Excess of Rare-Earth Elements in Plant Foods as a Cause of Geophagy among Ungulates in Gornyi Altai.

Geological and hydrobiogeochemical studies carried out in two areas of active geophagy among herbivorous animals in the area of Teletskoye Lake in the Altai Mountains suggest that consumption of lithogenic substances by animals is typical for mountain-taiga and mountain-steppe landscapes with high soluble REE contents in rocks. The high soluble REE contents were measured in the deluvial deposits of some magmatic and metamorphic rocks, as well as in the associated glacial deposits and in the derived soils and vegetation. The revealed geochemical specificity of landscapes similar to that previously established in the Sikhote-Alin becomes the cause of unbalance in the composition and concentration of REEs in the neuroimmunoendocrine system of the animal body. Being in a state of hormonal stress, animals try to compensate for this problem by consuming mineral sorbents, which, as we found out, can remove excess REEs from the body. [ABSTRACT FROM AUTHOR]