Danes, E.M., Chadwick, E.A., Oliver, K.J., Findlay, M.A. & White, P.J..C. 2026 https://doi.org/10.1007/s10344-026-02127-2 

This paper explores how camera trap footage could be used to age otter cubs, something CIEEM members may observe during survey work. It is known from data on road deaths, rescues and visual sightings that otters can give birth in any season but may show regional variation in birth peaks. Knowing when otter cubs are born may be useful both in understanding otter ecology and in planning surveys or works around natal activity. Because otters have a long parental care period (often >9-12 months), an ageing method could allow back calculation to estimate birth season. This study estimated growth curves across three litters of known emergence date (to about 7 months old) relative to their mother. The method involves measuring along the spine and tail from on-screen frames. It was tested to see how consistent it was across different observers and how accurate it was relative to domestic ferrets (a relative of otters) of known length. The method works best with good quality images and when the mother and cub are in similar positions and distances relative to the camera trap. Such measurements in conjunction with other morphological and behavioural cues may provide a reasonably reliable method to age otter cubs.