Swimming north rapidly

  

This was a little unexpected, but as I was watching the Humpback Whales yesterday (26 July 2025), I caught a glimpse of a fin much closer to shore and realized it was a Bottlenose Dolphin (Tursiops truncatus).

I wasn't quite ready and didn't get a great photo, but I thought one photo was possibly good enough to identify the individual.  So I sent it off to Bill Keener at The Marine Mammal Center.  Sure enough, Bill was able to match this to a known female in their catalog.  "Cepat" has been seen in Sonoma County before, and as far north as Sea Ranch. 

Here's a few of her heading north:

 

 

By the way, Bill mentioned that Cepat doesn't usually travel alone, so it's a good time to keep an eye out for other Bottlenose Dolphins in the Bodega Bay area.  Let us know if you see any!  

P.S.  I was curious about the name "Cepat," so I looked it up.  Sounds like it's an Indonesian word meaning rapid, quick, or swift.

P.P.S.  Many thanks to Bill for providing the background information about Cepat and for monitoring local marine mammals!

ADDENDUM (31 July 2025): Some people have inquired about how Bill identified Cepat.  Individual Bottlenose Dolphins have distinctive markings on or near their dorsal fins.  So if you get a good enough photo and the dolphin is a known individual in the photo catalog, you can match the markings.  Here's a close-up where you can see a couple of distinctive notches at the base of Cepat's fin:

 

 

Dolphin surprise

  

I was working at my desk this morning (19 March 2025), when a lot of splashing offshore caught my eye.  I checked quickly with binoculars and realized it was a large group of dolphins passing Bodega Head, so I went to get my camera to try for photos.

They were pretty far out, so the photos aren't great, but because this doesn't happen very often, here are a few images for the record.  [You can click on the images for sharper versions.]

 

 

This was a large group of Risso's Dolphins (Grampus griseus).  My estimate was somewhere ~100 individuals, but I ran into Lisa who wondered about ~50, so somewhere in the range of 50-100 dolphins.

Look for the relatively large body size (8.5-13 feet), overall grayish coloration, and tall dorsal fin.

 

 

The dolphins were swimming south fairly quickly, but they were in view from Bodega Head for at least 30 minutes (between 10:30-11:00 a.m.). 

Remarkably, we also observed a large group of Risso's Dolphins under very similar circumstances last year on nearly the same date (21 March 2024) -- see post called "Splashes, fins, and leaps!"  Perhaps the week after St. Patrick's Day is a good time to be watching for Risso's from Bodega Head?

Splashes, fins, and leaps!

Okay, here's a fun story.  Yesterday (21 March 2024) I was working at my desk, which at the moment has a view of the ocean, and something white offshore caught my eye.  I thought it might have been a whale spout at first, but I saw it again and could see it was more of a splash, so I grabbed my binoculars for a better view.  I could now see extensive splashing and backs of cetaceans that didn't look like whales, but they were ~3/4 mile offshore, so a bit distant. They were moving quickly to the south, but I had a spotting scope nearby, so I ran down the hall with it and set up just outside the door in hopes of identifying them.

Now I could see a very large group of dolphins, probably over 100 individuals!  I could see large distinct dorsal fins, some full-body breaches, some tail slapping — a very energetic group.  It was still far enough away that I wasn't sure about the species, but because it's rare to see so many dolphins close to shore off Bodega Head, I started shouting down the hallway for others to come see.

We had nice views of the dolphins, but I still wasn't sure about the species.  I could tell they weren't Bottlenose Dolphins (Tursiops truncatus) — they didn't have long beaks and the group size was too large.  I'd never seen Pacific White-sided Dolphins (Lagenorhynchus obliquidens) so close to shore, and usually they have some paler color on their dorsal fins and these dorsal fins looked dark to me.  Long-beaked Common Dolphins (Delphinus capensis) or Short-beaked Common Dolphins (Delphinus delphis) might have been possible, but they're not common in this area, and I couldn't see enough details to be sure.

At one point I had wondered about Risso's Dolphins (Grampus griseus) because some of the dorsal fins looked quite tall (tall enough that Orca even crossed my mind).  But I was thrown off because some of the smaller individuals leaping out of the water looked very pale below, especially in contrast with the darker backs.  I haven't seen Risso's Dolphins that often, but I think of them as being more uniform gray.  However, my lack of experience with the variation in this species likely biased my expectations.

I could see at least one boat out where the dolphins were, and was hopeful someone might have gotten a photo, so I sent out a few inquiries.  I didn't hear back...until this afternoon!  Bill Keener from The Marine Mammal Center let me know that they had a team on a research cruise out by Tomales Point around the same time.  They photographed a group of 100-200 Risso's Dolphins near Bird Rock.  The Marine Mammal Center kindly shared a couple of their photos, so here you go!  

Photo credit for both photos: N. Cristales/The Marine Mammal Center under NOAA permit # 26532.  [You can click on the images for larger versions.]

 

 

 

 

 

Such great photos!  

 

Risso's Dolphins are medium sized, reaching lengths of ~8.5-13 feet.  Note the prominent dorsal fin and the overall grayish coloration.  On a few individuals in the second photo you can also see that they're blunt-headed (similar to pilot whales).  Risso's Dolphins tend to prefer deeper water, but they are occasionally observed from shore.

 

With many thanks to The Marine Mammal Center crew for sharing their observations and wonderful photos.

Out of the water

  

Whoops, I'm running out of time tonight, but here's a dolphin photo for you — Pacific White-sided Dolphin (Lagenorhynchos obliquidens) from yesterday's pelagic trip out beyond Cordell Bank.

One fin at a time

 

 

Well, they're not great photos, but it still seems worthwhile to share this Bottlenose Dolphin (Tursiops truncatus) sighting from Bodega Head today (12 January 2022).  A few individuals swam by heading south at ~10 a.m. this morning.  

 

Larry mentioned others have been seen in the area recently, and Bill reported that a group was observed at Sea Ranch today, so it's worth keeping an eye out for them.

 

 

Power surge

 

I didn't get a chance to finish "pelagic week," so I'll be sharing a few more photos from the boat trip to Bodega Canyon and Cordell Bank on 25 August 2019.

Tonight's post features Pacific White-sided Dolphins (Lagenorhynchus obliquens).

 

 

 

Shadows of the sea

 

Ready for pelagic week?  I joined a trip to Bodega Canyon and Cordell Bank today (25 August 2019).  So I'll be sharing some photos from offshore during the next week.  Above, a Northern Right Whale Dolphin (Lissodelphis borealis) leaps from the water next to the boat.  They look unusual because they lack a dorsal fin.

Northern Right Whale Dolphins are fast and unpredictable, making them difficult to photograph.  When they break the surface, they produce an impressive splash:

 

These dolphins are very dark above, so they almost look like shadows when swimming under water.  But check out the paler frosting on the flukes:

 

Here's another example of their shadowy silhouette:

 

Because they lack a dorsal fin, when viewed from a distance Northern Right Whale Dolphins can look a little odd. Below, here's one surfacing — note the very streamlined shape: