 Due to the public change of attitude to animals kept in captivity and unsuitably cramped space, the zoo also suffered dwindling visitor numbers.However, when it was announced that London Zoo would close in 1991, a swell of public support in visitors and donations allowed the zoo to continue its work, attempt to balance its books, and take on the huge task of restoring its buildings and creating environments more suitable for animal behaviour in the late 20th century.One benefit of the 'swell of public support' was the development of volunteer staff.