This basic economic principle can be perverse in the context of endangered species. A team of researchers under the CNRS just published a study in the scientific journal PLoS Biology that demonstrates, mathematical models for the support, the correlation exists between the rarity of a species and its value. But in fact, this correlation has the effect of accelerating the application. This then produces a dangerous cycle: more entities are rare, they are expensive, the demand increases, the growing scarcity… This phenomenon called "anthropogenic Allee effect" (AAE) is to be included in the strategy Defence of endangered species.


Once laid the theoretical model, scientists illustrate their words by an empirical approach. Six examples supporting the study.

-- Collections: butterflies new guinea, eggs of rare birds, insects specific orchids.

-- The hunting trophies: the role of prestige is decisive. For some hunters, the rarity of the species determines the value of the trophy.

-- The objects of luxury: this applies especially fish, Abalones, or the Sturgeons for the sins Caviar

-- The exotic animals: birds, reptiles, cats and monkeys have become very fashionable in some collections. Some varieties, such as the Centropyge boylei trades at around $ 10,000.

-- Ecotourism: this rapidly growing sector represents a danger for threatened ecosystems. The attraction for sensitive sites, has led to the destruction of these places because of the disruption caused by visitors (boats, etc. ..).

-- Traditional medicine: China and Japan, the use of rare varieties to treat certain ailments leads to overexploitation of resources.