Why in News?
Marine biologists from National Geographic and Project CETI successfully captured the world's first clear footage of a live sperm whale birth in the wild.
Physical Characteristics
- Unmatched Scale: They are the largest toothed predators on Earth, with mature males averaging 16 metres (52 feet) in length and weighing up to 45 tonnes.
- Brain Power: They possess the largest brain of any animal species in evolutionary history, more than five times heavier than a human brain.
- Spermaceti Organ: Their massive square heads house a large cavity filled with a waxy liquid called spermaceti oil. This fluid acts as an acoustic lens used to focus sounds for echolocation and regulate buoyancy.
- Asymmetrical Breathing: Unlike baleen whales, sperm whales have a single blowhole located forward and strictly on the left side of their head, creating a distinct forward-left water spout.
Deep-Sea Diving and Diet
- Deep Divers: They are the third deepest diving mammals on the planet, capable of plunging to depths of over 2,250 to 3,000 metres.
- Breath Endurance: They can hunt in the pitch-black abyss for up to 60 to 90 minutes on a single breath of air.
- Prey Selection: Their diet consists primarily of giant squids, colossal squids, octopuses, and deep-sea fish dwelling in benthic ocean zones.
Social Structure and Communication
- Matriarchal Pods: Females and juvenile males live in highly stable, cooperative social units of about 10 individuals, while mature adult males lead solitary lives outside the breeding season.
- Coda Communication: They communicate via rapid bursts of rhythmic clicks called codas. They alter the pacing, pitch, and duration of these clicks to transfer detailed information over long distances.
Conservation Status and Threats
- IUCN Protection Status: Classified as Vulnerable (VU) globally on the IUCN Red List.
- Legal Shield in India: Listed under Schedule I of the Wildlife (Protection) Act, 1972, granting them the highest tier of legal protection against hunting inside Indian territorial limits.
- Historical Exploitation: They were heavily decimated by commercial whaling fleets between 1800 and 1987 for spermaceti oil used in candles and machinery lamps.
- Modern Anthropogenic Threats: Current population recovery is hindered by vessel strikes (ship collisions), entanglement in commercial fishing gear, plastic pollution ingestion, and deep-sea military sonar disruptions.
Download Pdf
