Competitive males are a blessing and a curse, study reveals

Date: November 14, 2016

Source: University of Queen Mary London

Showy ornaments used by the male of the species in competition for mates, such as the long tail of a peacock or shaggy mane of a lion, could indicate a species' risk of decline in a changing climate, according to a new study from Queen Mary University of London (QMUL).

Males of many animal species compete for mates, either by producing showy ornaments to attract females, such as the plumes and bright colours of male Birds of Paradise, or, like stags and elephant seals, by fighting with other males for access to mates. Scientists have shown over the last few years that in many of these cases the winning males are fitter because they carry genes that make them better adapted to the environment -- the so called 'good genes' effect.

The researchers from QMUL's School of Biological and Chemical Sciences investigated whether these 'sexually selected' animals might be better able to cope with changes in the environment such as increasing temperatures or acidity.

Using a sophisticated mathematical simulation model that integrates both ecological and evolutionary processes, the researchers found that sexually selected species can adapt faster to new environments, and are less likely to go extinct. There is a twist in this peacock's tail though -- this effect only happens when the animal populations are large. When the populations are small, the presence of competitive males can actually make a population more likely to become extinct.

This is because males pay a high price for engaging in their competitions. Either they have to invest lots of energy in expensive displays, which then make them more vulnerable to predators, or they get injured and even killed in fights with other males.

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Chimpanzees choose cooperation over competition

Study challenges distinctiveness of human cooperation

Date: August 22, 2016

Source: Emory Health Sciences

When given a choice between cooperating or competing, chimpanzees choose to cooperate five times more frequently Yerkes National Primate Research Center researchers have found. This, the researchers say, challenges the perceptions humans are unique in our ability to cooperate and chimpanzees are overly competitive, and suggests the roots of human cooperation are shared with other primates. The study results are reported in this week's early online edition of the Proceedings of the National Academy of Sciences.

To determine if chimpanzees possess the same ability humans have to overcome competition, the researchers set up a cooperative task that closely mimicked chimpanzee natural conditions, for example, providing the 11 great apes that participated in this study with an open choice to select cooperation partners and giving them plenty of ways to compete. Working beside the chimpanzees' grassy outdoor enclosure at the Yerkes Research Center Field Station, the researchers gave the great apes thousands of opportunities to pull cooperatively at an apparatus filled with rewards. In half of the test sessions, two chimpanzees needed to participate to succeed, and in the other half, three chimpanzees were needed.

While the set up provided ample opportunities for competition, aggression and freeloading, the chimpanzees overwhelmingly performed cooperative acts -- 3,565 times across 94 hour-long test sessions.

The chimpanzees used a variety of enforcement strategies to overcome competition, displacement and freeloading, which the researchers measured by attempted thefts of rewards. These strategies included the chimpanzees directly protesting against others, refusing to work in the presence of a freeloader, which supports avoidance as an important component in managing competitive tendencies, and more dominant chimpanzees intervening to help others against freeloaders. Such third-party punishment occurred 14 times, primarily in response to aggression between the freeloader and the chimpanzee that was cooperatively working with others for the rewards.

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Restricting competitors could help threatened species cope with climate change

Date:

June 24, 2014

Source:

Durham University

Summary:

Threatened animal species could cope better with the effects of climate change if competition from other animals for the same habitats is restricted, according to new research. Observing the goats in the Italian Alps during the summer, the researchers found that Chamois tended to move to higher altitudes where it is cooler on hotter days and in the middle of the day, but moved much higher when sheep were present. To their surprise, they discovered that competition with sheep had a far greater effect on Chamois than the predicted effects of future climate change.

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How Cooperation Can Trump Competition in Monkeys

ScienceDaily (July 4, 2012) — Being the top dog -- or, in this case, the top gelada monkey -- is even better if the alpha male is willing to concede at times to subordinates, according to a study by researchers from the University of Pennsylvania, the University of Michigan and Duke University.

Alpha male geladas who allowed subordinate competitors into their group had a longer tenure as leader, resulting in an average of three more offspring each during their lifetimes.

The findings, collected from data during a five-year period ending in January 2011 through the University of Michigan Gelada Research Project, were published in the Proceedings of The Royal Society.

The research was conducted by Noah Snyder-Mackler, then a graduate student in the Department of Psychology in Penn's School of Arts and Sciences. He collaborated with Thore Bergman, assistant professor of psychology at Michigan, and Susan Alberts, professor of biology at Duke.

Cooperation is surprisingly common among wild animals, the researchers said. While it makes evolutionary sense for animals to help their kin, it is harder to explain cases where competitors -- especially unrelated adult males -- join forces. This conundrum is particularly hard to explain because mating is generally a zero-sum game in which males can only reproduce by stealing mating opportunities from each other.

Continued:  http://www.sciencedaily.com/releases/2012/07/120704021831.htm