Orphaned as an infant, three-year-old Patrick takes a wary view of visitors. He crouches low, licks his claws and starts humming — a bear’s equivalent of thumb-sucking.

“It soothes him when he’s stressed,” says Melina Avgerinou, a caretaker at the Arcturos bear sanctuary in northern Greece.

Patrick’s tale is typical of many bears that have found refuge in the Arcturos sanctuary at Nymfaio on the slopes of Mount Vitsi, some 600 kilometres (350 miles) northwest of Athens.

He was less than a month old when found wandering near the Greek-Albanian border, his mother apparently killed by poachers.

Too young to know the ways of the wild, he never learned to survive without human assistance. The sanctuary released him to…