Wednesday, May 15, 2013

YES, WE HAVE VULTURES


We often think of vultures as big, ominous-looking birds sitting around the carcass of a lion-killed wildebeest in Kenya or lined up on rooftops next to a garbage dump in South America. But we have our own carrion-eating vulture in the Pacific Northwest, the Turkey Vulture (Cathartes aura).

Turkey Vultures occur throughout the tropical and temperate parts of the New World, from southern Canada to Tierra del Fuego. Those at the northern end of the range, in Canada and northern US, are migratory. Tremendous numbers of Turkey Vultures migrate through Mexico and Central America. The vulture migration over Panama in October has almost reached the status of a tourist attraction, as the birds wheel and climb above the high-rise towers of Panama City in the fall, along with Swainson’s and Broad-winged Hawks.

They return to Washington from their tropical wintering grounds in late March and April to occupy nest sites on cliff ledges or in broken-off hollow trees or other dark recesses, usually in remote areas well away from human disturbance. They lay 2 eggs that they incubate for about 40 days. The young remain in and near the nest for up to three months after hatching. Oddly, although commonly seen in the air, they are almost never seen at road kill, very different from the situation farther south.

These vultures are very often seen early in the morning perched with wings outspread, apparently to dry them out. Why this is so common in vultures and doesn't occur so much in other large soaring birds may be a mystery we never solve.

Turkey Vultures fly with their wings held up in a dihedral angle, which it turns out adds stability in turbulent air. They often fly close to the ground, so this is of great importance. As a wind current hits one side, that wing tilts up and the other down. As it tilts down, it approaches the horizontal, where lift is maximal, and that stabilizes it. Watch a vulture in windy conditions and see how it tilts from side to side.

Unlike most other vultures, Turkey Vultures have a well-developed olfactory sense. Field experiments have shown that they can find something as small as a dead mouse by its smell, even under a closed forest canopy. Watch a Turkey Vulture quartering on the wind, going back and forth as first one nostril and then the other picks up the smell of a carcass from upwind. By going back and forth as the smell gets stronger and weaker, they eventually home in on the spot.

At lower latitudes, where Black Vultures are abundant, they may use Turkey Vultures as their carcass finders, watching individuals of the other species and following them to the ground. The Blacks are also watching each other, so the stimulus from a descending bird spreads outward, probably for quite a distance. Blacks dominate Turkeys, so the Turkeys must be quick to take advantage of a “fresh” meal. In the forested tropics, the much rarer big white King Vultures may finally appear and scatter all the lesser birds.


Turkey Vultures have actually increased in the PNW in recent years, for reasons unknown. Are there more dead animals now? Are they being more successful on their wintering grounds? Were they reduced by DDT like so many other raptors and are still recovering? In any case, they are masters of the air and a pleasure to see in the sky.

Dennis Paulson

11 comments:

~gail said...

YES. We do have more than we used to. I first saw one a couple years ago when I was outside with my chickens near a building. All of the sudden, the chickens scooted into the overhang. I knew this meant a predator, but I looked around the sky and couldn't see it. Then for some reason, I looked straight up, and an enormous bird with a red head was hovering about five feet above me. I was in her way and she flew off. I said to myself, "What the *bleep* was that?"

Their visits, looking for my chickens, are becoming commonplace. Yesterday was a record breaker as I counted eight in the sky. One did a low flyover of the back yard. This is July 2019 in Burlington, WA.

Cassie said...

I live in Granite Falls WA. Yesterday I came around a corner on my road, and there were at least 6 to 8 giant turkey vultures scavenging a deer carcus in the ditch on the side of the road. I was so surprised to see these birds!

Unknown said...

I just saw a turkey vulture yesterday for the first time in our area. Fife hieghts in tacoma. He had a little family with him and they landed in my neighbors field! I took pictur

challenge said...

Do black vultures and turkey vultures hang out together

Unknown said...

Today my family and I had the pleasure of watching near 30 if not more, turkey vultures fly over our house. They all then perched in a tall fir tree in our yard for about ten minutes before slowing scattering and soaring over the port of Tacoma. First time for me and the kiddos found it to be pretty cool. This has lead to our research, and discovering their way of life. To be honest I was looking for a revelation, because this was a first for myself as well. Just wanted to share this.

Weather conditions were clear, mid afternoon, after the morning due had burned off. 09/21/2020

Drea said...

Saw a good 6-8 while tubing the Wenatchee River today just out of Leavenworth. Huge wingspan!

Rhonda Burke said...

Just had one fly low over the backyard this morning in Arlington. Never used to see these birds. Now they are everywhere. They are gross.

Unknown said...

Saw a turkey vulture eating roadkill on highway 97 at Pateros, WA just after the turnoff to Twisp .June 4,2022

Anonymous said...

I saw two this morning in Bow, Washington eating some roadkill.

Anonymous said...

We saw about 30 or more flying south over NE Seattle yesterday around 4 or 5pm. Never saw them like this before. Wow! They just kept coming.

speech analytics said...

They return to Washington from their tropical wintering grounds in late March and April to occupy nest sites on cliff ledges or in broken-off hollow trees or other dark recesses, usually in remote areas well away from human disturbance. They lay 2 eggs that they incubate for about 40 days. The young remain in and near the nest for up to three months after hatching. Oddly, although commonly seen in the air, they are almost never seen at road kill, very different from the situation farther south.
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