Document Type
Article
Journal/Book Title/Conference
Journal of Experimental Zoology Part A: Ecological and Integrative Physiology
Author ORCID Identifier
Susannah S. French https://orcid.org/0000-0001-8923-9728
George A. Brusch https://orcid.org/0000-0001-7740-6066
Karen H. Beard https://orcid.org/0000-0003-4997-2495
Volume
341
Issue
1
Publisher
John Wiley & Sons, Inc.
Publication Date
10-30-2023
First Page
73
Last Page
85
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Abstract
The coqui frog (Eleutherodactylus coqui) was introduced to the island of Hawai'i in the 1980s, and has spread across much of the island. There is concern they will invade higher elevation areas where negative impacts on native species are expected. It is not known if coqui change behavior and baseline physiology in ways that allow them to invade higher elevations. We investigated where coqui are found across the island and whether that includes recent invasion into higher elevations. We also investigated whether elevation is related to coqui's microhabitat use, including substrate use and height off the forest floor, and physiological metrics, including plasma osmolality, oxidative status, glucose, free glycerol, and triglycerides, that might be associated with invading higher elevations. We found coqui have increased the area they occupy along roads from 31% to 50% and have moved into more high-elevation locations (16% vs. 1%) compared to where they were found 14 years ago. We also found frogs at high elevation on different substrates and closer to the forest floor than frogs at lower elevations—perhaps in response to air temperatures which tended to be warmer close to the forest floor. We observed that blood glucose and triglycerides increase in frogs with elevation. An increase in glucose is likely an acclimation response to cold temperatures while triglycerides may also help frogs cope with the energetic demands of suboptimal temperatures. Finally, we found that female coqui have higher plasma osmolality, reactive oxygen metabolites (dROMs), free glycerol, and triglycerides than males. Our study suggests coqui behavior and physiology in Hawai'i may be influenced by elevation in ways that allow them to cope with lower temperatures and invade higher elevations.
Recommended Citation
Marchetti, J. R., French, S. S., Virgin, E. E., Lewis, E. L., Ki, K. C., Sermersheim, L. O., Brusch IV, G. A., & Beard, K. H. (2024). Invading nonnative frogs use different microhabitats and change physiology along an elevation gradient. Journal of Experimental Zoology Part A: Ecological and Integrative Physiology, 341, 73–85. https://doi.org/10.1002/jez.2762