I used to live near the Louisville Swamp nature reserve, southeast of Minneapolis, MN, along the Minnesota River. Many turkey vultures cruise the area. A few years ago I (and my wife) saw a foraging kettle of them (they sometimes stack in levels, as many as three distinct altitudes, and follow each other) attracted to an isolated fallen tree's trunk in a sort of prairie/ oak savannah - a couple actually landed on the horizontal trunk, hopping around and fluttering away and focused on a small area. The rest lowered and circled, going away and coming back, for a long time - we watched for at least fifteen minutes. When I went to see what the focus was, I hit a stench of dead animal but no carcass. It traced to a (badger sized) hole in the ground under the tree trunk and angling under a large boulder (glacial erratic, common in that park) and from the smell something was dead in that hole and had been for at least a day or so - but more than six feet under and not even slightly visible to me, looking into the hole from close range. No unusual number of flies or other insect activity at the surface, no fur, no bloodl. I can't think of any way the vultures would have focused on that spot except by detecting at fairly high (soaring) altitude, and tracking to its source, the smell.
They seem to forage as a group, with roles, and definitely track each other's behavior. How many first picked up the smell independently, I don't know. At least two were flapping around on the ground and tree trunk, looking confused by the absence of carrion. The others were swooping over, or soaring not high above.
If there is such a thing as a "death call" it must be a big secret. Try Googling it. You get down to sentences that contain the widely separated words "death" and "call," on the first page of hits.
I said that only animals can hear it didn't I? Then how can you Goggle it if no one knows that it exists? I need grant money to confirm my hypothesis.Please Register or Log in to view the hidden image!
So that it would let its mates know that it is dying and won't be home for dinner.Please Register or Log in to view the hidden image!
Perhaps not a 'death call', yet many creatures that are in a weakened or dying state exhibit symptoms, behaviors and possibly odors that are detectable to other creatures which may be observing them. As one who has worked extensively with dogs, horses, cats and wild fur-bearers, one becomes observant to any change in appetite, elimination, movement and other behaviors. Any change is important to note because it is an indication of change in the creatures homeostasis, which may be as simple as teething or breeding cycle, or the early signs of a more serious condition that could lead to debilitation or death. All predators and scavengers are alert to the movement patterns of their prey species and will watch for any change that may signal opportunity. We feed the grey jays in our yard, and the red foxes observe the flight of these resilient winged scavengers and the ravens follow the foxes, and so on in our northern paradigm. I would hypothesize that turkey vultures are likewise attuned to their environment and prey species.
