Zoo bosses are "confident" about the pregnancy prospects for the UK's only female giant panda, amid expectations that she will be ready to mate within a fortnight.

Edinburgh Zoo staff have been monitoring Tian Tian's hormones and believe she will soon enter her brief fertile period.

They hope she and resident male panda Yang Guang will produce a cub this year as the animals both start to show the tell-tale signs that they are ready to breed.

But they warned there are no guarantees.