Committee Co-Chair

Yong-Lak Park

Committee Member

Petra Wood

Abstract

Eastern whip-poor-will (Antrostomus vociferus), an insectivorous caprimulgid, have seen an approximate 2.76% annual population decrease since the 1960s, with their breeding and foraging ecology largely unknown due to their nocturnal and cryptic behavior. I conducted research to assess abiotic and biotic variables correlated with detection, and occupancy probability, and prey species diversity on ~104,000 hectares of forest in West Virginia, owned by the private timber company Weyerhaeuser. Previous literature indicates that Eastern whip-poor-will, and their prey, require ephemeral habitat such as recently cleared and early successional forests, like those historically created by forest fires, wind shears, hurricanes, and tornados. Research measuring the effects of forest stand specific, landscape features, and available prey species diversity with Eastern whip-poor-will occupancy has not been conducted. This gap in our knowledge of Eastern whip-poor-will is addressed by this thesis which includes three chapters examining how both abiotic and biotic factors affect the likelihood of Eastern whip-poor-will occupancy in sampled forest stands in central Appalachia.

In Chapter 1, I review pertinent literature to caprimulgid and Eastern whip-poor-will specific relationships with forest management and timber practices. I discuss the current ecological knowledge of Eastern whip-poor-will and the current rate of decline of the species including possible explanations. The foraging and breeding habitat requirements of the species are unique in that they differ in terms of vegetative structure. I outline that this research assesses the foraging ecology and therefore foraging habitat of Eastern whip-poor-will, which is typically ephemeral and considered early successional in structure. Finally, I provide my own research objectives and the rationale behind them based on our current gaps in knowledge pertaining to Eastern whip-poor-will, possible landscape predictors, and detection rates with available prey diversity.

In Chapter 2, I examined how Eastern whip-poor-will detection and occupancy in their foraging habitat was influenced by forest-stand specific features. I evaluated relationships among landscape and stand-level variables to Eastern whip-poor-will occupancy on Weyerhaeuser property in West Virginia. I surveyed using Autonomous Recording Units from June-July 2021 and 2022. Results indicate that lunar illumination as measured by percentage significantly influenced detection probability. On surveys with lesser illumination detection probability decreased. Elevation, distance to riparian area (in meters), basal area, % ground cover of grass, solidago, and forb were the most influential occupancy probability predictors. Ecological implications from my results suggest Eastern whip-poor-will selected early successional forest areas at lower elevations, with limited basal area and vegetative structure indicative of early age (e.g., grasses) to forage for insect prey.

In Chapter 3, I measured available nocturnal prey richness, evenness, abundance, and approximate biomass among forest stands ranging from 0 – 20 years old, against Eastern whip-poor-will occupancy on Weyerhaeuser property in West Virginia. Specific prey groups measured

were nocturnal volant Lepidoptera and Coleoptera. I failed to reject the null hypothesis that any prey diversity metrics were correlated with Eastern whip-poor-will occupancy probability. Additionally, richness, evenness, abundance, and total biomass of captured prey values were significantly positively influenced by basal area, and to a lesser degree stand age. Percent ground cover of forb and bare ground also negatively significantly affected prey species richness. Capture rate of moths was significantly influenced by the temperature at opening of the trap. Results suggest that available prey species are not a primary signal that Eastern whip-poor-will consider when determining foraging habitat, instead likely honing on vegetative structure cues (see Chapter 2). According to my findings, early successional forest structure is to be maintained to encourage both available prey species abundance and Eastern whip-poor-will occupancy. In conclusion, my results add to our understanding of this cryptic nocturnal species whose foraging ecology and landscape preferences are largely unknown.

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