Stress responses in free ranging brown bears (Ursus arctos) in eastern Türkiye

Title (eng)
Stress responses in free ranging brown bears (Ursus arctos) in eastern Türkiye
Author
Morteza Naderi
Author
Rupert Palme
Author
Kelly Yarnell
Author
Emrah Çoban
Author
Ayşegül Karaahmetoğlu Çoban
Author
Josip Kusak
Author
Çağan H. Şekercioğlu
Abstract (eng)
Brown bears (Ursus arctos) are a keystone species vital for maintaining ecological balance in northeastern Türkiye. However, increasing human activities—such as logging, agriculture, and recreation—pose significant threats to their conservation. It is therefore crucial to assess how these specific anthropogenic pressures influence bears’ physiological stress responses to inform effective conservation strategies. Our hypothesis that increased human activity would correlate with elevated stress markers in bears was tested by collecting blood serum samples from 50 free-ranging bears during live capture. Blood cortisol levels and fecal cortisol metabolites were measured to assess stress responses. We also employed camera trap surveys to quantify human activity levels across different habitat patches, calculating a Relative Abundance Index (RAI). Statistical analyses, including correlation and regression models, were used to assess relationships between cortisol measures, habitat features, and human presence. The study revealed an inverse correlation between bear mass and blood cortisol levels and a significant relationship between fecal cortisol metabolites and human presence, as quantified through camera trap data. These findings highlight the significant impact of human disturbances on bear stress physiology, the urgent need for effective conservation measures to minimize human-wildlife conflicts and support the long-term viability of bear populations in Türkiye. These findings highlight that fecal cortisol metabolites serve as reliable, non-invasive indicators of stress in free ranging brown bears, enabling large-scale monitoring to identify habitat disturbance hotspots, assess the effectiveness of protected areas, and inform targeted management actions to minimize human-wildlife conflicts and enhance habitat quality.
Keywords (eng)
Brown BearsStress IndicatorsGlucocorticoid MetabolitesWildlife ConservationEnvironmental Impact
Type (eng)
journal article
Language
[eng]
Persistent identifier
https://phaidra.vetmeduni.ac.at/o:5025
DOI
10.3389/fvets.2025.1639623
Is in series
Title (eng)
Frontiers in Veterinary Science
Volume
12
ISSN
2297-1769
Issued
2025
Number of pages
9
Publication
Frontiers Media SA
Version type (eng)
version of record (published version)
Date issued
2025
Access rights (eng)
open access
License
CC BY 4.0 International
Rights statement (eng)
© 2025 Naderi, Palme, Yarnell, Çoban, Çoban, Kusak and Şekercioğlu