Gray Whale
Gray Whale Facts
| Size | 42-49 feet (13-15 m) |
| Speed | 3-5 mph (5-8 km/h) |
| Weight | 25-45 tons |
| Lifespan | 50-70 years |
| Food | Little crabs, worms, small fish |
| Predators | Large sharks, Orcas |
| Habitat | Pacific |
| Order | Whales |
| Suborder | Baleen whales |
| Family | Gray whales |
| Scientific name | Eschrichtius robustus |
| Characteristics | Large whale, has the most baleen of all whales |
Main Characteristics
The gray whale is a large marine mammal. Out of all baleen whales, it has the highest number of baleen plates. Its behavior is unique as well: it travels the second farthest distances of any whale. Additionally, it is the only whale that spends most of its time close to the shore and the only one that primarily forages for food at the ocean floor.
Distribution and Habitat
In the past, gray whales inhabited the North Atlantic near Spitsbergen, Greenland, and Canada. Today, they are found only in the North Pacific. This decline is due to their near extinction from whaling. These animals typically stay close to coastlines, particularly off California and Mexico, as well as near Siberia, the Kamchatka Peninsula, and around Korea and Japan. In 2021, a gray whale named Wally gained attention for straying into the Mediterranean Sea. Unfortunately, he could not find enough food there and became quite emaciated. It remains uncertain whether he left the Mediterranean in time.
Way of Life
Gray whales form small groups of 2-3 individuals, and during migrations, they can sometimes gather in groups of up to 16. They are very social creatures, caring for their fellow whales and assisting them when they are sick or injured. In the summer, they inhabit the cold polar seas, while in the winter, they migrate to warmer southern waters.
Anatomy and Appearance
Size and Weight
Gray whales can reach lengths of 42-49 feet (13-15 meters) and weigh 25-45 tons.
Baleen
Among all whales, the gray whale has the highest number of baleen plates: 400-500. Baleen plates are very thin, long horn-like structures that baleen whales use to filter their food from the water.
Color
The skin color of the gray whale is – as the name suggests – gray. However, from a distance, it doesn’t appear gray at all, but rather white-speckled. What causes this? Barnacles often attach themselves to the skin of the gray whale.
Barnacles
Barnacles frequently cling to the skin of gray whales, particularly on the head and tail fluke. Why is that? Whenever the whale feeds, they get a small portion of the food. The whale doesn’t benefit from this, but the barnacles don’t harm it either. This phenomenon is known in scientific terms as "commensalism" (from the Latin "commensalis" meaning "table mate"). There is a specific type of barnacle that specializes in attaching to the skin of gray whales. Humpback whales and North Atlantic right whales also often have goose barnacles.
Gray Whale or Humpback Whale – What’s the Difference?
The gray whale and the humpback whale look remarkably similar. Both have a very similar gray skin tone. Additionally, both have “bumps” on their bodies. The humpback whale has what are known as tubercles (skin growths), while the gray whale has barnacles. The gray whale is slightly smaller and lighter. The major differences are evident in their behavior. The gray whale searches for invertebrates on the ocean floor, while the humpback whale hunts for krill and fish near the water's surface.
Diet
Gray whales are carnivorous. They primarily feed on amphipods, copepods, and small fish. In the summer, they eat abundantly and rely on their fat reserves during the winter.
Behavior
Spy-Hopping
Like many other whales, gray whales often and eagerly stretch their heads out of the water to look around. This behavior is called “spy-hopping”.
Hunting Grounds
Gray whales hunt differently than other whales. They are the only ones that primarily search for food on the ocean floor. Their favorite snacks include amphipods, copepods, and small fish. Since these creatures do not inhabit the open sea, gray whales are often spotted close to the shore.
Hunting Technique
To hunt, gray whales tilt slightly to the right side and swim slowly along the ocean floor with their mouths wide open. The mud they take in contains their prey. Excess water is expelled through their short, strong baleen, much like a sieve. Marine biologists suspect that the right side may provide a hunting advantage, but they are not entirely sure yet. What is certain is that the baleen on the right side wears down significantly faster than that on the left side.
Abilities and Senses
Migration
In the summer, gray whales reside in the cold but fish-rich polar seas. Like a car, they fill their "tank" with "fuel" - only this fuel consists of fish, which are stored as fat reserves. Before winter, they migrate south to warmer waters to mate and raise their young. The migrations last about 2-3 months. During this time, they do not take breaks but instead alternate shutting down one hemisphere of their brain to sleep. Gray whales are divided into two groups: one inhabits the East Pacific and the other the West Pacific.
East Pacific and West Pacific Gray Whales
The whales in the East Pacific spend their summers in the Bering Sea off the coast of Alaska. In the fall, they migrate southward to the California coast or even as far as Mexico. The whales in the West Pacific are found in the Sea of Okhotsk near Sakhalin Island off the Kamchatka Peninsula during the summer. In the fall, they also migrate south. In the past, they swam into the South China Sea, but nowadays they tend to stay closer to the coasts of Japan.
The Second Longest Journey
Until recently, the gray whale was considered the whale that migrates the farthest. A female whale swam a total of 13,987 miles (22,511 km) in 2015. In the spring, she traveled 6,993 miles (11,255 km) to her summer feeding grounds and then returned 6,993 miles (11,255 km) back to her winter habitat in the autumn. In 2024, a male humpback whale made headlines by swimming a remarkable 8,106 miles (13,046 km) from his summer feeding grounds to his winter habitat. This distance surpasses the gray whale's journey by 1.100 miles (1,800 km) when looking at the one-way trip (not counting the return). He now holds the record for the longest migration.
Life Expectancy
Gray whales can live between 50 to 70 years. Unfortunately, they are increasingly dying before reaching this age due to human activities.
Enemies and Threats
Natural Enemies
An adult gray whale has no natural predators. However, calves are sometimes preyed upon by orcas and large sharks.
Human Impact
Shipping Traffic
Gray whales are significantly affected by the noise from ships. While the oceans are vast, sounds can be heard underwater for hundreds of kilometers – at least by whales. This is similar to how we feel when we live near a busy road with our windows open, day and night. Over time, this creates a lot of stress, which can lead to illnesses, injuries, or even miscarriages. Besides the noise, gray whales are also fatally injured by collisions and ship propellers.
Fishing
Gray whales often get entangled in fishing nets and drown tragically. With every fish you choose not to eat, fewer fishing boats need to go out, and you help a whale survive.
Pollution
The oceans are becoming dirtier every day. Huge amounts of chemicals and plastics are entering the sea. These not only cause diseases in gray whales and reduce their reproductive capabilities but also affect all marine life.
Conservation Status
In the past, gray whales also inhabited the Atlantic. Today, they are extinct there. In the Eastern Pacific, the number of gray whales has significantly decreased, with an estimated 13,000 remaining according to NOAA's 2025 estimate. In the Western Pacific, only 150 remain. Currently, they are not considered endangered, but this status is likely to change soon.
Importance for the Ecosystem
Gray whales primarily search for food on the ocean floor, stirring up sand and mud in the process. This action releases nutrients back into the water, which many other marine creatures rely on for sustenance.
Reproduction
Mating Time and Gestation Period
Gray whales mate during the winter months while they are in the sunny southern regions. During the gestation period, they swim to the cold, fish-rich northern waters to build up fat reserves, returning the following winter to the warmer waters to give birth to their calf.
Birth
The calf is born in a sheltered bay or lagoon, where it is safe from orcas and sharks. At birth, it measures about 13-16 feet (4-5 meters) in length and weighs between 1,540-1,760 pounds (700-800 kg).
Raising the Calf
The calf is nursed for seven months, consuming 52-80 gallons (200-300 liters) of its mother's milk daily. The milk has a very high fat content of 40-50%. In comparison, human breast milk contains only about 4%. Thanks to this high fat content, the calf gains approximately 66 pounds (30 kg) each day, ensuring it is well-prepared for survival in the Arctic Ocean.
Animals in the Same Biome:
Sources:
- „Eastern North Pacific Gray Whales Continue Decline After Downturn During Unusual Mortality Event“ (https://www.fisheries.noaa.gov)
