REBECCA A. HAMILTON
Today Stefanie and I were scouting the local launching sites and completing some last-minute fixes on the trailer while the boat was in the water. Right next to the boat ramp, Stefanie spotted two dolphins... who started doing Driver-Barrier behavior! (See below for video!)
So what is DB behavior? It's a foraging technique used by some dolphins here and no where else in the world. It involves one 'driver' dolphins scaring and herding a school of mullet. Then, one or more 'barrier' dolphins block the escape of the fish. Trapped, the mullet choose to jump above the water's surface, where they then fall into the waiting mouths of the dolphins! This behavior is extremely interesting because it is the first confirmed example of role-specialization in a marine mammal, meaning that the 'driver' and 'barrier' dolphins never switch places and become specialists at their role only. My thesis will be the next piece of the puzzle to understand this behavior. I will be recording underwater sounds during DB to see if the dolphins use acoustic communication to coordinate their movements. If they do use consistent communication during DB bouts, it would be strong evidence that the behavior requires intentional cooperation, which would be a first in non-humans!
Needless to day, seeing DB today was very exciting and we are now even more eager to get out on the water to see more!