Hybrid Dolphin in the Making?

On May 7th, 2011 we witnessed some very interesting dolphin behavior. We were out on a skunk trip (no whales in sight) and the seas started turning ugly. When we were a couple miles outside of Moss Landing, we spotted a pod of about 75 dolphins-- a mix between mostly Risso's dolphins and only a few Pacific white-sided dolphins. The pod was quite active, approaching the boat and surfing in the breaking swells all around. We kept noticing a white-sided chasing a Risso, and when they sidled up next to the boat, we could see they were mating!

Pacific white-sided dolphin and Risso's dolphin mating. Photo by Kate Cummings

These shots show a Pacific white-sided dolphin belly to belly with a Risso's dolphin. They're size difference is obvious-- with the white-sided being around 7-8 feet long and the Risso about 10-12.

Pacific white-sided dolphin and Risso's dolphin mating. Photo by Kate Cummings.

There are known hybrids between Risso's dolphins and bottlenose dolphins, but I've searched the web and have asked a few researchers but haven't found anything on a hybrid white-sided/Risso. Dolphins are extremely social and will often use sex to bond with one another, not just to reproduce. In any case, we'll be keeping our eyes out for a Pacific Risso-Sided Dolphin!