Marine Mammal Spotlight - Toothed Cetaceans
There are at least 61 species of toothed whales dolphins and porpoises, ranging from the largest 16-20m sperm whale to the smallest 1-1.2m Hector dolphin.
Kaikoura is unique for both the sperm whale and the hector dolphin, both of which could be observed almost daily off the coastline. A total of around 9 different toothed whales and dolphins have been positively identified on more than one occasion off the Kaikoura coast which include: dusky dolphins, bottlenose dolphins, southern right whale dolphins, pilot whales, killer whales and the beaked whales, all being beautiful creatures to see in the wild.
Odontoceti’s use their teeth to seize prey such as fish or squid, which is then generally swallowed whole. In order to locate and catch their food, the toothed whales and dolphins, like bats have developed a sonar or echolocation system, in which sounds are emitted from their heads and reflect off solid objects. The returning echo is interpreted by the whales and dolphins and enables them to determine the size, composition, distance and direction of the object they have focused on. The sperm whales echolocation sounds like the rhythmic clicking sounds of a clock – such as this example.
The sperm whales echolocation is what we listen out for when using our captains use our purpose built hydrophones, listening out for the rhythmic clicking sound (like the ticking of a clock) as they are in search mode of their prey or navigating their way.
In addition to their echolocation most toothed whales and dolphins have developed the ability to communicate by using clicks, whistles, squeaks, squeals and some such as the orca have even developed dialects which differ from pod to pod.
Many toothed whales and dolphins utilize these communication skills to help catch their prey and form social groups to hunt cooperatively.
One way you can tell toothed whales & dolphins from baleen whales if by their blowholes with toothed whales and dolphins having one blowhole and baleen whales having two. Another difference being that baleen whales have a small throat and large tongue whereas the toothed whales & dolphins have a large throat and small tongue.