Tag Archive | cetaceans

Amazing Marine Mammals: Narwhal


The narwhal has longed been linked with the mythical unicorn for centuries due to it’s long spiral tusks. (Photo is public domain).

The narwhal (Monodon monoceros) is regarded as one of most complelling animals of arctic because of the remoteness and harshness of their frozen envrionment as well as their unsual apperance. For centuries, they have long been linked with mythical unicorns because of the fact that adult males have long spiral tusks that were unlike any other animal in nature that have ever existed. In fact, during the Middle Ages, traders and chemists alike have long been said to have conspired to cover up the existence of the arctic whale in order to sell the tusks off as “unicorn horns” for profit. Today, this marine mammal is no longer linked to mythical horned horse and has no become the subject of many field studies that aim at understanding the lives of narwhals year round.

Narwhals have short rounded heads with no beaks while their melons being bluff, protuding foward of the small upturned mouth. (Artwork by Science Photo Library).

Being one of two members of the Monodontidae family which the beluga whale is also part of, narwhals looks a little bit like belugas except, they are a little bit different from them. For example, adult narwhals have strongly conevexed flukes that are similar to that of butterfly wings while their small flippers short and broad. However, what makes narawhals very unique as a species of whale is the fact that they are the only cetacean species on Earth to lack functional teeth inside their jaws. In addition, starting at three years of age, male narwhals begin to develop their tusks which can grow up to 9 feet long and weight up to 22 pounds. Females on the other hand, remain tuskless for life. Unlike beluga whales which are completely white at adulthood, adult animals are always spotted with a black and white dorsal coloration although calves are born completely grey. Anyway, males can grow up to 15 feet long and weight in at 3.500 pounds while females weight in at around 14 feet long and weight in at 2,200 pounds. The ancesctors of modern day mondotiades, which includes both the narwhal and beluga first appeared in the fossil record around 3-5 million years ago though little is known about the evolution of this species of whale.

Narwhals are only found exclusively in the Arctic.

Narwhals have a dicontinuous distribution within the high Arctic region. However, they are commonly found in deep waters that branch northward from the North Atlantic basin which includes northwestern Hudson Bay, the Hudson Strait, Foxe Basin, Davis Strait, Baffin Bay, and Lancaster Sound. However, they often found in the Greenland Sea in which a population in that area has been known to mirgrate to the northern Barents Sea. Yet, their migrations are turned to the formation and movement of sea ice because as the ice breaks apart in the spring, hundreds of narwhals follow receding edges of pack ice and use the small cracks and melt holes to penetrate deep sounds and fjords right away. There, they will reside there throughout the summer and early fall while heading to offshore areas during the winter months.

Narwhals are the only know cetacean species to have no functional teeth in the jaw area. (Photo is public domain).

Narwhals are deep divers. They feed in in entire water columns, taking pelagic fish, squid, shrimp, and bottom-dwelling fish. On average, dives can last up to 20 minutes and they have been known to reach depth of more than 3,300 feet below the surface of the ocean. Researchers believe that narwhales suck their prey into their mouths and swallow it whole. They do not use their tusk as a spear weapon.

While narwhals live close-knit groups of up to 20 animals, they are seem to be more scattered and solitary. (Photo by National Geographic).

During the summer months, narwhals form large aggregations that consist of hundreds of animals although they may consist of much smaller close-knit groups of a few animals that number around no more than twenty individuals. These pods are usually homogeneous and consit of either animals of the same gender (like pods that are made of females with calves or breeding males), or of a single age class. In the winter however, these pods get scattered and result in solitary animals, perhaps it could be because of owing to the patchiness of cracks and holes in the ice. Adult males are known to fight one another due to the strong evidence of scars and wounds in the head region. Such fighting among the males could play a role in establishing dominance and breeding opportunities. Despite the fact that narwhals have been known to cross tusks above the surface, there’s no evidence to prove that that they fence with them.

At birth, narwhal calves are grey, just like beluga whales. (Photo by superstock.com)

Narwhals sexually mature at around four to seven years of age while they mate during the winter and early spring months when they become inaccessible for observation by researchers. With a gestation period of about fifteen months, the grey calves are born being around 5.3 feet long and weighting in are no more than 176 pounds. Births occur during  the summer months and will be weaned off at around a year old. Calves will normally still with their mothers for about three years and if they survive into adulthood, they may around 25-50 years.

For centuries, the Inuits of the Canadian Arctic have been known to have hunted the narwhal for food, oil and ivory. (Photo is public domain).

Although narwhals are not endangered, they have been threatned by centuries of commercial whaling which was for their meat, oil, and tusks, all of which have been subjected to forgein trade even though hunting them was only on a casual basis. When laws were established to have such trades banned, it also stated that only the Inuit tribes can sustainably hunt them for traditonal pruposes while only using arrows instead of commerical weapons. Surveys done on narwhals estimate that there are about 50,000 animals roaming the Arctic Ocean although some populations are being threatned by climate change and interbreeding with beluga whales.

Advertisements

How Pollution affects Orcas


Without further regulations that would either ban or place restrictions on the entry of pollutants in the oceans, wild orcas like Samish (J-14) would likely endure a bleak future. (Photo of Samish is by the Whale Museum's Killer Whale Adoption Program)

Around the world, killer whale populations are falling victim the effects of pollution mainly caused by man-made toxins. These toxins, which are usually made of various chemicals, are used on land often end up entering waterways through runoffs and eventually end up as pollution in the ocean. Various chemicals, such as flame retardants, industrial pollutants, oils, and pesticides have all been known to enter the oceans through waterways and they are all having a major impact on marine wildlife, including killer whales.

Because killer whales are known as the top predator of the ocean, it's very easy for pollutants to become concentrated and reach dangerous levels their bodies since these pollutants make their way through the marine food chain.

While wildlife experts agree on the fact that pollutants make their way through the marine food chain, some of them often get sorted into the body tissues of animals after they are ingested. For example, In the Pacific Northwest, the marine food chain is consisted of  zoo plankton feeding on phytoplankton, krill feeding on zoo plankton, salmon feeding on krill, and orcas (killer whales) feeding on the  salmon, which has become endangered because of pollution, over-fishing, and habitat loss. In the case of transient orcas,  dolphins, seals and sea lions feed on the salmon, while the mammal-eating transients feed on the very same marine mammals that feed on the salmon. This means that prey animals that contain toxins in their bodies pass them on to animals that are higher on the food chain and because of this, killer whales have been shown to have high and dangerous levels of concentrated pollutants in their bodies.

In the Pacific Northwest, resident killer whale populations in Washington and in British Columbia are among the most intoxicated marine mammals in that region due to not only being urban animals, but also, the salmon they depend on is also contaminated with pollutants. Research has also shown that resident orcas have 200 times more pollutants in their system in most humans do. (Photo of resident orca is public domain).

In Norway, studies on Norwegian herring-feeding killer whales have found that this population of killer whale has very high levels of PCBs. PCBs are type of industrial chemical that is used in transformers, oils, and insouciance. As a result, this makes Norwegian killer whales have the highest level of containments in high Arctic. (photo of Norwegian orca was taken by Jonathan Ball).

Studies done on the contamination levels of Pacific offshore killer whales have discovered to be very high because they are known to feed on large fish such as great white sharks, and tuna which can bio-accumulate containments over a period of a lifetime. (Photo of offshore orca is public domain).

Transient orcas, which specialize in feeding marine mammals, are more contaminated than resident orcas due to dietary differences. Their bodies are so full on toxins that when they are found dead on beaches, their remains are often treated as toxic hazardous waste when necropsies are performed on them. (Photo is public domain).

New Zealand is home to a small population of ray-feeding killer whales that have also been known to feed on certain species of sharks. In 2010, a study done by Dr.Ingrid Visser of the Orca Research Trust of New Zealand have shown that this population of about fewer than 200 animals are the most containment animals in the Southern Hemisphere. This could also be due to the fact that the mammals are mainly seen in harbors where such containments can mainly be found. (Photo of wild orca pod off the coast of New Zealand was taken by Dr. Ingrid Visser of the Orca Research Trust).

In the 1970’s, various pollutants were banned world wide because of the negative effects they posed both to humans and wildlife. Yet, many of these pollutants can still be seen in the form of containments and in various forms and it’s still to this day having a huge impact on marine wildlife, such as PCBs (polychlorinated biphenyls). PCBs are a type of organic compound that has a 1 to 10 chlorine atom attached to biphenyl, which is molecule composed of two benzene rings. When PCBs are ingested, they aren’t neither metabolized nor eliminated for these fat-soluble molecules go on to accumulate in fats, such as blubber. Just to make matters worse for the killer whales, the PCBs are affecting their reproductive health too and this is because they are known to be estrogen imitators and cause low sperm count in both humans and animals alike, including killer whales. Also, out in the wild, when a killer whale calf is born, chances are, it was born with toxins that have been passed on to them by the mother through the placenta  and goes on to receive these same toxins it developed before birth by nursing on the mother’s fat-rich milk. In some cases, the calf (mainly the first-born) dies likely due to heavy exposure to toxins. However, calves the mother goes on to have after that have been known to fare better because of the mother’s toxin levels decrease over time. PCBs have also been known to cause other problems too such as cause disease and developmental problems.

What can you do to reduce pollution…..

  • Reduce, Reuse and Recycle
  • Clean garbage off a beach
  • buy organically grown food to reduce the use of pesticides
  • Use biodegradable cleaning products that are plant-based.
  • Dispose paint, thinners and motor oil to prevent them from going down the drains

If you have any questions, or comments about killer whales, please email me at Animaltrainer104@aol.com and I hope you to do your part in caring for killer whales and the oceans by reducing pollution.

~Jenna~

More Orca FAQs


While resident orcas will remain in the same pod for life, this is not the case for transient orcas. Photo of orcas Unna, Kyuqout and Tuar was taken on July 24th, 2008 by yours truly.

Hello everyone,

In response I got from Yovani Valdes regarding my first blog entry that was about frequently asked questions about orcas, I decided to add a sequal to that blog entry. This entry is all based off six of seven questions that were asked by Yovani and the one other question that I have found on yahoo.com.

1. How are new pods formed?

Females will begin to branch off from from their birth pods when they start having calves of their own. From there on, they will eventually start new lines of their own even though they will continue to travel closely with their mothers and other family members.

2. How large can pods get?

Orca pod sizes can range from two to forty animals.

3. What’s a transient pod?

Most transient orcas may have short term associations with other pods from time to time. Photo by National Geographic.

Transient orca pods are small loosely-based social structures that may consist of an adult female and two or three of her offspring. However, while the eldest male calf will remain with the mother for life, the other calves must leave her. Transient calves will leave their mother’s pod at around 5-12 years. Females have been known to travel with other transient animals who they may or may not be related too while males will travel with one group after another for time to time. However, the only exception to this rule is if female offspring fail to produce any offspring of her own and will remain with the mother for life.

4. What are the intervals between births?

Born year around, killer whale calves may nurse from their mothers for up to two years. Photo of Katina with her son Makaio was by taken by yours truly in July 2011.

 

Female orcas will give birth to a single calf every 3-5 years. On average, females will probably give birth to 4-6 calves during her lifetime.

5. When do they start breeding and until what age?

While female orcas will mature at around 7 to 10 years of age, it could be another six to nine years before they have their first calf. The average age for females to give birth for the first time is around 11-15 years. They become post-reproductive in their mid-forties.

6. Why do dorsal fins bend? 

There are a series of theories about why an orca's dorsal fin bends. photo is by Public Domain

Although it’s not really known why an orca’s dorsal fin bends, many believe that gravity may have something to do with it. For example,  when orcas dive under water, the surrounding water helps support the dorsal fin which is made of nothing more than muscle and connective tissues. Also, orcas who spend most of their time at the surface with their fins protruding out of the water has greater chances of flipping over on a long-term scale. Additionally, the collagen becomes more flexible when warm such as exposure to the sunlight. However, there are also theories about collapsed dorsal fins being genetic (there there’s evidence to support that too).  Yet because the dorsal fins of male orcas can grow up to six feet tall, the height of the fins may have a great tendency for the fins to naturally collapse or become wavy over time. However, it must be reminded that neither the shape or droop of a whale’s dorsal fin are not indicators of an orca’s health, or well-being.

If you have anymore questions about orcas and other marine mammals, feel free to email me at Animaltrainer104@aol.com

Hope you all have a great weekend everyone,

~Jenna~

Right Whale Tale(s)


A female North Atlantic Right Whale swimming in a Provincetown Harbor in 2004.

Since the movie Big Miracle, a film that’s a about a grey whale rescue in Alaska is out in theaters, I thought to commemorate it by sharing with you two whale watch experiences I had with the endangered North Atlantic right whale. These encounters occurred in 2004 and 2010. 

The first encounter with a wild right whale took place in October 2004. I was 12 at the time and whale watch boat that my family and I were aboard on was just leaving the harbor to see some whales in the Stellwagen’s Bank National Marine Sanctuary which was 10 miles off of Cape Cod. About just a minute into leaving the harbor, the naturalist unexpectedly stopped the boat about 500 yards out of port; it was then, he announced that there were right whales in the harbor. He then went on to talk about the right whales when suddenly, two right whales, a mother and her calf surfaced about 150 yards from our boat and believe me, it was such a site to see. However, just as we were all enjoying the right whales swimming by the boat, two jet skiers passed by the boat and they were too close to the whales and just to make matters worse, the jet skiers were skiing to fast in the harbor. As a result, the horrified naturalist warned them that he would report them if they slowed down and stayed 300 yards away from the whales, but the skiers kept on ignoring the naturalist before he finally called the coast guard on them. That was such an unexpected day because normally, you will not find right whales swimming in harbors but rather like 10-30 miles offshore if you’re lucky.

Then about almost two years ago in March 2010, my mother and I went down to coastal town of Provincetown, Massachusetts for Easter weekend in hopes that we to try out some land-based whale watching and see some whales. One the first evening we were there, we were at Herring Cove Beach when three North Atlantic right whales were sighted just five and a half miles offshore. Although they were far away, but you were able to see them up-close via, binoculars. Just to make things more interesting, I witnessed a young right whale calf learning how to breach from her mother and “auntie”. One of the two adult animals would breach first before the calf would repeat the behavior over and over again. It was such a precious moment to watch a whale calf learn from her mother.

These two right whale encounters were just amazing and far beyond my wildest imaginations. I hope that the next time I go whale watch, I get to see some right whales again.

Have a whale of a Valentine’s Day everyone,

~Jenna~