Juvenile birds August 12
Juvenile birds August 12
In my previous column I traced the progress of two nestling turkey vultures as they matured and eventually emerged from their cave-like dwelling around July 27. On previous visits, the developing chicks had hissed harshly and assumed defensive body postures. Not this time. Perhaps the birds would reveal new details of their daily lives.

Now both chicks stood on the granite shelf above the nest cave. Most of their dark-brown upper feathers had emerged and tails had grown to half-length. A whitish downy collar and breast remained; their eyes were still a medium-blue color as when they had first hatched. One chick quickly retreated inside the cave, while the second bird eyed me with cautious conjecture. I noted the bird’s oversized nostrils. As scavengers, turkey vultures locate food by smell as well as sight. We often see them rocking high in the sky scanning for sizeable chunks of carrion. At other times, vultures cruise the lower heights as they quarter into the wind, sniffing at treetop level to detect a meal.

My August 3 visit provided momentum in gaining the birds’ acceptance and trust at my presence. By this point, they were spending daytimes outside the tight confines of the cave. It was 86 degrees F when I arrived at midday and the vultures had sought the shaded comfort of the leafy oak grove. They paced tentatively before stepping out of sight behind a rock. Within a minute, one bird returned into full view and settled itself onto the open ledge some 60 feet away. It lingered there confidently throughout my visit.

The following week, I witnessed other shifts in behavior as the chicks gradually strayed farther from the nest. They were flying by August 9 and made awkward short hops between forest openings, apparently to where the adults could readily spot them from the air to deliver food. Unlike many other birds, vultures do not transport food with their feet or bills. Instead, food is stored in the crop, an expanded muscular pouch in the gullet that is part of their digestive system. Adults regurgitate stored food bits down the throats of dependent young.

Realizing that the maturing birds would soon leave the site, I visited again on August 11 to find the pair nestled at the edge of an adjacent blueberry barren just outside the woods. The following day, I discovered them perched on a stout tree limb above the nest that doubled as a feeding station. The vultures were full size and feathered now and, except for the grayish head and bill of the immature plumage, they resembled adults.

On August 14 I had a final and fortunate encounter. With one juvenile bird sitting on the feeding perch, an adult vulture landed in a nearby pine tree. I wondered how the juvenile would react. Obviously aware and stimulated by the adult’s arrival, the juvenile leaned forward to eject a huge pellet onto the ground. Pellets contain indigestible or uneaten food matter coughed up prior to a next meal. This action typically occurs every day or two. When I investigated the pellet later, it held bits of juicy red meat. Studies have shown that, contrary to the popular perception that vultures seek out putrid or rotten food, they prefer fresher sources when available. The vulture’s ultra-strong stomach acids also afford it protection against bacterial forms, including anthrax, that would sicken or kill humans. And although it sounds counterintuitive, the vulture’s fecal output is entirely sterile.

My intriguing summer season with a vulture family ended in mid-August. Now in late October, I occasionally notice a vulture riding the fall winds. I am left to ponder where it had nested and where it will travel.