“I think, therefore I am.” The famous phrase by the French philosopher René Descartes from 1644 still shapes how humans view themselves today — but also how we view animals. Descartes regarded animals as a kind of automatons, capable only of instinctive, almost mechanical reactions to what happened in their environment. They could not reflect on things themselves, as humans can. All the knowledge they needed was simply passed on through their genes: where to fly, in the case of migratory birds; how to build nests; how to feed their young; which other animals — predators — to watch out for. They didn’t have to learn these things; they already knew them.

But that turns out not to be true. Animals also have to learn, and learning is even crucial for survival. How they do this, and how each bird differs in this respect, is what behavioral psychologist Frederick Verbruggen of Ghent University studies.

He conducts experiments with many kinds of birds, from seagulls along the Belgian coast to European songbirds that were brought to Australia by English colonists, escaped there, and managed to spread widely — some of them, at least, but not others, because they were unable to learn well enough. His most recent work focuses on a colony of cinereous vultures in a breeding program at Planckendael Zoo. The cinereous vulture is threatened with extinction, and a network of European zoos is trying to do something about this by breeding the species in captivity and then releasing the young back into the wild. However, more than 50 percent of these releases fail, because chicks raised in captivity do not learn enough to fend for themselves once they are back in the wild.

This is a problem faced by many breeding programs: endangered species also have endangered brains. Frederick Verbruggen explains: growing up in captivity affects the development of behavior, the development of personality, and ultimately — over several generations — even the development of the brain. In species that have been bred in captivity for a long time, brains become smaller. We may not necessarily be making animals less intelligent, but we are certainly making them different by raising them in captivity.

So we are now trying to see what we can do about this, on two fronts. First, are certain animals better suited to be released than others because they have a personality that enables them to learn quickly? And second, while they are still in the zoo, can we ensure that they already acquire some crucial skills, such as recognizing dangerous predators?

In the documentary, Lode Desmet closely follows one chick that is born at Planckendael Zoo and, at the end of the film, is relocated to a colony in Bulgaria. This story serves as the central thread, while Frederick Verbruggen talks about his other experiments in the meantime — and shows them.