Giant pandas Kai Kai and Jia Jia celebrated their birthdays - and their fourth year in Singapore - with special cakes yesterday. Keepers at River Safari made the honey-flavoured ice cakes, topped off with apple and carrot slices, for them. The male panda, Kai Kai, and female panda, Jia Jia, are seen here enjoying their birthday treats. Kai Kai turned nine yesterday, while Jia Jia turned eight on Sept 3. They arrived in Singapore on Sept 6, 2012, on a 10-year loan from China. Both pandas entered their second mating season in April, but both natural intercourse and artificial insemination have proved unsuccessful. Nonetheless, Wildlife Reserves Singapore said in a statement that keepers remain optimistic about the chances of pregnancy as Jia Jia is "still very young". River Safari will continue with the conservation breeding techniques that have had results in zoos elsewhere, it said. Giant pandas were recently reclassified from an "endangered" species to a "vulnerable" species, but still face the threat of extinction. They struggle to reproduce in the wild.