The American Black Vulture, or Coragyps atratus, is primarily a scavenger, but its behavior is not strictly limited to consuming carrion. The answer to whether black vultures attack live animals is nuanced: they exhibit predatory behavior only under specific, limited circumstances involving highly vulnerable or defenseless prey.
Scavenger by Nature: The Black Vulture’s Primary Diet
The vast majority of the Black Vulture’s diet consists of carrion. This scavenging role is beneficial to the ecosystem, helping to reduce the spread of disease by quickly removing carcasses. Unlike the Turkey Vulture, which uses a developed sense of smell, the Black Vulture relies primarily on its keen eyesight. They often locate large carcasses by soaring high and observing other scavengers, frequently displacing the smaller Turkey Vulture once food is found.
Black Vultures are highly social birds that typically forage and feed in groups, providing them with a competitive advantage at a carcass. This flocking behavior allows them to overwhelm other scavengers and secure the bulk of the meal. Their diet may also include eggs, fish, and decaying plant material, demonstrating an opportunistic approach. This highlights the species’ preference for easily accessible food rather than engaging in a sustained hunt.
Predatory Behavior: When Attacks Occur
Predatory behavior in Black Vultures is opportunistic and typically arises when a flock encounters a completely defenseless animal. Unlike true raptors, these vultures do not possess the strong talons necessary to capture and restrain prey. Instead, their attack relies on a coordinated group effort to disable a vulnerable animal. Attacks often involve groups of 20 to 60 vultures swarming the victim.
The attack focuses on inflicting debilitating injury, not a quick kill. Vultures frequently target the eyes, nose, tongue, and soft tissues like the navel or rectum. This action induces shock and severe trauma, effectively immobilizing the animal so the flock can feed. This aggressive strategy makes the Black Vulture the only New World vulture species that consistently preys on livestock.
Identifying High-Risk Livestock and Vulnerable Prey
The animals most susceptible to a Black Vulture attack are those unable to move or defend themselves, overwhelmingly including newborn livestock. Calves, lambs, and piglets in the first few hours or days of life are at high risk due to their immobility and lack of coordination. A newborn calf, for example, may allow a flock of vultures to approach without a defense response, making it an easy target. Vultures have also been observed attacking cows that are actively giving birth or are incapacitated by illness or injury.
The vulnerability is compounded if the mother is too exhausted or preoccupied to effectively shield her offspring. Vultures may harass the birthing mother and then quickly descend upon the newborn before it can stand. Smaller domestic animals, such as young poultry or incapacitated pets left outdoors, have also been reported as occasional targets. These incidents underscore that the animal’s vulnerability, rather than its species, is the primary factor triggering a predatory response.
Legal and Effective Deterrence Strategies
Black Vultures are protected under the Migratory Bird Treaty Act (MBTA), making it illegal to harm, capture, or kill the birds, their nests, or their eggs without a federal permit. This protected status necessitates the use of non-lethal, proactive deterrence methods for livestock operations. One effective visual deterrent is the use of an effigy—a replica or actual dead vulture hung upside down with its wings spread. This visual cue suggests danger to the highly social birds, causing them to vacate the area.
Other successful non-lethal techniques involve active harassment, especially when vultures congregate near birthing areas. This includes using loud noises, such as air horns or pyrotechnics, to make the birds feel unsafe. Ranchers can also reduce risk by moving expectant mothers and newborns into pastures closer to human activity, providing a greater degree of observation and quicker response time. If non-lethal methods are insufficient, producers can apply for a Migratory Bird Depredation Permit through the U.S. Fish and Wildlife Service, which may allow for the limited, legal removal of a small number of birds.