An essential skill when observing whales is the ability of being able to know not only the type of whale you have encountered, but who exactly. By individualizing every whale that we come across, it allows us to monitor their evolution over time which allows us to understand the quality of life they experience.
Many distinct details help us distinguish whales from one another. With whales only surfacing for moments at a time, this means we need to take photos of them every chance we get. LOTS of photos! This process is known as photo-identification.
Photo-identification allows the observer to locate unique tags, scars, or naturally-occurring marks. Unfortunately, it is not always that simple to identify a specific whale. Depending on the species, there are different techniques that are very effective for identifying individuals. Today, we will become experts on how to recognize our humpback whales!
Out of all the naturally-occurring features of humpback whales, the most commonly used indicator to tell them apart is their tail, also known as a fluke. Humpbacks are known for their distinct black and white pigmentation patterns on the underside of their fluke, which whale watchers often get to see when these whales are preparing for a dive. Essentially, they do a nose-dive to propel themselves down to deeper depths, showing their fluke to you on their way back down. With flukes the focus lies on noticing any pigment patterns, distinct markings or scars, and their trailing edge shape. Taken together, these features of a humpback whale’s fluke are like a fingerprint: no two individuals are exactly alike.
Features to look for when identifying humpback whales:
1. Pigmentation
Our goal is to observe the unique pigment pattern located on the ventral surface. These patterns are present at birth, although they may be hazy in calves and change over the course of a whale’s first few years. Fluke pigmentation can range from all white in some to all black on other individuals, with the majority lying somewhere in between. Note that if you spot a yellowish color on a fluke it is not pigment, but a temporary coating of diatoms (algae).
2. Distinctive marks or scars
Humpback whale flukes often have circular scars (sometimes from barnacles), linear scratches (sometimes from orca attacks!) and other marks that make them quite distinctive. If you closely observe the first image displayed above, you can make out a giraffe head and neck shape on the right fluke. Discoveries like this makes it that much easier name each whale! Scarring can actually be found on any part of the whale’s body, and the cause of these scars is wide-ranging. Some are naturally occurring and others result from injuries. It is important to keep in mind that as a whale ages, many new marks or scars may form and therefore are an ever evolving quality. It is helpful to note these specific marks or scars in case they are new.
3. Trailing edge shape
The trailing edge of a humpback fluke ranges from being smooth to having noticeable ‘hills’ and ‘valleys’. Sometimes the ‘hills’ are quite round, but they can also be pointy. We call these edges of the fluke the pattern of serrations – just like a serrated knife! The serrations are a very useful tool when trying to match whales without distinctive pigment patterns (for example, whales with nearly all-black flukes) and they won’t change over the course of a whale’s life unless scarring occurs.
4. Dorsal fins
Dorsal fins are another helpful feature, as they often have unique shapes and pigmentations. Humpback dorsal fins can differ in arch, curvature and pointiness, but sometimes these differences can be minimal. Therefore, it takes a keen eye for tiny details! To make it even more challenging, the appearance of humpback dorsal fins may change as time goes by. As mentioned in #2 above, this can be due to many reasons. To the right is an example of the same humpback whale a few years apart and the drastic difference its dorsal fin has experienced.
If you look closely, not only has the overall shape of the dorsal fin changed slightly, but due to a previous entanglement, it now has an indent in an area it did not before. Other reasons for a drastic change in dorsal fin for males includes rough mating encounters. These are the types of challenges that can appear when trying to identify a humpback whale from solely its dorsal fin. Because of this, a combination of identifying features is helpful to document in order to have the best chances of identifying an individual.
Tedious? Yes. Important? Also yes!
The ease of matching and identifying humpbacks depends greatly upon the quality of the photograph (distance and angle from the subject, as well as exposure). In addition, whales do acquire marks (scratches, nicks and notches) during their lifetime which can alter their appearance in a number of ways. Mastering the identification of humpbacks from a photograph, then matching to a catalog of over thousands of individuals takes good observational skills and patience.
So why do researchers spend so much time identifying whales?
We can learn a lot from tracking individuals over time. Most of what we know about whale migrations comes from photographing individuals at different locations. We can learn not only about their movements, but also how they are using their habitat, how much time they are spending in certain areas, and what threats they may be exposed to in those locations. We can also see who else they are spending time with, and in the case of females, we can track their reproductive history and even develop family trees for their family!
An example of this in action involves one of our whales, Flame. Happy Whale was able to track Flame from Juneau, AK to Maui, HI and back. This revealed to us that she had managed to conceive and raise THREE calves within three consecutive years. This is a very uncommon occurrence, so to have been able to track the entire process is incredible.
Want to start identifying whales? Honestly, all it takes is some practice and patience and next thing you know you’ll be the expert humpback whale detector! Start practicing by visiting our activities page.
Stay tuned for our next blog which will look at how we identify orcas!
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