This is the story of one unique month on planet Earth: May. Around the world, May brings new arrivals for five families of wild animals. As the month progresses, each will face their own challenges and each will have to fight for their lives. In Kenya, baby elephant Maya takes her first few steps. It's a good time for elephants, food is abundant and there's something of a baby boom, but Maya and her mum Zadie are in a dangerous position separated from their herd. In the Kalahari Desert, tiny meerkat pup Swift has just a 50/50 chance of surviving the coming winter. Food is scarce, the rains have failed and the cold is beginning to bite. She must rely on a strong, supportive family to help her through. In North America, black bear cubs Herbie and Fern have just emerged from their den. Their mum will be their guide through this tough month, but this year the weather threatens to play havoc with their world. In Sri Lanka, Gremlin is the newest member of a troop of toque macaques. It is a strong troop with a good territory, but she must battle to find her place in a complex and sometimes violent society. In Kenya's Masai Mara, lion cub Moja and his mum live alone, in constant fear of their neighbours. Mum Nyota is a skilful hunter, but food is scarce and Moja is starving. Five families must battle to survive - this could be the hardest month they will ever face.