In Israel’s Khai Bar Reserve, a pair of brown-necked ravens has a problem. They’re after the tasty contents of ostrich eggs and there are plenty to go around. The eggs – the largest of any bird – would provide a nutritious meal but they’re so thick that even a pair of ravens can’t puncture them. But they don’t need to. The ravens know that the desert is also home to a master egg-cracker – the Egyptian vulture. All they have to do is wait, and they can rob the robber.
Shai Kabesa from Ben Gurion University first noticed the ravens at work in 2008. Together with Reuven Yosef, she pieced together their strategy in the following years. The Khai Bar Reserve has no native ostriches – they were hunted to extinction in the area during the 1940s. There is, however, a thriving conservation project that’s breeding the birds in the hope of reintroducing them. Ostriches lay their eggs in a single nest. The dominant female goes first, laying around 15 to 20. Her subordinates follow with 3 to 4 of their own. However, the top pair of ostriches can only incubate around a dozen eggs effectively, and they roll the rest away from the nest. This creates a ring of nutritious treats for any bird skilful enough to break into the eggs. The Egyptian vulture does so with a special technique
