Carrion (care-EEE-on, rhymes with clarion, barbarian) is an animal's dead, decaying flesh that often serves as a food source for other carnivorous or omnivorous animals and birds. To be considered carrion, the food item must have died from another cause other than being killed by the animal consuming it. The word carrion comes from the Latin caro, meaning meat; synonyms or other words to describe carrion are "roadkill," "carcass," "remains," and "offal."
A wide range of birds may feed on carcasses. Birds that are regularly known as carrion-eaters include:
- Vultures, buzzards, and condors
- Eagles, hawks, and other birds of prey
- Crows, ravens, and other large corvids
- Gulls, skuas, and terns
Depending on the size of the carcass and how much activity is around it, other omnivorous birds such as jays, pigeons, roadrunners, and hoopoes may also take advantage of carrion. Even some seabirds, including fulmars, may scavenge carrion from beached carcasses.
In addition to birds, many insects, mammals, and even large reptiles such as Komodo dragons will eat carrion. Opossums, coyotes, and hyenas are other animals known for eating carrion. However, humans rarely eat these carcasses because not only is the meat unsafe for humans to eat but also many religious guidelines and social taboos prohibit carrion as a food source.
Sources of Carrion
Carrion can come from many sources and can be dead animals, from small rodents to larger mammals or even whales. Scavengers do not discriminate about where they get their next meal. Common sources of carrion include:
- Predator kills: Flocks of scavenging birds may chase away lone predators and take over a kill. They may also feed on an abandoned kill after the hunting predator has moved on.
- Hunting discards: Hunting animals' internal organs or unwanted pieces left behind by hunters are food for carrion-seeking birds, including wounded animals that die before a hunter claims them.
- Vehicle kills: Roadkill can occur anywhere, from highways and interstates to dirt roads, and is fodder for all types of scavenging animals, including bears, raccoons, and birds.
- Accidental deaths: Animals that die from accidents, such as window collisions, net tangles, or similar causes, can become carrion.
- Natural deaths: Animals that die of old age, disease, injuries, premature birth, or other causes can all become carrion.
- Beach strandings: Marine animals that get stranded on beaches and die will become carrion for scavenging gulls, shorebirds, corvids, and raptors.
As carrion ages, it is often accompanied by a foul, rancid smell caused by bacterial growth, making the meat unfit for human consumption. Animals and birds, however, have different digestive systems and better tolerance for old meat and can often feed on a carcass even if it has significantly decayed. In many cases, an older carcass is even more palatable to birds because it becomes softer and more manageable for smaller bills or talons to tear into as the meat rots.
Hazards of Carrion
Dead carcasses can be an easy food source for many birds, but carrion is not without risks. Depending on how the animal died and how long it has been deceased, hazards include:
- Disease transmission: Excessive bacteria, insects, or contamination from the feces of previous carrion-eaters can cause disease.
- Lead contamination: Birds may be inadvertently poisoned contracting lead contamination if they ingest any lead pellets from previously hunted offal.
- Poisoning: A carcass that has been poisoned as a trap for unwanted predators or contaminated with pesticides.
- Attacks by other predators: Other predators competing for food may be drawn by the scent of the decaying carcass, potentially causing casualties.
- Vehicle collisions: When feeding on carcasses on roadways, birds can get hit because they are too stuffed or immersed in their meal to fly away in time.
Many birds that feed on carrion have adaptations or strategies to deal with these risks. Stronger stomach acids can kill many disease-causing bacteria, and birds that regularly dig into carcasses, such as vultures, often have bare faces and heads to minimize insect and bacteria infestation. Smaller birds that eat carrion may feed in flocks, and large numbers can help deter other predators from taking over the carcass. Birds may also gorge on carrion, storing the meat in their crops and leaving it quickly to digest in a safer place.
Carrion birds cannot detect lead contamination or other toxic contamination in a carcass, and many vultures and large raptors are killed each year by this type of poisoning. Switching to non-lead ammunition can help reduce this threat, and drivers should also be aware of carcasses alongside roads and slow down to avoid hitting any feeding birds.
Lead Poisoning. The Raptor Center, University of Minnesota.