• Question: how do animals in colonies communicate to make a swarm?

    Asked by to Catherine, Thon, James, Natalie, Shaylon on 13 Jun 2014. This question was also asked by .
    • Photo: Catherine Offord

      Catherine Offord answered on 13 Jun 2014:

      Hi Chloe, great question – and one that lots of scientists are trying to answer!

      The way that colonies communicate depends a lot on what animals make up the swarm. For example, if we’re talking about a swarm of land mammals – such as a herd of wildebeest – then mostly animals are using sight. If one animal sees a predator, then it might respond by running in a certain direction. Other wildebeest see that behaviour, and they do the same thing, running in the same direction. We end up with a swarm because all the animals are moving together and responding to what we call ‘their near neighbours’ (i.e. who they can see in front and to the left and right).

      In bees, it works differently. Scientists have recently discovered that honeybees cause a swarm to happen by making a sort of high-pitched whistling noise (the behaviour is called ‘piping’) inside the hive. This noise gets all the other bees excited until they all fly out of the nest together in a swarm.

      My favourite example, however, is locusts. Normally, locusts are quite happy walking around on their own. But if they run out of food and get really hungry then they go through a very weird change. Firstly they change colour, and secondly they start trying to bite the back of nearby locusts. This causes other locusts to start walking away from them, and also bite the locusts in front of them. So locusts start swarming because of starvation, and they communicate by biting each other in the tails!

    • Photo: James Bell

      James Bell answered on 17 Jun 2014:

      This is more Catherine’s area of expertise and she’s given a really good answer (I love the bit about the locusts). I have thought of an extra way that animals communicate in swarms which is by making special chemicals called pheromones. These are like chemical messengers that tell other animals what to do. Bees use this kind of communication to co-ordinate group responses to a threat (for example when their hive is under attack from a hungry bear).

      Some scientists are even using the system used by bees as a model to design swarming robots that work together (although I don’t know how – robotics sounds very complicated to me)

    • Photo: Anthony Caravaggi

      Anthony Caravaggi answered on 24 Jun 2014:

      In birds, swarming (or ‘flocking’) seems to depend on your neighbours. Scientists have found that starlings, which can form large flocks (see the video below), react to their nearest 7 neighbours at most. A movement by one bird makes the 7 nearest it to react, which makes the 7 nearest each of them to react, and so on, resulting in coordinated movements.

      (Sorry about duplicating my earlier comment, by the way. It wasn’t showing up for me, so I thought I’d make sure).

Comments

  • Photo: Thon

    Thon commented on :

    I don’t have much to add Catherine’s excellent answer, other than to present a link to a video of a starling swarm (or, ‘murmeration’). Starling murmurations are one of my favourite natural spectacles. They work by each bird reacting to the behaviour of others around it. But they don’t affect all their neighbours. Scientists have found out that each bird only affects its closest 7 neighbours. These neighbours then affect their neighbours, and so on, resulting in magnificent rhythmic waves. If you have the chance to go and watch a starling murmuration, I highly recommend that you do so.

  • Photo: Ian

    Ian commented on :

    In film special fx we have special software to simulate “flocking systems”. While they’re not intended to be “scientifically accurate”, its important they produce results that look a like what be see in nature.

    There’s no explicit communication, but each animal is trying to do three basic things:
    1) avoid hitting or getting tool close to other birds
    2) try and move in the same direction as neighbouring birds
    3) try and move toward the centre of the flock.

    There are loads of variations, but these three basic rules are used whenever your see a flock or a herd in a movie. You can read more here:http://www.red3d.com/cwr/boids/

  • hannah133 commented on :

    what is your favourite part of being a scientist