The term “buzzard” in North America is most often used colloquially to describe the New World Vultures, specifically the Turkey Vulture (Cathartes aura) and the Black Vulture (Coragyps atratus). These birds are obligate scavengers, meaning their diet consists almost entirely of carrion. They play a vital ecological role by consuming decaying flesh that would be toxic to most other animals. Their specialized biology, including corrosive stomach acid, allows them to safely ingest and neutralize pathogens like anthrax, botulism, and cholera. Despite their reputation as the ultimate clean-up crew, the buzzard’s diet is not limitless, and there are specific items and conditions they must reject.
Healthy and Large Living Prey
Buzzards are fundamentally equipped for scavenging, not for active predation of healthy animals. Their anatomical design makes it difficult to successfully hunt and kill large, strong, or fast-moving prey, such as adult deer or cattle. Unlike true raptors, which possess powerful grasping feet, vultures have weak talons better suited for walking or perching. Their feet function more like those of a chicken, lacking the necessary strength and curvature to seize and hold struggling prey.
They rely on thermal currents to soar for long periods to locate carrion, which prevents the rapid pursuit required to catch live animals. Black Vultures are occasionally opportunistic, targeting extremely vulnerable prey like newborn calves, piglets, or sick and injured animals. Even then, they often work in groups to overwhelm the compromised animal, preferring a low-risk food source. A healthy, large animal that can fight back poses too great a risk of injury, which a scavenger cannot afford.
Indigestible Man-Made Materials
Buzzards avoid or cannot process synthetic items that lack the biological cues of food or are simply indigestible. Highly processed human foods, such as sugary waste or baked goods, are often ignored because they do not emit the specific volatile organic compounds associated with decomposition that Turkey Vultures use to locate carrion. Black Vultures, being more reliant on sight and often foraging in urban areas, are more likely to investigate dumpsters and landfills.
In human-dominated environments, they frequently ingest non-biological debris like plastic, glass, metal, and fabric. Studies show that a significant percentage of vulture regurgitated pellets contain plastic, often originating from commercial food providers. They may consume these materials accidentally, mistaking them for bone fragments, but they cannot be broken down by the digestive system. The non-organic material can lead to internal injury or nutritional issues, demonstrating an ecological limit imposed by human waste.
Carrion Exceeding Dietary Limits
Despite their robust digestive systems, buzzards still reject certain types of dead matter. Their unique digestive adaptations, including a stomach pH near zero, are highly effective against most bacteria, but they are not impervious to chemical toxins. They reject carrion contaminated with specific chemical compounds that bypass their natural defenses, such as lead fragments from ammunition or certain veterinary drugs. The anti-inflammatory drug diclofenac, for instance, has been devastating to Old World vulture populations, causing fatal kidney failure when ingested via livestock carcasses.
Vultures typically reject carrion that has undergone extreme environmental changes, such as mummification. Carcasses that are completely dried out or frozen solid lack the necessary moisture and are too tough for the birds’ beaks to tear effectively. Turkey Vultures prefer carrion in the early stages of decay, which is moist and easy to dismember. While rare, some species may avoid consuming highly putrefied carcasses of certain animals, such as those that naturally concentrate specific toxins like the skin secretions of some amphibians.