RISSO'S DOLPHIN(Grampus griseus)
- to a maximum of 4 m
- mostly grey, with white on the belly
- dorsal and pectoral fins are dark grey
- body is usually covered with many scars and scratches; older animals may appear completely white
- large, dark grey dorsal fin, resembling that of a female killer whale
- small and bushy
- may porpoise, spyhop or breach
- Unlike other dolphins, they rarely bow ride
Group size / social behaviour
- social, usually in groups of 10 – 50 animals. Most sightings of Risso’s dolphins in BC are of groups with less than 25 animals.
- very robust head with a prominent “melon”, contrasting with a thin tail stock
Can be confused with
- killer whales or pilot whales (but color is very light grey; killer whales and pilot whales do not typically have a multitude of scars and scratches)
- feed almost entirely on squid
- have been found to depedate fish from long lines.
- Can be found in mixed groups with Pacific white-sided dolphins and Northern right whale dolphins
- life history of this species has been little studied, but sexual maturity is thought to be attained at 8-10 years for females and 10-12 years for males. Intervals between calves average 2.4 years, and gestation is approximately 13 months. Lifespan is 35+ years.
- Listed as Not at Risk in Canada by COSEWIC , BC Yellow list.