Honest and Dishonest Signaling in Animals: A Biological Game Theory
Game theory takes place at the most basic levels of animal communication, I realized as I was sitting in my Intro to Animal Behavior class. Animal communication involves a sender and a receiver. A sender communicates a signal to a receiver, and the receiver acts upon the signal. In some cases a signal may be ‘honest’ meaning that the sender is displaying a reliable signal. A ‘dishonest’ signal is when the sender is sending out false information to a receiver. As detailed below, animals have to reconcile whether they want to send out such signals or not, since sending out such signals may also put them in danger. This reconciliation, or their cost-benefit decision they have to make is an example of game theory in action.
Peacocks bare flamboyantly colored feathers that attract other peacocks. The brighter the colors, the more attractive the peacocks appear to their potential mates. However, opening their colorful tails is a costly signal since peacocks risk being seen by predators. Game theory comes into play when the peacocks must choose whether they should open their tails to attract females or risk getting caught by the predators. In this case, the peahans have to decide whether the cost outweighs the benefits. If they are fit enough to out run predators and ready to mate, they may choose to take the risk and send their signal to the peahens. However, they may decide to not show off their colors if they decide they are too weak to run away from a lurking predator.
Dishonest signaling, although may not sound like it, can be a signal that animals relay at their own expense as well. The fiddler crab, notoriously known for its one large claw, must battle with other male crabs in order to win over the female. If a fiddler crab loses its claw in the fight, another claw grows in its place. This replacement claw is lighter and also not as effective as the original. The crab can still scare off other mates with its claw. His regrown claw sends a dishonest signal to other males that he is strong and able to fight. In addition, his claw still attracts females who don’t take notice of the change in claw weight. However, if challenged in a fight with another fiddler crab, he will likely lose. In this case, the crab is also playing with game theory. He can choose to send a signal to the other males by showing off his claw. In some cases, showing off may end up scaring other males and he may end up getting the female. In other cases, he may show off his claw and end up being challenged to a duel that he would not win.
- http://octavia.zoology.washington.edu/handicap/honest_biology_02.html
- http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1690591/