Why vultures hang out on cars

In Everglades National Park, these black vultures hang around in parking lots, standing on cars.  (Notice the bird book on the dashboard.)

I didn't see a problem from vultures on cars, erxcept for a little whitewash.  The cars aren't going to burst into flame, as they do from pack rat nests.

Why do they stand on cars?  Probably several reasons: 

• First, there aren't many open places in the Evergaldes for vultures to congregate--since the surface everywhere is covered with either water or dense vegetation.  And the parking lots have an  added attraction--the chance for garbage.
• The cars park in what little shade there is, and of course, vultures like the shade. 
• Vultures are probably safer on cars--mammalian predators can't sneak up on them there. 
• Vultures like to hang out on cliffs, where it's easy to get airborne and there isn't vegetation to interfere with their big wingspread.  To a vulture, a car is something like a cliff--an easy place to take flight from.

Condors like to hang out in busy places

Several years ago, I was crossing the Colorado River on the bridge below Paige, AZ.   There was a man there sitting on the bridge on a chair, with his dog next to him.  He had a radio antenna, so I asked what he was doing.  He said he was checking the whereabouts of California condors, which had been reintroduced to the wild and were wearing radio transmitters.  He said there were about 9 of them nearby, and pointed to a group on a rock promontory, not far away.

I was surprised that they were hanging out around people, and asked him about this.  He said: "Oh, they are intelligent birds.  They are curious.  They like to see what's going on."  I suppose, if you are a vulture in the wild, you might hang out at the water hole.  Animals come and go, including sick animals.  So, being "where the action is" might just be adaptive for a scavenger.

So... maybe this explains why Everglades vultures like to hang out in parking lots.