Juan Geyser and his wife were sitting in Kruger National Park's Lower Sabie region, enjoying their holiday, when they witnessed the killing. Overlooking the Sunset Dam watering hole, Geyser caught the moment on tape.
In front of them, a young African harrier-hawk begins tearing chunks out of a weaver nest with sharp jabs of its black-tipped beak, searching for a snack. Seconds later, the brightly colored wing of a weaver bird flashes into view. Using its small feet to hold the nest still, the hawk rips the bird from its twiggy home and carries it to a neighboring branch.
The surprised bird struggles against the hawk's strong pecks, which strip out chunks of the prey's feathers. Then, the hawk goes for the head. Pulling with its beak, it stretches the young bird's neck several times before dislocating it. Dead, the bird slumps on the branch.
The hawk picks at its kill a few more times, looks around, and then decapitates its prey, gulping down the head intact.
Going in for the Kill
"Many birds of prey go for the head. It is an almost guaranteed way to kill prey," says Washington Wachira, a wildlife photographer and National Geographic explorer. "Some rip it off like this hawk in the video. Some puncture the head, perforating the skull to kill prey."
Wachira says birds of prey will sometimes go for other parts of the body; the head is not exclusive.
In Africa, weaver birds form communal nests by sewing grasses into pods in areas with trees and shrubs. They tend to build their homes near water, which defends against many snakes but apparently doesn't deter birds of prey.
Still, boomslang snakes and rats will chick-knap the eggs for food. In addition to African harrier-hawks, spotted eagle-owls, chacma baboons, and domestic cats commonly eat weaver eggs as well. Diderick cuckoos have been known to infiltrate and commandeer weaver nests.
A Flexible Killer
African harrier-hawks eat a whole host of animals, from mammals like rodents and bats, to small birds, lizards, amphibians, and insects. They normally hunt by swooping low over vegetation or spying on future meals from a perch, but they have been known to actively scope out snacks.
"I wouldn't say hawks are violent. Rather, I would say they are skilled," Wachira says. "I have seen them balance upside-down on trees to pull out chicks from bird nests. I have seen them run on the ground like athletes chasing down lizards."
Harrier-hawks have unique, double-jointed legs and small feet. Wachira says the birds can bend their long limbs forward and backward easily at obscure angles. This helps them infiltrate nests and other tight squeezes.
Unfortunately for the hawk's prey, it seems nowhere is safe.
The harrier-hawk's nature may start with its upbringing. Chicks hatch in large nests built on the ledges of cliffs, constructed out of sticks and lined with leaves. A clutch will normally contain three eggs, which hatch after about 35 days of incubation. Then, like avian gladiators, older chicks will fight their siblings to the death. Only the strong survive.
"They indeed do what it takes to get the job done," Wachira says.