Hack and fly Today’s boat trip was fantastic. The sun was shining and the water was almost not-freezing! My first few entires were close to the pier as we followed a large group of socializing mothers with their calves. #161 Koshakure was there again (she is everywhere this year), together with #145 – Y-chan. Dokkiri was babysitting Y-chan’s 1 year old calf while Y-chan was busy swimming circles around me. At one point, she started to open her mouth. I immediately started to think what this meant – what kind of signal was she trying to send. Was she threatening me? Was she threatening Koshakure? Was this a playful open mouth display? Was she just stretching her jaw muscles? My mind was going through all the possible meanings, and got me thinking about the research of another Mikura researcher (Nahoko Ueda) who is studying open mouth displays in the Mikura dolphins. Alas, there was no need to spend so much time thinking about the meaning of her open jaw – a few seconds later she opened her mouth and vomited up a fish. You can see in the images here that first she has an open mouth (image 1) and then she is in mid-hack (image 2). Oh well, sometimes trying to be all fancy with scientific thinking clouds the reality of the situation – Y-chan just needed a good old upchuck. A few moments later we witnessed some amazing jumping displays by the same group. I have never seen this species jump this high (around 3 meters) and I didn’t know they ever jumped like this. In the final image you can just about make out a dolphin coming in for a landing after a super high jump. It was really amazing to watch! They were not riding the waves this time – the water was flat. They were likely just jumping for the fun of it. Great stuff!