Rob-servations #3: Blue whale identification

by Rob Nawojchik

During our 12-day trips to Baja, we are very fortunate to see blue whales on most trips. Blue whales are the largest animals to ever live on Earth, and even veteran whale watchers are stunned by their presence. Unfortunately, blue whale populations were severely decimated by industrial whaling. The good news is that, now that they are protected worldwide, their numbers are starting to trend upwards. The eastern North Pacific population of blue whales (the group which includes the Baja blue whales) is among the healthier populations and seems to be increasing. In contrast, the North Atlantic population (a group with which I’m familiar from my marine mammal stranding days) remains at low levels.

Today we’ll focus on the identification (ID) characteristics of blue whales, using the ID categories I mentioned in the last blog. One caveat before we begin: many of the ID descriptions I’ll be using are relative terms, terms such as larger vs. smaller, taller vs. bushier, pronounced vs. modest, etc. When first starting out on your inaugural whale watch, it probably doesn’t help you when you say, “How do you know it’s a blue whale?” and the naturalist says, “Well, for one thing, it’s a lot bigger than a humpback.” When seeing your first whale, how big is “big”? What does “big” look like on the ocean when you’re seeing a tiny fraction of the whale? What does “big” look like from three miles away? The best remedy for this dilemma is repetition. By observing many whales every day, you too will soon appreciate the subtle (at times) differences that allow us to identify whales at sea.

A reminder: we are focusing only on species found in Baja. By eliminating non-Baja species from our identification algorithm, we can more quickly hone in on the ID.

Size and shape of spout/blow: Befitting the largest whale in the world, the blue whale has the tallest spout. The blow can be seen from miles away. Also, the blow is roughly columnar in shape, as opposed to the more-bushy blow of a humpback, the heart-shaped blow of a gray whale, or the angular blow of a sperm whale. The spout of a whale is heavily affected by wind, so on windy days the blow tends to get “knocked-down” and is not as obvious, or at least not as stereotypical in size and shape.

Size of animal: As mentioned, this is the largest species of whale. Adults in the Northern Hemisphere typically range from 75 to 90 feet long (~23-27m). There is some size overlap with the fin whale, but a large blue whale is larger than a large fin whale. A good rule of thumb: if the whale is over 50 feet, then it will be either a blue whale or a fin whale (note: male sperm whales can get over 50 feet, but we’ll account for them in a different blog).

Color: The color of a whale, although often diagnostic, will vary dramatically depending on light conditions. The relative position of you, the whale, and the sun will affect your perception of the color. Also, the whale’s color will appear different on sunny vs. overcast days. The color of the blue whale is best described as a mottled blue-gray. The mottled nature of the pigmentation pattern will probably best help you in separating the blue whale from the color pattern of other large whales.

Dorsal fin: The placement of the dorsal fin on the blue whale is far back on body. Typically, during a surfacing, you will first see the head and blowhole, then the back, eventually the dorsal fin, and finally (sometimes) the tail flukes. Usually the head has already re-submerged by the time the dorsal fin is seen. This is in contrast to some other species in which you may see the head and dorsal fin at the same time. The shape of the dorsal fin in the blue whale is variable, but ranges from triangular to “falcate” (curved, in a similar fashion to a dolphin’s dorsal fin). Perhaps the most distinguishing feature of the blue whale dorsal fin is its comically small size. For such a large whale, the fin is disproportionately modest.

Tail flukes: When discussing the flukes, the first consideration is behavior. Some species sometimes (but not always) show their flukes when they dive. Other species (almost) never do. Thus, when you see a whale’s flukes, even from a distance, you can narrow down the identification. Blue whales are among those species that sometimes show their flukes. The second consideration is size and color pattern. Blue whales have broad tapered flukes with a smooth trailing edge. They tend to have a uniform gray color, with maybe some lighter streaking. In subsequent blogs, we’ll see how the flukes of other species differ from the blue whale.

Species-specific traits: For the blue whale, I think the two unique characters that stand out are the extreme size and the mottled color pattern.

Behavior: Many of the blue whales we see in Baja display the “typical” baleen whale dive pattern: about three to five blows while swimming near the surface, then a dive of about 10-15 minutes. As mentioned, they sometimes show their flukes when diving. We have encountered some blue whales whose dive times were much longer than 15 minutes. In general, we do not see blue whales exhibit some of the behaviors that we’ll discuss with other species, behaviors such as spy-hopping, lob-tailing, breaching, or pectoral-flipper slapping.

2020-07-15T16:34:50-07:00January 21st, 2016|Rob-servations|

Rob-servations #2: Whale identification 101

by Rob Nawojchik

When viewing cetaceans (whales and dolphins) in the wild our initial sighting is most typically from quite a distance, perhaps miles away. Even at such distances, there are characteristic clues we use to identify species. As we get closer different identification clues become evident. Environmental factors such as wind, waves, overcast, time of day, position of the sun, and other variables play a role in how well we are able to observe field characteristics of whales and dolphins. Thus our ability to identify a cetacean will be dependent on our flexibility in using all the information available, and processing different information as distances and environmental conditions change.

Illustrations in field guides usually depict the entire animal, with all the diagnostic features in full view. In the wild, however, we almost never get to see the whole animal. So we rely on certain key features: blow size and shape; size of animal; color; dorsal fin size, shape, and placement; tail fluke shape and color; other species-specific color patterns and/or anatomical features; and behavior. These features are dependent on how far away the animal is from us, and how well we can see those features.

We’ll begin by highlighting the baleen whales. Cetaceans are divided between the baleen whales (mysticetes) and the toothed whales (odontocetes). The baleen whales do not have teeth, but rather have a brush-like structure (baleen) hanging down from their upper jaws. This anatomical feature is composed of overlapping plates that form a sieve for filtering water out of the whale’s mouth when feeding. In Baja we rarely get good looks at the baleen because much feeding activity occurs elsewhere.

If we can’t usually see the baleen, how do we know we’re looking at a baleen whale? A second diagnostic trait separating mysticetes from odontocetes is the number of blowholes: two in mysticetes and one in odontocetes. If we’re lucky to get close enough to a cetacean, we can see the blowhole. When we’re visiting the gray whales at Laguna San Ignacio we get VERY close to the blowhole, sometimes inches away. Many a passenger has ended up with a face-full of whale breath. I’m not sure how many people take note of the double-blowhole during the exhilaration (and exhalation!) of a gray whale close encounter.

Similarly it can sometimes be hard to detect the single blowhole on a dolphin as a herd of hundreds of common dolphins surround the boat. Fortunately many dolphins like to body surf on the pressure wave of the bow of the Searcher (this behavior is called “bow-riding”). When bow-riding, dolphins are close enough to easily see their blowhole.

Our ability to identify whale species will be aided by knowing which species occur in the area and which do not. Of the 14 species of baleen whales worldwide, we typically see six during our Baja trips: blue, fin, Bryde’s, minke, humpback, and gray. Also by knowing life history information of these whales specific to Baja, we can anticipate certain species in certain areas. For example if we are in Laguna San Ignacio, then we are looking at gray whales. If we are at the Gorda Banks (offshore Cabo San Lucas), then most of the whales are humpbacks.

In upcoming blogs we will examine the various whale species and compare field characteristics to help identify them.

2020-07-15T16:34:50-07:00January 14th, 2016|Rob-servations|

Rob-servations #1: Recognizing Baja’s whales

by Rob Nawojchik

Eco-tourists are attracted to Baja California for many reasons. For whalewatchers, the attraction is the great abundance and diversity of marine mammals. “Abundance,” in simple terms, refers to the number of individuals. Some species of marine mammals occur in huge numbers in Baja. For example, it’s not uncommon to see herds of dolphins numbering in the hundreds or even thousands. “Diversity” refers to the number of species. The waters around the Baja peninsula contain one of the most diverse assemblages of “cetaceans” (whales and dolphins) in the world. Not only do we see lots of individuals (i.e., abundance), but many species (i.e., diversity).

Because of the great diversity in Baja, identification of cetacean species can be challenging. One of the advantages of our 12-day trips is that each participant gets daily repeat training in cetacean identification. Regardless of whether you’ve never seen a whale before, or are an experienced whalewatcher, your identification skills will improve dramatically with each day.

Cetacean identification can be difficult at times because whales and dolphins spend most of their time underwater and are at the surface usually for just a moment. Also, some of the initial sightings are of animals quite a distance away, sometimes miles away! Imagine trying to identify an animal two miles away that surfaced for a second.

When first learning whale identification, guide books and boat naturalists will refer to “field characteristics” and other identifying features. As you start to see more and more whales, you will learn to focus on these traits. With practice, you will glean much information from a surfacing whale in those few seconds, often enough to suggest an identification.

The captain and crew of the Searcher have spent literally years of their lives at sea, and have seen many more cetaceans than most marine mammal scientists. Their identification skills have developed into what I call the “gestalt phase”–they can see a dot on the horizon and know intuitively the species identification. This ability stems from seeing so many animals, over so many years, under so many conditions, that the crew have developed a subconscious sense of knowing what they’re looking at.

In upcoming blogs, we’ll examine field characteristics of Baja cetaceans to help you better identify these species.

2020-07-15T16:34:51-07:00January 10th, 2016|Rob-servations|

Introducing “Rob-servations”

Superlative professional naturalists join Searcher crew on each Baja Whalewatching tour. They are aboard to enhance a guest’s experience of enjoyment and learning about this amazing destination.

We are happy to welcome one of our naturalists, Rob Nawojchik, (seen in the photos above) to the Captain’s Blog. He’ll provide occasional posts–called Rob-servations–on Baja’s wildlife and provide a sneak peek to what you’ll encounter on your upcoming tour!


2020-07-15T16:34:51-07:00January 9th, 2016|Rob-servations|

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