| Abstract: | Abstract: Animal ecology research could benefit from the measurement of individual morphological traits. In bovids, male horn size often correlates with annual reproductive success, is sensitive to resource abundance, and could be a predictor of survival. However, live captures are costly, involve some risk of injury or substantial disturbance to the animals, and are impossible in many situations. To remotely measure horn growth of free-ranging Alpine ibex (Capra ibex), I designed an aluminum frame that holds parallel laser pointers and a digital camera. I took digital pictures of ibex horns and calculated horn growth based on the fixed distance between the 2 laser points. This simple and accurate technique could benefit many ecological studies that require linear measurements, such as shoulder height, body length, leg length, or fin length. It could also help measure body features (e.g., fur or skin patterns, scars), increasing the reliability of individual photographic identification. |
