Adaptation to a specific vegetarian diet means that the animal becomes entirely dependent on certain vegetable species. That is exactly what happened to the lemurs on the island of Madagascar, just 400 kilometres from the south-east coast of Africa.
To maintain the 7,000 kilos which an adult elephant can weigh on the basis of a vegetarian diet, they need to spend a lot of time eating and searching. In fact, they spend three quarters of their life doing just that. A large male consumes around 300 kilos of food a day, and the name number of litres of water.
Therefore, a large herd must constantly be on the move, because it exhausts an area in just a few hours. However, a large part of Africa owes much to the elephants, and to a considerable extent this is due to the fact that their digestive system is not very efficient.
Of the vegetable matter they consume, almost 80% is expelled virtually undigested. In this way the nutrients which, over many years, the roots of the trees had taken from deep down in the soil, are returned to the surface, fertilising it. If we take into account the fact that an elephant defecates around thirty times a day and produces some 275 kilos of manure, we can see just how important this is.
In addition, it transports seeds which are then expelled at a considerable distance from where they were ingested, and deposit them with their dose of natural fertilisers, thus guaranteeing germination.
They are, therefore, the great gardeners of Africa.
If the elephants must travel long distances in search of plants, on the other side of the planet there is another species that also has considerable difficulties in this respect.
Sometimes, a gatherer’s main problem is simply reaching the places where the food grows. These marine iguanas on the Galapagos Islands are reptiles, generally called ‘cold blooded’, when in fact they simply need the sun to heat up their bodies. One after another, they dive back into the cold water, each time forced to swim further out to find the most nutritional banks of seaweed.
Their lives are a constant fine balance of energy, which at any moment could turn against them. That is the price they must pay for exploiting a resource which no one will steal from them.