Wednesday, October 15, 2008

Eew! That smell!

"Ooooh that smell! Can't you smell that smell? Ooooh that smell! The smell of death surrounds you..." (Lynyrd Skynyrd). Well, we couldn't smell it on Tuesday, but today the smell of a dead deer was quite apparent to the Goose Creek High School juniors and seniors as they walked on the boardwalk. However, there were those in the Francis Beidler Forest that had no problem picking up the scent of death on Tuesday.

With a mug that only a mother could love, we introduce the Turkey Vulture (Coragyps atratus).

Until recently, the New World vultures were thought to be related to raptors as are their Old World cousins. However, DNA analysis has shown that the New World vultures are actually related to storks and ibises. Differences in physical characteristics support the DNA findings. New World vultures have weaker, thinner beaks than Old World vultures and the feet of New World vultures are chicken-like when compared to the raptor-like feet of their Old World cousins.

Most people realize that Turkey Vultures (named for their nearly-featherless, turkey-like head) eat carrion, but the birds also supplement their diet with shallow-water-aquatic vegetation and vegetable crops. The Turkey Vulture's digestion system has the ability to kill any virus or bacteria in the food that they eat. The nearly-featherless head allows the species to stick its head into a carcass without accumulating excessive carrion and its associated bacteria. Any bacteria that does stick to the head can be baked off by perching in the sun, which is partially the purpose of spread-wing Horaltic Pose. Heat regulation is another purpose of this pose.

Turkey Vultures use their keen eyesight AND sense of smell to locate a meal. Turkey Vultures are one of the few birds that use a sense of smell. If the deer by the boardwalk is what they're smelling, we'll pass on a keener sense of smell! Unlike reports of Black Vultures (Coragyps atratus), Turkey Vultures are non-aggressive and will not dine on living prey. If threatened, Turkey Vultures may hiss (they can only hiss or grunt) and vomit their partially-digested carrion meal. The foul smell and possible burning if the vomit contacts sensitive tissue (eyes) will likely deter a predator. A heavy meal might also be jettisoned if a bird needs to quickly attain flight. The inability to get off the ground in a hurry is a danger when feeding on roadkill and dealing with automobile traffic.

Turkey Vultures usually raise two chicks that appear white with dark heads. These birds do not build typical nests. Eggs are laid on the ground of caves, scratched out depressions in the soil, or in abandoned buildings. Chicks fledge after 70-80 days.

Turkey Vultures are tremendous soaring birds. They generally will not leave their roosting site until the air has warmed and begun to rise (as warm air is wont to do!). The vultures will flap their way into a thermal of rising warm air and then slowly soar their way to the top of the thermal with their 6-foot wingspan. Turkey Vultures can move laterally across the landscape by gliding towards another thermal. The birds will lose altitude as they move between thermals, but they can gain back the altitude by slowly soaring to the top of the new thermal. In this manner, Turkey Vutures can stay aloft for over six hours, travel up to 140 miles, and never flap their wings! This tactic is quite beneficial during long-distance migrations. Although we have Turkey Vultures here all year, the winter birds may not be the birds that are here in the warmer months. Turkey Vultures made up some of the birds spotted during the Rivers of Raptors trip to Mexico.

Turkey Vultures often defecate on their own legs, using the evaporation of the water in the feces to cool itself down. Really? Along with the vomitting, diet of decaying flesh, and the ugly mug, we suggest the Turkey Vulture gets a better PR rep!

Images by Mark Musselman

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