This last week we’ve spotted six species during our tours: common dolphins, sperm whales, bottlenose dolphins, Atlantic spotted dolphins, striped dolphins and short-finned pilot whales. The pilot whales group was of about 10 individuals including a male, adult females, juveniles and one calf.
A study carried out in the Canary Islands (Aguilar Soto et al., 2008) found that short-finned pilot whales unlike other cetaceans perform accelerations of 9m per second when diving at great depth hunting for prey. Accelerating uses up lots of oxygen which in turn reduces the time they can spend underwater, especially when reaching 1000m in depth. Deep diver species like beaked whales are known to speed up 1-2m per second, allowing them to stay underwater for up to 1 hour. Pilot whales on the other hand dive for about 20 minutes. Scientists compare these whales to the land predator cheetah; just like the big cat, pilot whales chase their prey instead of using darkness for surprise attacks. Pilot whales’ prey is mainly made up of cephalopods e.g. squid, octopus and cuttlefish, as well as fish and crustaceans. Squid are known to be fast swimmers, which also explains the need to accelerate.
Most of the time we encounter short-finned pilot whales they seem relaxed, almost motionless at the surface or performing slow movements and staying within the same area for prolonged periods of time. This may be explained by the fact that they spend most of their energy during foraging.