Category Archives: Humpback Whale

The Status of Whales in the North Pacific

Since 2019, the carcasses of 332 gray whales have washed up on beaches in the Western United States. One-hundred-and-thirty-five deaths occurred in Alaska, prompting the National Oceanic and Atmospheric Administration (NOAA) to declare an “unusual mortality event.” However, there is good news this year. The gray whale deaths have tapered off, and biologists believe the population might be recovering.

During the summer of 2018, waters in the Bering Sea soared nine degrees warmer than average. These increasing seawater temperatures have reduced winter ice cover in the region, leading to reduced productivity.  Primary productivity in the northern Bering Sea declined by 70% from 1988 to 2004. This previously ice-dominated, shallow ecosystem favored large communities of benthic amphipods (the favorite food of gray whales), but it has now been replaced by an ecosystem dominated by zooplankton, such as krill. Gray whales have responded by migrating further north to the Chukchi Sea, but amphipods might now be disappearing from this region as well, forcing gray whales to consume less nutritious krill, and krill might not contain the amount of fatty acids the whales need to build adequate blubber.

Biologists estimate that one-quarter to one-third of the West Coast’s gray whale population has died in recent years. The dead whales appeared extremely emaciated, and researchers think there were too many whales for the amount and type of food they could find to eat as the oceans warm and the environment changes. However, this die-off was not a novel situation. Gray whales suffered a previous mortality event over two decades ago and slowly recovered.

This year, researchers counted more gray whale calves than in the previous few years, and the whales looked healthier during their annual migration north. Only time will tell if the population is recovering, but it seems to be on the rebound.

Meanwhile, the news is not as good for humpback whales in Alaska. Four humpbacks have been found dead on Kodiak this year. The whales were extremely decomposed, leaving scientists with no clues as to the cause of their deaths.

Orca populations in Alaska appear healthy, but the endangered southern resident orcas near Puget Sound and the San Juan Islands continue to struggle. A research study in the Public Library of Science suggested that 99% of the orcas studied in the area had photographic evidence of skin lesions. Researchers evaluated photos from nearly 20,000 orca sightings from 2004 to 2016 and noted that the lesions became more prevalent.

The lesions usually appear as gray patches on the orca’s skin. Biologists don’t know what causes the lesions but fear they are a sign of continued declining health in the animals. While researchers cannot directly correlate the lesions with whale deaths, they think they are likely signs of an embattled immune system.

The southern orcas face several threats. A growing population of humans in the area where the whales live has caused more pollution. More sources of underwater noise have affected the ability of the orcas to hunt using echolocation. Increased water temperatures and solar radiation probably also stress the animals. One of the most significant factors leading to the decline of the southern orcas is the dramatic decrease in the number of Chinook salmon, the orca’s favorite food, in the area. Researchers documented a 75% drop in reported sightings of southern residents from 2004 to 2020, corresponding with a 50% decline in Chinook salmon from British Columbia’s Fraser River.

Changes in whale populations reflect the health of our oceans. Gray whales prefer to feed on benthic amphipods, but as sea ice diminishes and the environment of our northern oceans changes, benthic amphipods are on the decline. Humpback whales feed on zooplankton and small fish, but as the seas warm, zooplankton isn’t as plentiful as it once was. Orcas eat fish, but salmon and other species have declined in many areas.

The whales are telling us they don’t like their changing environment, but will we listen and do something about it?


Read more about Kodiak Wildlife in my book Kodiak Island Wildlife.


My true crime book, Murder and Mystery in the Last Frontier, is a finalist for the Silver Falchion Award for the best true-crime book of 2023. Thank you to the Readers and Writers Book Club for mentioning it in their August Newsletter.

Robin Barefield is the author of five Alaska wilderness mystery novels: Big Game, Murder Over Kodiak, The Fisherman’s Daughter, Karluk Bones, and Massacre at Bear Creek Lodge. She is also the author of the non-fiction book Kodiak Island Wildlife and the true-crime book Murder and Mystery in the Last Frontier. Sign up below to subscribe to her free monthly newsletter on true crime and mystery in Alaska, and listen to her podcast, Murder and Mystery in the Last Frontier.

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In Conclusion

When I reach the end of a manuscript, I dread writing the conclusion because a conclusion requires a great deal of thought and effort. Just as we were nearly done polishing my non-fiction book, Kodiak Island Wildlife, the editor said he believed the book needed a conclusion, and I groaned, but I also agreed with him.

I don’t know how long I stared at a blank computer screen, but I could think of nothing to write. How do you sum up a book about wildlife? Then, as I stood on our boat one morning, watching giant fin whales with our guests, the conclusion for my book popped into my mind, fully formed. When I read it to my husband, tears came to my eyes, and I knew I had done my best work. My editor agreed, and he said it was the perfect ending. The following is the conclusion for my recently released book, Kodiak Island Wildlife.

Emerald cliffs plunge into the gray ocean, and only a slight breeze stirs the surface of the water. In front of our boat, three huge fin whales feed, frequently surfacing to breathe. Their exhalations sound like cannon shots, and our guests capture every moment with their cameras. A sea otter bobs placidly a short distance from our boat, and a bald eagle circles overhead. I have seen all of this many times, but still, it takes my breath away, and a chuckle escapes my lips. How have I managed to live my life in one of the most beautiful places on the planet? To me, Kodiak is paradise. Sure, the weather here throws frequent tantrums, and mistakes in the hostile wilderness do not go unpunished, but I have found nowhere else I would rather live.

One of my greatest joys is to guide visitors into the Kodiak wilderness. I love the look on a newcomer’s face the first time she sees a Kodiak bear or watches a sea otter eat a crab. I wrote this book to honor the wild animals we’ve watched over the years and to thank the many folks who have visited our lodge. I know they would tell you that Kodiak is a special place. The island is mysterious and magical.

It is a short conclusion, but it sums up how I feel and accurately describes my motivations for writing the book. I am grateful for the many experiences I’ve enjoyed. My life is an adventure filled with wonder in the Kodiak wilderness, and I can’t imagine living anywhere else.


Speaking of wildlife, I hope to return to regular and more frequent posts soon. The past two months have been hectic. I’m writing this while I sit on our boat. We are cruising 100 miles around Kodiak Island from our lodge to the town of Kodiak, where we will have our boat lifted out of the water so that we can clean and paint the bottom. As soon as we return home, we have endless jobs awaiting us before our summer season begins. Meanwhile, I am trying to promote my new book and keep up with my scheduled newsletters and podcasts. I realize I’ve let my blog posts fall through the cracks, and I vow to make my posts more of a priority in the future. Thank you for your patience.


Kodiak Island Wildlife is now Available


Robin Barefield is the author of four Alaska wilderness mystery novels: Big Game, Murder Over Kodiak, The Fisherman’s Daughter, and Karluk Bones. Sign up below to subscribe to her free, monthly newsletter on true crime and mystery in Alaska, and listen to her podcast, Murder and Mystery in the Last Frontier.

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Whale Season

Spring marks the beginning of whale season here in Alaska. The humpbacks and grey whales begin arriving from their long migrations north from their wintering grounds, and the north Pacific Ocean teems with life as the waters warm and phytoplankton blooms. Swarms of krill and other zooplankton feast on the abundant plant life, and fish such as herring, eulachon, and similar species follow the zooplankton into the bays on Kodiak Island. In turn, huge baleen whales, including fin, sei, and humpback, gather to eat the krill and small fish. I am thrilled any time I see a whale, but I think it’s a special treat to stand in my front yard and watch these magnificent creatures feed and blow.

Fin Whale

 Sea mammals evolved from land mammals, and they resemble us in many ways. Whales, like humans, have lungs and must breathe air to survive. They are warm-blooded, and they bear live young. Whales nurse their young with milk, and while you might not think of a whale having hair, all whales do have hair at some stage in their development. All members of the order Cetacea evolved 45 million years ago from hoofed mammals, such as cows, sheep, and camels. Comparisons of specific milk protein genes indicate the hippopotamus is the closest, living, land relative to whales.

The order Cetacea contains more than eighty species; although, taxonomists debate the precise number. Biologists have recorded thirty-nine cetacean species in the North American Pacific.

Cetacea comes from the Greek word “ketos,” which means “whale.” All cetaceans have forelimbs modified into flippers and no hind limbs. They have horizontally flattened tails, and they breathe through a nostril, or blowhole, located on the top of the head. A blowhole has a nasal plug that remains closed except when forced open by muscular contractions to breathe. This plug seals when the whale dives. A whale has internal sensory and reproductive organs to reduce drag while swimming, and they do not have external ears but instead have a complex internal system of air sinuses and bones to detect sounds.The lungs of a cetacean are relatively small, highly elastic, and elongated. A whale has a muscular diaphragm, allowing the animal to purge a large amount of air in a short time. With each respiration, a whale replaces 80% to 90% of the air in its lungs. During a deep dive, a cetacean slows its heart rate and decreases blood flow to peripheral tissues.

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Cetaceans living in the cold ocean waters of the North Pacific must somehow maintain a body temperature nearly the same as a human’s body temperature. A whale uses several mechanisms to accomplish this feat. First, it has a thick layer of blubber with few blood vessels, reducing the heat loss at the body surface. A whale has a counter-current heat exchanger, with arteries surrounding veins at the periphery. Hence, vessels flowing from the cold periphery to the warm core partially absorb heat lost by vessels flowing from the core toward the surface. A cetacean also has a high metabolic rate to produce heat, and it has a low body surface to volume ratio, which conserves heat. Finally, a whale has a slower respiration rate than a land mammal, so the whale expels warm air less frequently.

Most cetaceans produce large calves, and the large body volume relative to surface area minimizes heat loss in the calf. Calves are born tail first, and as soon as the calf emerges from the birth canal, the mother or another whale nudges it to the surface for its first few breaths.[3] Cetacean mothers nurse their calves with a pair of teats concealed in slits along the body wall. The milk has a high-fat content, and the calves grow at a rapid rate. Whale mothers tend and guard their calves closely, and a calf often rides the bow wave or the convection currents produced by its mother or another adult when the whales travel. This method of travel is so efficient that the calf barely needs to move its flukes to keep up with the group.

Killer Whale (Orca)

Two suborders comprise the order Cetacea: The Mysticeti or baleen whales and the Odontoceti, or toothed whales. We most commonly see fin whales in Uyak Bay, but we also spot sei, humpback, minke, and killer whales. No matter the species, whenever I see a spout of water, excitement buzzes through me while I watch one of the largest animals on the planet.


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Robin Barefield is the author of four Alaska wilderness mystery novels, Big Game, Murder Over Kodiak, and The Fisherman’s Daughter, and Karluk Bones. Also, sign up below to subscribe to her free, monthly newsletter on true murder and mystery in Alaska, and listen to her podcast, Murder and Mystery in the Last Frontier.

Alaska Wilderness Mystery Novels by Author Robin Barefield: Big Game, Murder Over Kodiak, The Fisherman's Daughter, and Karluk Bones.
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Spring

Bald Eagle in Flight

According to the calendar it is spring, but in Alaska, we won’t see much evidence of spring for another six weeks. The days are getting longer, and when the sun shines, I can feel some warmth in its rays, but it easily could snow six inches tomorrow, and no one would be surprised if the temperature dropped into the low twenties or even the teens.

After an abnormally warm winter this year, I don’t mind waiting until late May for wildflowers and leaves, but before the first forget-me-not blooms, other signs of spring will be evident. Bald eagle pairs will soar, circle, dive, and even cartwheel during their mating rituals; schools of herring will arrive to lay and fertilize eggs; and baleen whales, seals, and sea lions will follow the tasty herring into the bays. I dream about sitting on our dock on a sunny day, watching whales and other sea mammals chase and feed on herring. Some years the show is spectacular, and other years, the herring run is insignificant, and the whales are absent. The red foxes are also active in the spring, and their haunting mating screams often awaken me. By early June, we should start seeing does and their newborn fawns. By then, the eagle pairs will be tending their nests as their eggs hatch and the chicks depend on them for a nearly constant supply of food.

I am busy this time of year getting the camp ready and the meals cooked for the spike camps for our spring hunting season. I also have a trip planned to visit my family in Kansas in mid-May, so I can watch two of my nephews graduate from high school. Meanwhile, my novel, Murder Over Kodiak, is being re-released by a small publishing company in Anchorage, so I’m preparing for another round of promotion, and that is hard work. The first thing I’m planning to do is to host a “virtual” book-release party on Facebook. I’ll write more about this next week. For now, I’m trying to learn everything I can about hosting a virtual party. It’s overwhelming, and I hope I’m not in over my head! I admit that I have an uncomfortable relationship with social media.DSC_0168

Between my day job, promoting my novel, keeping up with my blog and my mystery newsletter, working on my next novel and my other writing projects, and getting ready for a trip to visit my family, my spring will be busy. No matter how rushed I am, though, if the sun is shining, and the wind is calm, you can find me sitting on our dock, craning my neck to watch eagles circle and soar, and inhaling the sweet, salty scent of the low tide while scanning the beach for foxes eating clams and mussels. I’ll also be glancing hopefully at the ocean for roiling schools of herring, and listening for the powerful exhalations of large fin and humpback whales. Spring is my favorite time of year, and I am never too busy to enjoy it. I’ll let you know what I see.

Fin Whale near Kodiak Island

Tell me about your spring. I want to hear about the beautiful tulips, daffodils and other flowers already blooming in most places, or if you live in New Zealand or anywhere else in the southern hemisphere, how is your autumn?

If you haven’t already done so, sign up for my mystery newsletter. I am working on my next edition. Also, I apologize to anyone who has recently tried to order my novel Murder Over Kodiak. As I mentioned above, it is currently being re-released, and it will be available again soon with a bright, new, shiny cover. I’ll give you a sneak preview next week and tell you about my mixed emotions going from an indie author/publisher to working with a publishing house.

 

Dead Whales

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This summer and fall several dead whales were spotted in the Western Gulf of Alaska, with the majority clustered around Kodiak Island. The number of deaths now stands at 43 whales, including fin whales, humpbacks, and, at least, one gray whale. So far, none of the whale carcasses that could be accessed have been in good enough shape to provide a clue to the cause of the deaths, but the National Oceanic and Atmospheric Administration (NOAA) is so concerned that they have classified the deaths an “unusual mortality event” (UME). A UME is defined as a significant die-off of a marine mammal population that demands an immediate response.  This designation triggers a focused, expert investigation into the cause.

At nearly the same time dead whales were being discovered in Alaska, whales were also dying off the coast of southern Chile. In November, biologists in Chile announced that in June, 337 sei whales were found beached in a region of southern Patagonia in Chile. This is one of the largest whale strandings ever recorded. While these whales were found beached, researchers think they died at sea and washed up on the beach.

What caused the deaths of the whales in Alaska and Chile, and did they all die from the same cause? Sadly, we may never know the answers to these questions, but biologists in both Alaska and Chile suspect a harmful algae bloom may be the culprit. Most of the dead whales are baleen whales that feed low on the food chain, making them highly susceptible to a toxic algae bloom. What makes this scenario even more believable is that abnormally warm water conditions in the Pacific Ocean this summer led to a massive toxic algae bloom of the single-celled algae Pseudo-nitzschia.

Pseudo-nitzschia produces domoic acid, a powerful neurotoxin. Under normal circumstances, a domoic acid concentration of 1,000 nanograms per liter is considered high, but in mid-May, concentrations 10 to 30 times this level were found in the North Pacific. Domoic acid accumulates in zooplankton, shellfish and fish, and when mammals and birds eat these organisms, the accumulated acid over-stimulates the predator’s nervous system, causing the animal to become disoriented and lethargic. Ingestion of high concentrations of domoic acid can lead to seizures and death.

In addition to Pseudo-nitzschia, the warm ocean water conditions in the Pacific also may have resulted in blooms of other toxic algae, but if toxic algae are the culprit, why aren’t other mammals or birds dying as a result? These are questions researchers are scrambling to answer, and recently they have been rechecking photos to see if there is evidence that the whales may have starved to death. Warmer ocean conditions could have led to a reduction in the prey of these huge whales that must eat  continuously all summer to build a blubber layer that will last them through the winter.

There is no time frame for when a UME must end, and biologists plan to keep researching the whale deaths for a while longer, but they admit the cause may never be known. One dead whale washed up a few miles from where we live, but we saw many other whales this summer that seemed to be feeding and acting normally, and I hope the whale deaths were an anomaly that won’t continue next spring and summer.

Next week I’ll go into more detail about toxic algae blooms. For those of you who have read my novel, Murder Over Kodiak, you may remember that Jane Marcus was studying paralytic shellfish poisoning, a condition caused by a poisonous algae bloom, and since toxic algae have been in the news this year, I think it will be an interesting topic to tackle.

I am FINALLY ready to send my first Mystery Newsletter to those who have signed up for my list. I plan to mail it on January 6th, so if you haven’t signed up for my list yet, do so soon on my home page. My first newsletter will chronicle the events of the McCarthy massacre of 1983. Thanks, and be sure to leave a comment to let me know what you think of my post!

Whale Behavior

This week, I want to take a closer look at whale behavior. Over the past few weeks, I’ve mentioned various behaviors, and while the reason for some behaviors seems obvious,others are not so easily explained.

Fin Whales
Fin Whales

Blowing or spouting: This is how whales breathe, so there is no mystery why whales blow. The spray of water is of course not from the whale’s lungs, but it is water that is blasted from the top of the blowhole when the whale exhales. What is interesting is that whales can sometimes be identified by their blow. If all I see is an exhalation and very little of the body, I can usually tell whether I’m looking at a humpback or a fin whale, the two most common whales in Uyak Bay. A fin whale’s blow is very tall and column-shaped while a humpback has a shorter, bushy blow.

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Fluking: Some species commonly raise their tail flukes in the air before a deep dive, and others do not. A humpback often raises its tail, while a fin whale seldom does. Why? I don’t know. Humpbacks are more acrobatic than fin whales, and this may have something to do with it.

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Breaching: This is when a whale propels its body upwards until at least 40% of it is clear ofDSC_0077 (2) the water. Adult blue whales rarely, if ever, breach, because they are too heavy. Fin whales are also very heavy and rarely breach, but when they do, it’s impressive! Humpbacks breach fairly often, and like most large whales, a humpback breaches by raising 90% of its body clear of the water surface and then twisting and crashing down with a large smack and a torrent of spray. Killer whales are capable of acrobatic leaps and somersaults. Scientists have offered many explanations as to why

Minke Whale
Minke Whale

whales breach, and it is probable they breach for a variety of reasons, including mating display, annoyance, aggression, a show of strength, a means of stunning prey, or removing parasites. I suspect one of the main reasons whales breach is because it’s fun. Wouldn’t you do that if you could?

 

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Slapping: This category includes flipper slapping, tail slapping, dorsal fin slapping, DSC_0650lobtailing or tail lobbing, and head slapping. Possible explanations for this behavior include a display, aggression, communication, or a means of stunning prey. Humpbacks often lobtail and flipper slap, and both actions make a very loud noise, so it would be an DSC_0642effective means of communication.

 

 

Spyhopping: This is simply when a whale sticks its head out of the water and

Photo by Bob Munsey
Photo by Bob Munsey

looks around. By doing this, it can locate a passing vessel or find escape holes or channels in pack ice. Whales may also spyhop to look at people on a boat. Since visibility is better in air than it is in water, it only makes sense that a whale might want to stick its head out of the water to get a better look.

 

DSC_0072Flipper Waving: Whales sometimes float on their backs and wave their fins in the air. No one knows why, but it looks fun.

Sleeping: One of our brilliant summer guests (I’m talking about you, Karin!) asked me how whales sleep. I was embarrassed to admit that I didn’t know, so I checked and was quite surprised by the answer. Since whales are mammals, they must breathe air, so how do they sleep without drowning? Research has shown that they either sleep while swimming slowly next to another animal, or they rest vertically or horizontally in the water. Scientists believe that when a whale or dolphin sleeps, it shuts down only half of its brain, and the other half stay awake. The side that is awake watches for predators or other dangers and also signals the animal to rise to the surface and take a breath of air every few minutes. After approximately two hours, the whale shuts down the active portion of its brain and the other side wakes up and takes over.  To read more about this amazing behavior, check out this article.

Photo by Bob Munsey
Photo by Bob Munsey

There are many other whale behaviors, including feeding behaviors that I did not cover here. If you have any questions, please ask. Also, if you love mysteries, sign up for my monthly Mystery Newsletter. I am currently working on the first issue, and I apologize to those of you who have already signed up for it. It is taking me longer than I anticipated to get the first installment ready to go.

 

Humpback Whales

Humpback Breaching
Humpback Breaching

Humpback whales are the best-known members of the family Balaenopteridae. Like other rorquals, humpbacks have a dorsal fin, and they have ventral throat grooves running from the tip of the lower jaw to the belly, but humpbacks differ in many ways from the other species in the family Balaenopteridae, and because of these differences, humpbacks are classified in a separate genus from the other rorquals. The body of a humpback is more robust and not as sleek as the bodies of fin, sei, blue, and minke whales. The top of the head and the lower jaw of a humpback are covered by rounded bumps, each containing at least one stiff hair, and the pectoral flippers are very long, spanning one-third of the body length. The tail stalk is thin, and the tail has a series of ridges on the trailing edge. Humpbacks are slower swimmers than other rorquals, but they are more acrobatic than their cousins. They often raise their tails high in the air before diving and engage in breaching, tail slapping, flipper slapping and other physical activities. It is this acrobatic behavior, their curiosity, and their beautiful, haunting songs that make them so popular with humans.Humpback2

Adult humpbacks average 49 ft. (15 m) in length and weigh approximately 35 tons. They are predominantly black on the dorsal side and have varying degrees of white on the throat, belly, flippers, and flukes. The shape and color pattern on a humpback’s dorsal fin

Photo by Tony Ross
Photo by Tony Ross

and flukes are unique to the individual, much like a human’s finger prints. Once biologists realized this, they were able to catalog and follow individual whales during their migrations and throughout their lives, greatly increasing our understanding of humpbacks’ social, mating, calving, and feeding behaviors, as well as giving researchers a better estimate of population sizes.

The baleen of a humpback is black in color, and like most other baleen whales, humpbacks feed in high latitudes and breed and give birth in low latitudes, near Mexico, Hawaii, and in the western Pacific near Japan. We mostly see humpbacks in the summer near Kodiak Island, but a few individuals spend the winter here as well. Since humpbacks don’t reach sexual maturity until they are 5 to 7 years old, it is possible that some whales we see in the winter are not yet sexually mature, so they do not migrate to breeding and birthing areas. Humpbacks feed on krill, other zooplankton, and small schooling fish. As with other baleen whales, humpbacks feed almost exclusively during the summer months and live off their fat reserves in the winter. It has been estimated that a humpback eats up to 1.5 tons of food per day when it is feeding. Humpbacks sometimes employ a method known as bubble net feeding, where they release air bubbles while swimming in circles beneath their prey and then lunge open-mouthed to the surface through the center of the concentrated prey.

Humpbacks are known for their acrobatic displays, including breaching, spy-hopping, lob-tailing, tail-slapping, and flipper slapping, and some of these displays can last for hours, especially during mating. In a few weeks, I will discuss these behavioral displays in more detail

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Humpbacks are also famous for their long, complex songs. These songs are sung by male humpbacks in the winter, and it is believed that their primary function is to attract females, although it has also been suggested that the songs may be used between two males in order to establish dominance. All whales in a particular population sing essentially the same song, and as the song changes slowly over time, the males somehow coordinate these changes. A typical song lasts 10 to 20 minutes, but it may be repeated continuously for hours. During mating, males compete very aggressively for females, and these competitions that sometimes last several hours may involve tail slashing, ramming, and head butting. Although humpback whales are quite social during the mating season, they are usually found alone or in small groups on their summer feeding grounds.

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Next week, I will post about gray whales, one of the most-researched and best-understood species of whales. As always, I welcome your comments, and would love to hear about some of your whale encounters.

For mystery lovers, please visit my home page and sign up for my monthly Mystery Newsletter. I will be sharing details of some true-life Alaskan crimes!

Family Balaenopteridae: The Rorqual Whales

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Members of the whale family Balaenopteridae are known as the Rorqual whales. “Rorqual” is a Norwegian term that means “furrow whale,” referring to the throat grooves found in all species in this family. These grooves extend from underneath the lower jaw back to at least the pectoral flippers and are folds of skin and blubber. When a rorqual feeds, it lunges forward at high-speed, and these grooves expand, filling the mouth with a huge amount of water and prey. When the whale closes its mouth, it uses its tongue to strain the water through the baleen plates, trapping small fish and zooplankton. In addition to throat grooves, the other characteristic common to all rorquals is a dorsal fin.

With the exception of the minke whale, all rorquals are very large, but they are also streamlined and capable of swimming at incredible speeds. Most of the whales in this group have similar body shapes and fin shapes and placements, sometimes making it difficult to distinguish one species from another. At a distance, a small blue whale looks much like a fin whale, and unless you are close enough to see the lower jaw, a small fin whale and a large sei are identical in appearance. Humpback whales with their long pectoral fins are usually easy to differentiate from other rorqual species, and minke whales are much smaller than any other species in the family Balaenopteridae. Rorquals have flattened heads and two, centrally-located blowholes. The dorsal fin is located approximately one-third of the body length forward from the fluke notch, and the tail flukes are large and wide.

In this post, I will briefly cover blue whales, fin whales, sei whales, and minke whales, and next week, my post will be about humpback whales. The reason why I’m dividing it up like this is that there is far more information about humpbacks than there is about the other species in this family. While it is known that most rorquals feed in high latitudes during the summer and breed and give birth during the winter in temperate or tropical latitudes, biologists do not know how far they migrate and what percentage of the population migrates. We see fin whales and even humpbacks all winter here on Kodiak Island, so it is clear that not all individuals migrate every year.

Blue whales are the largest animals to have ever lived on earth. Females may reach 90 ft. (28 m) in length. They are a mottled bluish gray and streamlined with a broad, rounded head, long, slim flippers, and a very small dorsal fin that is located so far back toward the flukes that it is usually only seen when they are about to begin a dive. They have broad, triangular flukes are only slightly notched, and their baleen is solid black. I have never seen a blue whale, because they are usually far off shore in deep water near the continental shelf. They are rarely seen in the bays around Kodiak Island, but in the summer, they can be found in the Gulf of Alaska and the Bering Sea. I think it is interesting that the largest animal on the planet dines on one of the smallest animals. Blue whales primarily eat euphausiids, small shrimp-like organisms that are commonly called krill.

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Fin whales are the second-largest species of whale. An average adult female fin whale is 73 ft. (22 m) in length, while an average male is 70 ft. (21 m). A fin whale’s upper jaw is V-shaped and flat on the top, and it has a distinct ridge on its back that extends from the dorsal fin to the tail fluke. Its dorsal fin is up to two feet tall and is curved with a steep backward angle and a blunt tip. The flukes are broad and triangular with pointed tips and a central notch. A fin whale has a light gray to brownish-black back and sides, with two lighter-colored chevrons that begin behind the blowholes and slant down the sides toward the fluke and then swirl up and end behind the eye. The undersides of the body, flippers, and fluke are white. The left lower jaw of a fin whale is dark gray, but the right lower jaw is white, and this asymmetrical coloration extends to the baleen plates. Scientists think this asymmetrical jaw color may somehow aid fin whales in capturing prey. If seen up close, the right lower jaw of a fin whale clearly distinguishes it from a blue or sei whale. Fin and blue whales produce the loudest biological sounds in the ocean, and recent research on fin whales shows that only males produce these vocalizations. The sounds are simple and consist of low-frequency moans and grunts and high-frequency pulses. Scientists suspect that males emit these sounds to attract females from great distances, and they worry that sounds from commercial ships, military sonar, seismic surveys, and ocean acoustic research may reduce the distance over which receptive females can hear the vocalizations of males.

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Of all the large whales, perhaps the least is known about sei (pronounced say) whales. In the southern part of their range sei whales coexist with Bryde’s whales, and until the early 1900s, they were considered the same species. The name “sei” comes from the Norwegian word “seje”, which means pollock, because sei whales appeared off the coast of Norway each year at the same time large schools of pollock arrived to feed on the abundant plankton. Sei whales are sleek and streamlined, and are one of the fastest swimming baleen whales, reaching speeds of 22 mph. They may reach a length of 65 ft. (20 m), but a length of 54 to 55 ft. (3.7 to 16.8 m) and a weight of 14 to 17 tons is more typical. Sei whales have a dark bluish-gray body with white on the ventral surface. The flukes and flippers are dark on both the dorsal and ventral surfaces. The snout is pointed, and there is a single prominent rostral ridge running from the blowholes to the snout. The dorsal fin is tall and curved, and the baleen is uniformly ashy black with fine, silky fringes. Sei whales normally feed near the surface, and they are primarily skimmers instead of gulpers like blue and fin whales. Small copepods are their preferred food, although they will also eat other zooplankton and small fish.

Minke Whale
Minke Whale

 

Minke whales are the smallest of the rorquals. Males average 26 ft. (8 m), and females average 27 ft.(8.2 m). Both males and females weigh approximately 10 tons. The story is that the minke (pronounced mink-ey) whale was named after a Norwegian whale spotter named Meincke, who mistakenly identified a small minke whale as a blue whale, the largest of all whales. Minke whales have a very narrow, pointed jaw, a single ridge that runs from the tip of the jaw to the blowhole, and a dorsal fin that is tall and curved. The flippers are slender and pointed at the tips, and the flukes are broad, pointed, and notched in the center. The body is dark gray on the back and white on the ventral surface. There is a distinctive white band on each flipper, and the extent and orientation of the band varies between individuals. The baleen is yellowish-white. Minke whales have an inconspicuous blow that is often hard to spot in the ocean, but they do occasionally breach, and you can see the white fin band on the fin of the breaching minke in the above photo.

My post next week will be about the most famous member of the rorqual family, the humpback whale. Please let me know if you have any questions or would like to add anything to these posts.

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Baleen Whales

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Baleen whales are in the suborder Mysticeti. They differ from toothed whales in a number of ways. All mysticetes have two nostrils or blowholes, while toothed whales (odontocetes) have only one blowhole. Mysticetes have a symmetrical skull, while most odontocetes have assymetrical skulls. Most toothed whales have a specialized echolocation system that is lacking in baleen whales. Female mysticetes are usually larger than their male counterparts, but other than that, there is no sexual dimorphism, while there is often marked sexual dimorphism in odontocete species. The most obvious difference between these two suborders, though, is that instead of teeth, mysticetes have baleen made from keratin, the same substance that comprises hair and fingernails. Stiff plates of baleen grow down from the gum of the upper jaws, and depending on the species, the baleen may be black, gray, creamy yellow, white, or a mixture of these colors. The outer edge of each plate is smooth, and the inner edge is frayed. The frayed inner edges intertwine to form a mat, allowing whales to filter feed and trap zooplankton and small fish in their baleen. Like hair and fingernails, baleen continues to grow at its base and wear along the edges.DSC_0670

All baleen whales are carnivorous, and most eat zooplankton or small schooling fish.  Most mysticetes employ one of two different systems for feeding, and some species use both systems, depending on the situation and prey density. These systems can be described as “skimming” and “gulping.” Skimming is when a whale swims open-mouthed through a food supply, while gulping, as its name implies, is achieved when a whale swims through a food swarm and gulps large amounts of water and food by extending the ventral grooves in its throat to greatly enlarge the size of its mouth, depressing its tongue, and opening its lower jaw to a nearly 90 degree angle from the body axis. After engulfing the prey, the whale closes its mouth and forces the excess water out through the baleen. It then uses its tongue to transfer the prey to its gullet, and from there, it passes into the stomach. Gray whales, which are mainly bottom feeders, have their own unique style of feeding. Most baleen whales feed for only four months during the summer, and they must consume enough food during this time to sustain them for the rest of the year. It has been calculated that a baleen whale consumes 4% of its body weight per day during the summer feeding season.

Baleen whales are some of the largest animals on earth. In fact, blue whales are the largest animals to have ever inhabited the planet. The buoyancy of water supports a whale’s body, allowing it to grow to a greater size than it could if it lived on land. This large size has several advantages. The decreased surface to body-volume ratio helps a whale conserve heat. The large body size also makes a whale safer from predators, and it allows a whale to eat large quantities of food when food is available and then store this energy in the form of blubber that can be broken down for energy during periods of fasting.

The general body shape of most baleen whales is cylindrical, tapering at the ends. This shape is energy-efficient for swimming and creates less drag. A whale’s skin is smooth and has no oil glands or pores. Many species of mysticetes have sparse hairs on the snout, jaws, and chin, but the lack of hair or fur on the body is an adaptation to reduce drag when swimming.

DSC_0650A baleen whale has a small, external ear opening on each side of its head that leads to an auditory canal. The middle and inner ear is similar to that of other mammalian species, but the ears are adapted for hearing under water.

Baleen whales produce low-frequency sounds, mostly below 5000 Hz. These are some of the loudest sounds produced by any animal, and the sounds travel hundreds of kilometers under water. Scientists think these loud sounds may be used for long-range contact, advertising for a mate, greeting, orientation, navigation, or announcing a threat. The sounds consist of very-low frequency moans, grunts, thumps, and knocks and higher frequency chirps, cries, whistles, and songs.

Some baleen whales can swim as fast as 20 mph (32 kph). They swim by using powerful up-and-down strokes with their tails to push their streamlined bodies through the water. While some mysticetes can dive to depths over 1000 ft (355 m), most species feed at relatively shallow depths. A whale holds its breath when under water, and when it surfaces, it opens its blowholes and blasts a loud exhalation. The whale then quickly inhales and closes its blowholes before diving. Most baleen whales surface and breathe several times before diving. The spout of water that is often the first visual clue of a whale’s presence, does not come from the whale’s lungs. As with other mammals, a whale’s lungs do not tolerate water. Instead, the water spout is produced from water that was on top of the blowhole when the whale exhaled, and the water condenses as the respiratory gases expand in the air. The size and shape of a whale’s “blow” varies from species to species.

Mysticetes can be found in all oceans. They live in polar, tropical and temperate zones. There are three families in the suborder Mysticeti. These are Balaenopteridae, or the Rorqual Whales; Balaenidae, the Right Whales; and Eschrichtidae, the Gray Whale. In my next few blogs, in the family Balaenopteridae, I will cover the blue whale, the fin whale, the sei whale, the Minke whale, and the humpback whale. In the family Eschrichtidae, I will cover the gray whale.

While I see these whales on their summer feeding grounds, I know many of you have watched whales in their winter breeding areas, perhaps in Mexico or Hawaii. Please share your experiences!

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Whales

Fin whales in Uyak Bay
Fin whales in Uyak Bay

Whales have been on my mind lately; probably because I’ve seen some nearly every time I’ve gone for a boat ride this summer and fall. Zooplankton and schools of small fish have swarmed the bay all summer and fall, providing abundant food for everything from larger fish, gulls, eagles, other birds, harbor seals, sea lions, and of course whales. I’m certain that if I jumped in my boat right now, within in minutes, I’d be in the midst of several huge fin whales, whose 18-ft. tall exhalations surpass any choreographed water-fountain show in Las Vegas. I’d probably also see two or three humpbacks waving their tail flukes in the air and perhaps leaping out of the ocean and slapping their large pectoral fins and tail flukes on the water.

I’ve also been thinking about whales, because that is the chapter I’m working on for my book on the wildlife of Kodiak Island. While I love whales, writing about them has been an arduous process, since little is known about many species, and I must draw bits and pieces of information from an array of sources. This painstaking research, though, has provided me with a better understanding of these huge, intelligent creatures, so I thought I would write a few posts about them. I will focus on the whales that can be seen near Kodiak Island, and I will admit that I have not seen all these species, because either they migrate past the island and do not enter the deep bays, or they spend their lives off shore. There is also another, darker reason for me to write about the whales near Kodiak Island. This summer more than 30 whales (mostly fin and humpback) died near Kodiak, and biologists are scrambling to discover the cause.

Whale species commonly found near Kodiak include fin whales, the second largest species of whale; sei whales, the third largest species of whale; humpbacks; Minke whales; and Orcas, or killer whales (although Orcas are actually dolphins, not whales). Gray whales migrate past Kodiak on the way from their breeding and birthing areas near Mexico to their northern feeding grounds, and blue whales, the largest species of whale, can be found off shore in the Gulf of Alaska. Blue whales, fins, sei whales, humpbacks, Minkes, and gray whales are all filter feeders and have baleen instead of teeth. Killer whales, of course, have teeth.

As you probably know, whales, like humans, are mammals. They have lungs and must breathe air to survive. They are warm-blooded, and like most mammals, they bear live young. Whales nurse their young with milk, and while you may not think of a whale having hair, all whales do have hair at some stage in their development. Whales are in the order Cetacea, and all members of this order are believed to have evolved from hoofed animals, such as cows, sheep, and camels, 45 million years ago.

All cetaceans have forelimbs that have been modified into flippers and no hind limbs. Their tails are horizontally flattened, and they breathe through a nostril or blowhole, located on the top of the head. Whales have internal sensory and reproductive organs to reduce drag when swimming, and cetacean mothers nurse their calves with a pair of teats that are concealed in slits along the body wall.

Cetaceans living in the cold ocean waters of the North Pacific must somehow maintain a body temperature that is nearly the same as a human’s body temperature, and a whale uses a number of mechanisms to accomplish this feat. First of all, it has a thick layer of blubber which has few blood vessels, reducing heat loss at the body surface. A whale has a counter-current exchanger, where veins at the periphery are surrounded by arteries. Heat lost by vessels flowing from the warmer core toward the cold periphery is at least partially absorbed by vessels flowing from the periphery to the core. A cetacean also has a fairly high metabolic rate to produce heat, and it has a low body surface to volume ratio, which conserves heat. Also, a whale breathes at a slower rate than a land mammal does, so warm air is expelled less frequently.

The order Cetacea is divided into two suborders: The Mysticeti or baleen whales and the Odontoceti, or toothed whales. I primarily will be discussing the Mysticetes, and next week, I’ll describe baleen and how it is used. Please leave a comment if you have any questions or would like to add anything about whales. I would love to hear about your whale experiences!

In late November or early December, I plan to start a monthly newsletter focused more on mysteries and my fiction writing. My first several newsletters will chronicle some true-life Alaska crimes. If this sounds interesting, please subscribe to my e-mail list.

Subscribe to my monthly e-mail mystery newsletter. Beginning in late November, I will begin chronicling some true-life Alaskan crimes!

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