The beluga whale, Delphinapterus leucas, is an instantly recognizable Arctic cetacean known for its striking white color and highly flexible neck. Often called the “canary of the sea” due to its varied vocalizations, the beluga is considered a medium-sized whale. Its body mass is largely influenced by a thick layer of blubber, which provides insulation in icy waters. The weight of a beluga can vary significantly, ranging from a newborn calf to a fully grown male, with distinct differences between the sexes and regional populations.
The Weight of a Mature Beluga
A fully mature adult beluga whale generally weighs between 2,200 and 3,300 pounds (1,000 to 1,500 kilograms). This considerable bulk is distributed across an average length of approximately 13 to 16 feet (4 to 5 meters).
The beluga’s weight is heavily supported by its thick layer of blubber, which provides insulation and serves as an energy reserve. This blubber can make up between 40% and 50% of its total body mass. The largest individuals can occasionally reach up to 4,190 pounds (1,900 kilograms).
Factors Influencing Beluga Size and Weight
The weight of an adult beluga is not uniform across the species, driven primarily by sexual dimorphism and geographical location.
Sexual Dimorphism
Adult males are noticeably larger and heavier than females, often being up to 25% longer. A mature male typically weighs between 2,430 and 3,530 pounds (1,100 to 1,600 kilograms). A mature female’s weight usually ranges from 1,540 to 2,650 pounds (700 to 1,200 kilograms).
Geographical Variation
Geographical location and diet also influence the overall size and weight of beluga populations. Populations in different Arctic regions may exhibit fluctuations in average body size due to variations in prey availability and specific habitat conditions. Climate is thought to be a factor in determining body size. The amount of blubber they carry, which directly impacts their total weight, reflects the nutritional richness of their local feeding grounds.
Weight at Birth and Growth Rate
Beluga calves are born with a considerable starting weight, typically weighing around 110 to 176 pounds (50 to 80 kilograms). They measure approximately 5 feet (1.5 to 1.6 meters) long at birth. Unlike adults, newborn calves are born a dark gray or bluish-gray color.
The initial growth rate is fast, driven by the high-fat content of the mother’s milk. Calves may gain about 50 pounds in their first month and nurse for a prolonged period, typically between 20 and 24 months.
Belugas take many years to reach full adult size. Females attain sexual maturity between four and seven years of age, continuing to grow until about 10 years old. Males reach sexual maturity later, between seven and nine years, and may not achieve maximum size until they are around 14 years old.