These are some comments about small birds commonly called "finches" from around the world. Over the years, we've probably had 100 different species and so have had a good opportunity to look at different behaviors.

One thing that we have noticed is vastly different abilities to "learn". Brain cells take more energy than other cells and so if a species doesn't need more brain cells, it won't use the energy to produce them.

The "smartest" birds are those that must forage in a large variety of habitats where they never know where there next meal or drink will come from. In general, these are desert birds. The "dumbest" birds are those that live where the climate is constant. These tend to be tropical wetland species.

I think this idea translates into fish also. Species that live in big lakes where everything is the same tend to not be as "smart" as those species that live in a changing environment such as a river that floods and drys up in an irregular schedule.

Norm Kopecky