A child could tell you

I was invited to discuss with 5th standard children at Hebron, Ooty, about the elephant corridors of the Masinagudi-Sigur Region. I was surprised by this choice, but many children live in and around Ooty and are familiar with the difficult issue of maintaining passages for elephants. Their teacher asked them to define an action plan and my role was to help them understand some of the technical issues. The class was curious about the identification of corridors, which is done with field data, maps and whatever relevant document put together in a geographic information system (GIS). We also watched our video Maximus (link here) in order to help them realize that a corridor’s width depends on human activity. Whenever humans are discreet, corridors can be narrow, whenever humans are causing disturbance, corridors must be wide so that animals can move around. After a week or so later, I was requested to rate their action plan. I was not disappointed.

All the children had concluded something like: “elephants are harassed, the Government should remove anyone in the way of the animals, punish encroachment, night safaris, flashing wildlife, etc.” At first, I was surprised and smiled of the innocence borne by these statements. But I could not find anything wrong with them. The children proposed solutions that targeted people who mostly, are in the wrong. So what should adults be doing? Should we teach children to compromise and continue to destroy a world that will soon belong to them, or should we learn from them? The truth is that many scientists are concerned that if we continue to damage our biosphere the way we do, humanity will face enormous problems. These problems have the potential to ruin our civilization. It is strange that children sense potential solutions when we, adults, cannot. My only explanation for this amazing state-of-affairs is that greed and compromise haven’t destroyed their power of reason yet. And actually, when you think about it, we humans show very little reason in the way we manage our planet.

Jean-Philippe Puyravaud

If you think India has a population of 2000 tigers, you are mistaken

Photo: Rémi Daudin

I follow Conservation Bytes (https://conservationbytes.com), a blog maintained by Dr. Corey Bradshaw, an Australian scientist. He specializes in mathematical modeling of ecological processes, in particular, that of population genetics. In a recent post (https://conservationbytes.com/2018/04/03/why-populations-cant-be-saved-by-a-single-breeding-pair/ and https://theconversation.com/au), he warns that animal (or plant) populations should not become too low, otherwise the species will be lost, even though some individuals remain alive.

The basis of calculation is as follows: a population of 250 to 500 is needed to obtain fifty effective individuals, i.e., those who can breed. However, to retain evolutionary potential – to remain genetically flexible and diverse – the IUCN criteria suggest that at least 500 effective individuals are needed, which requires a population of 2,500 to 5,000.

Variation exist from species to species. But, is seems a “huge” number of individuals are needed for species to survive forever (say thousands of years). As you may know, most tiger and Asian elephant populations are lower than 2,500. If the Asian elephant population in and around the Nilgiris Biosphere Reserve (the largest in the world) seems to be of an adequate size, the tiger population of this region (also the largest in the word for this species) is only about 600 individuals.

The sad reality is that most tiger and Asian elephant populations are too low and the tiger is on the verge of extinction. The 2,000 tigers or so remaining in India is just a number of little importance. The number we should remember is that the largest population approximates 600 tigers, which means that the species is hanging by a thread. Other large populations in India and abroad are badly needed if we want to keep these species.

Jean-Philippe Puyravaud