The meerkat is one of the most cooperative mammals in existence — so says University of Cambridge professor Timothy Clutton-Brock. He has been watching the animals in their home in Africa's Kalahari Desert since 1993. Meerkats are so cooperative that females cannot rear pups without a team of personal assistants, who help with feeding and defending the young. Yet despite this cooperation, females do compete to determine who gets to be the breeder of the group.

To understand the nature of this competition, Clutton-Brock relied on data he had collected during a 12-year collaborative study with the University of Pretoria in South Africa. Six years ago, the team bought a 3,500-hectare area in the Kuruman River Reserve, just south of the South Africa–Botswana border, which is home to 15 distinct groups of meerkats. “It was important to have our own study site, because you run into all kinds of problems if you work in an area that someone else controls,” says Clutton-Brock. “It's like setting up laboratory in someone else's kitchen.”

Working around the clock in teams of six to eight researchers, they gathered data on the behaviour and characteristics of individual meerkats, identified by markings on their fur. They studied more than 1,000 meerkats, and scored them on their attempts to breed, contributions to the group, social interactions and other behaviours. Data collection was helped by the fact that the meerkats quickly became used to having people watching them. “They took as much notice of us as rabbits do of grazing sheep,” says Clutton-Brock. They were so tame that the researchers trained them to walk onto electronic scales at dawn, midday and dusk to monitor their food intake and growth.

Sex difference is not the only factor that determines competition.

In meerkat groups, females compete more intensely than males to gain dominance (see page 1065). This is unusual, because in most animal species the males, who spend less energy rearing the young, tend to compete more intensely for breeding opportunities. Although meerkat females invest more in their young than do males, they are also the more aggressive competitors. “This means that sex difference is not the only factor that determines competition,” says Clutton-Brock.

Generally, only one female in a group of between 3 and 50 meerkats gets to breed, typically two to three times a year for a tenure of up to 10 years. Each group also includes one or more dominant males — who father most of the offspring — and several helpers of both sexes. In extremely harsh environments, where chances of survival are slim, females may have to compete more intensely than males to keep other females from breeding. To ensure their status, dominant females have a suit of typically male characteristics, including high levels of testosterone and higher body mass. Conversely, dominant males do not have these attributes.

As data collection continues, the South African research facility will allow researchers to ask increasingly sophisticated questions, such as how cooperative behaviour is inherited. “Projects like this provide an important facility for the future,” says Clutton-Brock. “The studies may well go on indefinitely.”

Clutton-Brock's meerkats are not only advancing science; they are also making a splash in the movie world. After the success of The March of the Penguins, the BBC has started filming a full-length feature film focusing on the meerkats' struggle to survive. This follows in the wake of the successful docu-drama Meerkat Manor, a TV series shown in the United States, United Kingdom and Australia that followed the everyday life of a meerkat family.