Beluga whales are marine mammals known for their white coloration and bulbous forehead, or “melon.” These social whales are well-adapted to Arctic and sub-Arctic waters, inhabiting regions across North America, Russia, and Greenland. Their physical characteristics allow them to navigate and thrive in icy environments.
Understanding Beluga Whale Size: Length, Weight, and Sex Differences
Adult beluga whales show sexual dimorphism, with males generally larger than females. Males typically measure 3.5 to 5.5 meters (11 to 18 feet) in length, while females range from 3 to 4.1 meters (9.8 to 13.5 feet).
Adult male belugas can weigh 1,100 to 1,600 kilograms (2,430 to 3,530 pounds), occasionally reaching 1,900 kilograms (4,190 pounds). Females are lighter, typically weighing 700 to 1,200 kilograms (1,540 to 2,650 pounds). This sexual dimorphism means males can be approximately 25% longer and heavier than females.
Beluga whales have a robust, torpedo-shaped body insulated by a thick layer of blubber. This blubber can account for 40% to 50% of their total body weight, providing insulation in cold Arctic waters. The blubber layer can be up to 15 centimeters (5.9 inches) thick, typically around 10 centimeters (4 inches).
From Calf to Adult: Beluga Whale Growth
Beluga whale calves are born measuring 1.5 to 1.6 meters (5 to 5.2 feet) in length, with birth weights ranging from 36 to 80 kilograms (80 to 176 pounds). Unlike adults, newborn calves are dark gray or brownish-gray and gradually lighten to white as they mature.
Calves are dependent on their mothers, nursing for at least two years. Mother’s milk is rich in fat and nutrients, supporting rapid growth. Calves can gain length at a rate of 0.15 to 0.24 centimeters per day in their first 200 days.
Females typically attain sexual maturity between 4 to 10 years old, while males mature later, from 7 to 15 years of age. Females generally reach adult size around 7 years, whereas males continue growing until approximately 14 years.
Factors Influencing Beluga Whale Size
Several factors influence beluga whale size. Geographical location plays a role, with different Arctic populations exhibiting variations in average size. Environmental conditions, such as climate, also contribute to these regional differences.
Diet and food availability significantly affect an individual’s size. Beluga whales are opportunistic feeders; their diet varies by location and season. They consume a wide range of prey, including fish (salmon, cod, smelt) and invertebrates (shrimp, squid, crabs).
Belugas typically consume 2.5% to 3% of their body weight in food daily. Their blubber layer is thickest in late winter and early spring and thinnest in the fall, reflecting seasonal feeding patterns and energy storage. Health and age also contribute to ultimate size, with older individuals, particularly males, often reaching the upper end of the size spectrum.