Natural-Born Cheaters: A Look at Double-Dealing Animals [Slide Show]

How animals deceive rivals, peers and mates to get what they want

CROSS-DRESSING CUTTLEFISH: A male cuttlefish places himself strategically between the female he wants to woo and a rival male (to the right of the image). He displays his masculine stripes on one half of his body but tricks his rival by donning a female spot pattern on the other half. While the rival ogles what he thinks are two females, this trickster passes on a capsule of sperm to his mate. But if he doesn’t position himself at exactly the right spot, he risks a fight with the often larger male. Martin Garwood
COWARDLY CAPUCHINS: This Capuchin monkey may be dodging battle. Capuchins live in groups and often fight over territory. Researchers have found that the more members in a group, the more likely individuals are to rely on others to defend their turf for them. Less cheating occurs in smaller groups, in which just one capuchin can swing the outcome of a skirmish. An attack’s location also predicts behavior: Less shirking occurs if the invaders reach the middle of a group’s home than if they’re on the outskirts. These dynamics mean that small groups often have a fighting chance. Flickr/maryatexitzero
DOUBLE-CROSSING MOTHS: A yucca moth deposits its eggs inside a yucca flower. Normally, moths pollinate the plants at the same time as they lay their eggs. Once hatched, the larvae feed on the product of pollination: yucca seeds. If the plant detects too many eggs in the flower, it will abort seed and fruit growth, but can only do so within five days of pollination. Some moths have evolved to exploit the system: They lay their eggs three to five days after other moths have pollinated the plant, bypassing the plant’s self-defense strategy and ensuring a hearty meal for their future larvae. Adding insult to injury, cheater progeny devour about two thirds of a plant’s seeds compared with the measly one quarter consumed by non-cheater larvae. Olle Pellmyr
SNEAKY CLEANERS: Cleaners swim alongside larger fish, such as this surgeonfish, munching on parasites that live on the host’s surface. They often perform this service in male–female pairs. But sometimes one cleaner will break the social contract by taking a tasty bite of the mucus that coats the larger fish’s skin. Hosts retaliate by shaking cleaners off and swimming away, and the rule-abiding cleaner will often chase its miscreant partner. Researchers have found that male cleaners are the bigger cheaters, but they’re also more likely to retaliate when a female snags a bite. Gerry Allen
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DIRTY DICTYOSTELIUM: The fruiting body shown here is the amoeba Dictyostelium discoideum’s response to low food conditions. In trying times some amoebae will sacrifice themselves to form the stem of this structure, so that other members of the group can climb up to become the bulb. There they have a better chance of dispersing their spores to new places that may have more food. A mutant amoeba, aptly named cheater C, takes advantage of this division of labor and resists becoming part of a stem. When in a group with noncheaters, cheater C mutants are overrepresented in the bulb, forcing more of those without the gene to become part of stalk. Alex Wild
FINCHES WITH FORESIGHT: Zebra finches know when not to double-cross a fellow finch. In a bird version of the prisoner’s dilemma game, zebra finches were trained to decide between sharing seeds with another finch by hopping onto a lever or doing nothing. Over multiple rounds mutual cooperation garners more seeds for both players. But if only one round is played, the birds gain a larger reward by being uncooperative. When pitted against their mate (with whom they form a monogamous pairing), finches cooperate—but not when they’re up against another player of the opposite sex. These finches seem to cheat only when their opponent is a bird they’re unlikely to interact with in the future. Flickr/wwarby
CUCKOLD BABOONS: This Gelada baboon couple is copulating after the male’s victory over the former alpha male. Geladas live in communities that consist of an alpha male, many females and a few weaker males. The dominant male tries to maintain sexual exclusivity with his females by charging at them when they try to mate with another male. Fortunately for him gelada females are quite vocal, making it easy to catch them in the act. But some gelada females are devious. Researchers have observed them keeping mum when they’re with a nondominant male, a strategy that helps them get away with the duplicitous deed. Aliza le Roux

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