Friday, August 28, 2009

Vulture Awareness Day

Although schools and businesses are usually closed on International Vulture Awareness Day due to the vital role these birds play in our planet's varied ecosystems, this year September 5th falls on a Saturday. Oh, September 5th is also Labor Day.

Just like the decomposers on the forest's floor, vultures prevent the accumulation of organic material by rapidly and efficiently consuming dead animals. In the case of the Turkey Vulture (Cathartes aura) shown in the images, the genus name Cathartes means purifier. Their keen sense of smell allows them to locate carcasses under the forest canopy. More-aggressive Black Vultures (Coragyps atratus) may follow Turkey Vultures down to the food, so Turkey Vultures tend to specialize one smaller items that can be consumed quickly. Not having feathers on their heads makes it easier for vultures to stay clean while reaching into a carcass. Urinating on their feet helps vultures cool themselves while simultaneously killing dangerous pathogens collected from their last meal. Due to strong stomach acids, vultures are capable of eating carrion in all stages of decay.

Threats to vultures include pesticides, powerline electrocution, aircraft strikes (Turkey Vultures are the main avian species causing damage and fatalities in military aircraft), automobile strikes (while feeding on roadkill), and ingestion of pharmaceuticals or contaminants in carcasses. In fact, the last threat listed was sufficiently devastating to the vulture population in India that the sale of the veterinary drug diclofenac, which was used in cattle, was banned in 2006. The vulture population will be slow to rebound in India as the birds do not reproduce until age five and lay only one egg per year. Although the sale of the drug was banned, stock remained on the shelves and subsequently in the carcasses of dead cattle. Fewer vultures eating dead cattle could also lead to an increase in cattle-borne diseases, including anthrax.

Some information from:
Kirk, David A. and Michael J. Mossman. 1998. Turkey Vulture (Cathartes aura), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online:

Images by Mark Musselman

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