Secretarybirds hunt by walking, flushing prey and killing it with rapid downward blows of the foot. A study by Portugal and colleagues trained a captive bird to strike a rubber snake on a force plate and recorded peak forces near 195 newtons, roughly five times the animal's body mass in weight terms.
The more surprising number is the contact time. Strikes lasted on the order of fifteen milliseconds, shorter than the bird's visual reaction time. That implies the kick is largely ballistic: the target is located first, then the strike is committed and cannot be steered mid-flight, which places a premium on accurate aim.
The popular claim that secretarybirds are immune to snake venom is not supported. They avoid bites by keeping the head far from the snake and by the speed of the attack, and birds are occasionally bitten and killed. The species is now assessed as Endangered, with grassland loss the leading pressure.