Speaker 1: Welcome to the I Can't Sleep Podcast, where I help
Speaker 1: you drift off one fact at a time. I'm your host,
Speaker 1: Benjamin Boster, and today's episode is about otters. Otters are
Speaker 1: carnivorous mammals in the subfamily Lutrini. The fourteen extant otter
Speaker 1: species are all semi aquatic, both freshwater and marine. Lutrinia
Speaker 1: is a branch of the Mostellite family, which includes weasels, badgers, mink,
Speaker 1: and wolverines, among other animals. Otters are distinguished by their long,
Speaker 1: slim bodies, powerful webbed feet for swimming, and their dense fur,
Speaker 1: which keeps him warm and buoyant in water. There are
Speaker 1: playful animals, engaging in activities like sliding into water on
Speaker 1: natural slides and playing with stones. Otters exhibit a varied
Speaker 1: life cycle, with a gestation period of about sixty to
Speaker 1: eighty six days, and offspring typically stay with their family
Speaker 1: for a year. They can live up to sixteen years,
Speaker 1: with their diet mainly consisting of fish and sometimes frogs, birds,
Speaker 1: or shell fish, depending on the species. There are fourteen
Speaker 1: known species of otters, ranging in size and habitat preferences,
Speaker 1: with some species adapted to cold waters, requiring a high
Speaker 1: metabolic rate for warmth. Otters hold a place in various cultures,
Speaker 1: mythology and religion, symbolizing different attributes and stories, from Norse
Speaker 1: mythology to Native American totems and Asian folklore, where they
Speaker 1: are sometimes believed to possess shape shifting abilities. The word
Speaker 1: otter derives from the Old English word odour. This and
Speaker 1: cognate words in other Indo European languages ultimately stem from
Speaker 1: the Proto Indo European word wooder, which also gave rise
Speaker 1: to the English word water. The gestation period in otters
Speaker 1: is about sixty to eighty six days. The new born
Speaker 1: pop is cared for by the female, male and older offspring.
Speaker 1: Females reach sexual mature at approximately two years of age
Speaker 1: and males at approximately three years. The den is built
Speaker 1: under tree roots or a rocky cairn more common in Scotland.
Speaker 1: It is lined with moss and grass. After one month,
Speaker 1: the pup can leave the den and after two months
Speaker 1: sick and swim. The pup lives with its family for
Speaker 1: approximately one year. Otters live up to sixteen years. There By,
Speaker 1: nature playful and frolic in the water with their pups.
Speaker 1: Its usual food is fish and further downriver eels, but
Speaker 1: it may also sample frogs and birds. Otters have long,
Speaker 1: slim bodies and relatively short limbs. Their most striking anatomical
Speaker 1: features are the powerful webbed feet used to swim and
Speaker 1: their seal likabilities for holding breast underwater. Most have sharp
Speaker 1: claws on their feet, and all except the sea otter
Speaker 1: have long, muscular tails. The thirteen species range in adult
Speaker 1: size from ero point six to one point eight meters
Speaker 1: in length and one to forty five kilograms in weight.
Speaker 1: The Asians small clod otter is the smallest otter species,
Speaker 1: and the giant otter and sea otter are the largest.
Speaker 1: They have very soft, insulated underfur, which is protected by
Speaker 1: an outer layer of long guard hairs. This traps a
Speaker 1: layer of air which keeps them dry, warm, and somewhat
Speaker 1: buoyaned underwater. Several otter species live in cold waters and
Speaker 1: have high metabolic rates to help keep them warm. Eurasian
Speaker 1: otters must eat fifteen percent of their body weight each day,
Speaker 1: and see otters twenty to twenty five percent, depending on
Speaker 1: the temperature. In water as warm as ten degrees celsius,
Speaker 1: an otter needs to catch one hundred grams of fish
Speaker 1: per hour to survive. Most species hunt for three to
Speaker 1: five hours each day, and nursing mothers up to eight
Speaker 1: hours each day. For most otters, fish is the staple
Speaker 1: of their diet, is often supplemented by frogs, crayfish, and crabs.
Speaker 1: Some otters are experts at opening shellfish, and others will
Speaker 1: feed on available small mammals or birds. Prey dependence leaves
Speaker 1: otters very vulnerable to prey depletion. Sea otters are hunters
Speaker 1: of clams, sea urchins, and other shelled creatures. They are
Speaker 1: notable for their ability to use stones to break open
Speaker 1: shellfish on their bellies. This skill must be learned by
Speaker 1: the young. Otters are active hunters, chasing prey in the
Speaker 1: water or searching the beds of rivers, lakes, or the seas.
Speaker 1: Most species live beside water, but river otters usually enter
Speaker 1: it only to hunt or travel, otherwise spending much of
Speaker 1: their time on land to prevent their fur becoming waterlogged.
Speaker 1: Sea otters are considerably more aquatic and live in the
Speaker 1: ocean for most of their lives. Otters are playful animals
Speaker 1: and appear to engage in various behaviors for sheer enjoyment,
Speaker 1: such as making water slides and sliding on them into
Speaker 1: the water. They may also find and play with small stones.
Speaker 1: In nineteen ninety an otter was observed belly sliding in Singapore,
Speaker 1: likely as a form of amusement. Different species vary in
Speaker 1: their social structure, some being largely solitary, while others live
Speaker 1: in groups and a few species. These groups may be
Speaker 1: fairly large for many generations. Fishermen in southern Bangladesh have
Speaker 1: bred smooth coated otters and use them to chase fish
Speaker 1: into their nets. Once a widespread practice passed down from
Speaker 1: father to son throughout many communities in Asia. This traditional
Speaker 1: use of domesticated wild animals is still in practice in
Speaker 1: the district of Noreal, Bangladesh. Norse mythology tells of the
Speaker 1: dwarf foder habitually taking the form of an otter. The
Speaker 1: myth of Otter's ransom is the starting point of the
Speaker 1: Volsunga saga. In Irish mythology, the character lie Ban was
Speaker 1: turned from a woman into a mermaid half human and
Speaker 1: half salmon, and given three hundred years of life to
Speaker 1: roam the oceans. Her lap dog assumed the form of
Speaker 1: an otter and shared her prolonged lifetime and her extensive wanderings.
Speaker 1: In some Native American cultures, otters are considered totem animals.
Speaker 1: In popular Korean mythology, it is told that people who
Speaker 1: see and otter will attract rain clouds for the rest
Speaker 1: of their lives. In the Buddhist Chakada tales the Otters
Speaker 1: and the Wolf, two otters agreed to let a wolf
Speaker 1: settle their dispute in dividing their cod fish, but it
Speaker 1: was taken away by the cunning wolf. In Japanese, otters
Speaker 1: are called the Kawauso. In Japanese folklore, they fool humans
Speaker 1: in the same way as foxes and tanuki. In the notoregion,
Speaker 1: Ishikawa Prefecture, there are stories where they shape shift into
Speaker 1: beautiful women or children wearing checker pattern clothing. If a
Speaker 1: human attempts to speak to one, they will answer oarya
Speaker 1: and then answer aarya. If anybody asks them anything, they
Speaker 1: say cryptic things like kawai. The sea otter is a
Speaker 1: marine mammal native to the coasts of the northern and
Speaker 1: eastern North Pacific Ocean. Adult sea otters typically weigh between
Speaker 1: fourteen and forty five kilograms making them the heaviest members
Speaker 1: of the weasel family, but among the smallest marine mammals.
Speaker 1: Unlike most marine mammals, the sea otter's primary form of
Speaker 1: insulation is an exceptionally thick coat of fur, the densest
Speaker 1: in the animal kingdom. Although it can walk on land,
Speaker 1: this sea otter is capable of living exclusively in the ocean.
Speaker 1: The sea yotter inhabits near shore environments, where it dives
Speaker 1: to the seafloor to forage. It preys mostly on marine
Speaker 1: invertebrates such as sea urchins, various mollusks and crustaceans, and
Speaker 1: some species of fish. Its foraging and eating habits are
Speaker 1: noteworthy in several respects. Its use of rocks to discy,
Speaker 1: lodge prey, and to open shells makes it one of
Speaker 1: the few mammal species to use tools in most of
Speaker 1: its range. It is a key stone species, controlling sea
Speaker 1: urchin populations, which would otherwise inflict extensive damage to kelp
Speaker 1: forest ecosystems. Its diet includes prey species that are also
Speaker 1: valued by humans as food, leading to conflicts between sea
Speaker 1: otters and fisheries. The sea otter is the heaviest the
Speaker 1: giant otter is longer but significantly slimmer member of the
Speaker 1: family Mustellity, a diverse group that includes the fourteen otter
Speaker 1: species and terrestrial animals such as weasels, badgers, and minks.
Speaker 1: It is unique among the mustellids and not make dens
Speaker 1: or burrows, and in being able to live its entire
Speaker 1: life without leaving the water. The only living member of
Speaker 1: the genus in hydra, the sea otter is so different
Speaker 1: from other Mustellid species that as recently as nineteen eighty two,
Speaker 1: some scientists believe it was more closely related to the
Speaker 1: earless seals. Genetic analysis syndicates the seaotter in its closest
Speaker 1: sext and relatives, which include the African speckle throated otter,
Speaker 1: Eurasian otter, African clalless otter, and Asian small cloud otter,
Speaker 1: shared an ancestor approximately five million years ago. The sea
Speaker 1: otter is one of the smallest marine mammal species, but
Speaker 1: it is the heaviest mustelid. Male sea otters usually weigh
Speaker 1: twenty two to forty five kilograms and are one point
Speaker 1: two to one point five meters in length. Those specimens
Speaker 1: up to fifty four kilograms have been recorded females are smaller,
Speaker 1: weighing fourteen to thirty three kilograms and measuring one to
Speaker 1: one point four meters in length. The average weight for
Speaker 1: adult sea otters that are in more densely populated areas
Speaker 1: at twenty eight point three kilograms and males and twenty
Speaker 1: one point one kilograms and females, was considerably lighter than
Speaker 1: the average weight of otters and more sparse populations at
Speaker 1: thirty nine point three kilograms in males and twenty five
Speaker 1: point two kilograms and females. Presumably, less populous otters are
Speaker 1: more able to monopoly food sources. Unlike most other marine mammals,
Speaker 1: the sea otter has no blubber and relies on its
Speaker 1: exceptionally thick fur to keep warm. With up to one
Speaker 1: hundred fifty thousand strands of hair per square centimeter, its
Speaker 1: fur is the densest of any animal. The fur consists
Speaker 1: of long, waterproof guard hairs and short underfur. The guard
Speaker 1: hairs keep the dense under fur layer dry. There is
Speaker 1: an air compartment between the thick fur and the skin,
Speaker 1: where air is trapped and heated by the body. Cold
Speaker 1: water is kept completely away from the skin, and heat
Speaker 1: loss is limited. However, a potential disadvantage of this form
Speaker 1: of insulation is compression of the air layer as the
Speaker 1: otter dives, thereby reducing the insulating quality of fur at depths.
Speaker 1: When the animal forages, the fur is thick year round,
Speaker 1: as it is shed and replaced gradually rather than in
Speaker 1: a distinct molting season. As the ability of the guard
Speaker 1: hairs to repel water depends on utmost cleanliness, the sea
Speaker 1: otter has the ability to reach and groom fur on
Speaker 1: any part of its body, taking advantage of its loose
Speaker 1: skin and an unusually supple skeleton. The coloration of the
Speaker 1: pellage is usually deep brown with silver gray speckles, but
Speaker 1: it can range from yellowish or grayish brown to almost
Speaker 1: black in adults. The head, throat, and chest are lighter
Speaker 1: in color than the rest of the body. The sea
Speaker 1: otter displays numerous adaptations to its marine environment. The nostrils
Speaker 1: and small ears can close. The hind feet, which provide
Speaker 1: most of its propulsion in swimming, are long, broadly flattened,
Speaker 1: and fully webbed. The fifth digit on each hind foot
Speaker 1: is longest, facilitating swimming while on its back but making
Speaker 1: walking difficult. The tail is fairly short, thick, slightly flattened,
Speaker 1: and muscular. The front paws are short with retractable claws,
Speaker 1: with tough pads on the palms that enable gripping slippery prey.
Speaker 1: The bones show osteously euroses, increasing their density to reduce buoyancy.
Speaker 1: The sea otter presents an insight into the evolutionary process
Speaker 1: of the mammalian evasion of the aquatic environment, which has
Speaker 1: occurred numerous times over the course of mammalian evolution. Having
Speaker 1: only returned to the sea about three million years ago,
Speaker 1: sea otters represent a snapshot at the earliest point of
Speaker 1: the transition from fur to blubber. In sea otters, fur
Speaker 1: is still advantageous given their small nature and division of
Speaker 1: lifetime between the aquatic and terrestrial environments. However, as sea
Speaker 1: otters evolve and adapt to spending more and more of
Speaker 1: their lifetimes in the sea, the convergent evolution of blubber
Speaker 1: suggests that the reliance on fur for insulation would be
Speaker 1: replaced by a dependency on blubber. This is particularly true
Speaker 1: due to the diving nature of the sea otter. As
Speaker 1: dives become lengthier and deeper, the air layer's ability to
Speaker 1: retain heat or buoyancy decreases, while blubber remains efficient at
Speaker 1: both of those functions. Blubber can also additionally serve as
Speaker 1: an energy source for deep dives, which would most likely
Speaker 1: prove advantageous over fur in the evolutionary future of sea otters.
Speaker 1: The sea otter propels itself under water by moving the
Speaker 1: rear end of its body, including its tail and hind feet,
Speaker 1: up and down, and is capable of speeds of up
Speaker 1: to nine kilometers per hour. When under water, its body
Speaker 1: is long and streamlined, with a short forelimbs pressed closely
Speaker 1: against the chest. When at the surface, it usually floats
Speaker 1: on its back and moves by skulling its feed and
Speaker 1: tail from side to side. At rest, all fore limbs
Speaker 1: can be folded under the torso to conserve heat, whereas
Speaker 1: on particularly hot days the hind feet may be held
Speaker 1: under water for cooling. The sea otter's body is highly
Speaker 1: buoyant because of its large lung capacity about two point
Speaker 1: five times greater than that of similar sized land mammals
Speaker 1: and the air trapped in its fur. The sea otter
Speaker 1: walks with a clumsy rolling gait on land and can
Speaker 1: run in a bounding motion. Long, highly sensitive whiskers and
Speaker 1: front paws help the sea otter find prey by touch
Speaker 1: when waters are dark or murky. Researchers have noted when
Speaker 1: they approach in plain view, sea otters react more rapidly
Speaker 1: when the wind is blowing towards the animals, indicating a
Speaker 1: sense of smell as more important than sight as a
Speaker 1: warning sense. Other observations indicate the sea otter's sense of
Speaker 1: sight is useful above and below the water, although not
Speaker 1: as good as that of seals. Its hearing is neither
Speaker 1: particularly acute nor poor in adults thirty two teas, particularly
Speaker 1: the molars, are flattened and rounded for crushing rather than
Speaker 1: cutting food. Seals and sea lions are the only carnivores
Speaker 1: with two pairs of lower incisor teeth rather than three.
Speaker 1: The adult dental formula is three point one point three
Speaker 1: point one over two point one point three point two.
Speaker 1: The teas and bones are sometimes stained purple as a
Speaker 1: result of ingesting sea urchins. The sea otter has a
Speaker 1: metabolic rate two or three times that of comparatively sized
Speaker 1: terrestro mammals. It must eat an estimated twenty five to
Speaker 1: thirty eight percent of its own body weight and food
Speaker 1: each day to burn the calories necessary to counteract the
Speaker 1: loss of heat due to the cold water environment. Its
Speaker 1: digestive efficiency is estimated at eighty to eighty five percent,
Speaker 1: and food is digested and past in as little as
Speaker 1: three hours. Most of its need for water is met
Speaker 1: through food, although in contrast to most other marine mammals,
Speaker 1: it also drinks seawater. Its relatively large kidneys enable it
Speaker 1: to derive fresh water from seawater and excrete concentrated urine.
Speaker 1: The sea otter is diurnal. It is a period of
Speaker 1: foraging and eating in the morning, starting about an hour
Speaker 1: before sunrise, then rests or sleeps in midday. Foraging resumes
Speaker 1: for a few hours in the afternoon and subsides before sunset,
Speaker 1: and a third foraging period may occur around midnight. Females
Speaker 1: with pups appear to be more inclined and defeate at nine.
Speaker 1: Observations of the amount of time a sea yachtter must
Speaker 1: spend each day foraging range from twenty four percent to
Speaker 1: sixty percent, apparently depending on the availability of food in
Speaker 1: the area. Sea otters spend much of their time grooming,
Speaker 1: which consists of cleaning the fur, untangling, knots, removing loose fur,
Speaker 1: rubbing the fur to squeeze out water and introduce air,
Speaker 1: and blowing air into the fur. To casual observers, it
Speaker 1: appears as if the animals are scratching, but they are
Speaker 1: not known to have rice or other parasites in the fur.
Speaker 1: When eating, sea oatters roll in the water frequently, apparently
Speaker 1: to wash food scraps from their fur. The sea otter
Speaker 1: hunts in short dives, often to the sea floor. Although
Speaker 1: it can hold its breath for up to five minutes,
Speaker 1: its dives typically last about one minute and not more
Speaker 1: than four minutes. It is the only marine animal capable
Speaker 1: of lifting and turning over rocks, which it often does
Speaker 1: with its front paws when searching for prey. The sea
Speaker 1: otter may also pluck snails and other organisms from kelp
Speaker 1: and dig deep into underwater mud for clams. It is
Speaker 1: the only marine mammal that catches fish with its fore
Speaker 1: paws rather than with its teeth. Under each fore leg,
Speaker 1: the sea otter has a loose pouch of skin that
Speaker 1: extends across the chest. In this pouch, the animal stores
Speaker 1: collected food to bring to the surface, and sometimes a
Speaker 1: rock that is used to break open shellfish and clams
Speaker 1: at the surface. The sea otter eats while floating on
Speaker 1: its back, using its fore paws to tear food apart
Speaker 1: and bring it to its mouth. It can chew and
Speaker 1: swallow small muscles with their shells, whereas large muscle shells
Speaker 1: may be twisted apart. It uses its lower incisor teeth
Speaker 1: to access the meat and shellfish. Although each adult and
Speaker 1: independent juvenile forages alone, sea otters tend to rest together
Speaker 1: in single sex groups called rafts. A raft typically contains
Speaker 1: ten to one hundred animals, with male rafts being larger
Speaker 1: than female ones. The largest raft ever seen contain over
Speaker 1: two thousand otters. To keep themselves from drifting out to sea.
Speaker 1: When resting and eating, sea otters may wrap themselves in kelp.
Speaker 1: The species exhibits a variety of vocal behaviors. The cry
Speaker 1: of a pup is often compared to that of a goal.
Speaker 1: Females coup when they are apparently content, Males may grunt instead.
Speaker 1: Sea otters in captivity have been observed forming sibling like
Speaker 1: bonds with each other. Two females at the shed aquarium,
Speaker 1: Kiana and Kyukos, maintained a big sister little sister relationship
Speaker 1: with the younger Kayukos following around the older Kiana and
Speaker 1: mimicking her playful interactions with her Richmond toys. Formal assessment
Speaker 1: of social network formation and maintenance among sea otters has
Speaker 1: not been performed, largely because researchers had simply assumed that
Speaker 1: rafts were composed of randomly assembled collections of individuals that
Speaker 1: aggregated after solitary foraging. However, according to UC Santa Cruz
Speaker 1: professor Tim Tinker, preliminary analysis of long term spatial associations
Speaker 1: between tagged sea otters and Monterey Bay indicates that several
Speaker 1: distinct clusters occur within the large aggregations. Some individuals also
Speaker 1: show consistent associations over many years. As a result, formal
Speaker 1: network analysis for sea otters may reveal important information on
Speaker 1: the species in its social structures. Sea yotters have demonstrated
Speaker 1: the capacity for social learning, with knowledge passed down both
Speaker 1: vertically from mom to pop and horizontally within groups, although
Speaker 1: whether or not they display a full fledged culture remains
Speaker 1: unknown and under researched. Sea otters live in coastal waters
Speaker 1: fifteen to twenty three meters deep and usually stay within
Speaker 1: a kilometer of the shore. They are found most often
Speaker 1: in areas with protection from the most severe ocean winds,
Speaker 1: such as rocky coastlines, sik kelp forests, and barrier reefs.
Speaker 1: Although they are most strongly associated with rocky substrates, sea
Speaker 1: otters can also live in areas where the seafloor consists
Speaker 1: primarily of mud, sand, or silt. Their northern range is
Speaker 1: limited by ice, as sea otters can survive amidst drift ice,
Speaker 1: but not land fast ice. Individuals generally occupy a home
Speaker 1: range a few kilometers long and remain there year round.