Reliability of mouflon aging using morphological characteristics from observations in the field
2005
Garel, Mathieu | Cugnasse, Jean-Marc | Maillard, Daniel
In mouflon Ovis gmelini musimon ×× Ovis sp. populations, different morphological characteristics are often used to discriminate among age classes from observations in the field, such as horn size and horn development for males and size of white facial mask for females. In the Caroux-Espinouse mouflon population, we used linear discriminant analysis to test the ability of these two commonly used morphological characteristics to discriminate among age classes in the field. Models were developed using measurements taken from 643 mouflons harvested between 1977 and 1985. Classification ability of the horn length for males was poor (77.5%%, SD == 15.0, N == 404) but better than facial mask length for females (40.1%%, SD == 27.8, N == 212). Male lambs were the only age class successfully classified (≥≥ 90%%). As reported elsewhere, we found that facial mask length was not a reliable predictor of male age (classification ability: 40.3%%, SD == 21.7, N == 431). In the Caroux-Espinouse population, horn length and facial mask length were poor indicators of age. Our results suggest an important need to evaluate the reliability of criteria used in mouflon populations to discriminate among age classes from observations in the field. We recommend working with a restricted number of age classes and studying a combination of behavioural and physical characteristics.
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