By Florence Sullivan, MSc. Student, GEMM Lab
Happy Spring everyone! You may be wondering where the gray whale updates have been all winter – and while I haven’t migrated south to Baja California with them, I have spent many hours in the GEMM Lab processing data, and categorizing photos.
You may recall that one of my base questions for this project is:
Do individual whales have different foraging strategies?
In order to answer this question, we must be able to tell individual gray whales apart. Scientists have many methods for recognizing individuals of different species using tags and bands, taking biopsy samples for DNA analysis, and more. But the method we’re using for this project is perhaps the simplest: Photo-Identification, which relies on the unique markings on individual animals, like fingerprints. All you need is a camera and rather a lot of patience.
Bottlenose dolphins were some of the first cetaceans to be documented by photo-identification. Individuals are identified by knicks and notches in their fins. Humpback whales are comparatively easy to identify – the bold black and white patterns on the underside of their frequently displayed flukes are compared. Orcas, one of the most beloved species of cetaceans, are recognized thanks to their saddle patches – again, unique to each individual. Did you know that the coloration and shape of those patches is actually indicative of the different ecotypes of Orca around the world? Check out this beautiful poster by Uko Gorter to see!
Gray whale photo identification is a bit more subtle since these whales don’t have dorsal fins and do not show the undersides of their fluke regularly. Because gray whales can have very different patterns on either side of their body, it is also important to get photos of both their right and left sides, as well as the fluke, to be sure of recognizing an individual if it comes around again. When taking photos of a gray whale, it’s a good idea to include the dorsal hump, where the knuckles start as it dives, as an easy indicator of which side of the body you are looking at when you’re trying to match photos. Some clues that I often use when identifying an individual include the placement of barnacles, and patterns of pigmentation and scars. You can see that patience and a talent for pattern recognition come in handy for this sort of work.
While we were in the field, it was important for my team to quickly find reference features to make sure we were always tracking the same whale. If you stopped by to visit our field station, you may have heard use saying things like “68 has white on both fluke-tips”, “70 has a propeller scar on the left side”, “the barnacles on 54’s head looks like a polyp”, or “27 has a smiley face in front of the first knuckle left side.” Sometimes, if a trait was particularly obvious, and the whale visited our field station more than once, we would give them a name to help us remember them. These notes were often (but to my frustration, not always!) recorded in our field notebook, and have come in handy this winter as I have systematically gone through the 8000+ photos we took last summer, identifying each individual, and noting whenever one was a repeat visitor. With these individuals labeled, I can now assess their level of behavioral and distribution consistency within and between study sites, and over the course of the summer.
Why don’t you try your luck? How many individuals are in this photoset? How many repeats? If I tell you that my team named some of these whales Mitosis, Smiley, Ninja and Keyboard can you figure out which ones they are?
Keep scrolling for the answer key ( I don’t want to spoil it too easily!)
There are 7 whales in this photoset. Smiley and Keyboard both have repeat shots for you to find, and Smiley even shows off both left and right sides.
- Whale 18 – Mitosis
- Whale 70 -Keyboard
- Whale 23 -Smiley
- Whale 68 – Keyboard
- Whale 27 -Smiley
- Whale 67
- Whale 36 -Ninja
- Whale 60 – “60”
- Whale 38 – has no nickname even if we’ve seen it 8 times! Have any suggestions? leave it in the comments!
- Whale 55 – Smiley