Seal Species Diversity & Adaptations: A Closer Look
Disclosure: Some links may be affiliate links. If you buy an item via links on our site, we may earn a commission. Learn more.
Beneath the waves of our oceans, seals are more than just common marine inhabitants. Their exceptional hunting abilities and unique breeding habits make them truly fascinating creatures.
Seals, widely distributed across our planet’s oceans, have honed their abilities to match their distinct environments. From the icy seas inhabited by leopard seals in Antarctica to the coastal havens of harbor seals in the Northern Hemisphere, this article will explore the diverse and extraordinary world of seals.
Seal Overview
Seals are a group of marine mammals classified under the order Carnivora. There are various seal species, with approximately 32 recognized types, divided into two main families: Phocidae (true seals) and Otariidae (eared seals, including sea lions and fur seals). These animals are believed to have evolved from terrestrial carnivorous ancestors.
With streamlined bodies, flippers, a layer of blubber, and several other adaptations, seals are easily able to cope with the conditions of their marine environment. They’re often found in colder waters but are common in temperate and tropical waters from the Antarctic all the way up to the Arctic.
Being almost at the top of the food chain (some species are even apex predators), seals play an essential role in maintaining the balance of the food web within their ecosystems. Their diet varies between species but may consist of fish, krill, squid, and other marine life. To access their food, seals often have to go well below the ocean’s surface with some species, like the elephant seal, diving to depths of up to 5,000 feet (1,524 meters)! Their long whiskers allow them to detect prey in the water. However, many species are also predated by larger animals like orcas and polar bears.
In terms of breeding, seals are again perfectly adapted to their surroundings, with some species even delaying implantation to ensure that pups are born when conditions will be optimal. This is important as seal pups are born quite underdeveloped, so females must provide excellent care and feed their young on nutrient-rich milk. Usually, mothers will give birth to a single pup, either on land or on the ice, and seals can live in colonies, called pods, of up to several hundred individuals. Once fully developed, a healthy seal could live up to 35 years in the wild.
Seals are very intelligent and will use a range of vocalizations that allow them to communicate. This can include a hissing or snorting sound to tell another seal that they are a threat or sheep-like sounds made by pups to communicate distress to their mothers. Other vocalizations like low-frequency clicks, haunting songs, and barks have earned seals the nickname the dogs of the sea.
Seal Adaptations
Living in a marine environment can be challenging but fortunately, seals are perfectly adapted to their habitat.
Streamlined Body Shape
Seals often need to dive deep into the ocean to find food, and their streamlined bodies make for minimal resistance when moving through the water. Moreover, this shape ensures that the seal uses as little energy as possible. This makes them very efficient swimmers and allows them to move at impressive speeds of up to 22 mph (35 km/h)!
What’s more, having a streamlined body means greater agility, allowing seals to successfully chase their prey but also giving them an advantage when trying to escape predators.
Blubber Insulation
While found globally, seals tend to prefer colder waters, and they’re able to withstand low temperatures thanks to a special layer of fat known as blubber. This isn’t a trait that’s exclusive to seals, with many animals, like whales, also being equipped with this adaptation. Blubber sits just below the skin and serves as insulation so that the seal is able to maintain a healthy body temperature even in extreme cold.
In addition to blubber, seals are also equipped with a highly specialized vascular system that’s designed to further minimize heat loss. This works as warm blood flows through the arteries while cooler blood flows through the veins. These structures run alongside one another and so ensure a consistent and stable body temperature in a process known as countercurrent heat exchange. This is also useful in reproduction as it helps to keep the reproductive organs cool as well as ensuring a regulated temperature of the fetus.
What’s more, when food is scarce, this blubber holds onto a lot of excess energy, keeping the seal alive. And if that wasn’t enough, their blubber also makes seals more buoyant when hunting so they can control their ascent and descent in the water more efficiently.
The thickness of seal blubber changes with age and can also be affected by the health of an individual. However, in pups, it plays a very important role in temperature regulation for young seals that are not able to do this as efficiently as a mature individual.
During a period of molting, seals will often get itchy and can be seen rolling around trying to scratch. Interestingly, this itchiness goes right down to the blubber and individuals may be observed using their flippers to scratch their blubber.
Flippers for Propulsion
Seals, having evolved from otters, would have once had arm-like limbs, but these have evolved into flippers which aid them not only in swimming but also steering under the water. This is thanks to incredibly strong muscles within the flippers, over which, the seal has perfect control.
Typically, seals have four flippers, two lateral flippers at the front and two at the tail. The rear flippers are used for steering while the front are used to propel the animal in the water. Should the seal get too warm in the water, it can hold one flipper above the surface and the wind evaporates the water, cooling the seal down.
When on land or on the ice, the flippers are equipped with retractable claws, allowing the seal to have more traction as it moves around. While the rear flippers are usually kept off the ground, the front flippers are used to help propel the seal forward, although this movement can look clumsy.
Adapted Respiratory System
Many seal species are able to dive thousands of feet below the water’s surface in search of food, but this means that they need to be able to hold their breath for a long time. In some cases, seals can remain under the water for up to an hour, and this is thanks to their highly specialized respiratory systems.
Before heading under the water, a seal will release around half of the air in its lungs and then shut off its nostrils. While submerged, their adapted lungs have alveoli that are able to completely collapse during a deeper dive. Afterwards, the seal can simply inflate them! On top of this, their airways are reinforced with cartilage and strong, smooth muscles.
Since seals cannot store excess oxygen in their lungs when diving, it’s stored in their bloodstream. The oxygen here is sent to the vital organs as the blood vessels constrict to direct it. Plus, they’re able to tolerate higher levels of carbon dioxide in their blood, which allows them to remain submerged for longer. The recovery time for a 10 minute dive is pretty quick, but the longer the seal stays under the water, the longer it will need to recover.
Sensory Adaptations
Survival isn’t just about getting food, it also relies on effective communication and navigation of the environment. Seals have many sensory adaptations that allow for this.
For example, they have incredibly sensitive whiskers which allow them to pick up on small vibrations in the water when hunting, meaning they’re better able to locate prey in low light. That said, these animals have very good vision which allows them to see under the water, even when they’re hunting at night. This is thanks to a spherical lens and specially strengthened cornea. However, while these adaptations are great in the water, the seal isn’t so easily able to see on land.
These adaptations are coupled with amazing hearing so, they’re not only able to feel prey under the water but also hear it. Of course, this hearing also ensures effective communication between seals when using their vocalizations.
Seals also have an acute sense of smell, which allows them to pick up on odors and chemical cues when hunting in the water.
True Seals (Phocidae Family)
Seals within the Phocidae family are commonly known as true seals and can be identified by their lack of a visible ear flap. What’s more, unlike other seal types, they are not able to rotate their rear flippers and have a much more streamlined body.
This means that they are able to dive deep down under the water to hunt and are known for their ability to hold their breath for extended periods. This is thanks to adaptations like the ability to hold air in the upper airways when diving, as well as blood vessels in the inner ear to stabilize pressure.
There are 19 known species of true seals; let’s take a closer look at them.
1. Common/Harbor Seal (Phoca vitulina)
The common seal, sometimes called the harbor seal, can be recognized by its distinct markings and spots. Each individual has its own unique pattern and may be gray, brown, white, or tan in color. Individuals can grow up to 6.1 feet (1.9 meters) and weigh up to 370 lbs (168 kg), living up to 25 years, although females may live up to a decade longer than this.
While they do hunt in the water, common seals spend a lot of time on land in the northern parts of the Pacific and Atlantic Oceans. Their range is so wide that they’re considered to have the widest distribution of all true seals. On land, they engage in a behavior known as hauling out, which can be done for things like rest or even reproduction, which typically happens on sandbanks and rocky shorelines.
It’s thought that there are as many as half a million common seals in the wild, and they’re very adept hunters able to make aerobic underwater movements thanks to special adaptations to their metabolism. When hunting, they usually go after crustaceans and fish.
2. Gray Seal (Halichoerus grypus)
The gray seal is found in three populations around the North Atlantic Ocean, where it lives either as a solitary animal or in small groups, led by a dominant male.
When they’re born, gray seal pups have thick white fur, which is shed after around three weeks and they’re surprisingly large, weighing up to 77 lbs (35 kg). They quickly develop a thick layer of blubber, aided by their mother’s nutrient-rich milk. After this, individuals start to develop a unique gray pattern, with males being darker than females.
In some areas, like the Baltic Sea, gray seals are at the top of the food chain but in other areas, they may be predated by some shark species and orcas. These seals feed on a diet of lobsters, octopus, and fish and may eat up to 11 lbs (5 kg) per day. When hunting, they’re able to dive to an impressive 980 feet (299 meters) and remain underwater for up to 45 minutes.
3. Ringed Seal (Pusa hispida)
In the Arctic regions, the ringed seal is the most common pinniped and is considered a keystone species thanks to its role in maintaining the food web. Compared to many seal species, the ring seal is quite small, usually measuring up to 4.9 feet (1.5 meters in length). Still, they can live up to 45 years in the wild!
There are five subspecies of ringed seal but each is named because of the ring-shaped markings that appear when the seal reaches adulthood. These markings serve as camouflage to protect them from predation by polar bears.
Ringed seals typically feed on fish and are known to dive to around 150 feet (46 meters) when hunting; relatively shallow compared to other species. When under the water the animal needs to surface for air, but this can be difficult in winter when the ice cover is greater. As a result, ringed seals will use their claws to make air holes in the ice. They may even build a snow lair over these air holes, which offers protection from predators and a place to give birth to their single pup in spring.
As a result of climate change, sea ice availability is reduced, which can affect the breeding potential of the ringed seal. For this reason, some subspecies are known to migrate to areas where sea ice cover is more than 90%.
4. Harp Seal (Pagophilus groenlandicus)
The harp seal is maybe one of the most well-known seal types because of the instantly recognizable white fur of young pups. However, this is just one of three life stages which also include a silvercoat pup, which then transitions into an adult silver coat. At this stage, harp seals have markings that, you guessed it, resemble a harp shape, which is where the seal gets its name.
Harp seals mature very quickly, and that’s largely because mothers will often abandon their pups within a few days in favor of further mating. It’s at this point that the weaned pup loses its initial coat and enters the beater stage, which is named in reference to how the seal starts beating its tail to learn to swim. However, they don’t become self-sufficient for around four weeks, making them vulnerable to predation.
Another interesting thing about the harp seal is that it is one of the few pinnipeds to migrate between feeding, breeding, and molting grounds. However, with climate change impacting the availability of sea ice, this has had a profound effect on them. Still, they’re listed as being of least concern on the IUCN Red List, with around 4.5 million individuals in the wild.
5. Hooded Seal (Cystophora cristata)
The hooded seal is found in the western and central parts of the north Atlantic and is one of the most distinct-looking seals with an inflatable appendage on the nose. Males are able to inflate this so greatly that it covers half of their face and is used in courtship displays.
Male hooded seals are much larger than their female counterparts and can grow to 900 lbs (408 kg). In terms of coloration, these seals have a silvery colored body with dark markings and a uniform dark colored head.
Hooded seals are carnivores that feed on fish like herring, cod, and flounder. In order to access their prey, they’ll dive up to 3,280 feet (1,000 meters) below the surface, where they can remain for up to 16 minutes.
Females give birth to a single pup, which is largely underdeveloped. However, the nutrient-rich fatty milk they feed on over the first 12 days of life means they’re ready to take care of themselves after abandonment from their mothers. While they can live for up to 35 years in the wild, human hunting has been problematic leading to the hooded seal being listed as vulnerable.
6. Leopard Seal (Hydrurga leptonyx)
The leopard seal is so named because of its black spotted coat, as well as being one of the top predators within its ecosystem, only being predated by orcas. These seals not only feed on fish but also penguins and even other seals.
They’re found in the Antarctic where they’re the largest type of seal, growing up to 1,200 lbs (544 kg), with females being slightly smaller. Despite their huge size, leopard seals are incredibly agile when it comes to hunting and have sharp teeth that kill their prey.
These seals are thought to live for around 30 years in the wild, but not much is known about their breeding behavior as they live in such remote locations. However, while they’re currently listed as being of least concern, there is worry that the melting sea ice could negatively impact their numbers. Fortunately, there are several conservation efforts in Antarctica that aim to protect the species under the Conservation Of Antarctic Seals 1972 act.
7. Bearded Seal (Erignathus barbatus)
Sometimes called the square flipper seal, this species is found in the Arctic in shallow waters with lots of ice floes where the seals can haul out. Despite living in shallower areas, the bearded seal is able to dive up to 1,600 feet (488 meters)! However, typically, they stay between 300 and 600 feet (91 and 183 meters) when hunting for crustaceans and mollusks as well as cod.
Adult bearded seals grow to around 7.5 feet (2.3 meters) in length, which is only double the size they are when they’re born. They take their name from the thick bristly hairs around the muzzle that give it the appearance of having a beard. Their fur is dark gray to brown, and the face tends to have a more rusty color.
Bearded seals, like other seals, go through a seasonal molt, which is incredibly important in ensuring efficient buoyancy and insulation in the cold waters. This typically happens when resting on the sea ice, but they’ll always have their heads pointed down into the water in case they need to make a quick getaway from predators like polar bears.
8. Southern Elephant Seal (Mirounga leonina)
With a name like elephant seal, you won’t be surprised to learn that this is the largest seal species, growing up to 20 feet (6 meters) and weighing as much as 8,800 lbs (3,992 kg)! While the females tend to be smaller, they lack the prominent inflatable snout that distinguishes the males. These males employ this unique feature to produce load roars when competing for a mate.
The southern elephant seal is found in various locations in the southern hemisphere, such as off the coasts of South Africa and South America as well as Antarctica, and the Australian coast. They spend a lot of time in the water, diving up depths of up to 5,000 feet (1,524 meters) in search of squid and fish. However, they can be seen on the beach for resting and breeding and are even known to travel thousands of miles between feeding and breeding grounds.
While this species is predated by orcas, sharks, and sometimes leopard seals, they have strong teeth that they use to defend themselves. Furthermore, numbers are healthy, and the Southern elephant seal is listed as being of least concern.
9. Caspian Seal (Pusa caspica)
There is only one type of seal found in the Caspian Sea, and it’s aptly named the Caspian Seal. However, there are very few Caspian seals in the wild; as few as 68,000, so they are listed as endangered. This is largely because of their limited range but also because of other threats like a loss of prey as a result of commercial fishing.
Caspian seals are a small species that typically only weighs up to 190 lbs (86 kg) at adulthood. They’re predated by eagles and wolves, but have the potential to live as long as 50 years in the wild. You can recognize a Caspian seal from its gray to dark fur with a lighter belly. However, this coloration doesn’t occur until later in life, as pups are born covered in white lanugo.
While the Caspian seal is adapted to be exposed to varying air temperatures, climate change does threaten the species with reduced water levels. This is why it’s incredibly important that the Caspian seal habitat is protected. Unfortunately, at this time, no such protected areas exist.
10. Ribbon Seal (Histriophoca fasciata)
The ribbon seal is certainly one of the most unique-looking pinnipeds with its dark black skin and white ringed markings around the neck, tail, and sides of the body. Found in the subarctic regions of the Pacific Ocean, this seal has one of the most limited ranges and is therefore one of the lesser-studied species.
Sadly, the number of ribbon seals is unknown but in 1979, researchers estimated there to be anywhere between 450,000 and 500,000 individuals in the wild. The species is protected in the United States and in Russia, commercial hunting has been outlawed.
Ribbon seals feed on a diet of fish as well as cephalopods and will dive up to 656 feet (200 meters) in search of food. After mating, this species experiences delayed implantation for up to four months, allowing the female to time the birth in accordance to sea ice levels where her pup will be born.
11. Baikal Seal (Pusa sibirica)
In eastern Siberia, we find Lake Baikal which is the oldest and deepest lake on the planet. It’s home to just one seal species, the Baikal seal and while numbers are thought to only be around 100,000, this is to the capacity of the area so populations are considered to be healthy.
Despite their thriving communities, Baikal seals are protected as the area is a UNESCO World Heritage Site. What’s more, the Baikal seal is the top predator in its ecosystem, feeding on fish at depths of up to 591 feet (180 meters). Typically, this species hunts at night and, as a top predator, it’s responsible for maintaining the balance of this unique ecosystem.
Lake Baikal is a freshwater body of water, and the Baikal seal is the only type of freshwater pinniped. It’s not entirely known how the species got here but since it’s related to the Caspian seal, it’s thought that it could have stemmed from the Caspian Sea or even the Arctic when the areas were connected by rivers. It’s a small species, weighing up to 154 lbs (70 kg) and measuring just 4.6 feet (1.4 meters).
12. Weddell Seal (Leptonychotes weddellii)
The weddell seal is found all around Antarctica and is named after James Weddell, a British sealing captain, who discovered it back in the 1800s. Sadly, at this time, these seals were heavily hunted but today, numbers are healthy thanks to various protective measures, including the Antarctic Treaty.
Weddell seals live to around 30 years in the wild and will usually return to the same icy breeding grounds every year. They can be seen in large numbers and, in winter, often remain in the water to stay out of the blizzards. It’s a good job that they have more than 2 inches (5 cm) of blubber to keep them warm.
While in the water, weddell seals can dive up to 2,000 feet (610 meters) in search of fish, squid, prawns, and octopus. Adults are known to eat as much as 22 lbs (10 kg) of food every day and can weigh up to 1,320 lbs (599 kg).
13. Ross Seal (Ommatophoca rossii)
The ross seal is a type of Lobodontini seal which is found in the Antarctic. They’re often found in some of the most remote icy areas of this continent and are specially adapted to the conditions here, being able to dive up to 2,000 feet (610 meters) in search of food.
Unlike many other seal species, the ross seal is more solitary and only between 3 and 9 percent of sightings are pairs. That said, they do use a range of vocalizations for communication, which may include for courtship. However, since this is such a remote species, there’s still a lot to understand about their breeding habits.
Ross seals are the smallest Antarctic seal, weighing a maximum of 440 lbs (200 kg). They are dark brown in color with a lighter underside, dotted with dark markings. These seals are also known to have the shortest whiskers of any pinniped.
14. Spotted Seal (Phoca largha)
Spotted seals are so named because of their spotted markings, although these don’t develop until adulthood. Pups are born with a white coat in spring. Where mating is concerned, courtship and copulation take place in the water. Afterwards, mating pairs will join with two or three other pairs to form a small group.
The spotted seal is found in the north Pacific, particularly around Asian coastlines and live both on sea ice and on the shore, especially in autumn. Numbers are currently unknown, and the spotted seal is listed as data deficient on the IUCN Red List. Although conservation concerns include a reduction of sea ice and prey availability.
This species is known to migrate between breeding and feeding grounds and can travel more than 2,000 miles (3,219 km) during the course of each migration.
15. Mediterranean Monk Seal (Monachus monachus)
The Mediterranean monk seal is one of the rarest marine mammals on the planet and is only found in the Mediterranean Sea as well as small parts of the Atlantic, such as off the coast of Madeira and the Canary Islands. It’s thought that there are as few as 700 individuals left in the wild, and this number could decline further as they’re often killed by fishermen who see them as competition.
You’ll find Mediterranean monk seals, who are so-called because of their shy nature, in rocky caves and other inaccessible coastal habitats where they rest and raise their young. Females will tend to their pups in these caves for up to 6 weeks, and individuals can live for as long as 30 years.
These seals have a dark coloration with lighter skin on the belly, and the pups are born with a white coat, which they lose at around 4 to 6 weeks of age.
16. Northern Elephant Seal (Mirounga angustirostris)
Like the southern elephant seal, its northern cousin is a large species that can grow up to 5,500 lbs (2,495 kg) and measure up to 11.8 feet (3.6 meters). These huge seals can be found from the Gulf of Alaska down to Baja in the northern Pacific Ocean, where they spend some of their time on rocky or sandy shores.
However, like all seals, they hunt in the water, where they spend 90% of their time looking for squid and fish. Amazingly, the northern elephant seal can spend months at a time in the water looking for food, diving up to 2,500 feet (762 meters).
There was a time that it was believed the northern elephant seal had been hunted to extinction. However, while hunting them for their blubber to use as oil in the 19th century was popular, it fortunately didn’t kill off the species, which is now listed as being of least concern.
17. Hawaiian Monk Seal (Neomonachus schauinslandi)
Hawaii is a place steeped in legend and myth, and the monk seal is an important part of its culture. Locals believe that these seals are responsible for looking after human souls when we die and are also respected for their grace and intelligence.
Hawaiian monk seals are, however, sadly listed as critically endangered, and it’s thought that there are as few as 632 of this endemic species left in the wild.
Characteristics of the Hawaiian monk seal include the black lanugo that pups are born with. Once they’re weaned, they lose this hair and take on a gray appearance, which eventually becomes brown when they reach adulthood. A small species, the monk seal typically weighs no more than 400 lbs (181 kg).
18. Crabeater Seal (Lobodon carcinophaga)
While its name might suggest a diet of crabs, the crabeater seal actually feeds on krill, and there’s no evidence at all to suggest they ever eat crabs. This species is found around the coasts of Antarctica as well as pack ice and is a relatively large seal, growing to around 8.2 feet (2.5 meters) at maximum.
Crabeater seals have brown to silver fur, but the hair around their flippers tends to be darker. They have a series of chocolate brown markings around the shoulders, but these disappear as the seal reaches adulthood.
The crabeater seal is one of the most abundant seal species on the planet. While exact numbers are not known, it’s thought that there could be as many as 75 million in the wild! Fortunately, because of its remote location, there aren’t any major conservation threats to the species at this time.
19. Saimaa Ringed Seal (Pusa hispida saimensis)
The Saimaa ringed seal, a subspecies of the ringed seal (Pusa hispida), holds a unique status as one of the world’s rarest and most geographically restricted seal species. It is endemic to Lake Saimaa, situated in southeastern Finland and it is classified as critically endangered by the IUCN.
The Saimaa ringed seal is a small-sized seal with a coat that varies in color, ranging from grayish-brown to dark gray, adorned with light spots or rings on its back. Adults typically measure about 2.8-5.2 feet (85-160 cm) in length and weigh around 110-200 lbs (50-90 kg).
It primarily feeds on a variety of fish species, such as vendace, whitefish, and perch, all of which inhabit Lake Saimaa. In the winter, when the lake freezes over, these resourceful seals use their claws to carve breathing holes in the ice, allowing them to access the water beneath and continue their hunt for fish.
Eared Seals (Otariidae Family)
The second family of seals is the Otariidaee family which is made up of 16 extant species, including various sea lions. Unlike true seals, these species have visible ear flaps and are able to rotate their rear flippers, meaning they’re much more agile and mobile on land. They also have larger and more robust bodies.
Seals from this family are typically found around the coast, where they can be seen hauling out on rocky shores and beaches but will also head onto the ice to rest and breed.
1. Northern Fur Seal (Callorhinus ursinus)
The Northern fur seal is found throughout the northern Pacific Ocean, as well as in areas like the Sea of Japan. However, after being historically hunted for their fur and often the bycatch of fisheries, their numbers have begun to decline, resulting in them being listed as vulnerable on the IUCN Red List.
Northern fur seals come in a range of colors from yellow/brown to very dark and this is affected by their age. Fur is dense, and this species has a very stocky build. Males and females are incredibly different, with males being as much as 40% larger and having a distinct mane. Males will mate with several females in a breeding season and could be dominant over as many as 100 females within the territory.
Northern fur seals feed on a diet of fish and cephalopods and can live as long as 26 years in the wild. Historically, they were not only hunted for their fur but also as a food source for Alaskan and Asian people.
2. Juan Fernández Fur Seal (Arctocephalus philippii)
Found off the Pacific coast of South America on the Juan Fernández Islands, after which the species was named, these seals are one of the rarer types and are sadly listed as near threatened by the IUCN. However, in the 17th century, there were millions of individuals, but exploitation has decreased their numbers significantly to around 12,000.
Juan Fernández fur seals are often seen hauling out in rocky areas but will forage as far as 300 miles (483 km) from the coast, where they look for lanternfish and squid. This is a small species that measures around 4.6 feet (1.4 meters) in length and that has a long slender body covered in dark fur. Males have a long mane with frosted tips.
3. Australian Sea Lion (Neophoca cinerea)
Endemic to the coasts of Australia, the Australian sea lion is sadly listed as near threatened, with an estimated 10,000 individuals remaining in the wild.
This species feeds on an array of marine life and is described as being an opportunistic hunter. They have a stocky body with short flippers, and males tend to be much darker than the females, who have a more silvery coloration.
Found mainly around the southern portion of Australia and some of the surrounding islands, these sea lions can often be seen in isolated bays where they will breed. They don’t tend to migrate, and tagged individuals have only ever been seen a maximum of 186 miles (300 km) from their place of birth.
4. South American Fur Seal (Arctocephalus australis)
The South American fur seal is found in Uruguay, Chile, Peru, and Argentina, where it inhabits rocky shorelines. However, there are small populations also found on the Falkland Islands.
In years gone by, these seals were hunted by humans, although this is no longer the case, and it’s believed there are around 250,000 individuals in the wild, meaning they are of Least Concern in terms of conservation.
South American fur seals are usually dark gray to brown in color with a furry body, growing up to 4.9 feet (1.5 meters) in length. However, males can be slightly bigger. The size of the seal can also be affected by the environment, with those in Uruguay being much bigger than the Peruvian population.
Between October and December, males can be seen competing for females, and each will mate with several females who then go on to give birth to a single live pup, which could take up to 3 years to wean.
5. Guadalupe Fur Seal (Arctocephalus townsendi)
The Guadalupe fur seal is found along the coastline of Guadalupe Island, although individuals have been spotted as far away as the Channel Islands in California. They prefer a rocky habitat where they will pup and rest but hunt in the water up to a depth of just 56 feet (17 meters); that’s pretty shallow compared to other seal species.
Under the water, these seals are only able to hold their breath for two and a half minutes and during this time will hunt for various fish species as well as squid. They’re considered an important marine predator within their environment.
Guadalupe fur seals are listed as near threatened and at one point, in the 1980s, there were as few as 7 left in the wild. However, numbers are rising on an annual basis, but they face unique threats from military activities, oil spills, and ocean noise.
6. California Sea Lion (Zalophus californianus)
California sea lions are one of the most interactive types of seal and can often be seen around the city coasts as well as in marine shows. They’re native to the Californian and Mexican coastlines, but there are some individuals that inhabit the rivers leading up to the coast.
The differences between males and females are enormous especially in terms of size. The average female might only weigh 220 lbs (100 kg), while her male counterpart could be as large as 1,153 lbs (523 kg). What’s more, females tend to be much lighter in color than the males.
These sea lions feed on a diet of fish and cephalopods and will hunt either in small groups or alone. However, they may hunt in larger groups where there is an abundance of prey. They can dive to around 899 feet (274 meters) when looking for food.
7. Galápagos Fur Seal (Arctocephalus galapagoensis)
As its name suggests, the Galápagos fur seal inhabits the Galápagos Islands and the surrounding waters, where they enjoy diving for fish and cephalopods to a depth of around 98 feet (30 meters). Since the climate here varies considerably over the course of the year, these seals can often be seen taking shelter from the heat in rocky areas around the coast in summer.
Males can grow to around 140 lbs (64 kg) and are roughly double the size of the females. These beautiful seals are a unique attraction of the Galápagos Islands and, as such, contribute to the economy through tourism. Wildlife here attracts more than 270,000 visitors each year.
When hunting, these fur seals have large eyes, which allow them to see in the dark. Most of the time, prey is abundant but during an El Niño year, it becomes more scarce, and most pups will die as the adults prioritize their own needs. They’re predated by sharks and sometimes orcas and because of their predator and prey roles, they’re very important to the ecosystem.
8. Galápagos Sea Lion (Zalophus wollebaeki)
Endemic to the Galápagos Islands, the Galápagos sea lion is often confused with the Galápagos seal. They can be seen on all of the islands where they’re regularly spotted sunbathing on rocky coasts and are considered to be a very social species.
These sea lions exhibit a dark coloration with lighter patches around their eyes. While they can reach weights of up to 880 lbs (399 kg), males generally outsize their female counterparts. The breeding season, spanning from May to January, witnesses mothers providing extremely attentive care to their pups, further underscoring the species’ highly social nature.
Galápagos sea lions feed on fish, squid, and crustaceans and tend to stay in shallower waters when foraging. In the wild, individuals can live for an average of 20 years, although with numbers of around 50,000 in the wild, the species is considered to be endangered.
9. New Zealand Sea Lion (Arctocephalus forsteri)
An endangered species, it’s thought that there are around 100,000 New Zealand sea lions left in the wild. However, as of 1972, the species was given national protection, although trawling nets are still responsible for the death of thousands of individuals.
As their name suggests, this species is found around the coasts of New Zealand and has its primary breeding grounds on the South Island. They enjoy rocky coastlines and offshore islands and can sometimes be seen cooling off in the rockpools on the beach.
New Zealand sea lions have a pointed nose and long whiskers and can be characterized by their two layered fur that changes in color from dark on the sides to a much lighter gray on the underside. They feed on various marine life, including birds depending on what’s available and can live for around 23 years in the wild.
10. Steller Sea Lion (Eumetopias jubatus)
Listed as near threatened on the IUCN Red List, the steller sea lion populations could be as low as 81,000. This species is found in the cold waters of the North Pacific Ocean, where it can be found opportunistically hunting in the shallows for various species of fish. However, during the summer, these sea lions are known to move slightly further south.
Steller sea lions are much lighter in color than other sea lions but grow to around the same size. Males are slightly longer than females and can weigh up to 1,120 lbs (508 kg).
The steller sea lion is typically a nocturnal hunter but is also predated by things like sharks and orcas. However, they’re incredibly fast swimmers, moving 1.4 times their body length in just one second!
11. Subantarctic Fur Seal (Arctocephalus tropicalis)
The subantarctic fur seals typically breed on the islands off the coast of Antarctica, but several individuals have been found as far north as South Africa and South America. This species enjoys a rocky coastal habitat, but interestingly, the males do not return until after winter, spending the entire season out at sea.
Subantarctic fur seals grow to around 4.6 feet (1.4 meters) in length so are considered to be a mid-sized species. They have dark coats with a slightly lighter underbelly, but when they are born, they have a completely black coat. Pups feed on their mothers incredibly fatty milk (around 39% fat) for the first 11 weeks of life before heading towards adulthood when they hunt at night for fish close to the surface.
At the time of writing, there are more than 310,000 individuals in the wild and while the species if listed as being of least concern, a loss of genetic diversity as a result of dwindling numbers in the previous century, could put them at risk.
12. Antarctic Fur Seal (Arctocephalus gazella)
As is sadly the case with many fur seals, the Antarctic fur seal was heavily hunted in the 19th century, which drastically reduced its numbers. Today, their numbers have rapidly grown, and it’s thought that there could be as many as 4 million in the wild.
This species spends most of its time out at sea, where it hunts for fish, krill, crustaceans, and cephalopods. However, it is at risk of predation by things like leopard seals, which prey heavily on the pups during breeding season between January and March.
Antarctic fur seals are a medium sized species with dark fur and are known for their ability to remain submerged for up to 10 minutes at a time, diving to depths of 820 feet (250 meters).
13. South American Sea Lion (Otaria flavescens)
The South American sea lion is found along the Pacific coasts of South America from Rio right down to the tip of the continent. They frequent sandy or rocky habitats and, between August and December, males become very territorial, putting on impressive courtship displays that include loud vocalizations and biting, among other things.
The females will stop eating when it’s time to nurse their young and this lasts for around five to seven days. After this, she’ll head off to mate again, and the pups are left to fend for themselves. Adults feed on fish and crustaceans or occasionally penguins, and usually keep their foraging activities to shallower waters.
Sometimes, they can be seen hunting in groups and, when they catch a fish, they’ll shake it in the air before swallowing it whole. While they can live for up to 30 years, South American sea lions do have several natural predators, including pumas and sharks.
14. Brown Fur Seal (Arctocephalus pusillus)
I’ve saved the biggest until last, and that’s the brown fur seal, which can grow to 660 lbs (299 kg), although the females are markedly smaller. The brown fur seal has a healthy range around the coasts of southern Africa as well as around parts of Australia, where they can be found on rocky cliffs and ledges.
The brown fur seal is more common in South Africa, and while it is listed as being of least concern, if fishermen keep culling them in fear of competition, this could affect their numbers in the future.
As their name suggests, this species has a dark coat but it’s not brown, rather the coloration tends to be somewhere between gray and black.
During breeding season, males will make their appearance on the rocky shores, where they put on impressive displays, often battling other males and may command a harem of as many as 28 females.
Walrus (Odobenidae Family)
The walrus is in a different family to other types of seal but is still a pinniped. They can be characterized by their distinct whiskers and long tusks and are found in the Arctic and subarctic regions on the ice. They’re perfectly adapted for life in these challenging conditions, and while there were once several species within the Odobenidae family, now only one remains.
1. Walrus (Odobenus rosmarus)
The walrus is an enormous type of pinniped that can weigh up to 4,400 lbs (1,996 kg); only two types of elephant seal are larger than it. These majestic animals have long tusks that can grow up to 3.3 feet (1 meter), although they’re typically longer in males who use them for fighting and asserting dominance. Those strong tusks also have the ability to break through ice as thick as 7.9 inches (20 cm)!
While the walrus largely lives on the ice, in late summer and fall, they can often be found in groups numbering tens of thousands along rocky shorelines. During breeding season, males will use loud vocalizations to attract several females with whom he will mate. Females typically give birth to a single calf every three years but continue to do so for their entire lives, which could be as long as 40 years.
In some areas, the walrus is considered to be vulnerable, whereas there isn’t enough data to determine populations in other areas. What we do know is that the walrus was once hunted by humans for their tusks, meat, and blubber although today they are protected by several laws that prevent commercial hunting.
Threats Facing Seals
While some seal populations are healthy, others are suffering and there are several reasons for this. Even those species that are in abundance are facing threats, which could eventually lead to a decline in their numbers.
Climate Change
Climate change is a major threat to many animals, including pinnipeds. One of the most obvious effects of this is the melting sea ice on which many species rely for resting and pupping, like the bearded and ringed seals. In some species, like the ribbon seal, delayed implantation allows them to time their pups’ birth to when there is more sea ice and food sources. But with melting ice, this can impact their breeding patterns.
Moreover, with ocean currents being affected by rising temperatures, this can interfere with seal migration, which again has a direct impact on their breeding activities.
With less ice to rest on, pups are more at risk of predators in the water, like sharks and orcas. What’s more, they don’t learn to swim right away so are at greater risk of drowning. Worryingly, in the Arctic, sea ice is melting twice as fast as anywhere else on the planet.
But it’s not just their habitat that’s being affected, even the availability of food is decreasing as a result of climate change. For example, studies have shown that krill populations are declining as a result of changing water temperatures, meaning less prey abundance for species like the antarctic fur seal. Higher levels of carbon in the water can also impact prey species and reduce their availability.
Furthermore, seals are adapted to living in cold climates, but as the temperature rises, they may be susceptible to heat stress which can affect their health and longevity. In warmer waters, there is the risk of algal blooms which release toxins, again affecting the health of seal species.
However, there are programs in place, including government backed habitat protection, which not only protects seals from climate change but other issues like oil spills.
Seal Hunting & Culling
Seal hunting is something that has happened for many years, as these animals are prized for their fur, blubber, and meat. In some Inuit cultures, seals have played an important role for thousands of years as a food source, and there are pleas from these communities to lift seal hunting bans to save their traditions.
While it might seem counterproductive, and there are measures in place to prevent commercial hunting, other programs that permit controlled seal hunting for indigenous people are in place to avoid a loss of culture.
In Namibia, seal culls happen on an annual basis with fishermen concerned that they are natural competition. However, conservationists oppose this opinion and are worried that these culls could have a devastating effect on the overall population. This could be as a result of removing a species that acts as both predator and prey and is responsible for maintaining a healthy ecological balance.
That said, there are many protective measures in place including a ban on the trading of seal products, such as the EU’s Trade In Seal Products Basic Regulations. Moreover, where seal hunting does take place, many countries, including Canada, have a quota on how many can be caught.
While there are efforts in place, the views on seal hunting and culling come from two very opposing sides. It’s certainly a topic for debate and something that animal rights activists are hot on the tail of.
Overfishing & Bycatch
Commercial fishing is one of the biggest industries on the planet, but seals are the ones paying the price. There are so many occasions where these animals are caught in fishing gear and, even if they’re released, their injuries can often be fatal. That said, reports have shown that early intervention and release does reduce the number of seal deaths, which is something that needs to be implemented more often.
Furthermore, a change in the type of fishing gear used could prevent seals from even being caught in the first place. The addition of pingers that emit high frequency sounds could be enough to deter seals and other vulnerable marine life from even coming near the nets.
In Hawaii, reports of more than 300 monk seals caught in fishing gear have been made, and this is concerning because this is an already threatened population of seals.
Even where seals are safe from being caught in the net, the fishing activities within the area could be harmful to prey populations, with humans taking far more than necessary. When this happens, it can have a devastating effect on the entire food chain, with seals struggling to survive without sufficient food.
Other effective methods of protecting seals from fishing activities include better fishery management and even closed seasons to allow the abundance of prey species to return.
Habitat Loss & Human Disturbance
One of the dangers that seal populations face is the encroachment of human settlements on their habitats. Urbanization and the spread of built up areas is happening at an alarming rate, and even if we don’t build directly on seal habitat, we’re often building far too close to it. For this reason, buffer zones between seal and human habitats are vital. The more we build around coastal areas, the more breedings and hauling out spots these animals lose.
And what’s worse is that we’re basing a lot of our recreation around the coast with things like tourism and boating, all of which have an impact on the availability of habitat for seals. If they don’t have sufficient grounds to breed on, this will naturally affect their numbers. Moreover, it’s not uncommon for seals to collide with boats. Fortunately, the UK is seeking to put laws in place that protect seals from these often fatal collisions.
The noise and light pollution from coastal tourism can impact seal activity and cause mothers to abandon their pups too soon or even throw off their breeding times. Proper ecotourism management is essential and thankfully, seal wellbeing studies are starting to influence the ecotourism regulations.
And it isn’t just the direct effects of human presence, things like plastics and oil spills are having an impact on seal life. These pollutants not only contaminate the waters but can also cause a decline in prey species. Shockingly, while critical habitats to protect seals have been created, there are governments that are trying to reverse this.
Predation by Natural Predators
When it comes to predation, it’s just nature’s way of keeping everything in balance. While animals like orcas, sharks, and polar bears have preyed on seals for millions of years, their numbers are growing, and this is impacting seal populations.
Much of this is largely due to climate change, which is altering the distribution of predators at the same time as potentially decreasing available seal prey. This change in dynamic may have a critical effect on seal populations, so employing protective strategies around climate change and its effects is vital.
What’s more, some predatory species are even changing what they eat as they begin to adapt to the changes climate change brings to their own prey, and fur seals are often in the firing line.
