Behaviour of Whales and Dolphins Connected to Brain Size

Scientists have found out that the behaviour of marine mammals, especially dolphins and whales, is connected to their brain  size . In a recent study, researchers have found out that mammals with larger brains behave in a more complex way.

Researchers have collected information on about 90 different types of dolphins and whales. They found out that social behaviour among these two  species is more complex  than previously thought.

Whales, for example, change calling songs regularly and pass certain information on to their younger ones and other groups. They use various languages which are similar to human dialects. Sperm whales, with a brain six times the size of a human one, organise other whales to babysit for them while they go hunting for food.

Other whale species, like blue or humpback whales, have smaller brains. They live in a more solitary way and don’t have long-term relationships.

Dolphins have a way of contacting  other individuals , even if they are not present. Scientists regard this as a form of gossip. As well as having rich and varied diets, they play and hunt  together.

Scientists think that bigger brains have evolved in order handle the complex way that mammals socialise.

Sperm whales
Sperm whales – Image : Gabriel Barathieu

Words

  • behaviour = the things that a person or animal does
  • brain = the organ inside your head that controls how you think , feel and move
  • complex = here: with many different parts; difficult to understand
  • especially = above all
  • evolve = develop
  • gossip = information that is passed on to others about how they behave
  • handle = deal with
  • mammal = type of animal that drinks milk from its mother’s body when it is young
  • marine = in the sea or ocean
  • previously = before now; some time ago
  • recent = a short time ago
  • regard = think, consider
  • regularly = often
  • researcher = a person who studies something closely in order to find out more about it
  • scientist = a person who is trained in science and works in a lab
  • similar = like
  • size = how big something is
  • social behaviour = here: the way they behave in groups
  • socialise = here: to spend time together with others or in groups
  • solitary = spending a lot of time alone; not in a group
  • species = group of animals or plants that are similar and can have babies together
  • study =  a piece of work done to find out more about certain things
  • varied diet = here: they eat all kinds of different food
  • various = different kinds of …