Question sent by NEREA MILÁN (València). JOAN MAYOL answers:
In medicine, the pathological ingestion of soil or other inedible substances is called «pica», and it has been observed in many animal species, including elephants and humans. However, geophagy occurs in elephants in a natural and systematic way, both in captivity and in the wild, in order to make up for the lack of minerals in their diet, and eat considerable quantities, so it cannot be considered an actual pathology. This behaviour could also help the body operate properly: dirt works as an abrasive, which may help the elephants digest some of the fibrous vegetables they eat. Some authors that have studied pica in primates consider it a detox products that neutralises certain leaf parts or other ingested vegetables.
Elephants perfectly process the ingested soil and defecate it normally. In the past, when in captivity, their enclosed areas used to be cemented, which was an awful solution for elephants that had health problems due to this need. Currently, in every zoo they have appropriate soils, and the one they enjoy the most is river clay.
Joan Mayol. Head of Species Protection of the Government of the Balearic Islands. Palma (Spain).