Rob-servations

The Baja peninsula is the southernmost range limit of eastern Pacific harbor seals. R. Nawojchik Harbor seals haul out for molting, pupping and nursing. R. Nawojchik

The harbor seal (Phoca vitulina) is one of four species of pinnipeds regularly found in the waters around Baja California (for a discussion of pinnipeds in general, please see my Rob-servations Blog #10). Harbor seals are members of the pinniped family Phocidae, as is the northern elephant seal, another Baja pinniped species. All members of this family share various traits that help distinguish them from the other major group of pinnipeds, the family Otariidae (which includes the California sea lion and Guadalupe fur seal, also found in Baja. See photos below for comparison).

Guadalupe fur seal

California sea lions

Harbor seals (and other phocids) lack an external ear flap, have relatively small front flippers (compared to otariids), cannot rotate their hind flippers forward, hunch along awkwardly when on land, and primarily use their hind flippers and bodies when swimming underwater (see Blog #10 for more details).

As a general rule, phocids tend to have little to no sexual dimorphism, while otariids are characterized by having sexual dimorphism. The term “sexual dimorphism” refers to the differences between male and female members of a species. Many people equate the term with differences in body size, but the term also encompasses other differences, such as the bright colors in some male birds, or the antlers in male deer. Harbor seals fit the typical model for phocids, in that male and female harbor seals are generally indistinguishable by size. (The BIG exception to the lack of sexual dimorphism in phocids is the elephant seal.) When examining dead harbor seals on the beach, I can tell male from female by the relative positions of the genital aperture and anus. When viewing live harbor seals in the wild, however, we rarely get that close a look and consequently cannot distinguish male from female. Harbor seals in the Pacific Ocean can sometimes get a bit larger than six feet (1.82 meters) but are usually less than 300 pounds (136 kilograms) in weight.

Harbor seals are the most widely distributed of all 33 pinniped species. They inhabit both the North Atlantic and North Pacific oceans, and are typically found along both coasts of North America, northeastern Asia, and northern Europe (including the United Kingdom). Ironically, of the four species of pinniped seen on our Baja trips, the harbor seal is among the least likely to be seen. The reason for this is that the Baja peninsula is the southernmost range limit of eastern Pacific harbor seals. Much of our tour takes us south of and beyond the range of harbor seals.

The best chance to see harbor seals during our Searcher Natural History Tours is during the first two full days of the trip. On the morning of the first full day, after clearing Customs in Ensenada, Mexico, we sail past a group of islands called Todos Santos. From the Searcher, we can see many species of birds, as well as any pinnipeds associated with the islands. We sometimes see harbor seals hauled out on the beach or bobbing in the water.

The second full day of the trip is spent at the San Benito Islands, specifically at West San Benito Island. We sometimes see harbor seals here. However, because the San Benito Islands are close to the southern limit of eastern Pacific harbor seals, we see harbor seals here less frequently than we do at the Todos Santos islands. Once we depart the San Benito Islands and continue even further south, we almost never see harbor seals again. The southernmost haul-out site for eastern Pacific harbor seals along the Baja peninsula is San Roque Island, about 110 miles (176 km) southeast of the San Benito Islands. However, our cruise track does not take us close to this island.

Much of the haul-out behavior of harbor seals in Baja is related to the annual molt, in which old hair is shed. Loss of body heat is high during the molt, so seals mitigate some of this heat loss by hauling out on land, rather than remaining in water (the rate of heat loss is greater in water). The annual molt cycle is triggered by photoperiod. Thus, seals at more southerly locations start molting first, and the timing of molting then progresses northward. For example, molting occurs at San Roque Island from February to June, while molting occurs at Todos Santos Island from April to July. Because seals are more likely to be hauled out while molting, researchers use the peak of the molting season to conduct population census counts of seal numbers. Harbor seals also haul out for pupping and nursing. Pupping season provides another opportunity for researchers to make population counts. Most pupping by harbor seals in Baja occurs in February and March.

All four species of Baja pinnipeds were subject to commercial exploitation during the 19^th century and the first half of the 20^th century. Now, with the cessation of hunting, and with legal protections, these species, including the harbor seal, are recovering in numbers and are repopulating their historical range. Although harbor seals may not be a “target species” for many eco-tourists to Baja, it’s always wonderful to see them, especially considering their recovery from exploitation.

–Rob Nawojchik, marine biologist and Searcher naturalist

R. Nawojchik "Perhaps the best character is the shaggy mane of the fur seal; the hair around the neck of fur seals is thicker than the relatively shorter fur of sea lions." "Guadalupe fur seals have a mating system where bulls compete with each other for control of desirable sections of beach." Rob Nawojchik "Fur seals possess an external ear flap, have relatively large front flippers, are able to rotate their hind flippers forward, can walk quadrupedally when on land, and primarily use their front flippers for propulsion underwater." R. Nawojchik

The Guadalupe fur seal (Arctocephalus townsendi) is one of four species of pinnipeds regularly found in the waters around Baja California (for a discussion of pinnipeds in general, please see my Rob-servations Blog #10). There are nine species of fur seals in the world, one in the genus Callorhinus and eight in the genus Arctocephalus. All species of fur seals have many characteristics in common, particularly in regards to anatomy, behavior, and exploitation by humans.

Guadalupe fur seals are members of the pinniped family Otariidae, as is the California sea lion, another Baja pinniped species. All members of this family share various traits that help distinguish them from the other major group of pinnipeds, the family Phocidae (which includes the northern elephant seal and harbor seal, both species found in Baja).

Fur seals (and other otariids) possess an external ear flap, have relatively large front flippers (compared to phocids), are able to rotate their hind flippers forward, can walk quadrupedally when on land, and primarily use their front flippers for propulsion underwater (see Blog #10 for more details).

Otariids are “sexually dimorphic,” a term referring to the differences between male and female members of a species. Many people equate the term with differences in body size, but the term also encompasses other differences, such as the bright colors in some male birds, or the antlers in male deer. In the case of fur seals, body size is a good indicator of sex when viewing adult animals. Male Guadalupe fur seals are almost twice as long and 3-4 times heavier than adult females. As a species, however, Guadalupe fur seals are modest in size. Adult males reach about 2 m (6.6 ft) in length and about 160-170 kg (350-370 lbs) in weight, while females average 1.5 m (5 ft) and 40-50 kg (90-110 lbs). While in Baja, the only species with which you may confuse the fur seals is the California sea lion. However, adult California sea lions are noticeably longer and weigh about twice as much as fur seals.

Oftentimes a size disparity between male and female mammals suggests a polygynous mating system, in which a few males mate with many females. Guadalupe fur seals have such a mating system, where bulls compete with each other for control of desirable sections of beach. The dominant male defends his territory, and his harem of females, from other males. The average harem size is about six females. Guadalupe fur seals mate in the summer. Consequently, we do not see adult males or mating behavior during our Natural History tours, which run February to April (we do see elephant seal mating behavior, which occurs during our tour season).

Guadalupe fur seals on the rocks at Isla San Benito.

Despite the summer breeding season, we do see fur seals during our February to April tours. Early in the trip, we spend a day hiking around West San Benito Island, one of the three San Benito Islands off the west coast of the Baja peninsula. Younger, presumably non-breeding fur seals, occupy various sites around West San Benito Island at this time of year.

Interestingly, in the 11 years that I’ve been leading Searcher trips, I’ve witnessed the fur seals move their haul-out sites among the San Benito Islands. For a couple of years during this time, the seals were hauled out on East San Benito Island, where we observed them from the Searcher’s skiffs. A few years later, they were hauled out along the southern coast of West San Benito Island. Most recently, the majority of fur seals have been using the northwest coast of West San Benito Island. Of course, individual fur seals can be found anywhere in the San Benito Islands, but the primary haul-out site seems to change over time (at least during our observation period of January through April).

Even more interesting is the history of human exploitation of the Guadalupe fur seal and the role of the San Benito Islands in their comeback. All species of fur seals were hunted mercilessly in the 19^th century, to the point where they became “commercially extinct” (i.e., there were so few animals left that it wasn’t cost-effective to hunt them anymore). In the case of the Guadalupe fur seal, the species was thought to be biologically extinct. In 1954, an expedition to Guadalupe Island (northwest of the San Benito Islands) confirmed that a remnant population of a few hundred fur seals remained. With subsequent protection, that population has now grown to about 17,000 individuals. Despite that encouraging growth trend, the population size is still very small. While at first only found on Guadalupe Island, the breeding population has grown large enough that some individuals have colonized other islands for breeding, most notably the San Benito Islands in 1997. Thus, the San Benito Islands are a crucial habitat for the continued recovery of this species.

I mentioned earlier that the only species with which you might confuse the Guadalupe fur seal is the California sea lion. We do see lots of sea lions on our Searcher Natural History tours in Baja, including at the San Benito Islands. Some identification characteristics should allow you to separate them. As mentioned, California sea lions are larger than Guadalupe fur seals, about twice as heavy. Fur seals are darker, on average, than sea lions, with the coat of fur seals appearing dark brown to almost black. Sea lion color is highly variable, often depending on how wet the animal is. A sea lion just coming out of the water is usually dark brown, while a dry sea lion hauled out for hours may appear almost blond. The snout of a Guadalupe fur seal is more tapered and pointy compared to the relatively more-blunt snout of a sea lion. Perhaps the best character is the shaggy mane of the fur seal; the hair around the neck of fur seals is thicker than the relatively shorter fur of sea lions.

To the uninitiated, Guadalupe fur seals look like shaggy sea lions. And with sea lions so omnipresent on our trips, I think many people overlook the significance of seeing these fur seals. During the course of each Searcher Natural History tour, we witness the majesty of giant whales, the spectacle of a thousand dolphins in a single herd, and the wonder of innumerable other sights. But I always make a point of saying, while we gaze down upon a group of sparring fur seals playing in a wave-battered tide pool, that we are looking at the rarest of all the marine mammals that we will see on this trip.

Note: recent scientific opinion suggests that the Guadalupe fur seal is a subspecies of Arctocephalus philippii, with the other subspecies being the Juan Fernandez fur seal (found in the Juan Fernandez Islands off of Chile). Both subspecies share a history of exploitation to the point of near extinction, and a recent history of protection and population growth.

–Rob Nawojchik, Searcher Natural History Tours naturalist

"When elephant seals leave the San Benito Islands, they head to their feeding grounds thousands of miles away in certain areas of the North Pacific Ocean. While there, they dive very deep to feed on squid." R. Nawojchik "Male elephant seals are gigantic, much larger than the females." R. Nawojchik "...Elephant seals haul out later in the year for molting, a process by which they shed old hair and skin quite rapidly." R. Nawojchik R. Nawojchik A bellowing male elephant seal on the beach at Isla San Benito "Northern elephant seals haul out twice a year in certain select locations along the California and Baja California coasts." R. Nawojchik "Male elephant seal attempting to mate with female." R. Nawojchik "Much of what we know about the movements and diving patterns of elephant seals comes from the use of satellite-linked time-depth recorders (TDRs) that are attached to the seals at their haul-out sites." R. Nawojchik Rob Nawojchik Male elephant seal resting on Isla San Benito West "Northern elephant seals haul out twice a year in certain select locations along the California and Baja California coasts." R. Nawojchik Competing male elephant seals can draw blood. R. Nawojchik

The northern elephant seal (Mirounga angustirostris) is one of four species of pinnipeds regularly found in the waters around Baja California (for a discussion of pinnipeds in general, please see my Rob-servations Blog #10). There are two species of elephant seal in the world, the northern and southern, with the southern one being found in the southern hemisphere. The northern elephant seal is mostly found in the eastern North Pacific Ocean and is the species we see in Baja.

Elephant Seal by Mark Scilly

Elephant seals are members of the pinniped family Phocidae, as is the harbor seal, another Baja pinniped species.

Harbor Seal by Rob Nawojchik

All members of this family share various traits that help distinguish them from the other major group of pinnipeds, the family Otariidae (which includes the California sea lion and Guadalupe fur seal, both species found in Baja).

Elephant seals (and other phocids) lack an external ear flap, have relatively small front flippers (compared to otariids), cannot rotate their hind flippers forward, hunch along awkwardly when on land, and primarily use their hind flippers and bodies when swimming underwater (see Blog #10 for more details).

As a general rule, phocids tend to have little to no sexual dimorphism, while otariids are characterized by having sexual dimorphism. The term “sexual dimorphism” refers to the differences between male and female members of a species. Many people equate the term with differences in body size, but the term also encompasses other differences, such as the bright colors in some male birds, or the antlers in male deer. The BIG exception to the lack of sexual dimorphism in phocids is … the elephant seal! Male elephant seals are gigantic, much larger than the females. Elephant seals are not only the largest pinnipeds, but are also the most sexually dimorphic mammals. Adult male northern elephant seals get up to 4.2 meters (14 feet) and 2,500 kilograms (5,500 pounds), compared with 2.8 m (9 feet) and 600 kg (1,300 pounds) for females. Southern elephant seals get even larger!

Oftentimes a size disparity between male and female mammals suggests a polygynous mating system, in which a few males mate with many females. Elephant seals have such a mating system, where large bulls compete with each other for control of desirable sections of beach.

Much larger male elephant seal surrounded by much smaller females and others.

The best beaches have good haul-out sites for females to come ashore, give birth to their pups, nurse them for one month, and then mate again before heading back out to sea. The beachmaster bulls have mating access to many females (and get to pass on their genes to many pups), whereas the vanquished males may not get to mate at all that season.

Northern elephant seals haul out twice a year in certain select locations along the California and Baja California coasts. During our Searcher Natural History Tour to Baja, we spend a day on West San Benito Island, one of the three San Benito Islands that serve as the primary haul-out site for elephant seals in Baja. In addition to hauling out for pupping and mating, elephant seals haul out later in the year for molting, a process by which they shed old hair and skin quite rapidly (all mammals continuously shed old hair and skin, but elephant seals go through a “catastrophic molt”).

We always see elephant seals on West San Benito Island. However, the composition of the elephant seal groups varies by month. During the Searcher’s first trips of the year (late January and early February), we can see adult males and females, as well as very young pups. As the season progresses, we see fewer adult males and the pups are getting larger. By the time we get to April, few adult males are left, many of the pups have been weaned and their mothers have departed, and other elephant seals (mostly sub-adults) have arrived for molting.

Rob Nawojchik, author of Rob-servations, guides Searcher passengers around the elephant seal haul-out areas on scenic Isla San Benito.

When elephant seals leave the San Benito Islands, they head to their feeding grounds thousands of miles away in certain areas of the North Pacific Ocean. While there, they dive very deep to feed on squid. Elephant seals are the champion divers among pinnipeds, capable of diving deeper and longer than other species. In fact, the diving capabilities of elephant seals are comparable to that of sperm whales. Much of what we know about the movements and diving patterns of elephant seals comes from the use of satellite-linked time-depth recorders (TDRs) that are attached to the seals at their haul-out sites. Due to their double migration (one for reproduction and one for molting), northern elephant seals end up migrating more than any other mammal, up to 21,000 km (13,000 miles) per year!

While observing these amazing animals during our Baja tours, I like to remind everyone that elephant seals were hunted to the brink of extinction. It is only because of their current protected status, and safe havens such as the San Benito Islands, that the northern elephant seal has made such a remarkable recovery.

Searcher at Anchor – Isla San Benito, Mexico by Lee Morgan

California sea lions at Los Islotes R. Nawojchik Harbor seal at Islas Todos Santos R. Nawojchik Guadalupe fur seal at Isla San Benito R. Nawojchik Northern elephant seals at Isla San Benito R. Nawojchik

For the first nine blogs in this series, we’ve been focusing on various species of cetaceans (whales and dolphins). Another major group of marine mammals is the pinnipeds, a group that includes seals, sea lions, fur seals, and the walrus. Of the 33 species of pinnipeds in the world, four can be seen on a regular basis in Baja: harbor seal, northern elephant seal, California sea lion, and Guadalupe fur seal.

The group Pinnipedia is a taxonomic group that is embedded within the mammalian order Carnivora. The order Carnivora is the order that contains such species as lions, tigers, and bears, as well as dogs, cats, skunks, otters, raccoons, and hyenas, among others. The inclusion of the pinnipeds within the order Carnivora tells us that the closest relatives of the pinnipeds are the members of the Carnivora, rather than other marine mammals or other orders of mammals. More specifically, the pinnipeds are more closely affiliated with the “arctoid carnivores” (a group that includes weasels, otters, and bears) as opposed to the “aeluroid carnivores” (a group that includes mongooses, hyenas, lions, leopards, cheetahs, etc.).

The pinnipeds are comprised of three families: Phocidae (18 species), Otariidae (14 species), and Odobenidae. The family Odobenidae contains just one species, the walrus. The walrus is perhaps the most recognizable of all the pinnipeds, mostly due to the large tusks. Found only in the Arctic and sub-Arctic, we do not see any walruses in Baja. However, it is interesting to note that during the Middle Miocene and Late Miocene epochs (16 – 5 million years ago), a time of great radiation of pinniped lineages, there were many more species of odobenids. Some of these Miocene odobenids lived along California and Baja. Paleontologists have discovered many fossils of Miocene “walruses” in sandstone formations in Baja.

The family Phocidae includes the harbor seal and northern elephant seal. Phocids (i.e., members of the family Phocidae) have several characteristics in common. Phocids have relatively small front flippers that are of limited use on land. Their hind flippers cannot be rotated beneath the seal for body support or land locomotion; instead, the hind flippers extend back from the animal’s body. When we see harbor and elephant seals on the beaches of Baja, they hunch along like giant caterpillars.

Small front flippers on the elephant seal at Isla San Benito. Photo R. Nawojchik

When swimming, phocids extend their hind flippers behind them and splay out the digits, forming a tail-like structure. The seals then undulate their bodies in a sinusoidal fashion, propelling them forward in what is known as “axial locomotion.” Phocids are sometimes called “earless seals”, a phrase I do not like. Phocids most certainly do have ears. What phocids lack is the earflap, found in most mammals, surrounding the outside ear opening. If you are close enough (which you are in Baja!) to see the side of the head of a phocid seal, you can easily see the ear opening behind the eye.

The family Otariidae includes the California sea lion and Guadalupe fur seal. In contrast to phocids, otariids have large front flippers, large enough to support some of their body weight while on land. Their hind flippers can be rotated under their body, again supporting some of the body weight. These features of the front and hind flippers allow otariids to walk on land in a quadrupedal fashion. Because of this ability, we often see sea lions and fur seals climbing rock faces in search of resting spots, areas not accessible to ungainly phocids.

Guadalupe fur seals on the rocks at Isla San Benito. Notice rotation of front flippers. Photo A. Cornick

In water, otariids use their large front flippers in an almost-flapping sort of motion to thrust themselves through the water. We get an up-close view of this “appendicular locomotion” when we snorkel with sea lions at Los Islotes, a rocky outcrop hosting a sea lion colony in the southern Gulf of California. Like most other mammals, but in contrast to phocids, otariids have an earflap around their ear opening.

California sea lion. Note external ear flap. Photo A. Marsh

This feature is one of the more easily discernible characteristics allowing us to separate otariids from phocids.

Unlike cetaceans, which spend their entire lives in water, pinnipeds “haul out” onto land for resting and reproduction. To avoid predators and human disturbance, pinnipeds tend to haul out on islands and isolated beaches. During our Searcher Natural History Tours to Baja, we visit at least three pinniped haul-out sites. On our first full day in Baja, we sail past the Todos Santos Islands, where, from the Searcher, we often can observe some hauled out elephant seals, harbor seals, and sea lions. The next day, we spend much of the day hiking around West San Benito Island.

Rob Nawojchik guides Searcher passengers around the elephant seal haul-out areas on Isla San Benito.

The main attraction at San Benito is the elephant seal colony, but we have also seen the other three species of Baja pinnipeds here.

Later in the trip, we visit Los Islotes to view California sea lions both above and below the water.

Viewing California sea lion characteristics underwater. Photo L. Morgan

In upcoming blogs, we’ll focus on each pinniped species in more detail.

"Long-beaked common dolphin (cow and calf): This is by far the most common species of cetacean associated with Baja." R. Nawojchik "These (bottlenose) dolphins often engage in acrobatic behavior, making them favorites among whale watchers." R. Nawojchik False killer whale cow and calf pair R. Nawojchik "Killer whale near Cabo Pulmo, Gulf of California. Note the white patch near the eye." R. Nawojchik "(Pacific white-sided dolphins) are characterized by a very small rostrum, a complex white-gray-black body coloration pattern, and a prominent recurved dorsal fin." R. Nawojchik "Risso's dolphin: Note the tall thin dorsal fin, the extensive scarring on the body, and the light-gray color." R. Nawojchik "The short-beaked (common dolphin) species tends to be found in deeper water, and is not as abundant or widely distributed in the Gulf of California as the long-beaked species." R. Nawojchik "Short-finned pilot whales: note the broad-based dorsal fin and the round bulbous melon." R. Nawojchik

For many people who participate in our Searcher Natural History Tours to Baja California, the large whales are the big attraction. It’s certainly easy to be mesmerized by the spectacular behaviors of a humpback whale, awestruck by the immensity of a blue whale, or emotionally transformed by a close encounter with a gray whale. However, despite the top-billing status of these giant creatures, they are often upstaged by the smaller species of marine mammals. Today we’ll examine one group, the dolphins, that are certainly charismatic in their own right.
All the dolphins we see in the waters around the Baja peninsula belong to the same family, Delphinidae. The family Delphinidae is comprised of about 38 species and contains the dolphin species most familiar to whale watchers. Included in the family are some species that have the word “whale” attached to their common name, such as the killer whale and the short-finned pilot whale. Some people get confused by the use of the words “whale” and “dolphin” and will ask, “Well, is the killer whale a whale or a dolphin?” In the context of the family Delphinidae, the word “whale” attached to the common name simply indicates a larger species of delphinid.
Fourteen species of delphinids have been documented in Baja. Some species, such as the bottlenose dolphin and the long-beaked common dolphin, are observed on almost every Searcher trip. Other species, however, are much less common. For example, the first scientific record of the pygmy killer whale in the Gulf of California (Sea of Cortez) was from October 2014 in La Paz Bay. In eleven years of trips to Baja aboard Searcher, I’ve seen eight of the fourteen species. These eight species are discussed in approximate order from most-likely-to-be-seen to least-likely-to-be-seen, focusing on identification characteristics.

Long-beaked common dolphin: This is by far the most common species of cetacean associated with Baja. We see them from the Searcher on both the ocean and gulf sides of the peninsula. Long-beaked common dolphins are known for occurring in huge herds, often numbering in the hundreds of individuals, and sometimes in the thousands. However, we also often encounter much smaller groups. These dolphins are typically 6.5 – 8 feet long (2 – 2.5 m). They have a characteristic “hourglass” color pattern on their body that becomes more pronounced in older individuals. Closely related to the short-beaked common dolphin, long-beaked common dolphins can be distinguished by their relatively longer rostrum (along with some very subtle color differences). It can be challenging at times to separate the two species in the field, especially because younger individuals of both species can look quite similar to each other both in terms of coloration and rostrum length.

Bottlenose dolphin: These dolphins are found throughout the Baja California region, both on the ocean side and in the Gulf of California. We see them on a regular basis in Laguna San Ignacio, where they are the only species of dolphin represented. Bottlenose dolphins can get large, with adult lengths ranging from just over six feet to almost 12 feet (1.9 – 3.6 m). They are mostly uniform gray in color, with some slight color variations. Their rostrum (beak) is stocky and short to moderate in length. These dolphins often engage in acrobatic behavior, making them favorites among whale watchers.

Short-beaked common dolphin: In general, the distribution of the short-beaked common dolphin in Baja overlaps that of the long-beaked common dolphin. However, the short-beaked species tends to be found in deeper water, and is not as abundant or widely distributed in the Gulf of California as the long-beaked species. There are some subtle color differences between the two species, but I think in most cases the relative length of the rostrum is the more dependable characteristic. Even then, distinguishing between the two rostrum lengths (especially with younger dolphins) takes some practice and experience.

Risso’s dolphin: We’ve seen Risso’s dolphins both in the Gulf of California and on the Pacific side of the peninsula, although they are more likely to be found on the Pacific side. Risso’s dolphins can get up to 12 feet (3.6 m) long. They are characterized by such morphological features as a tall slender dorsal fin, a lack of a rostrum, and a crease in the melon. Probably the most distinctive feature is the amount of scarring on the body. Whereas young animals have a uniform gray color, older animals are typified by increasing numbers of scars and a resultant lightening of the overall body color. These scars are most likely the result of encounters with their squid prey and/or rake marks from other Risso’s dolphins.

Short-finned pilot whale: This is one of the larger members of the family Delphinidae, with females reaching 18 feet (5.5 m) and males 23 feet (7 m). Identification characteristics include a black to dark-gray body color, no rostrum, a prominent bulbous melon, and a dorsal fin with a very broad base. Pilot whales are highly social and live in tight-knit family groups.

Pacific white-sided dolphin: Although there are records of Pacific white-sided dolphins occurring along the entire Pacific coast of the Baja peninsula, and into the gulf as well, in my experience we usually encounter them only along the northern half of the Pacific side. By the time we get south of Laguna San Ignacio, we rarely see this species. Pacific white-sided dolphins get up to 8 feet (2.4 m) in length. They are characterized by a very small rostrum, a complex white-gray-black body coloration pattern, and a prominent recurved dorsal fin (mostly light colored with a dark leading edge).

Killer whale: The killer whale is the largest member of the family Delphinidae, with males reaching 32 feet in length (9.7 m); females are about a meter shorter than males. In addition to their large size, their dramatic black and white color pattern makes them instantly recognizable. The underside of the whale is white, with a lobe of white extending onto the flank. There is also a white oval patch near the eye and a gray “saddle” behind the dorsal fin. The pectoral flippers are large and paddle-shaped. The dorsal fin is quite tall and straight in males. As with all apex predators, the numbers of killer whales are always much fewer than animals lower in the food web, which helps explain why we rarely see them on our Baja trips.

False killer whale: The false killer whale is another large species of delphinid, with males reaching lengths of almost 20 feet (6 m) and females 16 feet (5 m). They have a slender body, no beak, a melon that overhangs the mouth, and pectoral flippers with a distinctive S-shape. They are black to dark gray in color, with some areas of lighter gray.

Others: The following delphinid species are rarely seen in Baja, but there are some records of their occurrence: rough-toothed dolphin, pantropical spotted dolphin, spinner dolphin, striped dolphin, melon-headed whale, and pygmy killer whale. In 2016 the Searcher encountered a few dolphins that may have been rough-toothed dolphins.

The flukes have a broad, rounded appearance, as opposed to the more-tapered appearance of a blue whale’s flukes. R.Nawojchik "The dorsal fin of sperm whales is smooth and rounded, perhaps more of a hump than a fin." R.Nawojchik "One offshoot of this diving behavior is that sperm whales must spend some time at the surface to physiologically recover from a deep dive. While doing this, they typically are relatively immobile at the surface in a behavior called 'logging.'" R.Nawojchik "The shape of the head is quite different from other large whales, comprising about one-third the body length and appearing box-like or squared-off when viewed from the side." R.Nawojchik "The interesting feature of the sperm whale’s blow is that it comes out at about a 45-degree angle, rather than straight up as in other whales." R.Nawojchik

The sperm whale is the largest toothed whale (odontocete), reaching lengths comparable to some of the baleen whale species. Male sperm whales can reach up to 66 feet (20 meters) in length while females normally do not exceed 40 ft (12 m). This disparity in size is an example of “sexual dimorphism” and is most likely related to the sperm whale’s reproductive behavior. Male sperm whales compete for access to groups of females in a harem-like mating system, thus establishing an evolutionary selection pressure for large body size in males.

Of the cetaceans, sperm whales have long been considered the champion divers, diving longer and deeper than other species (recent research has indicated that Cuvier’s beaked whales may out-perform sperm whales in depth and duration). Some sperm whales have achieved dives of over an hour and to depths of over a mile (1.6km)! Whereas all marine mammals are capable of diving underwater for periods of time, it’s important to remember that diving capabilities vary widely by species. Also, dive depths and durations are dependent on specific activities (e.g., traveling vs. feeding).

Much more could be discussed about sperm whale diving physiology or social behavior. However, the remainder of our discussion will focus on identifying sperm whales while whale watching.

Size and shape of spout / blow: As a large whale, the sperm whale consistently produces a noticeable blow, even when seen from a distance. The interesting feature of the sperm whale’s blow is that it comes out at about a 45-degree angle, rather than straight up as in other whales. As a toothed whale, the sperm whale has a single blowhole. Unlike other cetaceans where the blowhole is located on top of the head along the midline, the blowhole of sperm whales is located asymmetrically at the left front part of the head. This location results in the angled blow. If a whale watcher is located off to the side of the whale, the angled blow is quite evident, aiding in the ability to identify this whale even without seeing the body. As always, be wary of weather conditions. On windy days, the blows of other whales may get “knocked down” and may appear superficially like that of a sperm whale.

Size of animal: As mentioned, the sperm whale is the largest toothed whale. Of the other species of whales in Baja, the humpback, gray, and Bryde’s whales are roughly similar in size. However, there are many field characteristics that distinguish these whales from each other, and certainly distinguish the sperm whale from all other species.

Color: Sperm whales are mostly a uniform gray-brown to almost-black color. Some individuals have white around the lower jaw and along the ventral part of the body. However, we rarely see the jaw and lower body, so these white markings go unseen by most whale watchers.

Dorsal fin: Instead of the classic curved “falcate” dorsal-fin shape that we usually associate with whales and dolphins, the dorsal fin of sperm whales is smooth and rounded, perhaps more of a hump than a fin. Whether we call it a hump or a fin, there is certainly something there, in contrast to the lack of a dorsal fin in the gray whale. Other large cetacean species can be distinguished from sperm whales by the shapes of their dorsal fins.

Tail flukes: Sperm whales quite often show their tail flukes when commencing a dive. Both surfaces of the flukes are typically the same gray-brown color as the body. The flukes have a broad, rounded appearance, as opposed to the more-tapered appearance of a blue whale’s flukes. The trailing edge of the sperm whale’s flukes is smooth, in contrast to the serrated trailing edge of humpback flukes.

Species-specific traits: Sperm whales have several anatomical traits that distinguish them from all other large whales. The shape of the head is quite different from other large whales, comprising about one-third the body length and appearing box-like or squared-off when viewed from the side. We’ve already mentioned the unusual location of the blowhole. The mouth is subterminal, located on the bottom of the head, rather than at the front of the head as in other whales. We rarely see the mouth of sperm whales (although on a 2016 Searcher Natural History Tour a sperm whale swam upside down just below the bow and several people were able to see the narrow lower jaw). The skin of sperm whales has a wrinkly appearance, in contrast to the smooth skin of other whales.

Behavior: We’ve already discussed the fluking behavior of sperm whales, as well as the unique orientation of the blow. We’ve also mentioned the deep diving abilities of these whales. One offshoot of this diving behavior is that sperm whales must spend some time at the surface to physiologically recover from a deep dive. While doing this, they typically are relatively immobile at the surface in a behavior called “logging.” Whaling captains were certainly aware of this behavior and were able to maneuver close to the whales before the whales were fully recovered during their surface interval. While whale watching in Baja, we’ve noticed that some of the whales will start “rocking” their bodies for the last two or three breaths of their surface interval, in preparation for fluking and beginning their next dive.

By understanding the typical dive times of various species, we can tailor our whale-watching strategy to each species. For example, when watching humpback whales on the Gorda Banks, we know that the typical dive is only 8-12 minutes and it’s worthwhile to wait for the whale to re-surface. In contrast, while watching sperm whales, we know that it’s probably not worth waiting around for almost an hour. This is especially true if a group of sperm whales is diving synchronously. If the group is diving asynchronously, then it’s worth standing by, as some whales are diving while others are surfacing and logging.

"The underside of the whale is white. This 'counter-shaded' color pattern (dark above, light below) is common in many open-water species." R. Nawojchik "Also, the minke whale has a pointier snout than the other whales in its family..." R.Nawojchik "The dorsal fin of the minke whale has the classic curved 'falcate' shape that we usually associate with whales and dolphins." R.Nawojchik "If a curious minke circles the boat under calm conditions, we can sometimes get a good look at the flukes." R.Nawojchik "Minkes seem to 'pop' to the surface at a relatively steep angle, such that the front of the head, including part of the lower jaw, breaks the surface." R.Nawojchik

The minke whale is the smallest baleen whale in the Baja region, reaching lengths of up to 29 feet (8.8m). We do not always see minke whales on our 12-day Natural History Tours to Baja, although that doesn’t mean they aren’t there. Because of their small size they are not as visible from a distance compared to the larger whale species. The minke’s modest size also accounts for the lack of a visible blow under most conditions, adding to the difficulty of noticing them from afar. Most of the minke whales we see in Baja are single animals, once again making it tough to initially spot them (groups of whales are easier to see than single whales. Gray whales and humpback whales in Baja are sometimes seen in associations of two or more individuals).

Some of the minke whales we see ignore us and go about their business. Occasionally, however, we get a curious individual who circles the boat and gives us great views of the animal. If the water is calm, we can see detailed features of the whale. The traits described below will help you distinguish minke whales from other whales in Baja.

Size and shape of spout / blow: As noted, the minke whale does not usually produce a noticeable blow. In climates colder than Baja you are more likely to see the blow of a minke, as the cold air condenses the moisture in the exhalation (similar to seeing your breath on a cold winter’s day). Larger species of whales produce a visible blow regardless of local air temperature as the amount of water vapor in their massive exhalation is enough to produce a condensation cloud.

Size of animal: As mentioned, the minke whale is the smallest baleen whale in Baja and you are unlikely to confuse it with the larger baleen whale species. Among the toothed whales, the killer whale is comparable in size to the minke whale, and we do occasionally see killer whales on our trips. The minke and killer whales are easily distinguished using a variety of field characteristics (e.g., the black and white color markings on a killer whale are diagnostic).

Color: The minke whale is mostly dark gray, with some animals appearing black or dark brown, depending on individual variation and lighting. The underside of the whale is white. This “counter-shaded” color pattern (i.e., dark above, light below) is common in many open-water species, including many other cetaceans and most pelagic fishes (e.g., tuna, jacks, etc.). For identification purposes, the most important coloration feature is a white patch on both pectoral flippers, the only Baja whale with such a characteristic.

Dorsal fin: The dorsal fin of the minke whale has the classic curved “falcate” shape that we usually associate with whales and dolphins. This shape is in contrast to the lack of a dorsal fin in the gray whale and the hump-like dorsal fin of the humpback whale. The minke whale’s dorsal fin seems appropriately sized for the body, in contrast to the smaller-than-it-should-be dorsal fin of the blue whale or the dramatically over-sized dorsal fin of the male killer whale. Both Bryde’s and fin whales have dorsal fins similar in shape to that of the minke whale. Don’t let the dorsal fin fool you, as the Bryde’s and fin whales are significantly larger in body size than the minke whale. As always, account for individual variations in size and shape of the dorsal fin within a species.

Tail flukes: Minke whales almost never show their tail flukes when diving. If a curious minke circles the boat under calm conditions, we can sometimes get a good look at the flukes. The flukes are similar in shape to that of the blue whale (i.e., wide and tapered) but obviously scaled down in size.

Species-specific traits: The unique traits of the minke whale (as compared to other Baja baleen whales) are the relatively small body size and the white patches on the pectoral flippers. Also, the minke whale has a pointier snout than the other whales in its family (family Balaenopteridae, which includes the blue, fin, Bryde’s and humpback whales).

Behavior: The minke whale does not normally exhibit the demonstrative behaviors that we see from humpback whales. Minke whales are known to breach on occasion, but I’ve never seen a breach in over ten years of whale watching in Baja. One behavior I find distinctive of minke whales is the manner in which they surface for air. From what I’ve seen, minkes seem to “pop” to the surface at a relatively steep angle, such that the front of the head, including part of the lower jaw, breaks the surface. Plus, they seem to be at the surface for just a moment, less time than the other baleen whales.

"The fin whale has several color features that are diagnostic, but are sometimes difficult to see. The color of the right lower jaw is white, unlike the gray color of the left jaw or the rest of the head. " R. Nawojchik "There is a V-shaped light-gray or white mark on the back called the 'chevron'.” R. Nawojchik R. Nawojchik The dorsal fin of the fin whale has the classic curved “falcate” shape that we usually associate with whales and dolphins. "The overall color of the fin whale is slate gray, but the appearance of the animal will depend on lighting and individual variation. Some animals appear more brown than gray. " R. Nawojchik

The fin whale is one of the largest animal species in the world, second only to the blue whale. During our 12-day Searcher Natural History Tours to Baja, we can see fin whales at any point during the trip (except for the two days when we visit San Ignacio Lagoon to observe gray whales up close). Fin whales on the Pacific side of the peninsula seem to be part of the greater eastern North Pacific population, whereas those in the Gulf of California/Sea of Cortez are apparently a resident population with limited interaction (i.e., low gene flow) with fin whales elsewhere.

Fin whales are among the fastest of the large whales, with burst speeds up to 23 miles per hour (37 km/hr). For this reason, they were able to evade many of the Yankee whalers during the early years of commercial whaling. Unfortunately, modern whaling fleets wreaked havoc on all whale populations, including fin whales. Much is not known about current population trends, but for some populations of fin whales it seems their stock status is improving.

For the most part, fin whales do not usually exhibit the dramatic out-of-water behaviors that we see with humpback whales. Fin whales tend not to breach, fluke, flipper-flap, or lob-tail. In all my years of whale watching, I’ve seen the flukes of a fin whale on only two occasions, once off Long Island, NY and once off the California coast. Between their fast speed, their lack of demonstrative behaviors, and their relative elusiveness (compared to a humpback), it can be difficult to get a good look at a fin whale. Nevertheless, there are some useful traits we can use to help identify them.

Size and shape of spout/blow: The fin whale’s blow is usually tall and columnar, similar to but not quite as tall as that of a blue whale. From a distance, it would be difficult to distinguish the blows of a fin whale and blue whale. Even large humpbacks are capable of producing blows that might be construed as being from either a blue or fin whale. The blow alerts us to the presence of the whale, and we then use other clues to confirm the identification.

Size of animal: Fin whale adults are normally well over 50 feet in length, making them longer than most of the other baleen whales we see (humpback, Bryde’s, gray, and minke). When a whale surfaces for air, only a small portion of the animal is visible, so it takes some practice to develop a sense of the size of an animal based on this partial view.

Color: The overall color of the fin whale is slate gray, but the appearance of the animal will depend on lighting and individual variation. Some animals appear more brown than gray. The fin whale has several color features that are diagnostic, but are sometimes difficult to see. The color of the right lower jaw is white, unlike the gray color of the left jaw or the rest of the head. Asymmetry is uncommon in animals. Another asymmetrical color feature is a swirly color pattern (sometimes called the “blaze”) on the right side of the head. Finally, there is a V-shaped light-gray or white mark on the back called the “chevron.” Please note that these color features are not always obvious. I’ve seen many fin whales, but rarely have I had a good look at the white lower jaw. Many times I’ve been on the left side of the animal and could not see the blaze or the right lower jaw. More times than not the lighting was such that I could not clearly make out the blaze or chevron.

Dorsal fin: The dorsal fin of the fin whale has the classic curved “falcate” shape that we usually associate with whales and dolphins. This shape is in contrast to the lack of a dorsal fin in the gray whale and the hump-like dorsal fin of the humpback whale. The fin whale’s dorsal fin is prominent and appropriately sized for the body, in contrast to the smaller-than-it-should-be dorsal fin of the blue whale. Both Bryde’s and minke whales have prominent dorsal fins similar to that of the fin whale. The fin whale’s dorsal is more swept back than the slightly more-upright dorsal of the Bryde’s whale. The fin whale and minke whale can easily be separated by body size, so don’t let the dorsal fin fool you. As always, account for individual variations in size and shape of the dorsal fin within a species.

Tail flukes: Fin whales almost never show their tail flukes. The flukes are similar in shape to that of the blue whale (i.e., wide and tapered). The color is grayish-white, with perhaps a darker edging on the underside.

Species-specific traits: The unique traits of the fin whale are the asymmetrical color features: the white lower right jaw and the blaze color swirl on the right side of the head.

Behavior: When we see fin whales in Baja, most of the time they are simply swimming and diving. If they are traveling, the Searcher can sometimes match their speed and heading and we can anticipate where they will re-surface. If the whales are feeding underwater, their movements are more erratic and it becomes more difficult to predict their re-appearance.

"Humpback whales exhibit a variety of high-energy out-of-water behaviors that are spectacular to witness. A 'breach' is when the whale jumps out of the water. " R. Nawojchik "Yet another distinctive feature of humpbacks is the presence of a series of bumps on the head. " R. Nawojchik "Humpbacks have a step-like base that forms the foundation of the upper, more-typically-shaped portion, of the dorsal fin. This overall shape may be the origin of the name 'humpback.'" R. Nawojchik "For the humpback, the blow is usually described as 'bushy,' reaching heights of about 10 feet or so." R. Nawojchik "The 'lob-tail' is yet another high-energy behavior best seen in humpbacks. The whale is oriented vertically in the water, with the tail and caudal peduncle (the base of the tail) raised high out of the water. " R. Nawojchik "The behavior of showing the flukes, coupled with the flukes’ high variability, makes fluke patterns a perfect characteristic to use for individual identification. " R. Nawojchik Breaching calf R.Nawojchik Rainbow blow R.Nawojchik

by Rob Nawojchik

The humpback whale is perhaps the favorite species of many whalewatchers. Humpbacks are well known for their diverse repertoire of dramatic behaviors, from fluking and breaching to flipper slapping and lob-tailing. Certainly, other species of whales exhibit these behaviors at times, but humpbacks seem to be particularly demonstrative when they’re showing off. Humpbacks seem to be oblivious to our presence and will carry on with their high-energy behaviors even when close by. At times, they seem curious and will approach or circle the Searcher as we drift alongside. (This is in contrast to a shy and elusive species such as the Bryde’s whale, which rarely affords us a close-up look.)

There are several places around the world where humpback whales congregate during mating season. One of these places is the Gorda Banks, off the southern end of the Baja peninsula. During our 12-day Natural History Tours, one of our days is devoted to watching humpbacks on the Gorda Banks. We can (and do) see humpbacks at any point in our trip, both on the Pacific side of the peninsula and in the Gulf of California, but by far the greatest concentration and numbers of humpbacks are in the Gorda Banks region. Although we can’t see the Gorda Banks from the surface, the humpbacks apparently use the underwater feature as a focal point of their activities. This association with underwater geological features is typical for humpbacks and other species of whales. For example, western North Atlantic humpbacks (another population I’ve observed) congregate around Silver Bank and Navidad Bank off the Dominican Republic during breeding season, and around Stellwagen Bank off New England during the summer feeding season.

In addition to their spectacular behavioral repertoire, another aspect of humpback whales that makes them fan favorites is that humpbacks are probably the easiest large whale species to identify. Once you’ve seen a humpback whale, you are unlikely to confuse it with anything else.

Size and shape of blow: As always, keep in mind that the appearance of a whale’s blow is highly variable among individuals and is affected by the wind. For the humpback, the blow is usually described as “bushy,” reaching heights of about 10 feet or so. As we discussed in prior blogs, the blue whale often has a taller blow, the gray whale’s blow can appear heart-shaped of V-shaped, and the sperm whale’s blow is at a 45-degree angle (i.e., not straight up).

Size of animal: Humpback whales reach about 50 feet (16m) in length. Among the other baleen whale species in Baja, blue and fin whales can get larger, gray and Bryde’s whales are about the same size, and minke whales are smaller.

Color: Humpback whales are mostly black in color, with areas of white on the flippers and abdomen. The underside of the tail flukes ranges from all black to all white (more on that later). The black body color is in contrast to the mottled blue of blue whales, the blotchy gray of gray whales, and the slate gray of fin whales.

Dorsal fin: Humpback whales have a dorsal fin, but its appearance is different from other whales. Humpbacks have a step-like base that forms the foundation of the upper more-typically-shaped portion of the dorsal fin. This overall shape may be the origin of the name “humpback.” Humpback whales arch their entire back quite dramatically when diving, and that behavior may also contribute to the name “humpback.” There is individual variation in the shape of the dorsal fin in humpback whales.

Tail flukes: Humpback whales often show their tail flukes when diving. As mentioned earlier, the color pattern on the underside of the flukes is highly variable and individual-specific. The behavior of showing the flukes, coupled with the flukes’ high variability, makes fluke patterns a perfect characteristic to use for individual identification. Since the early 1970s, marine mammalogists have photographed the flukes of humpback whales and compiled catalogs of thousands of individual whales. By photographing and identifying individuals, many behavioral and ecological questions can be answered. I’ve been photographing the flukes of humpbacks during 10-years’ worth of Searcher Natural History Tours to Baja and have over 250 individual whales in my catalog. We’ll talk more about that in a subsequent blog. One last feature about the tail flukes: the trailing edge of the flukes often has a serrated appearance, in contrast to the more-smooth trailing edge in most other species.

Species-specific traits: Humpback whales have several anatomical features that distinguish them from other whale species. We’ve already discussed the uniquely-shaped dorsal fin. Another unique character is the extremely long pectoral flippers. The flippers of humpbacks are one-third the body length, much longer than what we see with any other cetacean species. Thus, a 45-foot humpback would have 15-foot flippers! Yet another distinctive feature of humpbacks is the presence of a series of bumps on the head. These bumps, sometimes called “tubercles,” are over-sized hair follicles and in fact do contain a tiny hair in the middle. The function of these hairs is still speculative, but may be sensory. Regardless, the presence of these tubercles on the head of a whale is diagnostic for the humpback. All of the other whale species we see have a smoother head and lack large tubercles.

Behavior: As mentioned, humpback whales exhibit a variety of high-energy out-of-water behaviors that are spectacular to witness. A “breach” is when the whale jumps out of the water. Sometimes the whale will breach just once, while other times a whale may breach repeatedly. Single breachers are hard to photograph as you never know where and when they will breach. With repeat breachers, you can sometimes anticipate the next breach.

Although a few other species of cetaceans have been seen to smack their pectoral flippers on the water, this behavior is best exemplified with humpbacks, given the humpback’s giant pectoral flippers and the particular enthusiasm with which they perform this behavior. Referred to as both “pec-slapping” and “flipper flapping,” this behavior can be seen (and heard!) from quite a distance.

The “lob-tail” is yet another high-energy behavior best seen in humpbacks. The whale is oriented vertically in the water, with the tail and caudal peduncle (the base of the tail) raised high out of the water. The tail is then smacked aggressively against the water, created a big splash and a loud sound. As with the breach and pec-slap, this behavior most likely has some communication value. We don’t have space today to discuss exactly what is being communicated, except to say this: for me, the first step when analyzing behavior is to determine the CONTEXT. Who is displaying the behavior? (calf? adult male? etc.) Where are they? (breeding grounds?) Who else is around? (other males? receptive females? etc.).

Another behavior worth mentioning is one that you won’t see but will hear. Humpbacks are famous for their songs, usually produced by males on their breeding grounds. Aboard Searcher we have a hydrophone that we sometimes turn on while we’re drifting at the Gorda Banks. If the whales are singing and they’re close enough we can pick up their songs, which Captain Art then broadcasts on the Searcher’s speaker system.

Superlatives always come to mind while watching cetaceans of any species. If there were a cetacean awards show, the humpback whale would get my vote for “Easiest to Identify” and “Most Entertaining.”

"The color of gray whales can best be described as blotchy gray and is very distinctive compared to other whales, thus serving as a useful species-identification character." R. Nawojchik "In the Baja region, the gray whale is the species most likely to produce a heart-shaped blow." R. Nawojchik "If you are lucky enough to be at one of the gray whale lagoons between January and April, then the large whales you are seeing are gray whales." R. Nawojchik "There is a slight dorsal hump where the fin would normally be, followed by a series of bumps along the dorsal ridge between the dorsal hump and the tail." R. Nawojchik R. Nawojchik "Another very useful identification feature is the encrustation of ectoparasites, in particular barnacles and “whale lice”, on the skin of gray whales." "We also see lots of calves at San Ignacio Lagoon. Gray whales are about 15 feet (4.5m) at birth, but grow rapidly while nursing in the lagoon." R. Nawojchik "Gray whale calf showing off its baleen!" R. Nawojchik "We sometimes see “rake marks” on the tail flukes, pectoral flippers, or elsewhere on the body. These patterns are scars left by the teeth of killer whales, a testament to failed attacks." R. Nawojchik "Breaching is when a whale jumps from the water, either partly or entirely, and then re-enters with a huge splash. A breach might be the most dramatic behavior in a whale’s repertoire." R. Nawojchik R. Nawojchik

by Rob Nawojchik

The gray whale is perhaps the species of whale that inspires the most people to take our 12-day Natural History Tour to Baja California, Mexico. There are many fascinating aspects of the gray whale’s story, from biology and behavior to the history of human exploitation. Gray whales are the most coastal of all the large whales and can often be seen from shore during their annual migration between Alaska and Baja. Hunted to near-extinction, the eastern North Pacific gray whale population has recovered to healthy numbers, the epitome of a conservation success story. During their winter/spring reproductive season, gray whales congregate in shallow-water lagoons along the west coast of Baja California. Because of the high concentration of gray whales in the relatively confined areas of the lagoons, the whale-watching opportunities are unparalleled. Perhaps the most astonishing thing is the gray whales’ penchant for “friendly” behavior, in which they approach and get very close to exuberant whale watchers (who are floating in the lagoon in small skiffs or “pangas”), sometimes initiating physical contact with the astounded eco-tourists.

Much can be (and has been) written about the ecology and behavior of the gray whale. Today’s focus, however, is on identification (ID). If you are lucky enough to be at one of the gray whale lagoons between January and April, then the large whales you are seeing are gray whales. The other large whale species of the region do not enter the lagoons. (Note: San Ignacio Lagoon, the lagoon the Searcher visits each year, is alive with all sorts of marine life: bottlenose dolphins, a few California sea lions, sea turtles, and lots of seabirds, but no whales other than gray whales.) In addition to the lagoons, we see gray whales in the ocean along the Pacific coast of the Baja peninsula (and every once in a while in the Gulf of California / Sea of Cortez). The following ID characters will help you identify gray whales, whether it’s from a distance in their oceanic migratory corridor, or up close and personal from inches away in the lagoon. One last side-note before we begin: in past blogs I warned how whale sightings are often from miles away and how difficult it is to get a good view of the animal. You will NOT have that problem in the lagoon! Your biggest problem in the lagoon will be keeping your glasses and camera lens clean after repeatedly getting drenched by the whales spouting next to the panga.

Size and shape of spout/blow: Like most of the large whales in the Baja region, the gray whale produces a visible blow that can be seen from quite a distance under good conditions. However, the height of the blow is perhaps only a third to a half of the height of a blue whale blow (which makes sense; the height of the blow is partly a function of the size of the animal). In terms of shape, the gray whale blow might be described as “bushy” when viewed from the side, but can appear to be heart-shaped or V-shaped when viewed from in front of or behind the animal. In the Baja region, the gray whale is the species most likely to produce a heart-shaped blow. From a distance, the bushy blows of gray and humpback whales can appear similar, especially under windy conditions or if your view of the blow is at the wrong angle. As always, when identifying whales at sea, multiple clues are usually needed before a confident ID can be made.

Size of animal: I like to organize the six species of baleen whales commonly seen in Baja into three size categories: big (blue and fin whales), medium (humpback, Bryde’s, and gray whales), and small (minke whale). Most of the adult gray whales we see are probably between 36 and 50 feet (11-15m) in length (roughly similar to the humpback and Bryde’s). Of course, we also see lots of calves at San Ignacio Lagoon. Gray whales are about 15 feet (4.5m) at birth, but grow rapidly while nursing in the lagoon.

Color: The color of gray whales can best be described as blotchy gray and is very distinctive compared to other whales, thus serving as a useful species-identification character. The color pattern is highly variable between gray whales, providing a feature useful for photo-ID catalogs of individuals. Photo-ID is a very important tool used by marine mammalogists to answer all sorts of ecological and behavioral questions.

Dorsal fin: The gray whale does not have a dorsal fin, which will distinguish it from all the other baleen whale species in the region. Instead, there is a slight dorsal hump where the fin would normally be, followed by a series of bumps (often referred to as “knuckles”) along the dorsal ridge between the dorsal hump and the tail.

Tail flukes: The gray whale is among those species that sometimes show their flukes when diving. As with the body, the color of the flukes on both surfaces (dorsal and ventral) is blotchy gray. The trailing edge is generally smooth. We sometimes see “rake marks” on the tail flukes, pectoral flippers, or elsewhere on the body. These patterns are scars left by the teeth of killer whales, a testament to failed attacks.

Species-specific traits: Already-mentioned diagnostic characters include the lack of a dorsal fin and the particular color pattern of gray whales. Another very useful identification feature is the encrustation of ectoparasites, in particular barnacles and “whale lice”, on the skin of gray whales. Most, if not all, species of whales have external parasites of various types. In the case of gray whales, the parasites are quite obvious and can cover a significant portion of the skin, especially around the head. The species of barnacle found on gray whales is host-specific; in other words, it is found only on gray whales. The “lice” are really a type of crustacean called a cyamid; four species of cyamids can be found on gray whales. Gray whale calves are born without any ectoparasites, but soon start acquiring them even while nursing in the lagoons. During our visits to San Ignacio Lagoon, we can get a rough idea of the age of a calf by the number of barnacles and cyamids encrusting the skin. (Note: although I’ve referred to cyamids as parasites, they may be harmless to the whale or even beneficial in some ways.)

Behavior: I’ve already mentioned the fluking behavior of gray whales (other flukers include the blue, humpback, and sperm whales). I’ve also remarked on the gray whales’ use of lagoons for breeding and calving. Among large species of whales, this use of lagoons is unique to gray whales. Two additional behaviors of gray whales worth noting, both commonly seen in the lagoons, are spyhopping and breaching. Spyhopping is when a whale lifts its head out of the water, ostensibly to take a look around. Although humpback whales are known to spyhop, we do not normally see spyhopping behavior with humpbacks in the Baja region. Breaching is when a whale jumps from the water, either partly or entirely, and then re-enters with a huge splash. A breach might be the most dramatic behavior in a whale’s repertoire. Many species of whales have been known to breach, but in the Baja region the two species that breach most often are the gray whale and humpback whale.