By LESLIE BISHOP, guest columnist
The word “beauty” usually is not our first thought when we think of scavengers picking at a decaying carcass.
And we usually do not say “beautiful” when we look at the bald red head, the hooked beak and the hunched shoulders of the turkey vulture.
And yet, if we take a closer look at these creatures, we may see beauty after all.
Whoever gave turkey vultures their scientific name understood their value. Cathartes aura, derived from Greek, means “cleansing breeze.” Turkey vultures play an important role in nature as scavengers of carrion.
[sc:text-divider text-divider-title=”Story continues below gallery” ]Their job as cleanup crew is vital in protecting other animals as well as humans from a buildup of toxic bacteria and pathogens found in rotting meat. A world without vultures would certainly not be beautiful.
On most clear days, it is not unusual to see vultures circling and soaring at high altitudes. When groups of them are floating on air currents it’s called a “kettle,” which have been spotted as high as 20,000 feet — some 4 miles — in the air.
Turkey vultures are masters of using updrafts and thermals (columns of rising warm air) for effortless flight, with their large broad wings held in a “V” shape.
On cool and cloudy days without conditions favorable for thermal development, turkey vultures demonstrate a second type of soaring at low altitudes (less than 50 meters), which was described in 2016 for the first time by Julie Mallon, an ornithologist at the University of Maryland, and her colleagues. The authors call the behavior “contorted soaring” because it looks like gliding, but the birds continually drop in altitude.
Contorted soaring is facilitated by air turbulence formed by the movement of horizontal air bumping into a barrier like a forest edge, which can create enough updraft to keep vultures aloft with minimum wing flapping.
Turkey vultures can find carrion by both keen eyesight and a good sense of smell. When soaring, they also can cue into the behavior of other vultures, who may be finding food, and follow their lead. Or, they can follow a scent with their acute ability to follow odor trails.
As carrion specialists, turkey vultures have specific adaptations for eating decaying carcasses. With a bald head, they can plunge their face into a decaying body without fouling feathers.
As soon as an animal dies, the carcass is invaded by a host of bacteria that starts the decomposition process. As the bacteria break down the meat, they release toxic metabolites that make the meat hazardous for ingestion by most animals. Yet, the vultures’ amazing immune system allows them to successfully eat the carcass without getting sick.
A recent study showed that a vulture’s face has about seven times more bacterial diversity compared with the intestines; thus, the acidic environment of the vulture’s gastrointestinal passage destroys most of the bacteria.
In an extensive analysis in 2014, scientists described the bacterial community living within vultures. The pathogenic bacteria (clostridia and fusobacteria) in vultures’ hind-guts live in a mutual relationship with the vultures. The bacteria receive a steady flow of protein-rich food in an anaerobic environment, while the vultures obtain nutrients provided by bacterial breakdown of carrion. That is beautiful.
I am thinking about how perspective changes perceptions: how we see what we want to see and refuse to see what is often fleshy and messy. On the other hand, we get entrapped by the gore and absorbed by the ugliness. We forget to look closely and to search for meaning.
There is beauty in decay. There is beauty in the vulture’s appetite. And, there is beauty in the cleanup.
To me, this is beauty: A vulture swoops and glides on broad, bold wings in the unimaginable vastness of a blue February sky.
Leslie Bishop is a Brown County resident and retired biology professor from Earlham College. She is a volunteer interpretive naturalist at Brown County State Park. She can be reached through the newspaper at [email protected].
