Seals vs. Sea Lions: What are the Differences?

Seals vs. Sea Lions

The ocean is home to a diverse array of marine life, and among the fascinating creatures that inhabit its waters, seals and sea lions often capture our attention. These marine mammals are often confused due to their similar appearances, but they belong to different families within the order Pinnipedia. In this comprehensive blog, we will explore the distinctions between seals and sea lions, covering aspects such as size, appearance, coloration, behavior, and more.

What are the Differences Between Seals and Sea Lions?

This is the table of quick differences:

Feature	Seals	Sea Lions
Taxonomy and Classification	Belong to Family: Phocidae	Belong to Family: Otariidae
External Ear Flaps	Absent	Present
Front Flipper Rotation	Limited mobility	Rotatable
Movement on Land	Belly flopping or wriggling	Walk using all four flippers
Facial Features	Short snouts, round eyes	Longer snouts, more dog-like eyes
Fur Characteristics	Shorter, denser fur	Longer, coarser fur
Coat Color	Varies from light to dark shades, including gray, brown, and spotted patterns	Lighter, often with golden or reddish tones
Habitat and Distribution	Found in polar, temperate, and tropical waters; adapted to Antarctic waters	Commonly found in warmer coastal areas; abundant along the western coast of North America
Locomotion in Water	Hind flippers for propulsion	Front flippers used for steering
Vocalizations	Grunts, growls, clicks	Barking or roaring sounds
Reproduction	Give birth on land or ice; bonding period crucial for pup survival	Give birth on land or rocky shores; pups born precocial

Taxonomy and Classification

Before delving into the differences, let’s take a closer look at the taxonomic classification of seals and sea lions. Both belong to the suborder Pinnipedia, but they are further divided into two distinct families:

A. Seals (Family: Phocidae)

Characteristics: a. Lack external ear flaps b. Short, sleek bodies c. Propelled through the water primarily by their hind flippers

B. Sea Lions (Family: Otariidae)

Characteristics: a. External ear flaps present b. Long front flippers that can be rotated c. Able to “walk” on land using their front and hind flippers

Size Comparison Between Seals vs. Sea Lions

One noticeable difference between seals and sea lions is their size. While there is considerable variation among species, sea lions generally tend to be larger than seals. The California sea lion, for example, is one of the most common sea lion species and can reach lengths of up to 7 feet (2.1 meters) for females and 8 feet (2.4 meters) for males. In contrast, the harbor seal, a common seal species, typically measures around 6 feet (1.8 meters) in length.

External Appearance Comparison Between Seals vs. Sea Lions

A. Facial Features:

1. Seals: a. Lack external ear flaps b. Short snouts c. Wide, round eyes
2. Sea Lions: a. Prominent external ear flaps b. Longer snouts c. Eyes that are more dog-like in appearance

B. Fur and Coloration:

1. Seals: a. Typically have shorter, denser fur b. Coat color varies from light to dark shades, including gray, brown, and spotted patterns.¹
2. Sea Lions: a. Longer, coarser fur b. Fur coloration tends to be lighter, often with golden or reddish tones.²

Habitat and Distribution

Both seals and sea lions are found in a variety of marine environments, but their preferred habitats and distributions can differ:

A. Seals:

1. Often inhabit icy polar regions as well as temperate and tropical waters
2. Species like the Weddell seal are adapted to life in Antarctic waters.³

B. Sea Lions:

1. Commonly found in warmer coastal areas, including rocky shorelines and sandy beaches
2. California sea lions, for instance, are abundant along the western coast of North America.⁴

Behavior and Locomotion

A. Seals:

1. Move on land by flopping or wriggling on their bellies
2. Excellent swimmers, relying on their hind flippers for propulsion

B. Sea Lions:

1. Capable of “walking” on land using all four flippers
2. Agile swimmers that use their front flippers to steer through the water

Vocalizations

Another interesting point of comparison between seals and sea lions is their vocalizations. Both use a variety of sounds to communicate, but there are distinctions in the types of calls they produce:

A. Seals:

1. Vocalizations include grunts, growls, and clicks
2. Use vocalizations to communicate underwater during mating and social interactions

B. Sea Lions:

1. Known for barking or roaring sounds
2. Communicate both on land and underwater, with distinct calls during breeding seasons.⁵

Reproduction and Life Cycle

Reproductive strategies and life cycles vary among seal and sea lion species:

A. Seals:

1. Give birth on land or ice
2. Mothers nurse their pups with rich milk, and the bonding period is crucial for the survival of the young seals

B. Sea Lions:

1. Most sea lion species give birth on land, although some may use rocky shores or caves
2. Pups are born precocial, meaning they are more developed and mobile at birth compared to seal pups

Conclusion

In conclusion, while seals and sea lions share similarities as marine mammals adapted to life in the water, several key differences set them apart. From their taxonomic classifications to size, appearance, and behavior, understanding these distinctions enhances our appreciation for the diversity of life in our oceans. The next time you spot a pinniped lounging on a beach or swimming gracefully in the sea, you’ll be better equipped to identify whether it’s a seal or a sea lion.

References:

1. MarineBio. (n.d.). Seal Facts and Information. [https://marinebio.org/seals/]
2. MarineBio. (n.d.). Sea Lion Facts and Information. [https://marinebio.org/sea-lions/]
3. National Geographic. (n.d.). Weddell Seal. [https://www.nationalgeographic.com/animals/mammals/w/weddell-seal/]
4. NOAA Fisheries. (n.d.). California Sea Lion (Zalophus Californianus). [https://www.fisheries.noaa.gov/species/california-sea-lion]
5. The Marine Mammal Center. (n.d.). Marine Mammal Sounds. [https://www.marinemammalcenter.org/science/cetacean-sound]