KNEPP ESTATE, ENGLANDHigh in an oak tree in the county of West Sussex, in southeastern England, a pair of free-flying white storks hatched three chicks. It was May 6, 2020, a landmark moment: It had been 604 years since the previous written record of white storks breeding anywhere in Britain. Two weeks after those first chicks emerged at Knepp Estate, another pair of storks, in another shaggy nest of sticks in a nearby oak, hatched three more.

“This achievement is beyond thrilling. We dreamed of this moment, and now the storks have done it—we have British-born chicks again!” says Tim Mackrill, a reintroduction expert with the White Stork Project. Launched in 2016, the project aims to establish 50 breeding pairs of white