Strange vulture occurence

Saturday afternoon a very odd thing happened here. I stepped out on the back porch, and noticed a few Turkey Vultures circling high. As I stood there the flock grew to a kettle of about two dozen birds, and they began circling lower and lower. Within a few minutes they were at and below treetop level, taking swoops barely above head height around the house, yard, and pond, passing very close to us at times. A few began alighting in some of the trees in the yard. They never seemed to find any food item, and a search didn't show any evidence of a fish kill in the pond. After about 15 or 20 minutes of this, they all began heading off to the north. Two of them flew off up the road in front of the house, making a beeline right up the center of the road not more than 5 feet off the ground. Most of the vultures remained airborne through all this.

I can't recall anything like this before. They were evidently not coming in for an evening roost, nor were they feeding. There were no Black Vultures in the mix. One off-the-wall thought occurred to me... Peggy had a crock pot outside on the back porch with her vegetable soup cooking, one of the major ingredients of which is cabbage. The soup is banished to the back porch because I object to the "aroma" of boiling cabbage in the house. Maybe the vultures mistook the smell of a pot of simmering cabbage for the smell of a rotting carcass?

I doubt she'll be happy if I refer to her recipe henceforth as "Vulture Soup."