This thread got interesting. And if anyone is interested, I'd like to add:
In 2007 and in the-middle-of-nowhere AZ just south of the Grand Canyon, I sat in my car eating a Wendy's cheeseburger. There were three ravens digging around the dumpster. One raven emerged from under the lid with something sizeable in its beak and hopped down to the ground. The other two ravens immediately started chasing it. That first raven went around the back of the dumpster, and one of the other two stopped, turned around, and cut it off on the other side of the dumpster. I can remember that strategy working as a young child, which tells me that ravens can come up with strategies somewhat on-par to very young human children.
Also, there's video documentation of another wild raven in the UK taking bread from the area where people were feeding ducks at a park, flying over to a rock in the middle of a pond with that bread, and then tearing off and throwing small pieces into the water to bait a fish, which it then caught and flew off to eat.
There's yet another documented case of either a crow or raven, under scientific observation, gathering small stones and dropping them into a narrow cylinder with a tray of food floated part-way up the cylinder in order to raise the water level and access the food. They also showed these crows/ravens bending a hook onto the end of a stick or piece of wire or something and reaching into a cylinder to get food out of it.
I don't know how smart other birds really might be when compared to ravens and crows, but it wouldn't surprise me one bit of birds that make their entire living by eating fish either intentionally move fish for stocking purposes, or maybe even coincidentally move fish because over millions of years there was an evolutionary advantage that favored individuals who happened to be sloppy about dropping their food.
I will also say that a starling knows damn well that when you walk out of the house carrying a rifle/shotgun, it should relocate a couple hundred yards out into the field. And yes, I did attempt to "test" this as a kid by walking out of the house with and without a rifle. They flew away immediately at the sight of a rifle, or if they could tell that I was looking at them/hunting. They'd sit undisturbed if I simply walked out of the house unarmed and seemingly uninterested.
One last thing- what are the chances that a bird might transport eggs that could then hatch? Doesn't seem far-fetched to me that a bird might slowly wade through a shallow spawning bed, which I assume would be a likely/preferable place to fish, pick up a couple eggs in its feathers- especially if it makes a strike and gets its head/neck wet or splashes the water/gets splashed by a fish, and dislodge those eggs into another body of water. That wouldn't require any intelligence/instinct/evolutionary programming at all, as long as it would be viable for eggs to hatch after transport.
Last edited by jason miller; 06/29/18 04:44 AM.