GoKawiilMost birds of prey are loners. They might form huge flocks during migration, but for the rest of the year, they stick to themselves. The red-footed falcon is different. This kestrel-size bird frequently travels and roosts in large groups across Eastern Europe and Central Asia. It even nests in colonies, with hundreds of pairs of slate gray males and buffy-red females all living together in what Hungarian ornithologist Péter Palatitz calls “super-busy cities.” Within these avian metropolises, the falcons fight for nests, steal from each other, mate outside their partnerships, and leave eggs for others to raise. For scientists interested in how birds behave, “this system is a heaven,” says Palatitz, who has studied the falcons for 20 years.
These raptors don’t build their own cities. Instead, they occupy the abandoned nests of the rook, a relative of crows. But rooks have long been seen as agricultural pests and were so thoroughly persecuted in the 1980s and ’90s that their population crashed. The red-footed falcons, with nowhere to nest, plummeted to a quarter of their former numbers. In 2006, Palatitz launched a plan to reverse that decline by placing thousands of nest boxes throughout Hungary. The falcons responded enthusiastically. Over the next decade, their numbers doubled.
As the falcons rebounded, Palatitz took the opportunity to answer some long-standing questions about these little-studied creatures. For example, he knew that they winter in Africa but not their route or specific destination—key information for understanding how the species spends half its life. So, between 2009 and 2015, Palatitz and his team fitted 28 individuals with satellite transmitters. The devices revealed that the birds, which weigh just four to seven ounces, can cross the Mediterranean and the Sahara in a nonstop five-day flight. A week later, they end their 6,000-mile trek in southern Africa, where they stay for months.