A Giant Extinct Sea Cow

Summary

The story of Steller's sea cow, a massive marine mammal related to dugongs and manatees, serves as a poignant lesson in conservation. First discovered in 1741, these gentle giants, adapted to cold waters with unique anatomical features, were driven to extinction within 30 years due to overhunting by fur traders. Their demise marks a tragic milestone in human history, highlighting the urgent need for conservation to prevent future losses of such unique species.

Takeaways

• 🐋 Steller's sea cow, scientifically known as Hydrodamalis gigas, was a massive marine mammal, reaching up to 9 meters in length and weighing around 10 tonnes.
• 🌐 First discovered in 1741 by German zoologist Georg Wilhelm Steller, the species was found in the sub-Arctic waters around Bering Island.
• 🚫 Extinct within 30 years of its discovery, it's considered the first marine mammal to be driven to extinction by human actions.
• 🔍 Steller's sea cow was adapted to cold waters, with a large body size and thick blubber to reduce heat loss, unlike its tropical relatives.
• 🌿 The species had unique feeding adaptations, using keratinous pads instead of teeth and bristles on their snouts to consume kelp and algae.
• 👥 They were social creatures, living in family units and exhibiting behaviors like monogamy and altruism, such as protecting their young and assisting injured members.
• 🔪 Overhunting by Russian fur traders, who used the sea cows for food and oil, was the primary cause of their extinction.
• 🐾 The habitat shared with sea otters, which were hunted for their fur, indirectly contributed to the sea cow's decline by disrupting the ecosystem.
• 🌊 The species' inability to fully submerge and their reliance on shallow coastal waters may have made them more vulnerable to hunting.
• ⏳ Despite the extinction date being estimated around 1768, there were unconfirmed sightings reported in later centuries, emphasizing the tragedy of their loss.

Q & A

What is the significance of Steller's sea cow story in terms of conservation?

Steller's sea cow story is significant as it serves as a cautionary tale highlighting the devastating effects humans can have on marine life and the importance of conservation efforts to prevent such extinctions in the future.

How large was Steller's sea cow and what did it weigh?

Steller's sea cow was approximately eight to nine meters in length and weighed around 11 tonnes.

When was Steller's sea cow first discovered and by whom?

Steller's sea cow was first encountered by a scientist in 1741, and it was named after the German zoologist Georg Wilhelm Steller.

How are Steller's sea cow related to modern marine mammals?

Steller's sea cow, technically named Hydrodamalis gigas, is related to dugongs and manatees and is classified as a sirenian.

What adaptations did Steller's sea cow have to survive in colder sub-Arctic waters?

Steller's sea cow adapted to colder sub-Arctic waters by growing to enormous sizes, developing thick blubber, and having a unique skin texture that was bulk-like and rough along the sides but smooth on the back.

How did Steller's sea cow feed and what did its feeding adaptations include?

Steller's sea cow primarily fed on kelp and algae. It lacked teeth as an adult but had keratinous pads in its mouth to grind food, and interlacing white bristles on its snout to slice and grasp kelp and seaweeds.

What were the physical characteristics of Steller's sea cow's limbs?

Steller's sea cow's limbs were heavily modified, described as short and hooked, and did not have any phalanges. The skin on the limbs was thick, aiding in various activities such as pulling, swimming, and clasping.

How did Steller's sea cow differ from manatees and dugongs in terms of buoyancy control?

While manatees and dugongs can control their buoyancy, Steller's sea cow was reportedly unable to fully submerge, possibly due to its larger size, more blubber, and increased lung and intestine volume.

What social behaviors were observed in Steller's sea cow?

Steller's sea cow was gregarious, living in small family units and gathering into large groups to feed. They were also monogamous and showed evidence of altruistic behavior, such as protecting their offspring and assisting wounded individuals.

What were the circumstances that led to the extinction of Steller's sea cow?

The extinction of Steller's sea cow was primarily due to overhunting by Russian fur traders who used the sea cows for food, blubber, and oil. The already small population was further threatened by habitat changes and a decrease in their primary food source, kelp, due to an increase in sea urchin populations.

What is the estimated extinction date of Steller's sea cow and what evidence supports this?

The estimated extinction date of Steller's sea cow is around 1768, based on reports of fewer sightings and eventual absence of the species. This was confirmed by a German naturalist in the 1800s.

Outlines

00:00

🐳 The Tragic Extinction of Steller's Sea Cow

Steller's sea cow, scientifically known as Hydrodamalis gigas, was a unique marine mammal that lived in sub-Arctic waters. It was first documented by German zoologist Georg Wilhelm Steller in 1741. The species was remarkable for its size, reaching up to 9 meters in length and weighing 10 tonnes. It was related to dugongs and manatees, but had adapted to colder waters, which led to significant anatomical differences. These included a larger body size to reduce heat loss, thick blubber, and a unique skin texture. The sea cow had no teeth as an adult, using keratinous pads to grind food, and had specialized bristles for feeding on kelp and algae. Despite being social creatures that lived in family units, their peaceful nature and unique adaptations were not enough to save them from extinction, which occurred within 30 years of their discovery due to human actions.

05:02

🦭 The Downfall of Steller's Sea Cow and Lessons for Conservation

The extinction of Steller's sea cow was largely due to overhunting by Russian fur traders who sought food during their voyages. The sea cows were an easy target due to their large size and the nutritional value of their meat and blubber. The species was already vulnerable with a small population, and the hunting pressure led to their rapid decline. By 1768, the species was considered extinct. The loss of Steller's sea cow serves as a cautionary tale about the impact of human activities on marine life and the importance of conservation efforts. It highlights the need for understanding and protecting marine species to prevent future extinctions. The video also touches on the potential role of native hunting and ecological changes in the sea cow's decline, emphasizing the complex factors that can lead to extinction.

Keywords

💡Steller's sea cow

Steller's sea cow, scientifically known as Hydrodamalis gigas, was a massive marine mammal that became extinct in the 18th century. It was first documented by the German zoologist Georg Wilhelm Steller in 1741. The creature was unique due to its adaptation to colder sub-Arctic waters, unlike its relatives the dugongs and manatees. The video emphasizes the tragic loss of this species as a result of human actions, highlighting the importance of conservation.

💡Extinction

Extinction refers to the state of a species that no longer has any living members. In the context of the video, Steller's sea cow became extinct due to overhunting by humans, particularly Russian fur traders who sought the animal for food and its blubber for various uses. The video uses this example to underscore the devastating impact humans can have on biodiversity and the urgency of conservation efforts.

💡Adaptation

Adaptation in biology refers to the process by which organisms become better suited to their environment through genetic changes. The video describes how Steller's sea cow adapted to cold waters by becoming large to reduce heat loss, developing thick blubber, and having a unique skin texture. These adaptations highlight the evolutionary process and the video uses them to illustrate the creature's unique characteristics and its struggle for survival in a changing environment.

💡Buoyancy control

Buoyancy control is the ability of an organism to regulate its buoyancy in water. The video explains that while related species like manatees can control their buoyancy, Steller's sea cow was unable to fully submerge, possibly due to its large size and the increased volume of blubber and internal organs. This lack of buoyancy control is an example of how the sea cow's adaptations to its environment had both advantages and limitations.

💡Altristic behavior

Altruistic behavior is when an organism performs an action that benefits others at a cost to itself. The video recounts instances where Steller's sea cows were observed helping injured members of their group, demonstrating a form of altruism. This behavior is significant as it reflects the social nature of the species and adds to the emotional impact of their extinction.

💡Conservation efforts

Conservation efforts are actions taken to protect and preserve species and their habitats. The video emphasizes the importance of such efforts, using the extinction of Steller's sea cow as a cautionary tale. It suggests that without effective conservation, more species could suffer the same fate, highlighting the responsibility humans have towards biodiversity.

💡Sub-Arctic waters

Sub-Arctic waters refer to marine environments located just south of the Arctic Circle, characterized by cold temperatures. The video explains that Steller's sea cow adapted to these colder waters, which were a significant departure from the tropical habitats of its relatives. This adaptation is crucial to understanding the species' unique biology and the challenges it faced.

💡Blubber

Blubber is a layer of fat found beneath the skin of marine mammals, serving as insulation and an energy reserve. The video describes Steller's sea cow's thick blubber as an adaptation to cold waters, which also made it a target for hunters. The blubber's dual role in the animal's survival and its eventual demise underscores the complex relationship between biology and human activity.

💡Kelp and algae

Kelp and algae are types of marine plants that form the primary diet of some marine mammals, including Steller's sea cow. The video notes that these plants were the main food source for the sea cow, highlighting the creature's herbivorous nature. The dependence on kelp also illustrates the interconnectedness of marine ecosystems and the impact of changes in one species on others.

💡Fur traders

Fur traders were individuals involved in the trade of animal furs, particularly in historical contexts. The video discusses how Russian fur traders hunting sea otters for their valuable fur indirectly led to the extinction of Steller's sea cow, as the sea cows were hunted for food during these expeditions. This historical context is crucial for understanding the human activities that contributed to the species' demise.

Highlights

Steller's sea cow is an important cautionary tale for understanding human impact on Earth's biodiversity and the importance of conservation efforts.

The Steller's sea cow, or Hydrodamalis gigas, was an enormous marine mammal, reaching up to 9 meters in length and weighing 11 tonnes.

First encountered by scientist Georg Wilhelm Steller in 1741, the species went extinct in less than 30 years, marking a significant event in modern human history.

Steller's sea cow is related to dugongs and manatees, classified as a sirenian, but adapted to colder sub-Arctic waters.

The species' large size, up to 10 meters, was an adaptation to reduce heat loss in cold waters, similar to some whale species.

Thick blubber, up to 10 centimeters, and a unique, rough skin texture were adaptations to the cold, protecting against ice and rock.

Steller's sea cow had no teeth as adults, using keratinous pads to grind food, and had interlacing white bristles for feeding on kelp and algae.

The limbs of Hydrodamalis gigas were short, hooked, and thick-skinned, aiding in movement, feeding, and mating behaviors.

Unlike modern sirenians, Steller's sea cow could not control its buoyancy and was unable to fully submerge.

The species lived in small family units and exhibited social behaviors, including monogamy and protective parenting.

There are accounts of altruistic behavior in Steller's sea cow, with individuals assisting wounded companions.

The sea cow's extinction is linked to overhunting by Russian fur traders who used them for food and oil, as well as habitat changes.

The hunting of sea otters, a natural predator of sea urchins, may have indirectly contributed to the sea cow's food scarcity and extinction.

The last confirmed sighting of Steller's sea cow was in 1768, but there are unverified claims of sightings into the 20th century.

The extinction of Steller's sea cow serves as a lesson in the consequences of human actions on marine life and the urgent need for conservation.

The story of Steller's sea cow emphasizes the importance of understanding and preventing the extinction of unique marine species.

Transcripts

the story of Steller's sea cow is an

important one to know it's a cautionary

tale that everyone should be aware of to

truly appreciate the devastating effects

that humans can have on the life of this

planet and the relevance of conservation

efforts there once existed an incredibly

remarkable creature quite unlike

anything alive today and we were so

close to seeing them in the flesh

approaching eight to nine meters in

length and 11 tonnes in weight this

organism was first encountered by a

scientist in the year 17 41 and then in

less than 30 years it was completely

extinct the death of stellar sea cow

seems to have therefore been the first

instance in modern human history that a

marine mammal fell prey to the direct

actions of our own species there really

is nothing like these animals left

around today stellar sea cow technically

named Hydra demolish gigas is related to

the dugong and manatees and are thus

classified as Cyrenians along with these

modern taxa being placed within the

dugong add a family but these extinct

sea cows had adapted to some very

different habitats and this had led to a

pretty different Anatomy evolving

instead of inhabiting warm waters around

the tropics like extant Cyrenians do

hydro Tomales had spread into much

colder sub Arctic waters further north

and therefore some novel changes

occurred in the species to make them

better suited to these areas most

obviously the creatures got enormous

this would probably have been in order

to reduce the surface area to volume

ratio of the animal's body and as a

result reduced the amount of heat loss

to the surroundings cold waters the huge

sizes of almost 10 meters long means

that Steller's sea cow would actually

have been one of the biggest mammals

alive at a time rivaling some whales in

its dimensions also like whales Hydra

domalis had very thick blubber

underneath its skin apparently getting

to around 10 centimeters thick in

certain regions another adaptation to

reducing heat loss the skin of the

organism was reported to have been quite

unique to being bulk like and rough

along the sides but smooth on the back

with a mostly black brown coloration and

sometimes a few white patches

this unusual Ruffins texture is

suggested to have protected the animals

from cuts and scrapes due to sharp bits

of ice and rock as they swam in their

shallow water habitats hydro Tomales had

some pretty interesting feeding

adaptations as they mostly ate kelp and

algae the Cyrenians completely lacked

teeth as adults but instead used to

keratinous pads one on the roof of its

mouth and one at the bottom to grind up

their food in addition to these pads the

creatures possessed interlacing white

bristles on the front of their downtown

snouts which apparently were used in

slicing up and grasping the kelp and sea

weeds they were feeding on bristles were

also present on the insides of their

four limbs and the four limbs themselves

were pretty heavily modified structures

compared to those seen and living

Cyrenians they did not have any

phalanges four finger bones and were

described by people who witnessed them

as being short and hooked allowing for

many uses of the limbs such as pulling

the creatures along in shallow water

swimming picking up food and clasping

during mating the skin was also very

thick on the limbs aiding in these

activities another way that Hydra

demolish differed from the manatees and

dugongs

is in its buoyancy control extent

Cyrenians are capable of controlling

their buoyancy

however Steller's sea cow was reportedly

unable to even a fully submerge

underneath the water's surface this has

been suggested to be due to the larger

size of this species which resulted in a

lot more blubber and an increase in lung

and intestine volume these animals were

gregarious creatures living in small

family units of a bull cow and calf and

gathering into large groups to feed they

were also apparently monogamous and

would protect their offspring when

feeding by staying behind them and other

sites witnesses reported that Hydra

Tomales actually showed evidence of

altruistic behavior as in one case where

a member of a grazing herd was shot by a

harpoon other sea cows gathered around

and attempted to assist the wounded

individual then there was also the story

of a female sea cow being caught and her

bull partner following her and ramming

the boat she was taken on before waiting

for three days near the beach where she

was brought and killed so seeing how

unique this species was and how

seemingly peaceful they were it makes

their loss all the more

but how exactly did this occur how were

they even discovered in the first place

well in 1741 a German zoologist called

Georg Wilhelm Stella was onboard a ship

that became wrecked on Bering Island

staying on the island for about a year

Stella was able to research and document

the animals that lived there including

the sea cows that would be named after

him most of the information we currently

have about this species is thanks to the

observations made by stella including

details of anatomy that were gained from

individuals caught and cut up by the

sailors however despite the significance

of the discovery of a giant Cyrenian

living in sub arctic waters in the

bering sea around the commander and

Aleutian Islands this did not stop what

happens just 27 years later the sea cows

were in a very unfortunate situation

since they shared their habitat with

large populations of sea otters which

were the target of Russian fur traders

at this time in the 1700s fur was

becoming increasingly valuable and so

furry animals became highly sought after

the problem for Steller's sea cow came

when the traders needed food to keep

them going along the route between

Russia and America and the large bodies

of Hydra Tomales with a thick blubber

and masses of meat proved to be the

perfect prey apparently the meat of

these animals tasted similar to beef and

the blubber was tasty too in addition to

being useful in cooking and as lamp oil

it also now seems as though the sea cows

were already under threat from when

Stella first documented them with a very

small population and this hunting

pressure from humans pushed them over

the edge and into extinction as the

hunting continued the population grows

smaller and smaller until natural ists

concluded that the species must have

completely disappeared by 1768 there is

fossil evidence that indicates the

previous range of the genus Hydra

domalis will spread much further along

the coast of Japan and over to the North

American coast so the population

inhabiting the Bering Sea appears to

have been a radek's population in danger

of dying out anyway as they had already

undergone local extinctions in other

regions it's also possible that

Europeans travelling between Russia and

America may not have been the only ones

involved in the sea cow extinct

with natives of the Aleutian Islands and

the Siberian Yupik people potentially

having preyed on the species in the past

reducing their populations before their

final extinction the death of this

species has also been proposed to have

been linked to the hunting of otters in

another way too

when Aboriginal peoples went after the

sea otters and their populations

decreased as a result sea urchin

populations would have risen since

otters feed on them and control their

numbers sea urchins are capable of

significantly depleting supplies of kelp

the primary food source of stellar sea

cow and so with fewer otters about Hydra

da Morris was also facing a shortage of

food the hunting by sailors would

certainly have been the final straw in

their demise though and by the time

anyone had realized that the sea cows

were becoming rarer and rarer it was too

late for them the 1768 extinction date

was given by a German naturalist in the

1800's based on reports of fewer

sightings of the animals and eventual

reports of their absence there are

actually a few claimed sightings of the

species from after 1768 into the 1800s

and even supposedly from the 1900s the

20th century reports are most likely

misinterpreted sightings of other

animals such as elephant seals and would

be impossible to properly verify anyway

the earlier reports though could

possibly imply that the sea cows had

just moved away from land and into

deeper waters by 1768

before then succumbing to the

difficulties brought about by a new

habitat they weren't as suited to

whatever the exact extinction date was

there have not been any confirmed

sightings of hydro domalis for many

years our species undoubtedly has a lot

to learn from the loss of these animals

this was the first time in the modern

history of humanity that we were

responsible for the total extinction of

a marine mammal it would not be the last

time this occurred though hopefully

something like this never has to happen

again it's interesting to consider what

the sailors might have been thinking

about the fewer and fewer sightings of

the sea cows at a time when extinction

was not well understood or even thought

to be possible at all

so I think it's important to know how

close we came to being able to see these

fascinating animals with our own eyes

only for the wastefulness and lack of

understanding of humanity to rob us of

this opportunity these creatures were so

unique really unlike anything else that

lives on this planet right now and it's

truly heartbreaking to think that we've

lost them forever it would be even worse

to think that more unique species of

incredible marine mammals could one day

disappear to and I hope future

generations of humans will not be

looking back on species of whales and

pinnipeds and making videos about how

they wish they could have seen those

recently extinct animals anyway I hope

you enjoyed this video and perhaps now

have a greater appreciation of the need

for effective conservation efforts in

order to avoid any more disasters like

this one if you would like to learn more

about our world its history and the

wonderful wife this surrounds us all

please feel free to subscribe to the

channel if you think we deserve it and

if you would like to see more from us

[Music]

you