From Lynn Swearingen:

Re: What? Where? When? Some animals may know (Aug. 12): I observed a wild Mocking Bird, catching insects on a lawn, then dropping them onto the concrete, below the curb. When he had several insects, he hopped down off the curb and ate them.

That is problem solving. That is intelligence.

I also watched my horse eating milk thistle. When a large plant was pulled up by the roots, he first shook it to try and remove the roots. When that failed he hit the plant on the fence. When that failed he dropped it to the ground and stepped on it; pulling the plant away from the roots, leaving the roots under his hoof.

Problem solving equals intelligence.

I believe that animals need to be observed in their environment to determine their intelligence.