How monkeys make friends in high places

Scientists have found how ‘immigrant’ species of monkeys make friends with other species in order to be accepted in their new community. Despite competing for the same living space and food, the monkeys manage to coexist successfully, by helping their new neighbours defend against mutual predators.

The psychologists at the University of St Andrews studied an area of rain forest in West Africa’s Ivory Coast for levels of co-operation and co-existence between forest monkeys. They found that because of its merits in warning fellow monkeys of potential predator threat, one immigrant species was welcomed to the existing community rather than avoided or not allowed to settle there.

The research was conducted in the Taï National Park by Dr Klaus Zuberbühler of St Andrews and Winnie Eckardt of the University of Leipzig, over a period of 2 years.

They initially found that seven species of monkeys managed to co- exist peacefully in the same community by restricting their living space to separate areas of the forest, thus not having to compete for food.

Dr Zuberbühler explained: “Diana monkeys typically forage in the highest tree crowns, while the closely related Campbell’s monkeys exploit the vegetation close to the ground. Such niche separation decreases interspecies competition and makes coexistence of closely related species possible.”

However, there was a potential conflict with one immigrant species, which preferred the same living space as an existing species – the newly migrated putty- nosed monkey preferred the same high living area as the Diana monkey. The researchers believe that the putty-nosed monkeys immigrated into the rainforest because of the destruction of their preferred natural savannah habitats by humans.

Though the more dominant Diana monkey was found to prevent the putty-nosed from successfully colonizing the rainforest, the researchers found that they allowed the newcomer to live and eat almost in the same area of the forest. Despite chasing the immigrants away from feeding areas when food was scarce, the Diana monkey was found to tolerate the incomers because of the advantages they offered through vigorous anti- predator behaviour. The loud and conspicuous warning call of the male putty-nose whenever a crowned eagle was present, was recognised as a warning by the Diana monkeys, thus making the putty-nosed an extremely valuable partner species.

Dr Zuberbühler explained: “Our results show that Diana monkeys tolerate immigrating putty-nosed monkeys and form mixed-species groups with them because of their merit in predation defense. Particularly, male putty-nosed monkeys play a vital role in defense against crowned eagles, suggesting that putty-nosed monkeys obtain access to feeding trees by offering anti-predation benefits to Diana monkeys.” The findings of the research are published in the paper ‘Cooperation and competition in two forest monkeys’ in the current issue of ‘Behavioral Ecology’.

ENDS

NOTE TO EDITORS:

DR ZUBERBÜHLER IS AVAILABLE FOR INTERVIEW ON 01334 462080 OR [email protected]

NOTE TO PICTURE EDITORS:

JPEGS AND SOUND FILES OF THE MONKEYS AND THEIR CALLS ARE AVAILABLE FROM THE PRESS OFFICE – CONTACT DETAILS BELOW.

Issued by Beattie Media On behalf of the University of St Andrews Contact Gayle Cook on 01334 467227, mobile 07900 050 103, or email [email protected] Ref: immigrant monkeys pr 310504.doc View the latest University news at http://www.st-andrews.ac.uk