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September 26, 2018

Overcrowding affects animals' behaviour too

Overcrowding affects animals’ behaviour too
Overcrowding affects animals’ behaviour too

I am not anymore in wonder why we have such bad traffic snarl ups on Magadi road as you approach Ongata Rongai. Since I moved to this part of the larger Nairobi, I have almost stopped going to town. I mean, Nairobi city centre. It takes a whole day to go to the city centre and back to Ongata Rongai, a distance of 30kms. All because of traffic jams. But I realise that what made me move away from the city was reason enough to attract the same move from other Kenyans living in the big city. We all want to move away from the hustle and bustle of city life to a more serene and quiet environment. While that is happening, those who have not experienced the vagaries of city life are streaming in from the rural areas to join the city of hope. As the tap empties the pot, another pipe is feeding the pot. Now the Magadi Road has become as bad as the city roads. The effects of mass exodus is overwhelming. Population overcrowding can bring about behavioural change in people, just as it does in the animal world. Some changes in behaviour can be detrimental, as research scientists have found out

Universe 133 is a name given to a mouse cage with four levels, built for science research. The cage is at the American National Institute of Mental Health, in Bethesda, Maryland. It contains eight cells of equal size, where they put water and food dispensers for the mice. In total, they had 192  animals living in the cells. They exhibited normal behaviour since this number was the optimum figure for a comfortable life. But the researchers at the institute wanted to find out the effect it would have on the mice if the figure exceeded the optimum level. So they allowed the population to grow without changing the living space, but giving the mice enough food and keeping them in good hygienic environment. The mice mated, produced a second generation, a third and so forth. The population grew to such a figure that the mice could no longer interact with one another in the normal way as they used to do. Their universe was shrinking fast.

Initially, it was possible for the mice to develop a certain feeling of ownership, to albeit a small world that a male would call his conquest. Territories were known and even if not totally isolated and guarded, there was a semblance of hierarchical order. But with the population explosion, there was no longer space enough to be owned by individuals. There was no order in establishing mating partners. Things just fell apart.

Mating eventually ceased altogether and the numbers started falling precipitously from a peak of nearly 1,600 mice. The mice, it seemed to the researchers, were so overwhelmed by the congestion that they were failing to develop mating relationships. What is more, the behaviour necessary for the parental care of the young was also extinguished by overcrowding. The usually good mothers were becoming neglectful. It was no longer important for fathers to behave like fathers. The usual respect accorded to the territorial leader was lacking. Each mouse was concerned with its own existence.

If these findings can tell us anything about human population patterns, then they can represent an important warning. It is most likely that the behavioural changes we are seeing in people today are caused partly by overcrowding. We might exclude the effect of poverty from the equation because as we have seen, the mice were kept well fed and in a hygienically sound condition, but allowed to populate with limited space. And that is where the trouble was to be found.

Over Christmas, the city was like a ghost town. All those who could, had migrated to the rural area, and those who could afford had gone to the national parks – not necessarily to see the animals, but to experience the peace and tranquility found in the quiet and unpopulated environment. Even if it is just a week, the difference in behavioural aspect is enormous. A peaceful mind enables other parts of the body to function normally. Ten months from now, we will begin to see the results of a peaceful out of town vacation during Christmas. But that will ultimately add to our dilemma... More people.

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