About the wisdem of children (part six)
by firmm Team
Do Orcas eat Blue Whales?
Text: Edeltraud Konradt; photos: firmm
Every year I am amazed at the children's knowledge and interest in marine animals.
In one of my talks in April, I had a 5-year-old boy who told me with full conviction that
I first researched the statement myself to see if it was true. That Orcas attack large whales and separate the calves from the mother to drown the calf was already known. They then eat only the tongue of the animal. The assumption here until now was that it is not about the food, but about the knowledge of hunting techniques that is passed on to the young animals.
Concerning the claim of the boy, my research has revealed:
Yes, the child's statement is correct. Scientists have observed Orcas attacking an adult Blue Whale off Australia in 2019 in order to kill it. There exists a video on with the title "14 orcas kill adult blue whale." The German magazine “Stern” also published an article on this.
What is a longline?
Longline fishing is a type of industrial deep-sea fishing. It involves setting side lines equipped with many baited hooks on a main line made of plastic. These longlines can be up to 130 kilometres long and have more than 20,000 baited hooks.
Here in the Strait of Gibraltar, fishermen also fish with them, but they are only about 1-2 km long. To catch tuna, however, they take single lines, about 120 meters long, with a stone attached to the bottom end and a single fishhook with bait (fish or squid). In the case of the Spanish fishermen, the stone comes off the line when the bait reaches the bottom, and the line tightens. The Moroccans pull the stone back up, along with the catch.
Do whales have milk teeth?
No. If whales and dolphins lose a tooth, none grows back. Only the Sperm Whale has several teeth that can grow back. The German newspaper “die Welt” published on this subject:
Sperm Whales repair even their teeth themselves. (03.01.2003) The whale researcher G. Behrmann examined 50 different fossil teeth of Sperm Whales. It can now be said with certainty that Sperm Whales repair their teeth themselves. Their teeth have an ivory layer on the outside that can continue to grow for a lifetime.
If a hole has formed in the tooth due to decay, the ivory forms a fine mesh over it. This net is slowly closed. In addition, around 200 tiny, so-called tooth germs sit under each tooth in the Sperm Whale jaw. These are activated, push out and are incorporated into the net-like covering. In this way, holes with a diameter of 5 cm are closed again.
How deep can dolphins/whales dive?
It's not an easy question to answer. It is now known from Bottlenose Dolphins off the Bahamas that they dive up to 1000 meters deep. However, their diving time is not known.
Here in the Strait of Gibraltar, resident dolphins dive for 8 to 20 minutes at depths of 100 to 200 meters. The Sperm Whale, which is present here at times, dives up to 900 meters deep, with an average dive time of 40 minutes. The Fin Whales dive in the Ligurian Sea about 450 meters deep, with a dive duration of about 15 minutes.
Do the baleen whales' baleen fall off and grow back?
No, the baleens do not fall out, do not break off and do not grow back.
The horn plates that hang down from the upper jaw of a baleen whale are called baleen. They are made of the horn substance keratin, like human fingernails; they are also called whalebone. The baleen plates are one to three centimetres apart, fringed with hairy fibres, and together form a kind of sieve. Whales use the finely feathered baleen to filter plankton such as krill from the water.
How big is the brain of dolphins?
The brain of a Bottlenose Dolphin is comparable to ours in size, but there are differences in anatomy: it has more folds on the surface and the cerebellum is larger than ours. Sperm Whales have the largest brain in the animal kingdom, weighing up to 9 kg. Compared to the 1.5 kg in humans, it is several times bigger.
Dolphins are very intelligent. They have a self- awareness and personality. Their social behaviour is highly complex. They use tools, give themselves individual names, mourn their dead, can even adopt and apply behaviours across species. (Source Wikipedia)
Why do we let dolphins suffer in dolphinariums?
Dolphinaria are purely commercial facilities. Offering their visitors the chance to see dolphins or photograph them is supposed to bring them a lot of cash.
People are often unaware of how much the intelligent animals have to suffer in tanks that are far too cramped and filled with chlorinated water.
Torn from their family groups and their natural environment, they now have to live with other dolphins whose language they do not understand. Provided with food they don't like, which they nevertheless have to earn with acrobatic jumps to avoid constant hunger.