Facts about Risso's Dolphin

1. 07

   The blunt, bulbous head of Risso's dolphin lacks a distinct beak, setting it apart from most other dolphin species.

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2. 06

   Risso's dolphins reach sexual maturity between ages seven and eleven, with females typically producing a single calf every three to four years throughout their reproductive lifespan.

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3. 05

   Risso's dolphins produce distinctive clicks and whistles at frequencies up to 130 kilohertz, allowing echolocation in the pitch-black depths where they hunt at night.

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4. 04

   Risso's dolphins typically dive to depths of 600 meters while hunting squid, making them among the deepest-diving dolphins in the ocean.

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5. 03

   Risso's dolphins have a brain-to-body mass ratio of approximately 1.5 percent, among the highest of all cetaceans and comparable to some great apes.

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6. 02

   Groups of Risso's dolphins typically contain five to twenty individuals, though aggregations off California have exceeded six hundred members during feeding events.

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7. 01

   Extensive scarring covers adult Risso's dolphins' bodies from squid beaks and intraspecific conflicts, creating a distinctive pale appearance by age thirty.

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