Taxonomy
- Kingdom
- Animalia
- Phylum
- Chordata
- Class
- Mammal
- Order
- Artiodactyla
- Family
- Delphinidae
- Genus
- Grampus
Habitat
Risso's dolphins inhabit deep, offshore waters in temperate and tropical oceans, typically over the continental slope at depths greater than 1,000 meters. They are found worldwide but prefer areas away from shallow coasts, often associating with underwater features like seamounts or canyons. Their range includes the Atlantic, Pacific, and Indian Oceans.
Diet
Risso's dolphins primarily feed on squid, which constitutes the majority of their diet, along with various fish species like mackerel and occasionally crustaceans. They use echolocation to hunt in deep waters, often at night or during dawn and dusk when prey is more abundant. Feeding involves deep dives lasting up to 30 minutes.
Behavior
Risso's dolphins are highly social, forming groups of 10 to 50 individuals that may merge into larger aggregations for feeding or socializing. They are active during the day, exhibiting behaviors like breaching, spyhopping, and playing, which makes them noticeable to boaters. While generally curious and approachable, they can be territorial around prime feeding areas.
Conservation Status
Risso's dolphins are classified as Least Concern by the IUCN, with a stable global population trend, though they face threats from bycatch in fishing nets and marine pollution. Conservation efforts focus on reducing entanglement and habitat degradation.