Monday, July 21, 2008


It's been a year, if not two, since I've checked in on the York, PA, Turkey Vultures. This power tower is on top of a hill. On top of a hill that overlooks a landfill, woods, yards, a major highway and farms. The possibility for a buffet for vultures are nearly endless.

It's late in the day, so one would assume that these fellows have eaten and are now doing the very necessary preening that all birds do. But perhaps even more necessary for vultures as dinner remnants are even more likely to carry "passengers" of various kinds than a more usual dinner for birds.

For whatever reason, an American Crow is on a shorter structure of a different power line and is raising Crow Cain. I am also hearing a Catbird scolding and for a few moments I thought I heard what might have been Red-tail begging, but it was too short lived to track it down in the dense trees and understory in the direction the sound was coming from.

Whatever is going on has attracted the interest of a number of the vultures. I'm not sure if they've a vested interest as in possible "food", or whether it's more like watching a little news or a TV drama before going to sleep for the night.
Here's a juvenile Turkey Vulture who doesn't seem all that interested in the drama concerning the Crow and Catbird and is beginning to get that young bird drowsy look. She of course is not only missing the red head of a mature vulture, but she's also without the yellowish knobbly irregularities of facial skin so common in Turkey Vulture adults.
Ah, the group is watching a truck head up the hill toward the landfill. Perhaps they're wondering as I am what a truck is doing going up there on a Sunday, later in the day? Does someone actually have Sunday garbage pickup in the Little Bible Belt of Pennsylvania or is something being disposed of discretely? Only the vultures know for sure. And perhaps not even them.
Because, after all the looking, one vulture takes off and starts circling toward the land fill. She's doing the lazy circles so common in vulture sky travel...
...but she's definitely heading for the truck and the landfill. (In reality I didn't see the aberration in the wing that seems apparent in the photo. I think it's an aberration in the photography process as opposed to the bird.)
Eventually some 10 or more vultures take off and join a kettle that raises them into the 94 degree heavily humid air and then they drift over towards the dump. The truck is leaving now so they are unlikely to be disturbed at their meal, whatever it turns out to be.
So some of nature's number one clean up crews goes into action, the others preen and as it gets closer to bed time, some drift into the trees in the opposite direction. I'd thought that perhaps they'd roost for the night on the tower, but there seems to be a definite migration towards the woods. Perhaps they lay themselves open to some kind of predator if they remain in the very open struts of the tower. Though I do wonder who eats vultures? Or perhaps it's the thunder storm that is about to blow in. Foliage does give some cover after all from the rain. I suppose one does lay one's self open to lightning strikes as well, up there on that nice metal tower on top of the hill.
It's a rather prickly business being a carrion eater in the modern world. Many humans are so distanced from nature that they aren't familiar with the importance of what these birds do. In fact some people find them not at all attractive with nasty dining habits.
Not a bit of it, they are specially evolved to fill the necessary niche of garbage disposers. Their heads are free of feathers because skin doesn't catch and keep as much bacteria as feathers are likely to do.
They're rather heavy clunky fliers but it isn't as if they've got to out fly their lunches, now do they? What those big clunky wings do give them though is plenty of surface area to mantle with. Thus preserving their personal portion of the food.
The list does go on as these birds are quite specialized to succeed in the world of left overs. I was thinking a good bit about specialization today.

The Thistle has developed rather substantial prickers to protect it's seeds so that they're still there on the seed head and ready to float high on the wind come maturation time. Though they don't protect them all, for small birds do find ways of harvesting them for food.

No these aren't our indigenous raspberries. These are an exotic called Wineberries though I would assume closely related to our raspberries. Note the stems. Every possible place on a stem for a sticker, has one. Now berries are supposed to be an evolutionary advantage because mobile creatures eat them and disperse the seeds to a larger area. So why all the stem defense? Is it possibly to protect the canes, which produce berries for a number of years before giving way to new growth? The berries don't have prickers.

Now in some species of raspberry type berries, in Wineberries in particular, the very ripe fruit commonly falls off the stem and tends to break into individual fruit enclosed seeds. Whereas in Red Raspberries the over ripe fruit often stays on the stems and dries. Are these berries specific to particular eaters? And as the Wineberries evolved in a different ecosystem entirely are their berries particular to an eater that isn't even in this ecosystem? Possibly, but there seem to be more than enough dispersers of their seeds to allow them to thrive without cultivation.

As you yourselves know, for the curious-- there are so many questions and so little time.

Donegal Browne

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