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13-Year Resurvey of Emys orbicularis (Linnaeus, 1758) in the Kavak Delta (Northwestern Türkiye): Population Density, Morphology, and Body Condition : Population Dynamics of Emys orbicularis After 13 Years

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  • Ceren Nur Özgül,
  • Begüm Boran,
  • Didem Kurtul,
  • Bengi Baycan,
  • Çiğdem Gül,
  • Murat Tosunoğlu
Ceren Nur Özgül
Çanakkale Onsekiz Mart University
Begüm Boran
Çanakkale Onsekiz Mart University
Çiğdem Gül
Çanakkale Onsekiz Mart University
Murat Tosunoğlu
Çanakkale Onsekiz Mart University
DOI: https://doi.org/10.36253/a_h-20318

Published 2026-10-02

Keywords

  • Emys orbicularis,
  • capture-mark-recapture,
  • population density,
  • body condition index (BCI),
  • wetland ecology

How to Cite

Özgül, C. N., Boran, B., Kurtul, D., Baycan, B., Gül, Çiğdem, & Tosunoğlu, M. (2026). 13-Year Resurvey of Emys orbicularis (Linnaeus, 1758) in the Kavak Delta (Northwestern Türkiye): Population Density, Morphology, and Body Condition : Population Dynamics of Emys orbicularis After 13 Years. Acta Herpetologica. https://doi.org/10.36253/a_h-20318

Copyright (c) 2026 Ceren Nur Özgül, Begüm Boran, Didem Kurtul, Bengi Baycan, Çiğdem Gül, Murat Tosunoğlu

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

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Abstract

This study examines the morphological and demographic changes of the Emys orbicularis population living in an isolated wetland habitat in the Kavak Delta of northwestern Türkiye over a 13-year period between 2012 and 2025. Population size and density were estimated through capture-recapture studies conducted during both periods, and morphometric characteristics and body condition indices (BCI) of individuals were analyzed. The results revealed the presence of female-biased sexual size dimorphism (SDI > 0) in both periods, showing that females were significantly larger than males in all morphometric parameters. However, significant changes were detected between years, particularly in some morphometric measurements and body condition. The decrease in BCI values ​​in both sexes in 2025 suggests the possibility of resource constraint due to increasing population density. Overall, this study highlights the importance of wetland ecosystem conservation by revealing the changes in population dynamics and individual condition over time in long-lived freshwater turtles.

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