Every so often when diving Koh Tao we have an opportunity to see things we don’t see often and it gets everyone talking on our boat. Recently, during both our morning and afternoon dive trips, our divers were lucky enough to see a huge pod of Pilot Whales – appearing on opposite sides of the Island!
Pilot Whales are members of the Dolphin family and you can definitely see why, as they effortlessly glide through the ocean breaking the surface with their dorsal fin. The Pilot Whale has a very distinct rounded head and slight beak shaped mouth and are generally all black/coal grey in colour.
They get their name from the belief that the groups when migrating will follow one sole whale that navigates the entire matriarch. The males are the bigger of the sexes and can reach up to 6 meters in length weighing in at around 3 tons.
As for the females, they aren’t much smaller and can reach up to 5 meters weighing around 1.5 tons.
Hunting In Pods
A Pilot Whales main diet consists of squid; however it’s not uncommon for them to eat other cephalopods like octopus and cuttlefish or other smaller fish if squid isn’t available. Their mouths consist of between 40 to 48 teeth and are only used for catching and grasping their food not chewing, meaning they eat their food whole.
Known to eat around 30 pounds of food per day they work in teams called ‘Pods’. Using high-pitched whistles and different formations they force their prey into one concentrated area and take turns in moving in on the catch.
Males will reach sexual maturity at around 12 years of age and females earlier at around 6 to 7 years of age. The gestation period last a whole 12 to 15 months and calving will only happen once every 3 to 5 years. With a slow reproduction rate it is very important that a sustainable eco-system is kept for these beautiful creatures to flourish.
Calves are born just under 2 meters in length and weigh around 225 pounds. These calves will nurse from the mother for up to 22 months. Baby Pilot Whales are usually born in the summer in the warmer waters, to take advantage of the higher numbers of food available although it has been known for these Whales to give birth all year round.
The fight for a female in breeding season is quite an aggressive time of the year as males are known to fight with each other in competition for females. Butting, ramming and biting are the most common methods used between males. These activities are also involved in the mating process and females have been known to carry scars as a result of this.
Researchers have found that the females can give birth up to 35 years of age and have also been found to nurse their final calf until it reaches around 10 years old.
All Around The World
Generally speaking Pilot Whales can be found in both northern and southern hemispheres, where they find tropical and temperate waters. However the two different types tend to differ in preference as to where they live. Short finned pilot whales frequenting in warmer waters around the world and the long-finned pilot whales preferring the cooler temperate waters. There are some minor parts of the oceans where the two species overlap and share waters however in most cases they stay segregated.
These whales are huge social creatures and can be found in pods up to around 100 at a time. Within these groups you kind find several families. The females generally stay within the pods long term with their calves and research has found that males in the pods may only stay short term to breed with the females usually mating with several of the females within the group resulting in a number of calves. The females are very loyal to their pod, so loyal in fact that mass strandings have been found with upto 100 whales at a time.
Some Cool Pilot Whale Facts
- Pilot Whales eat Giant Squid! They dive down into the depths and fight with the squid, pulling them to the surface where the squid explode from the change in pressure.
- Pilot Whales are not actually whales – they’re from the dolphin family.
- They use echolocation – a series of clicks which bounce off of nearby objects and are picked up by their ears, allowing the whales to locate predators, prey and their environment.
- The only country that has specific laws on viewing pilot whales is New Zealand.
- They can dive up to 600 metres deep when hunting for pray.
- They are called the “Cheetahs of the Deep” because of their fast diving style.
- Their dorsal fins are like human finger prints – no two are exactly the same.
- When they sleep on the surface it is called “logging” and when they’re swimming around in no particular direction it is called “milling”.
Author: Kieran Hooley (PADI DM #364105)