Animal encounters, science experiments and wildlife boat tours – all are in the line-up at this year's Festival of Nature which is preparing to return to the Harbourside.

The UK'S largest celebration of the natural world will take place on the weekend of June 6 and 7, and is completely free.

The festival is a weekend of films, exhibitions, walks, talks, workshops and competitions for all ages. There will also be a food market, selling produce from across the South West.

As 2009 is the bicentenary celebrations of Charles Darwin, the festival will feature the British Council's international Darwin Now exhibition, giving visitors the opportunity to explore the ideas that lie at the heart of the theory of evolution.

There will also be an interactive Darwin Now tree, encouraging visitors to leave their thoughts on Darwin and the exhibition.

Another highlight will be a large 'Alice in Wonderland' tent where visitors can discover different natural habitats under one roof and a preview of Bristol's first BioBlitz wildlife survey, a 30-hour event where scientists, local naturalists and members of the public will work together to find and identify all the wildlife in certain areas of the city.

Savita Custead, director of the Bristol Natural History Consortium which organises the event, said: "This year's Festival of Nature is set to be bigger and better than ever.

"The Consortium's national profile has meant we have been able to attract a fantastic range of exhibitors in 2009, which are sure to offer something for all visitors.

"The festival is now an established part of Bristol's lively public events calendar, and it's fantastic for the city as no other location in the country offers such an event.

"We look forward to announcing further exciting additions to the Festival programme in the coming weeks."

Other events already confirmed are talks by BBC2 presenter James Wong and Stephen Moss, a producer at the BBC Natural History Unit, and a chance to watch previews of the Human Planet production by the BBC.

In the run-up to the festival, we are running a 24-hour live video feed of a bird box installed at Folly Farm in Pensford.

A couple of blue tits have just moved into the box, which was put into a tree in the farm's apple orchard a few weeks ago.

The cedar wood box has a camera in its roof – all supplied by the UK's leading supplier of such equipment, Gardenature.

Philip Niemand, centre director of Folly Farm Centre, an education and conference centre in Avon Wildlife Trust's 250 acre nature reserve, which overlooks Chew Valley lake, said: "We are really looking forward to being able to watch what goes on in there.

"We have never had anything like this on the farm, it is a great opportunity for us."

Jason Alexander, of Gardenature, said: "The birds have already started building their nest and you can see them flying in and out.

"It won't be long before they start laying eggs, and then probably at the end of May we will see the young birds leaving the nest."

To see the birdbox click here.