Communication is a critical element in social behavior. Communication can be as simple as a female moth producing an odor which attracts potential mates, or as complicated as the information about food locations conveyed in honey bee dances.

Modes of communication

Animals choose among a wide variety of media for communication. These inlcude the big four--vision, olfaction, hearing, contact--plus a plethora other possiblities, such as magnetic fields and electrical discharges. Choice of signal medium is driven by differences in how directional a signal might be, how far it might travel, and how fast it might travel. Distance and speed are not always maximized, as some signals are best restricted to close-by individuals, and may actually attract predators or parasites if they travel too far.

This link leads to a more detailed comparison of the communicatory modalities.

Communication requires a sender and a receiver. The sender has an organ or structure which constitutes the signal (for example, the peacock's tail) or which produces the signal (examples inlcude vocal cords and associated structures, scent glands, and electric organs. The receiver has receptors, which are usually modified nerve cells. These cells, such as rods and cones in the eyes, hair cells in ears, and the olfactory epithelium, transduce the signal into nerve impulses which are processed by the nervous system. Decoding sensory information is a critical task of the nervous system; noise and extraneous impulses must be separated from meaningful signals.
In some cases an animal communicates with itself, as in the echolocating behavior of bats. This is autocommunication when the sender and receiver are the same animal.

Evolution of communication

You might assume, because communication often involves individuals who share a common goal, such as mating, feeding, or caring for their young, that communication evolves as simple sharing of information. This sharing then would enhance their aility to reach the goal. In fact, however, conflicts of interest and assymetries underly many, perhaps most, interactions among animals. Deceit may be more common than honest signalling; interacting animals act in their own best interest and convey the information, honest or not, needed to enhance their fitness.

Follow this link for a consideration of deceit versus honest signalling.

From the sender's point of view, communication evolves

  • To minimize the time and effort spent on communication
  • To present a message (signal) advantageous to the sender

From the receiver's point of view, communication evolves

  • To enhance acuity, so that the maximum information can be obtained from the signal
  • To separate honest from deceitful signals

Game theory and communication

Game theory provides a very useful framework for analyzing communication. Remember that an animal communicates, it has a goal, which may be in conflict with the goals of other animals. This means that strategy and tactics play very important roles in animal communication.

To apply game theory, an animal behaviorist goes through the following steps

  1. Identify possible strategies. These may be based on observation (what do the animals actually do?) or logic (what alternatives can the scientist think of?).
  2. Determine the outcomes when different tactics are played by each animal. In the Prisoner's dilemma, we specified payoffs for cooperating and defecting, depending on the behavior of the opponent.
  3. Through repeatedly playing the game, determine whether one strategy is always superior (an evolutionarily stable strategy).
  4. Observe animals in the field to see if their communicatory strategies fit game theory predictions.

The hawk versus dove game, which models whether animals should fight or not in territorial disputes, is an excellent example of the application of game theory in the analysis of communication.

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copyright ©2001 Michael D. Breed, all rights reserved