Rupert Sheldrake, a biologist, has done pretty extensive research on animal behavior and earthquakes, among other phenomena. A quick Google search on his name will yield results.

I also performed a Google search on "animal behavior earthquakes" and found that there is a lot of scientific disagreement on this subject. The USGS, not surprisingly, is very down on this method of predicting earthquakes. The link below, however, is intriguing, as were many of the links I followed. As far as I could see, no seismologist has yet to write a definitive article on animal behavior as a precursor to earthquakes. Some studies refute the theory entirely.

Still, these observations have been documented since Aristotle wrote about his earthquake theory (pockets of warm air underground expanding and displacing the ground). IMO, there have been too many correlations between observations and phenomena to dismiss such a link out of hand. (Interestingly, seismologists disagree upon whether or not there were foreshocks to the Haicheng earthquake. If they can disagree on something that quantifiable, how are we to believe anything they claim?)

Has it been scientifically proven? Not that I can tell.
Is it a likely provable hypothesis? Yes, by what I have read and observed myself.

Cathryn

http://www.deprem.cs.itu.edu.tr/Animal_patterns.htm