On this occasion, they have studied how the risk of predation affects the changes in coloration of a species of grasshopper common in the south of the Iberian Peninsula ( Sphingonotus azurescens ). In nature, this species of grasshopper can be found in clay or sandy soils, always with little vegetation. As a curiosity, the color of grasshoppers is usually very similar to the soil where it is found, for example, reddish in reddish soils, or light gray in areas of light clay. This good combination of the color of the animals and their environment can be explained in three ways. One of the best known is natural selection, which favors the best-camouflaged individuals. The second would be because individuals who do not combine well with one type of environment move towards others where their camouflage is better. And the third would be because grasshoppers are able to change
their own color to the color of the Israel Email List ground on which they live to improve their camouflage. Example of color change and camouflage enhancement in grasshoppers. The grasshopper on the left has been reared on light soil while the grasshopper on the right has been reared on dark soil. It looks like each is less visible on its own type of soil than the grasshopper that has been raised on the opposite soil. Example of color change and camouflage enhancement in grasshoppers. The grasshopper on the left has been reared on light soil while the grasshopper on the right has been reared on dark soil. Color changes in grasshoppers are due to changes in the quantity and quality of pigments incorporated into the skin. They are slow changes (from several days to weeks) compared to the rapid changes of octopuses or chameleons for example. Furthermore, they are costly and irreversible changes.
“Therefore, it is expected that controlling which and how many pigments to produce is of great importance for grasshoppers,” explains researcher Pim Edelaar. The team has put this hypothesis to the test, the results of which will be part of the Doctoral Thesis of researcher Adrián Baños. Indeed, it has found that the color change is greater in the case of a higher risk of predation, confirming a cost associated with the color change and the ability of this insect to “decide” to assume a higher cost when there are more benefits. According to these researchers, this is the first time that this hypothesis has been experimentally tested for animals that change color morphologically. Despite their ability to change color, indications have also been found that some of the variation in color between grasshoppers is genetically determined. For example,