Monumental Questions - Monumental Clean Up Crew!
Maybe you’ve seen some roadkill while driving through the Berryessa Snow Mountain National Monument, along the freeway, or even in your neighborhood. Or maybe you’ve been hiking and caught a whiff of something really, really foul. Or maybe you’ve seen ants swarming on another dead insect or even come upon an animal skull during a day on the trail. Have you ever thought about what happens when an animal dies in nature and how does it “go away”? Enter nature’s clean up crew! Carrion eaters are organisms that eat dead and decaying animals. This can be roadkill, leftovers from other carnivores’ meals, animals that simply expire from old age or injury or those that have been hunted and unfortunately never recovered by their pursuer. It sounds pretty gross but carrion eaters play a critical role in ecosystem nutrient recycling.
Sometimes they’re loosely called “scavengers” and one of our most valuable scavenger species is pretty common and can be seen almost anywhere in our region from urban to rural areas. Do you want to take a guess at what species it is? I’ll give you some clues…
- They have an exceptionally fine-tuned sense of smell and can detect the scent of rotting flesh from over a mile away. Are you jealous?
- Their stomach acid is ultra acidic and allows them to eat bacteria and virus-laden decaying flesh and still remain healthy.
- When they feel threatened they will vomit in self-defense. Considering what they eat, it’s pretty clever and effective. It also makes them weigh less so they can escape quicker.
- To cool off in hot weather they will defecate and/or urinate on their own legs. This is called urohydrosis.
- They lack vocal cords and cannot make vocalizations, they can produce only grunts and hiss sounds.
Did you guess what species I’m talking about yet? Of course, it’s the Turkey Vulture! Their scientific name, Cathartes aura, literally means, “cleansing breeze”. It seems appropriate when you consider their role in removing carcasses that spread disease such as anthrax, botulism and cholera from the environment. Turkey Vultures do not have feathers on their heads and resemble wild turkeys which is where their common name came from. Although their bald, red heads don’t help endear them to those that like “pretty birds”, it does keep them clean while they jam their naked heads into sticky, stinky dead animal carcasses. Although Turkey Vultures are classified as a bird of prey, they do not have strong talons like other raptors and are not able to kill their own food which makes them reliant on carrion left behind by other carnivores, mother nature, or vehicles. Turkey Vultures also do not build nests like most other birds. Instead they lay their eggs on the ground in a sheltered place like a cave, hollow tree, rocky crevice or cliff or even in an abandoned building. I see a lot of Turkey Vultures so apparently that nesting strategy works well for them. California Condors are also carrion eaters and use the same nesting strategy but struggle with success in the wild. Unfortunately poor nesting success and other identified dangers continue to keep their free flying population fairly meager.
Turkey Vultures are widely distributed and occur in nearly all of the Americas from southern Canada to the southern tip of South America. It is a permanent resident in the southern United States but northern birds may migrate south. It is found in a diverse range of habitats including deserts, grasslands, farm and rangeland, wetlands, foothills and mountains, as well as suburbia. They prefer open county without dense tree cover where they can easily take flight and enjoy the thermals. While soaring they resemble a dihedral (shallow V) and although they are master fliers, rarely flapping their wings, they appear unsteady by rocking and tilting in flight. Their slow, teetering flight allows them to fly low aiding them in detecting their next meal. Their body feathers are dark iridescent brown-black with highly contrasting silvery-gray flight feathers. Their short, hooked beaks are ivory-white against their bright red heads, juveniles’ heads are black. Their wing span is similar to Bald and Golden Eagles at around six feet and they can weigh over five pounds. The oldest wild Turkey Vulture was 16 while captive birds have lived to be 51 years old.
Lead poisoning and outright killing of Turkey Vultures due to the false belief that they spread diseases (in reality they clean up the ecosystem!) are their main conservation concerns. Their population numbers remain strong with a global population estimated to be 18,000,000 individuals.
Other interesting Turkey Vulture fun facts include:
- In the air a group of Turkey Vultures are called a “kettle” but on the ground they go by “committee” or a “wake”. Large groups of them roost together in trees and although I'm not sure what that’s called but that is an impressive sight!
- Gas and oil companies have been known to employ Turkey Vultures to detect pipeline leaks because the scent added to natural gas is similar to that of decaying flesh that they are so fond of.
Next time you see a Turkey Vulture soaring over our favorite monument, on the way to our favorite monument or even on your way home from school or work, give them a nod for doing a bang-up job of waste management!
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