A beluga whale that was spotted in the River Thames nearly two months ago appears to be thriving, according to experts.
"Benny the beluga" was first spotted off Gravesend on 25 September, and has been regularly sighted every week.
It has stayed in the Kent stretch of the river, feeding in sheltered areas.
Tanya Ferry, of the Port of London Authority, said fish moving in and out of the estuary could affect the long-term future of the whale.
"It has been here for a considerable amount of time, longer than perhaps we had expected it to be.
"What we don't know is as those fish move in and out of the estuary, whether the animal will change its behaviour or become habitualised to the Thames and stay here," she said.
Crowds are still gathering on the river bank to catch a glimpse of Benny, but in smaller numbers since the weather started to change, Ms Ferry said.
"We've had a couple of sightings every week.
"It hasn't changed in its behaviour, but we haven't been able to establish if its behaviour is getting better or worse."
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Ms Ferry said the plan was to keep monitoring the movement and behaviour of the whale to see if there was anything that needed to be done to help keep it safe in the longer term.
Earlier this month, a fireworks display on the Thames at the Riverside Leisure Area was postponed by Gravesham Borough Council to help protect the whale.
About 15,000 people had been expected to attend the event.