Bill Oddie says the island is one of the best places to see red squirrels
The famous red squirrel was one of the animals television presenters Bill Oddie and Kate Humble found as they launched Autumnwatch 2008 in Dorset.
The pair were on Brownsea Island, Poole Harbour, in preparation for the BBC Two's week of live programmes following UK wildlife later this month.
They will host the show from the island, famous for its red squirrel, wading birds and wildfowl.
Mr Oddie said he hoped viewers would get involved.
The show will also feature Simon King who will travel the country with autumn missions.
Mr Oddie said they saw plenty of red squirrels on Thursday.
"This is one of the best places in the country to see red squirrel.
"We can 100% guarantee red squirrels."
The show will use thermal imaging to capture action at night on the island.
Bird feeders will also be used to give an insight into pecking orders, he said.
He urged viewers to join in and said: "Just keep looking, you won't see if you don't look. People do tend to go around with their eyes focused on the floor."
Brownsea is a haven for wildlife with more than 1,000 birds including the UK's largest wintering flock of avocets, Dartford warblers, herons and lesser-spotted woodpeckers.
Ms Humble said: "Autumn is nature's last firework display before everything beds down for the winter.
"You have incredible colour with leaves and a lot of activity amongst the birds and animals who are stocking up for the winter."
Autumnwatch will be broadcast on BBC Two from Monday 27 October to Thursday 6 November, at 8pm.