sis_10_2-25_RZ:Layout 1 14.11.2008 14:32 Uhr Seite 20 Sentinels: meerkat superheroes Mico Tatalovic from the University of Cambridge, UK, investigates the private lives of meerkats. Why do these small carnivores live in groups? Why do they feed each other’s pups, dig together and guard each other? And what makes a really good sentinel? lower is an internationally worry comes into her head: reproduc- Meerkats sunning themselves. Facclaimed television star. The Especially in winter months, meerkats ing. Such is the nature of natural Discovery Channel’s series Meerkat sun themselves to warm up in the selection: only those who survive Manor, the first ‘animal Big Brother’ morning before foraging, and in the long enough to reproduce will spread show, made her cute little face popu- evening before going to sleep their genes to the next generation. lar around the globe. Now a feature- Flower is a descendent of a long line length biography has also been Tatalovic Image courtesy of Mico of survivors. This means she has released with an accompanying book, adaptations that allow her to survive Meerkat Manor: The Story of Flower of despite the many predatory species the Kalahari. out to get her. Flower’s story only reached the Birds of prey, wild cats, jackals, world because of the research efforts snakes.... If it’s bigger than a meerkat of scientists based at the University of and it eats meat, it’s probably a threat. Cambridge, UK, who set up the Living in a group is an advantage; Kalahari Meerkat Projectw1 15 years many eyes see better. But meerkats ago and have studied the lives of sev- have evolved an even more sophisti- eral meerkat groups daily ever since. cated strategy to avoid predation: Such long-term field projects have posting sentinelsw2, usually one but become popular in the field of behav- sometimes several at the time. Like ioural biology because they permit soldiers on guard, meerkat sentinels the accumulation of an enormous scan the horizon from an elevated amount of data on every aspect of post and announce their duty with a animals’ lives, allowing scientists to special sentinel call, the ‘watchman’s ask and answer ever-more detailed song’. They have excellent depth per- questions about their evolution. ception that allows them to see preda- When not on camera, Flower, like tors at a great distance. Having a sen- other meerkats (Suricata suricatta), has tinel on guard reduces the possibility to worry about two main things in of surprise attacks and allows the rest life: finding food, and avoiding being of the group to be less vigilant. eaten herself. When the right time Sentinel behaviour may seem altru- (and the right male) comes, a third istic since the sentinels help others at 20 Science in School Issue 10 : Winter 2008 www.scienceinschool.org sis_10_2-25_RZ:Layout 1 14.11.2008 14:32 Uhr Seite 21 Cutting-edge science Meerkat research The Kalahari Meerkat Project was set up some 15 years All pups are caught and an identity microchip is inserted ago by Professor Clutton-Brock from the University of under their skin in case the dye marks on their fur wear Cambridge, UK. Since then, the Cambridge scientists have out. Blood samples are also taken at regular intervals collaborated with colleagues in other countries, especial- throughout their lives, to obtain both their DNA and hor- ly at the University of Zurich in Switzerland and Pretoria monal profiles. This helps researchers to determine rela- University in South Africa. tionships within and between the groups and to correlate All meerkats involved in the project are wild but habituat- behaviours with hormone levels. The animals are captured ed to people and are easily identifiable by small dye marks for only a few minutes, to avoid stressing them too much. that the researchers and volunteers have painted on them. For the scientists, a typical day of meerkat research These dye marks make for easy identification, as ‘head and involves waking up before sunrise to arrive at the sleeping shoulders’ is different from ‘right rib, right thigh’. Familiar burrow before meerkats get up. Various records have to be with people since birth, the animals ignore us so we can kept, such as where the animals slept, when they got up, observe them from as little as 0.5 m away and walk among how heavy they are (we use small crumbs of hard-boiled the group without disturbing their normal behaviour. Since egg to lure them onto scales, saying “yum, yum, yum!”). most meerkats are studied from birth, each individual’s We also count and identify all the animals to check the parentage and life history is recorded. group’s composition and then follow them for three hours The project manager makes a weekly schedule of group while they forage for food and avoid predators. When fol- visits to allow researchers (master’s students, PhD students lowing them, we also take regular GPS readings to calcu- and postdoctoral researchers) to visit the meerkat groups late the routes that the meerkats take on their foraging they need for their experiments and to make sure all trips. At midday, when the meerkats have a siesta to avoid Tatalovic Image courtesy of Mico groups are visited at least a couple of times a week by vol- the heat of the desert sun, we leave to have lunch and unteers to keep track of where the animals go and what return in the afternoon for more data collection. Afternoon they do. In every group, one animal has a radio collar that experiments might include playing the meerkats’ own allows it to be tracked; most of their sleeping burrows are vocalisations back to them or presenting them with pred- BACKGROUND also labelled with GPS points so it is easy to locate them. ator cues or faeces to observe their responses. Meerkats resting. In the summer months, meerkats rest at midday to avoid the heat www.scienceinschool.org Science in School Issue 10 : Winter 2008 21 sis_10_2-25_RZ:Layout 1 14.11.2008 14:32 Uhr Seite 22 Meerkat society Meerkats (Suricata suricatta) are small, carnivorous Meerkats reach adulthood at around one year of age. At mammals weighing on average less than one kilogram. around 18-30 months of age, males voluntarily leave the They inhabit the arid areas of southern Africa and live in group, either to join an existing group or to form a new social groups of 2-50 individuals, consisting of one dom- group with unrelated females. Adult females, particular- inant pair and a variable number of subordinate helpers ly pregnant ones, may be evicted from their home group who may or may not be related to the dominant pair. by the pregnant dominant female; this is thought to These members of the mongoose family (Herpestidae) reduce the chance of the dominant female’s pups being eat mainly arthropods (insects, spiders and their rela- eaten by the other females. Most females return to the tives), as well as the occasional small mammal, reptile or group once the dominant female has given birth, but plant bulb. some may permanently disperse to form new groups They have territories with several sleeping burrows, from with unrelated males. which they make daily foraging trips of up to a few kilo- Dominant meerkats live for 6-10 years on average, with metres. Depending on food availability and predation the oldest individual in the Kalahari Meerkat Project pressure at specific spots, they will either return to the being almost 13 years. The age of subordinate meerkats same sleeping burrow for several nights, or change bur- is more difficult to record, as many disperse or are rows quite frequently. evicted by the age of around three years, and are subse- On average, litters consist of three to four pups that stay quently lost to the project records. The most important within the burrow until they are approximately three known causes of death are predation, fights with other weeks old. During that time, while the pups are being meerkats (including infanticide), diseases and human- fed on milk, the group returns to the same burrow. At caused factors such as car fatalities – but for two-thirds four weeks of age, the pups begin travelling with the of the Kalahari Meerkat Project meerkats, the cause of group and for their first three months of life, are fed on death is unknown, since the individuals just disap- invertebrates and small vertebrates by helpers. peared. BACKGROUND Image courtesy of Mico Tatalovic Image courtesy of Mico their own expense: when they are meerkats, to give us preliminary guarding, they not only expend energy answers and to help us formulate and and lose valuable foraging time, but test theories. also expose themselves to predators. Flower keeps guard from trees, But are they really being altruistic? logs, bushes, grass tufts or even My research group investigates con- human heads. The average height of flicts and co-operation in meerkat the posts from which meerkats keep societies, and as part of this work, I guard is around 60 cm although the focus on sentinels. One of the main bravest sentinels will climb trees up questions I am investigating is why to six metres high. The height of the some meerkats spend more time on sentinel’s post also varies with the guard than others. An answer to a vegetation cover; during the rainy simple question like this can give us season when grass is tall, sentinels valuable insights into the evolution of guard from higher posts so that they Meerkats at a sleeping burrow.