You've heard of a strong stomach? Whatever the context, turkey vultures would always come first.

The acid in a vulture's digestive system is strong enough to destroy the DNA of the dead animal it's eating. (There's a good murder mystery lurking in there somewhere.)

The turkey vulture's Latin name is Cathartes aura. Very appropriate.

Cathartes means purifier. Aura means "distinctive atmosphere or quality associated with something." In this case that's the smell of death and decay.

Purifying something rotten. Nasty job. We should be grateful.

Turkey vultures mostly eat dead animals they find either by sight or smell. They have an excellent sense of smell, the brain's olfactory bulb larger than that of condors and most other birds.

We see vultures quietly gliding over a field or woods, gently tipping their wings in the wind, seeking the air currents and thermals they ride.

The way they hold their wings — a shallow V — is an excellent clue to identity. As large as eagles, vultures rarely flap their wings. They are dark brown that looks black, with a long tail and a red head.

Their head appears very small — another clue — because it is bald, no feathers to be fouled during dinner.

Minnesota's turkey vultures are seen in the metro area mostly in migration. Since robins have become birds for all seasons, I take returning vultures, usually in mid-March, to be the first sign of spring.

Once ingested, highly toxic substances such as anthrax, cholera, botulism and rabies are destroyed by what descriptive literature calls "immensely powerful acids" in the vulture's gut. The bird has a "dynamic digestive system."

Carrion eaten by a vulture is then not available for the many other scavenging animals and insects that could spread infection.

Turkey vultures, like bald eagles, are susceptible to lead poisoning. The lead most likely comes from deer caucuses or deer gut piles.

The Raptor Center in years 2014-2019 saw about a dozen poisoned vultures annually, according to Dr. Victoria Hall, executive director there. Most of those birds died or were euthanized.

Most poisoned vultures never make it to TRC. They aren't as visible as eagles, and lack charisma. Poisoned birds simply are not often found.

In Minnesota, vultures nest in the northeast, the Arrowhead. Nest is a word loosely used. The birds choose a cliff or rocky landscape, a forest, perhaps an old empty building to lay their usual pair of eggs.

They will nest on the ground, in cavities and caves. A scrape in dirt might be the only actual nest construction. Sites often are traditional. Privacy is important; vultures don't like to be near people.

These birds roost in groups. In April, I watched vultures return to a roost in a grove of tall white pines. The large black birds silently appeared low overhead from the woods behind me. They banked in tight circles once or twice, then settled onto the branches of the trees. Sort of spooky in the gathering twilight.

Vultures have no syrinx, the voice box, so they don't sing. They do grunt and hiss, the latter if disturbed.

In that case, that very powerful stomach acid becomes a defensive weapon. Threatened, turkey vultures will throw up with force, launching an acidic projectile with a range of up to 10 feet.

Lifelong birder Jim Williams can be reached at