Context:
Tests show that minke whales can hear high-frequency sounds
Baleen Whales:
- Large marine mammals with baleen plates in their mouths for filter feeding.
- Crucial in marine ecosystems and culturally significant in various societies.
Key Species of Baleen Whales:
- Blue Whale – Largest animal on Earth.
- Humpback Whale – Known for acrobatic behaviour and complex songs used for communication.
- Gray Whale – Undertake long migrations between Arctic feeding grounds and warmer breeding lagoons.
- Minke Whale – Smallest of the baleen whales.
- 2 recognized species of minke whales – Common minke whale and the Antarctic minke whale
- Distribution – Widely distributed through most tropical, temperate and polar regions
Morphology and Adaptations:
- Filter Feeding – Involves taking in large mouthfuls of water and filtering out prey using baleen plates.
- Migration – Many species undertake extensive migrations between feeding and breeding grounds, often covering thousands of kilometers.
- Songs and Communication – Notably humpback whales, known for complex songs related to breeding and communication.
- Acrobatic movement (manoeuvre their whole bodies when they feed) – Commonly observed acrobatic behaviours are called breaches, tail-slaps, and spy-hops
- Bubble netting – Process of sweeping a net of bubbles around its prey and trapping them
- Low-frequency hearing specialists
Conservation Status and Threats:
- Threats – Entanglement in fishing gear, ship strikes, pollution, climate change affecting prey availability, and habitat degradation.
- IUCN Status – North Atlantic right whale is ranked Critically Endangered by the International Union for Conservation of Nature.
- Conservation Efforts – International Whaling Commission (IWC) regulates whaling and protects baleen whales.
Source: The Hindu
Previous Year Question
Which one of the following is the correct sequence of a food chain?
[UPSC Civil Service Exam – 2014 Prelims]
(a) Diatoms-Crustaceans-Herrings
(b) Crustaceans-Diatoms-Herrings
(c) Diatoms-Herrings-Crustaceans
(d) Crustaceans-Herrings-Diatoms
Answer: (a)