Cornell Undergraduate Research Journal

Letter from the Editors

Isaac Chang — 2025-05-13

No abstract available.

The Ecotourism Snorkeling Industry and Hawai‘i Reef Soundscapes

Tiernan Tobin — 2025-05-13

Coral reefs have distinctive soundscapes consisting primarily of reef associated fish, with most sounds resulting from various behaviors of said species. Ecotourism, particularly through snorkeling in coral reefs, can affect behavior in fish, therefore potentially altering the soundscape. Four different reefs across the western coast of Hawai‘i were assessed both acoustically and visually through periodical deployment of a HydroMoth and a GoPro. Reefs were selected based on the amount of snorkelers present, ranging from none to high (over 16 visually identifed). Recordings were analyzed in RavenPro and VLC Media Player to identify species, create a count of instances of biophony, and a count of instances of anthrophony. Results indicated that the sites with higher amounts of anthrophony instances correlated with a higher amount of snorkelers present, but there were no correlations between amount of biophony and presence of snorkelers. This research serves as an exploratory study and aims to lay the groundwork for future research with interest in the correlations between snorkeler presence and reef soundscape by describing potential patterns observed and identifying common reef associated fish sounds.

Altitudinal Effects on Bioacoustics and Body Size Allometry on the Invasive Coquí Frogs in Hawai‘i

Kay (Akaysha) Williams — 2025-05-13

The island of Hawai‘i is a tropical and isolated island with unique endemic species. Over time, Hawai‘i has become a breeding ground for invasive species, the common Coquí (Eleutherodactylus coqui Thomas, 1966) being one of them. These small ectotherms have intense vocalizations used for establishing territory and locating potential mates. On the island of Hawai‘i, the Coquí has become persistent across many islands. There have been acoustic studies done on the frogs in their native habitat, Puerto Rico, yet little is known about the possible differences in calls between these two geographically distant groups. According to past studies, climate change in Puerto Rico could cause the Coquí frogs to expand their ranges into higher, cooler altitudes with larger body sizes and lower pitch ranges. This phenomenon has yet to be studied in Hawai‘i. Through this study, I directionally recorded Eleutherodactylus coqui to obtain information on the peak frequency, body size, and altitude differences. All frogs were handled with proper permits from Cornell University.

Acoustic Surveying for the Hawaiian Hoary Bat (Lasiurus semotus) in Māhukona Reserve, Hawai‘i

Grace Guo — 2025-05-13

We conducted passive acoustic monitoring for the Hawaiian hoary bat (Lasiurus semotus) in Mahukona Navigation and Ecological Complex, Hawai‘i, a reserve recently purchased by the Hawai‘i Land Trust in 2023. We aim to establish a baseline for bat acoustic activity in the area during the beginning of the reserve’s restoration. We collected nightly recordings in a grid layout throughout the reserve from January 3–18, 2025, cycling recorders between the sites. Preliminary analysis conducted in a BirdNET model trained on mainland U.S. bats revealed higher density of bat acoustic activity in certain areas of the reserve, but work remains to be done before any conclusions can be drawn regarding overall habitat usage.