Date of Award

2025

Degree Name

Biological Sciences

College

College of Science

Type of Degree

M.S.

Document Type

Thesis

First Advisor

Dr. Jayme Waldron

Second Advisor

Dr. Shane Welch

Third Advisor

Dr. Anne Axel

Abstract

The Longleaf pine ecosystem is one of the most endangered ecosystems in the world with only 3% remaining. Many endemic species to the longleaf pine ecosystem are also in decline and suffer from habitat loss resulting from fire exclusion, urbanization, agriculture, and industrial silviculture. Oak Toads (Anaxyrus quercicus) are a longleaf pine ecosystem obligate; the species is experiencing declines across its range and only has protections in Virginia and North Carolina. We used data from an array of Automated Recoding Units across four years (2013, 2014, 2015, 2019) at three state-owned wildlife management areas to capture audio files recorded 2000-0500 from April through July. We used autonomous call recognition software to create a detector for Oak Toad breeding calls and evaluated weather variables as they relate to Oak Toad call probability using a mixed effect model. Our detector suffered from high rates of false positives (68.1%) and a moderate rate of false negatives (28.1%). Oak Toads only occurred at 10 out of 37 wetlands and called between April 11th and July 20th. Daily mean temperature and daily precipitation were positively associated with Oak Toad calling probability. Oak Toad call probability was greater than 50% when daily precipitation was ≥ 46.63 mm, indicating heavy rainfall events are important drivers of chorusing. Improving detector design and sampling scheme to include dates when climatic conditions are ideal can lead to greater monitoring success and better information on population trends of this declining amphibian.

Subject(s)

Biology.

Ecology.

Sound -- Measurement.

Toads -- Monitoring.

Frogs -- Monitoring.

Longleaf pine.

Ecosystem health.

Biotic communities.

Rare amphibians.

Endangered ecosystems.

Sexual behavior in animals.

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