A new study finds that harbour seal pups rehabilitated in a sanctuary in Washington State, USA, did not behave normally after release. August 2011. Seal Conservation Society note: these pups were released when they were at least three months old, i.e. about 8–9 weeks after the natural age of weaning in the wild, after some weeks of social isolation and abnormal feeding on dead fish. All these factors could contribute to abnormal behaviour in the wild. See work carried out on rehabilitation methods to minimise these problems by mimicking the pups' natural development and developmental timetable.
A juvenile grey seal visits a beach in Upper Manhattan May 2011. The juvenile was probably a few months old and just visiting the beach to rest. It was considered healthy, and left alone.