Sea elephants are among the largest marine mammals, with adult males, or bulls, being particularly immense. Their impressive size and unique adaptations allow them to thrive in challenging marine environments. Bull sea elephants are uniquely adapted to a life of intense competition and deep-ocean exploration.
Distinctive Physical Characteristics
Adult male sea elephants are considerably larger than females, with some individuals reaching lengths of over 6 meters (20 feet) and weighing more than 3,600 kilograms (8,000 pounds). A prominent feature defining the bull is its large, fleshy proboscis, or trunk-like nose, which develops fully around seven to nine years of age. This proboscis serves as a resonating chamber, amplifying the male’s vocalizations during the breeding season, a sound that can travel long distances. Another characteristic is the thick, corrugated chest shield, a toughened area of skin up to 2.5 centimeters (1 inch) thick. This shield becomes heavily scarred over time from the numerous battles fought with rival males, offering some protection during aggressive encounters.
Dominance and Breeding Behavior
The breeding season transforms coastal areas into arenas of intense competition for bull sea elephants, typically occurring from December to March. Males arrive at breeding beaches earlier than females, establishing a dominance hierarchy through a series of aggressive displays and physical confrontations. These battles involve powerful charges, biting, and slamming their massive bodies against rivals, often resulting in deep gashes on their chests and necks.
Only the most dominant males secure access to breeding territories. These dominant males then establish harems, which can consist of 30 to 100 or more females, and they vigorously defend their group from challenging males. Vocalizations, including loud roars and guttural calls, are frequently used to intimidate rivals and assert their presence without always resorting to physical combat.
Life Outside the Breeding Grounds
Following the demanding breeding season, bull sea elephants embark on extensive migratory journeys, traveling thousands of kilometers into the open ocean, often heading north from their breeding grounds. These individual migrations are not directly linked to specific feeding grounds but rather represent a search for abundant prey. During these periods, they become impressive deep-sea predators, performing remarkably long and deep dives to forage for food. Dives can regularly exceed 300 meters (1,000 feet) in depth and last for 20 to 30 minutes, with some recorded dives reaching over 1,500 meters (5,000 feet).
Their diet primarily consists of squid, various fish species, rays, and even small sharks found in the mesopelagic zone. After months at sea, bulls return to land for their annual molt, a period of fasting where they shed their old skin and fur, a process that can last for several weeks.