Recent research has shown how female meerkats compete to be the biggest and ensure a dominant role.
A single pair of meerkats dominates over a group of roughly 20-50 individuals. The largest and heaviest of the meerkat community will become the dominant pair, and these two will become the main breeders of the group. The other meerkats will help raise, feed, and protect the dominant pair’s young.
To rise to the top of the pile, other females must wait until the dominant female dies. The once-dominant female tends to be replaced by the largest of her siblings, but this is where sibling rivalry comes in.
Researchers have studied this competition by keeping track of pairs of sisters. The younger of the two was regularly fed more than the older – a nourishing meal of hard-boiled eggs – allowing it to gain weight and grow rapidly. Over three months, the pairs were frequently weighed, and the team discovered that as the younger sibling grew, it triggered the older sister to increase her own food intake. In this way, she could ensure she wasn’t overtaken by her younger sister.
To show that she was no pushover in the face of a rapidly-growing sibling, the elder would continue to grow and gain more weight, keeping just ahead in the race, and so remaining dominant.
It appears that meerkats compete and keep an eye on the competition, adjusting their own growth rate and size to keep one step ahead of their rivals. This is the first evidence of competitive growth in a species of mammal, which may open the door for similar behaviours in other social animals.
Huchard, E, English, S, Bell, M, et al. (2016) Competitive growth in a cooperative animal. Nature, doi:10.1038/nature17986
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