evolution?

Question

in a Reuter's report this month it was reported that flocks of vultures were attacking livestock in northern Spain, for at least several months. these birds seem to prefer carrion. this came from a story on Yahoo so look it up if you wish. the thing i drive at is, why are animals like these starting to behave differently? i offer nothing here. i just want to see what you people think. there are plenty of other examples out there also.

Answer 1

Yes and no.

One of the better ways to think of evolution, I think, is to focus on the idea of 'fitness'. One way to conceptualize 'being fit' is to think of a creature as a description of its environment. Fish have gills which is handy for getting oxygen from water... this suggests that water is where you'll find them. Now take that to the nth degree.

And we can turn it backwards, too. We know that vultures typically feast on carrion and typically leave herd animals alone. Such an event would hardly have been news otherwise, neh? So we have a bunch of vultures behaving a atypically.

If evolution were the cause of that, why would all of them do it one day and not the other? Wouldn't a few be produced at first who 'describe' a more predatory environment, and then those tendancies spread one way or another? Evolution tends to work on an epochal time-scale!

A far more likely explanation is that all the vultures are being FORCED to rely on what are usually secondary food sources for them. Which is EXACTLY what we would expect if their environment was changing... say, if human activity removed all the carrion they would normally be eating.

So now we go back to our fitness. If the environment that a vulture describes ceases to exist, then either the vulture will also cease to exist, or it will have to describe a new environment. If we have wiped out the vultures' normal diet, one would expect them - over a long period of time - to develop entirely different dietary preferences. Or go extinct.

With the speed that humans do things, it's usually the latter.

Answer 2

Evolution? No. It's merely that people really don't understand the animal in question.

Vultures are NOT strictly carrion eaters. It is only their preferred feeding behavior. Vultures do indeed attack and kill prey just like hawks, falcons and eagles. Have you ever notice that vulture have the very same equipment as other predatory birds? They also share behavioral characteristics.

Many predatory birds, like the red-tailed hawk are also carrion feeders. Just because you see one siting on a road kill, feeding, does not mean the hawk has changed its behavior or is "evolving". What it means is that you like many folks don't really know wildlife as well as they think they do.

This is a huge problem. Many pet owners, many farmers and ranchers, many vets, many people that have something to do with an animal, for some reason think they know all there is to know about any animal. They see a hawk siting on a road killed deer and think "my that's unusual". When in reality it isn't. Animals rarely fit in a narrow niche or behavioral pattern.

Of course the worse offenders are journalist. Many times they write articles without any research or poor research or the wrong research or the worst research.

Answer 3

Animals act crazy when little things are off balance..things as simple as their normal food supply or shift in the weather...I'm sure they aren't evolving. That takes a while and for reasons that would be more apparent and logical...and more beneficial for the vultures survival.

Answer 4

damn these vultures,we send them to eat the spanish ,cant they get anything right guess the cows tasted better.

Answer 5

I am just guessing, maybe becasue something is interupting thier food chain, or maybe different environmental conditions are present...
No evolution is taking place