Size: 11 - 18m
Key feature: Large ‘box-like’ head
The sperm whale is the largest toothed whale. It is very distinctive for its large blunt, ‘box-like’ head. It has no distinct dorsal fin, but does have a small hump two thirds of the way along its back. Sperm whales have slate grey or brown wrinkly skin. They have one blow hole on the left side of their head and a distinctive bushy blow which is at a 45 degree angle to the left.
Sperm whales travel in small groups of up to 20 individuals, and sometimes the males travel alone. When they dive they raise their triangular flukes vertically into the air before plunging deep into the ocean. Sperm whales are one of the deepest diving mammals, sometimes diving deeper than 1000m and holding their breath for up to 2hrs! Their primary prey consists of deep-water fish and squid, including the massive giant and colossal squids found in deep-sea trenches and canyons. At the surface they are often seen logging (lying still on the surface) and occasionally breaching or fluking.
Sperm whales are found world wide, mainly in deep offshore waters. Females and young sperm whales tend to stay in the warmer tropical and subtropical regions, whereas males tend to go further into temperate and arctic waters. Sperm whales can be seen on ORCA survey trips through the Bay of Biscay, they are seen more regularly through the late spring and summer months.
Sperm whales have been heavily exploited in the past; not for their meat, but for their body oil and spermaceti. These oils can be used in the production of perfumes, cosmetics and candles. sperm whales are slow growing and have low reproduction rates; therefore they struggled to recover quickly from high rates of exploitation. Despite this, sperm whales are now relatively abundant and under no immediate danger. Sperm whales are still hunted for meat in Japan, and targeting of males has lead to population imbalances, further reducing reproductive rates. Other human induced threats to sperm whales include marine pollutants (particularly plastic), entanglement in fishing gear, collision with ships, overfishing of prey species and climate change, as this can alter the location of food and habitat.