What makes an elephant abandon her calf – and is it a growing problem?

A helpless baby elephant has won the Thai public's sympathy but her case has shed light on the pressures facing herds across Asia

Khao Tom, a two-month-old elephant, plays with a wildlife officer, nudging his face and curling her trunk around his wrist. When she lifts her trunk in the air, signalling that she is hungry, the team at the rescue centre seems relieved - she has not been eating well. A vet prepares a pint-sized bottle of formula, which she gulps down impatiently.

Khao Tom has been in the care of Thailand's national parks and wildlife department since September, when rangers rescued her from a farming area inside Lam Khlong Ngu national park. Born with a congenital disorder affecting her knees, she struggled to keep up with the herd. Within days of her birth, her mother had moved on without her.