BANGKOK (AFP) - A male panda in Thailand has been put on a low-carb diet because he is too heavy to mate with his partner, his caretakers have said.

Birds living in cities are performing a type of "avian rap" while their rural counterparts are sticking to more traditional sounds, a study shows.

Researchers at the University of Leuven in Belgium asked men to play an ultimatum game, in which they split a certain amount of money between them. High-testosterone men drove the hardest bargain unless they had previously viewed pictures of bikini-clad models, in which case they were more likely to accept a poorer deal.