Beluga are highly sociable creatures. They move in pods which commonly contain animals of the same gender and age. Groups of males may number in the hundreds. Mothers with calves generally mix in slightly smaller groups. When pods aggregate in estuaries they may number in the thousands. This can represent a significant proportion of the entire Beluga population and is the time when they are most vulnerable to hunting.
Beluga pods tend to be unstable, meaning that belugas tend to move from pod to pod. Pod membership is rarely permanent. Radio-tracking has shown belugas can start out in a pod and within a few days be hundreds of miles away from that pod. The closest social relationship between belugas is the mother-calf relationship. Calves often return to the same estuary as their mother in the summer, meeting with their mother sometimes even after becoming fully mature.
Belugas are slow-swimming mammals which feed mainly on fish. They also eat cephalopods (squid, octopus) and crustaceans (crab, shrimp). Foraging on the seabed typically takes place at depths of up to 1,000 feet, but they can dive at least twice this depth.
Beluga exhibit a wide range of vocalisations including clicks, squeaks, whistles, squarks and a bell-like clang. One noted researcher in the field likens a noisy Beluga pod to the string section of an orchestra tuning up before a concert. Researchers have recorded 50 distinct sounds; most in the range of 0.1 to 12 kHz.
Their main natural predators are polar bears, especially when the whales become encircled and trapped by ice. The Bears club the trapped whale with a paw and then drag it on ice for a feast. Beluga are easily small enough to also be a target for an orca.