07/13/2026
Could use them here
The loggerhead shrike is a songbird the size of a mockingbird that kills mice by biting the back of the neck and shaking its head so fast that the mouse's spine snaps from whiplash. High-speed video showed the force reaches six gs. Then it impales the body on a thorn or a strand of barbed wire because its feet are too weak to hold the carcass while it eats.
The shrike looks harmless. Gray body, black mask, black-and-white wings, hooked bill. It perches on telephone wires and fence posts across open grassland, ranch country, and desert scrub from southern Canada to Mexico. It could pass for a mockingbird from a distance. Then it drops off the wire, hits a mouse at speed, locks onto the base of the skull with its beak, and rolls its head at 11 revolutions per second.
Diego Sustaita, a vertebrate biologist at Cal State San Marcos, led the study. His team filmed 28 attack sequences using high-speed cameras running at up to 250 frames per second on San Clemente Island, California, where the U.S. Navy and the San Diego Zoo operate a captive breeding program for the endangered San Clemente loggerhead shrike subspecies. When the researchers slowed the footage down, they found something that had been invisible at normal speed.
The shrike bites the nape and pinches the spinal cord to induce paralysis. Then it begins shaking. The rolling motion runs at 6 to 17 cycles per second. At peak velocity, the angular speed reaches 71 radians per second. The mouse's body whips around its own neck as a pivot. But the head and body do not move in unison. The footage showed them progressively shifting out of phase, the head rotating one direction while the body lagged behind, then snapped the other way. The effect is like wringing a wet towel. Simultaneous flexion and extension of the cervical vertebrae from opposite directions generates compressive forces that the mouse's spine cannot withstand. Sustaita estimated a peak instantaneous acceleration of six gs on the mouse's body, comparable to the whiplash a person experiences in a low-speed rear-end car collision. For a mouse, it is fatal.
The killing method exists because of a mechanical limitation. A red-tailed hawk or a great horned owl kills with its feet. Raptors have thick, muscular toes armed with curved talons that generate enough crushing force to kill prey on contact. A shrike does not. Its feet are standard songbird feet, thin, light, and built for perching, not for killing. It cannot grip a mouse hard enough to crush it. It cannot carry heavy prey in flight the way a hawk does. It kills with its beak, and the beak alone is not strong enough to dispatch a mouse that weighs 40 percent of the shrike's own body weight. The violent shaking converts the prey's own mass into the killing force. The heavier the prey, the more destructive the whiplash.
The impaling serves the same mechanical function. A shrike that kills a mouse needs to tear it apart to eat it, but it cannot hold the carcass steady with its feet the way a raptor pins prey under a talon. Instead, it carries the dead mouse to the nearest sharp object, a thorn, a broken twig, a barb on a fence line, and pushes the body onto the point until it holds. The thorn becomes a vise. The shrike tears strips of meat from the carcass while the spike keeps it from moving. Ranchers and birders who find small animals impaled on barbed wire fences across the western United States are looking at a shrike's pantry.
Males stockpile. A 1989 study on a related shrike species in Israel found that males with the largest caches of impaled prey attracted mates earlier and sired more offspring. The impaled bodies are not just food storage. They are a display. A fence line decorated with dead mice, lizards, and grasshoppers is a male shrike advertising that he can kill.
Source: Sustaita et al. (2018), Biology Letters / Science / Audubon / Science News / The Nature Conservancy.
