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The use and preference towards different artificial shelters by European tree frog (Hyla arborea) in Škocjanski zatok Nature Reserve

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  • Martina Lužnik,
  • Martin Senič,
  • Matic Jančič,
  • Jure Jugovic,
  • Kevin Rečnik,
  • Sara Zupan
Martina Lužnik
University of Primorska, Faculty of Mathematics, Science and Information Technology, Koper, Slovenia
Martin Senič
University of Primorska, Faculty of Mathematics, Science and Information Technology, Koper, Slovenia
Matic Jančič
University of Primorska, Faculty of Mathematics, Science and Information Technology, Koper, Slovenia
Jure Jugovic
University of Primorska, Faculty of Mathematics, Science and Information Technology, Koper, Slovenia
Kevin Rečnik
University of Primorska, Faculty of Mathematics, Science and Information Technology, Koper, Slovenia
Sara Zupan
University of Primorska, Faculty of Mathematics, Science and Information Technology, Koper, Slovenia
DOI: https://doi.org/10.36253/a_h-18266

Published 2025-11-19

Keywords

  • Hyla arborea,
  • artificial shelters,
  • PVC pipes,
  • amphibian monitoring,
  • protected areas

How to Cite

Lužnik, M., Senič, M., Jančič, M., Jugovic, J., Rečnik, K., & Zupan, S. (2025). The use and preference towards different artificial shelters by European tree frog (Hyla arborea) in Škocjanski zatok Nature Reserve. Acta Herpetologica. https://doi.org/10.36253/a_h-18266

Copyright (c) 2025 Martina Lužnik, Martin Senič, Matic Jančič, Jure Jugovic, Kevin Rečnik, Sara Zupan

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

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Abstract

Monitoring amphibians in non-breeding habitats is often constrained by low detectability and potential disturbance to sensitive ecosystems. We tested the effectiveness of artificial shelters - PVC pipes - as a non-invasive method for monitoring the European tree frog (Hyla arborea) outside the breeding season in Škocjanski zatok Nature Reserve (Koper, Slovenia). Over three years (2022–2024), we installed 40- and 50-mm diameter shelters at 24 sites and conducted regular inspections. A total of 338 encounters were recorded, with frogs of all sizes using the shelters. Overall shelter occupancy declined across years, likely reflecting a combination of factors including reduced recruitment, vegetation changes, and demographic fluctuations. Preference analysis revealed a statistically significant, consistent trend: narrower (40-mm) shelters were used 1.6 to 1.7 times more often than wider (50-mm) ones, despite no significant difference in the body size of frogs occupying each type. With this approach, we greatly enhanced the detectability of Hyla arborea in the Škocjanski zatok Nature Reserve compared to classical monitoring methods such as acoustic surveys or netting. Importantly, a non-invasive approach using artificial shelters minimized the risk of disturbance to breeding and migratory birds, which is essential in areas with high avifaunal conservation value. Our results support the broader use of artificial shelters for monitoring arboreal amphibians in ecologically sensitive areas and suggest future research should explore finer-scale shelter design to improve detection and ecological interpretation across life stages.

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