Last updated at 13:14

In pictures: Top British garden birds revealed

The top bird visitors to British gardens have been revealed in the results of an RSPB survey.
The wood pigeon, not always a favourite in gardens because of the amount they eat, was the fifth most recorded bird.
Wood pigeon
The blue tit was the second most recorded bird, its highest position since the surveys began in 1979. Experts say they may have crept up the rankings thanks to food provided on garden feeders and tables.
Blue tit
In total 7,274,159 birds were counted in the survey. Starlings took third position in the results but remain a high conservation concern in the UK where numbers have declined 84% in the last 35 years.
Blackbirds dropped from second to fourth. Conservationists say this could be due to the mild winter, as they took advantage of the food available in the countryside rather than seeking garden supplies.
The chaffinch, easily spotted by its bright feathers, came in at number six. Chaffinch numbers have risen 37% between 1970 and 2011, according to the RSPB.
Goldfinches moved up a place from last year. Scientists believe they've been encouraged up the chart by food in gardens such as sunflower hearts.
Great tits were the eighth most recorded bird. In winter the birds form roaming flocks to find food in gardens.
Great tit
Collared doves first arrived in the UK in the 1950s, and since then have been spotted in lots of gardens. The birds came ninth in the Big Garden Birdwatch.
Collared dove
Robins dropped slightly to number 10. Survey organiser Richard Bashford said: “They were out and about in the wider countryside finding natural food instead of taking up our hospitality. This may mean we have more birds in our gardens in the coming breeding season because more survived the mild winter."
The great spotted woodpecker was a new addition to the top 20, rising five places from its ranking at 25 last year. Andy Brown snapped this individual from a portable hide in his garden. You can share your photos in the BBC Springwatch Flickr group via the link below this gallery.
Great spotted woodpecker
The RSPB has released the results of its yearly Big Garden Birdwatch survey held in January. Almost half a million people took part in the bird count, with the house sparrow the most spotted bird by eagle-eyed watchers. Despite this, the birds are still considered to be under threat in the UK following dramatic drops in numbers.
House sparrow