An unusually warm October is being credited for the birth of two cygnets born to a black swan at Slimbridge Wildfowl and Wetlands Trust reserve.
Black swans normally breed at this time of year in their native Australia.
Keepers at the Gloucestershire centre said the cygnets hatched earlier this month, on 15 October, and are now swimming around with their mother.
A trust spokesman said they had reached a good size and added staff were confident they would survive winter.
"She has been taking good care of her young and has even been spotted giving them rides on her back to help them through the deeper water," said aviculture and duckery warden at the centre Phoebe Young.
"It is lovely to see the attention the cygnets have been receiving from families.
"The cygnets have lots of personality and we are confident they will survive."