So there are singles, couples, families large and small, caring fathers and others who take no interest in their offspring. The researchers were surprised to discover that the striped mouse's social status also depends on different environmental conditions.

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In the Namaqualand region of southern Africa, researchers endure temperatures of over 40 degrees Celsius in the shade... while they wait to observe their study subject. The striped mice living in this semi-arid region exhibit varying social patterns - they can either set off on their own... or join together to form extended families.

Most commonly, two to four sisters pair up with a male from outside the family. Their grown male and female offspring then spend several months living with their parents. Such flexible family structures within an animal species are a rare occurrence. And in contrast to other mice, striped mice are active during the day. They're extremely adaptable.

Carsten Schradin, Biologist: "After five years of field study, we know more about the striped mouse's natural behaviour than any other species of mice."

In the Goegap Nature Reserve in northwestern South Africa, biologist Carsten Schradin from the University of Zurich has set up an observation post along a well-used mouse trail. But for the international team, the field research isn't as easy as it looks... even though curious mice often pay a visit to the station. Observation means hours of strenuous concentration in searing heat. And in order to make valid observations about the mice's family patterns, the biologists have to be able to identify the rodents individually, which means first having to catch all the mice in a group and mark them.

The striped mice aren't exactly afraid of the traps and are easily lured by the treats. But for some of the more clever mice, it doesn't take long to free themselves. And they're persistent ... they keep looking for what they came after. But in the end, they all get marked with the non-toxic dye. For the mice, the procedure is completely harmless.

The markings allow researchers to figure out who's sleeping with who from a distance ... and to untangle the mice's complicated relationship webs. They also study how long the adult offspring postpone their own reproduction in order to help raise their siblings. It usually only takes a few hours of observation to assign the various roles within the family group. And even though the biologists maintain their distance, sometimes they become the subject of observation themselves. Another of their methods is telemetry. This tracking tool allows the researchers to find out how far the individual family members travel in their search for food.

Carsten Schradin, Biologist: "The striped mouse lives under extreme environmental conditions - cold, damp winters... bountiful springtimes... then hardly any food at all during the drought of the dry period. But the conditions don't just vary within a year. The striped mouse's environment can also vary from year to year. Their social flexibility allows them to adapt to a changing environment and that's how they survive."

When there's enough food, the striped mouse of the Namaqualand prefer to live communally. The male, his female partners and their offspring gather in the early morning hours to snuggle and warm up. Then it's time for everyone to hunt for food. The family members don't meet near the nest again until early evening. And they sometimes encounter other species, like the elephant shrew, for instance. And here again the striped mice exhibit another advantage of communal living - they're better able to protect their food sources.

But in times of scarcity, the striped mouse is also able to function as a loner of sorts... The result is fewer mice living in the same settlement area, mostly just a few single mothers with their offspring. This kind of social flexibility has proved successful for the striped mouse. It's the most common mammal in all of southern Africa, and has even managed to thrive in extreme desert environments like Namaqualand.