So what comes more naturally, a Mother's Day kiss or a cuddle? Charming pictures of the maternal bond between animals around the world

All around the world, for any species, there's an unmistakable bond of affection between a mother and her young. 

So on this day, when dutiful human sons and daughters bring gifts of flowers and chocolates to their Mum - or at least they ought to do - we celebrate the strength of the maternal relationship in the animal kingdom. 

These heartwarming pictures take us from the mountainous forests of Borneo, where an orang-utan baby shows its love by planting a smacker on its mother (top, left), to the Chinese winter, where a panda mother and son share a warming cuddle in the snow (top, right).