The study used 1,833 cropped images from unconstrained camera-trap footage of endangered mountain gazelles. The researchers built on an existing deep-learning system by allowing it to learn visual examples of different sizes and shapes, rather than relying only on fixed-size image patches.

The system’s explanations often focused on the animals’ central body, legs and head. Male-related examples also frequently included horns, a known difference between the sexes, while differences in body proportions helped distinguish males from females. The researchers report a global accuracy and F1 score of 75%.