‘CARRION SCAVENGING’: TURKEY VULTURES ON ABACO
Turkey Vultures Cathartes aura [TUVUs, to use their Alpha Bird Code for brevity] are a familiar sight flying over Abaco, wheeling effortlessly overhead on thermals or gliding with the wind in singles, pairs, or flocks. Statistically, 83% of all photographs of turkey vultures are taken from below and look like this:
A very good cameraman with a very good camera and very good luck might catch this
Of in-flight shots, 57% are taken in unhelpful light or conditions, and look like the image below (mea maxima culpa). On a positive note, this picture shows the extreme delicacy of the wing-tip feathering (starboard wing, anyway) that enables these birds to adjust their direction and speed with minimal effort.
TUVUs have a wide range in the Americas and the Caribbean, and will prosper in almost any type of habitat. This is mainly because these large birds are almost exclusively carrion feeders, and carrion is everywhere. They spend their days scavenging, or thinking about scavenging, or recalling successful locations to re-scavenge. They do not generally kill live creatures.
The word ‘vulture’ derives from the latin word ‘vulturus‘ meaning ‘ripper’, ‘shredder’, or in more recent times, ‘very loud Metallica song*‘. TUVUs have very good eyesight, and an acute sense of smell that enables them to detect from a considerable distance the scent of decay and consequent release of the chemical ethyl mercaptan. The smell is variously described as ‘persistent penetrating decayed cabbage’ or a ‘pungent malodorous skunk-like odour’. A breeding pair will raise two chicks, which revoltingly are fed by the regurgitation of all the rank and foul… excuse me a moment while I… I feel a little bit… ~~~~~~~~~~~ …alright, fine again now.
When they are not flying, feeding, breeding or nourishing their young, TUVUs like best to perch on a vantage point – a utility post is ideal. But unusually for a bird, you won’t ever hear them sing or call. They lack a SYRINX (the avian equivalent of a larynx), and their vocalisation is confined to grunting or hissing sounds. Here’s a single hiss (at 10 / 15 secs).
These vultures are often seen in a spread-winged stance, which has several functions that include drying the wings, warming the body, and baking bacteria. Possibly it also reduces the miasma of rotting meat that may surround them after a good meal.
Equally happy to spread their wings on a debris-strewn shoreline
- One local name for a TUVU is ‘John Crow’
- An adult has a wingspan of up to 6 feet
- Sexes are identical in appearance, although the female is slightly larger
- The eye has a single row of eyelashes on the upper lid and two on the lower lid
- TUVUs live about 20 years. One named Nero had a confirmed age of 37
- LEUCISTIC (pale, often mistakenly called “albino”) variants are sometimes seen
- The TUVU is gregarious and roosts in large community groups
- The TUVU has few natural predators
- Though elegant in flight, they are ungainly on the ground and in take-off
- The nostrils are not divided by a septum, but are perforated – from the side one can see through the beak [some humans also suffer from this condition. They tend to ‘sniff’ a lot]
REVOLTING CORNER / DEPT OF ‘WAY TOO MUCH INFORMATION’
SQUEAMISH? THEN LOOK AWAY NOW
UNATTRACTIVE HABITS The Turkey Vulture “often defecates on its own legs, using the evaporation of the water in the feces and/or urine to cool itself, a process known as UROHIDROSIS. This cools the blood vessels in the unfeathered tarsi and feet, and causes white uric acid to streak the legs”. The droppings produced by Turkey Vultures can harm or kill trees and other vegetation. Maybe don’t park your nice car under one of their perching posts…
HORRIBLE DEFENCES The main form of defence is “regurgitating semi-digested meat, a foul-smelling substance which deters most creatures intent on raiding a vulture nest. It will also sting if the predator is close enough to get the vomit in its face or eyes. In some cases, the vulture must rid its crop of a heavy, undigested meal in order to take flight to flee from a potential predator”
DIETARY NOTES TUVUs tend to prefer recently dead creatures, avoiding carcasses that have reached the point of putrefaction. They will occasionally resort to vegetable matter – plants and fruit (you could view this as their side-salad). They rarely, if ever, kill prey – vehicles do this for them, and you’ll often see them on roadsides feeding on roadkill. They also hang around water, feeding on dead fish or fish stranded in shallow water.
ECO-USES If you did not have birds like this, your world would be a great deal smellier and less pleasant place, with higher chance of diseases from polluted water and bacterial spread. TUVUs kept the highways clear and work their way round the town dumps recycling noisome items.
FORAGING TUVUs forage by smell, which is uncommon in birds. They fly low to the ground to pick up the scent of ethyl mercaptan, a gas produced by the beginnings of decay in dead animals. Their olfactory lobe in the brain is particularly large compared to that of other animals.
SEX TIPS Courtship rituals of the Turkey Vulture involve several individuals gathering in a circle, where they perform hopping movements around the perimeter of the circle with wings partially spread. In humans, similar occasions are called ‘Dances’. A pair will fly, with the female closely following the male while they flap & dive… then they land somewhere private and we draw the veil…
Credits: Nina Henry (1); Bruce Hallett (2); Keith Salvesen (3, 4, 5, 11); Clare Latimer (4, 6); amy-at-poweredbybirds (7); Wiki, small pics 8, 9); Charlie Skinner (10); Craig Nash (12); Xeno-Canto / Alvaric (sound file); Info, magpie pickings; Birdorable (cartoon); RH (Keep Calm…); depressingnature.com (puking TUVU)
*As Metallica so appropriately wrote and sweatily sang (luckily there’s no verse referencing urination, defecation and puking). ALERT don’t actually play the video – the song hasn’t aged well! In fact… it’s terrible. Woe woe indeed…
The vultures come
See the vultures come for me
Fly around the sun
But now too late for me
Just sit and stare
Wait ’til I hit the ground
Little vultures tear
Little vultures tear at flesh