1. Department of Applied Biology, UWIST, Llysdinam Field Centre, Newbridge‐on‐Wye, Llandrindod Wells, Powys, LD1 6NB, UK
2. Animal Behaviour Research Group, Department of Biology, The Open University, Milton Keynes, MK7 6AA, UK
3. Department of Zoology, University of Leicester, Leicester, LE1 7RH, UK