Friday, May 24, 2019

Blue Whales and Fin Whales off San Diego

On the May 12th pelagic birding trip we encountered two Fin Whales together, followed an hour or so later by two Blue Whales.

The Fin Whale is the second longest whale (up to 80 feet), but first in speed. They move right along!

Fin whale and mylar balloon
Fin Whale. Mylar balloons are a common form of "garbage" at sea.
These whales are named for their obvious dorsal fins. The third largest whale is the Sei Whale, which has a slightly smaller dorsal fin that is more strongly falcate (curved). The dorsal fin is set back far on the Fin Whale, so you don't see the spout and fin at the same time. The dorsal fin on Sei Whale is not set so far back, so you may see a spout and dorsal fin at the same time.

Fin Whale
The left ("dark") side of a Fin Whale.
Fin Whale
The right ("white") side of a Fin Whale.
Fin Whale coloration is asymmetrical. The right jaw and baleen is white; the left side is dark. This color difference is readily seen when the whale spouts. I missed a photo of it though.

When it dives, the flukes rarely come out of the water as they do on many other whales.

Next, the Blue Whale. The largest animal to have ever lived. At 100 feet, they are as long as the longest dinosaur, Argentinosaurus, but twice as heavy. They weigh as much as 40 elephants... or 30 T-Rexes. [The Blue Whale on the BBC page, "Anatomy of a Blue Whale."]

The spout is very tall and thin. By the time you see it, it is too late to photograph it. So you get the following series of views...

Blue Whale blow hole
Immediate after a blow. Only the blow hole on the top of the head is above water.
The rest of the long head is under water on the right.
The head of a blue whale is very long and pointed, but usually stays under the water except for the blow hole on the top back of the head. The head of the Blue Whale is a little less than 1/4 of the entire length.

Blue Whale
Blue Whale swimming to the right. Top of head (right) and upper back visible.
Blue Whale
The middle half of a Blue Whale facing right. Small back fin on left, head under water on right.
Once you see the long straight back and small dorsal triangle, you know it's a Blue Whale.
The view above is the middle "half" of the Blue Whale. The head is almost 1/4, from blow hole to snout. The hind 1/4 of the whale is from dorsal fin to the flukes.

Diving Blue Whale
Diving Blue Whale. The flukes will follow the back fin as the whale dives to the right.
Forget seeing it again for 20 minutes....

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