OPINION - The secret science behind a simple count: why we do the London Zoo stocktake

Five Asiatic lions, seven western lowland gorillas, three reticulated giraffes, 53 Darwin’s frogs, 65 Humboldt penguins…it’s been a busy day at London Zoo as our zookeepers have begun the mammoth task of counting every animal for our annual stocktake, a headcount of every animal in our care.