When people think of whales, they think big. After-all, the worlds largest living creature is a whale, the blue whale to be exact, but whats on the other side of the spectrum. Whales, with their cousins dolphins and porpoises make up the group commonly known as cetacean. So instead of looking at the largest cetaceans, lets look at the other side, the smallest cetaceans. There are currently two animals that hold the record.
Hector's Dolphin
Image by Anjanette Baker
The only known cetacean that is endemic (meaning only found there) to New Zealand. The species is further subdivided into two subspecies, the Hector Dolphin found around the South Island and the Maui Dolphin found around the North Island. The species grows to between 1.2 and 1.6 m (3'11" and 5'3") as adults. It is the smallest known dolphin species as they have conical shaped teeth which is different to porpoises or whales. There is still a lot to discover about these animals, like their average lifespan in the wild. Photographic evidence does suggest that they can be at least 22 years old in the wild. It is believed that males attain maturity at around 6 - 9 years of age and females will start calving between 7 - 9 years of age. There is sexual dimorphism in the species with the females being about 7% larger than the females.
The species mainly feeds on fish found around their habitat. They seem to take most things that are under 10cm in length. The most common species found in their stomach is Red Cod.
Vaquita
The Vaquita is a species of porpoise that is endemic to the northern end of the Gulf of California in Mexico. They were first discovered by skull fragments on the beach in 1958. It wasn't until 1985 that fresh specimens were found. Since then it has been noted that the population of the Vaquitas is on the brink of extinction. It is believed that there are only 10 individuals left in the world.
Adult Vaquitas average out at about 1.4 m (4'6") for males and 1.5 m (4'9") for females. This means that like the Hector's dolphin, the species is also sexually dimorphic. However, one strange characteristic is that even though the male is smaller than the female, the males dorsal fin is taller than the female.
Like the Hector's Dolphin, the Vaquita is also a generalist feeder. THey have been found to eat fish, crustaceans and even squid. Although fish seems to make up most of their food.
In November 2017 an attempt was made to remove some Vaquitas and start a breeding program. This turned out to be a more detrimental as one of the two individuals removed died from stress, the other one was eventually released when it started showing stress characteristics too.
What are your throughts on these two tiny species of cetaceans? What is your favourite species? Looking forward to hearing from you.