About the wisdom of children

Text: Edeltraud Konradt

From the end of March until the middle of November many people came to us to do a whale watching tour, including many children. It is always amazing what children know about whales! Here are a few examples:

The children who came to me with their "knowledge" are between 5 and 12 years old.

- ) I know that: a Blue whale eats Sperm whales because it is the largest whale on earth....

That's not right:

- It's true, the Blue whale is the biggest whale on earth. It belongs to the baleen whale family. It can be up to 33 meters long, weighs up to 140 tons and has a life expectancy of 80 - 110 years. It feeds mainly on krill.

A sperm whale belongs to the family of toothed whales. It can grow up to 18 meters long, weighs up to 50 tons, has a life expectancy of 70 - 80 years and feeds on (giant) squids.

-) Dolphins eat garbage

Not at all.  

Dolphins are small whales, they belong to the family of toothed whales and, depending on the species, they vary in size and life expectancy from 35 to 80 years. They feed on fish, small squids or even small crustaceans.

The waste, especially the plastic waste, pollutes their habitat; of course, many other marine animal and fish species are also affected. Worldwide, more than 86 million tons of plastic waste pollute the oceans. 80% of it comes from land, 20% from the sea, e.g. fishing nets. The toxins contained in the plastic also pollute the oceans.(source WWF)

-) Whale sharks and marine crocodiles swim 60 km/h fast and eat orcas.

The child has this statement probably from a book about the adventures of a whale shark.

Whale sharks grow up to 12 metres long, feed on plankton and are on the red list of endangered species according to IUCN. They live in tropical and subtropical waters.

- Marine crocodiles lived at the time of the dinosaurs and belong to them themselves. Today researchers find fossils of these animals. The only exception is the saltwater crocodile, which belongs to the subclass of the great dinosaurs, which also included the extinct dinosaurs. It is known as saltwater crocodile because it is the crocodile which advances the most into the ocean (coastal waters, inlets).  

-) The whale shark is the largest animal of the oceans, it is much bigger than the blue whale.

Something got mixed up here.

The whale shark is the largest shark and also the largest fish; it belongs to the order of the nurse sharks. The whale shark reproduces only between 10 and 30 years of age and can become 100 years old. (Wikipedia whale shark). The blue whale belongs to the baleen whale family and is a marine mammal.

-) The orcas hunt other dolphins and humans

N O, orcas don't hunt people. There are different types of killer whales, which differ in body type, body coloration, social behaviour, sound expression, behaviour, and particularly in their preferred prey animals. These different types of killer whales are called ecotypes. The orcas that prefer meat live predominantly in cold waters e.g. in the Arctic, they hunt seals, penguins or small dolphins.

The killer whales that enter the Strait of Gibraltar belong to the other cultural circle of orcas and feed on fish. The migratory behaviour of these killer whales has been insufficiently researched.

- ) A about 12-year-old boy said: you don't know where the orcas are if they are not here. Why do people not do something to find out? For example, you can put transmitters in their bodies so you can find them.

What he's proposing is called invasive research. Invasive means to penetrate the animal by e.g. inserting a transmitter into the body of a whale. It hurts the animals and the injection areas can become inflamed, which means the animals are in pain and the transmitter disturbs and impairs them. Mostly the wounds heal eventually, but not always it goes well. In addition, the transmitters fall off at some point.

-) On the subject of dolphins as a by-catch in the nets of tuna fishermen..... But the dolphins can still flee; they can simply swim away...

Generally, that's true. But sometimes they get tangled up in the nets. Toothed whales are often unable to locate the so-called longlines as well as gill nets and trawl nets.

In addition, they are very social animals; they make sure that even the smallest or injured animals in the group can escape with them. If this is not the case, they sometimes stay with their group members to help them; they do not like to leave each other alone.

According to estimates by the International Whaling Commission (IWC), around 300.000 whales and dolphins are killed each year as by-catches of fishing worldwide. One solution could be the mandatory attachment of so-called pingers (acoustic deterrent devices) to the nets.

Tuna: there are eight species, including the bluefin, yellowfin and blackfin tuna, also the albacore tuna. Furthermore the long-tailed tuna and the bigeye tuna. The one that lives here in the Strait of Gibraltar is the bluefin tuna (Thunnus thynnus).

The size varies depending on the species between 1-4.5 meters, the weight between 20-700 kg. At the age of 5 a tuna is sexually mature and reproduces. Age varies according to species, the  maximum age is 30 years.

That was only a small part of what I remember. Whether correct or not, I am happy about the interest of the children.