The mute swan is one of Britain most iconic birds and a royal species by tradition, yet its welfare has been severely compromised by lead poisoning from discarded fishing weights, representing one of the most studied wildlife toxicology cases in UK history.
Despite the lead weight ban, mute swan poisoning continues from ingestion of larger lead weights still permitted, discarded lead from anglers, and agricultural lead contamination. Entanglement in fishing line causes leg amputations, wing injuries, and drowning. Deliberate feeding of white bread causes angel wing deformity in cygnets through nutritional imbalance. Swans respond to injury and partnership loss with extended behavioural changes consistent with grief.