Published: August 24, 2010 3:00 PM
Songbirds, owls, eagles, and herons have been frequent visitors to Mountainaire Avian Rescue Society (MARS) during the last few months so it is always exciting when a rare visitor is admitted.
Long perceived as disgusting, ugly birds, turkey vultures are actually incredibly fascinating creatures with some unusual features and habits. Their Latin name – Cathartes Aura – means “purifier” and the Cherokee Indian tribe called them the “peace eagle” due to their non-aggressive behaviour.
For years these birds were classified as raptors, but extensive studies of their habits, anatomy and DNA proved them to be related to the stork family. They certainly lack many raptor features, they do have talons but they have weak, flat feet which are not designed for grasping; beaks are short and not powerful or sharp enough to kill prey.
Unlike eagles they do not rely on their eyesight to locate prey, rather they detect prey by smell. The part of the brain that processes smell is larger than any other avian or mammal species and they can detect the gasses produced by rotting carrion.
Large dark brown birds that are often mistaken for bald eagles, turkey vultures have a wing span of 170-183 centimetres and can weigh between 850 grams to 2.2 kilos. Often seen in groups turkey vultures use the thermal currents to soar together. They carry their wings in a distinct V-shape but seldom flap their wings, they just turn to gain altitude.
Up close there is little doubt which is the vulture as these birds have featherless, red wrinkled heads, (juvenile heads are dark grey or black).
Instead of a curved yellow beak, the vultures is ivory with a single large hole through the middle which is their nostril.
This bald headed modification is thought to have evolved to prevent “feather rot” due to their feeding habits which requires them to bury their heads inside a carcass. Preening head feathers is not an easy task for any bird.
Scavengers by nature, they are not known to kill their food. Animals and fish are their main diet but they also include vegetation.
Turkey vultures have a very smart but repulsive way of protecting themselves and their food from predators. If cornered, they will regurgitate or projectile vomit over their food or intruder. Very few predators will be tempted to stick around to eat.
They probably have to resort to these habits as a means of defence as, unlike other birds, they lack vocal organs and are only able to groan and hiss.
Often accused of spreading disease, these vultures are an important part of cleansing our ecosystems, especially in arid areas.
Their digestive systems are extremely efficient and their immune systems very sophisticated, which prevents them from contracting diseases or from passing on any disease through their feces.
During the breeding season, turkey vultures do not build intricate nests, they lay their eggs on the ground in caves, crevices, animal burrows, hollow logs or even abandoned buildings. Usually they produce two chicks.
Adult vultures have few predators. Often these birds are hit by cars as they dine on road kill, but the young fledgling birds are prone to attacks from eagles, owls, crows and ravens. This was the case with the young vulture brought to MARS after a rescue at sea.
The vulture was attacked as it flew from Sonora Island and landed in the ocean. Luckily, some boaters witnessed the attack and were able to rescue the young bird.
Other than being traumatized, cold, wet, and weak it appeared to be healthy and soon recovered. It was transferred after a week to North Island Recovery Centre in Errington in order to exercise its wings and gain strength and stamina.Be sure to watch out for these “cool” birds. They are gathering in flocks ready to make the fall migration back to southern California and beyond.
