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ARS Home » Pacific West Area » Hilo, Hawaii » Daniel K. Inouye U.S. Pacific Basin Agricultural Research Center » Tropical Crop and Commodity Protection Research » Research » Publications at this Location » Publication #416790
Research Project: Development of New and Improved Surveillance, Detection, Control, and Management Technologies for Fruit Flies and Invasive Pests of Tropical and Subtropical Crops

Location: Tropical Crop and Commodity Protection Research

Title: Tracking movement, home range, and microhabitat use in a small terrestrial breeding frog using harmonic direction-finding technology

Author
item GROFFEN, JORDY - James Cook University
item HOSKIN, CONRAD - James Cook University
item Siderhurst, Matthew
item MENZ, MYLES - James Cook University

Submitted to: Wildlife Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/21/2025
Publication Date: 7/15/2025
Citation: Groffen, J., Hoskin, C.J., Siderhurst, M.S., Menz, M.H.M. 2025. Tracking movement, home range, and microhabitat use in a small terrestrial breeding frog using harmonic direction-finding technology. Wildlife Research. 52(7):WR24111. https://doi.org/10.1071/WR24111.
DOI: https://doi.org/10.1071/WR24111

Interpretive Summary: Frogs and other amphibians are among the most threatened group of animals with around 40% of species under threat. Better understanding the behavioral and spatial ecology of frogs is key to finding ways to protect them. This study uses the novel approach of using harmonic radar to track individual frogs using the lightest harness/tag yet described in the literature. The research focused on collecting data on movements, home range, nesting sites, and microhabitat use of a very small, cryptic, terrestrial microhylid frog species (Austrochaperina robusta) in an upland rain forest in Queensland, Australia, during the breeding season. Two sizes of harmonic radar tags were used and both were equally effective. Frogs were found to move only short distances. Harmonic radar tracking has the potential to fill important knowledge gaps regarding the ecology of small terrestrial-breeding frogs, providing insights that can inform conservation measures and population assessments for vulnerable species.

Technical Abstract: Tracking the movements of an animal increases our understanding of its behavior and ecological preferences. This study focused on movements, home range, nesting sites, and microhabitat use of a very small, cryptic, terrestrial microhylid frog species (Austrochaperina robusta) in an upland rainforest, during the breeding season. We used harmonic direction-finding (HDF) technology with ultra-light harnesses/tag combinations of two sizes (small 0.023 g and large 0.033 g) to track male A. robusta. These are substantially lighter than all tag/harness combinations previously used in amphibian tracking studies and represented a small proportion (1.8–2.58 %) of the mass of the very small study species (1.27 ± 0.20 g). Both tag sizes were effective and tag size did not affect the distance moved or time until an individual was found. Males did not move far between surveys (average 58.2 ± 24.7 cm) and had small home ranges (0.46 ± 0.20 m2) over the 5-day tracking period. Our study highlights that HDF can be used to track very small vertebrates in structurally complex environments. This method has the potential to fill important knowledge gaps regarding the ecology of terrestrial-breeding microhylids, providing insights that can inform conservation measures and population assessments for vulnerable species.