China is also hosting the Global Botanic Gardens Congress in Wuhan this month, where the BGCI will launch a survey of garden collections of threatened species.

CNN: Half of magnolias face extinction

The special exhibit gallery has been transformed into an intimate garden where 20 different species of North American butterflies such as monarchs, Western swallowtails, red admirals and even giant moths, flit from brightly coloured daisies, sunflowers, zinnias and other dazzling flowers.

BBC: See eye to eye with a butterfly in San Francisco

The Royal Society for the Protection of Birds (RSPB) said that as well as the house sparrow, the starling was another familiar garden bird to feature on the BAP list of 59 bird species.

BBC: NEWS | UK | Scotland | Highlands and Islands | Highland wildlife on updated list

Other attractions include a water discovery centre on stilts above one of seven lakes, a garden dedicated to the understanding of plant genetics and woodland containing species of trees from all over the world.

BBC: Botanic garden proves a hit

He added that although the starling was one of the commonest of garden birds, its decline elsewhere has put it on the "red list" of endangered species.

BBC: Starlings flocking over the old college, Aberystwyth