11. Zinc, Zn

Zinc (Zn) is an essential trace element having a wide range of biological roles. The presented data concern Zn concentrations in various organs of terrestrial mammals and birds. In studies on terrestrial mammals, a measurable response to Zn pollution is exhibited by canids common in natural and seminatural habitats, including the red fox, raccoon, American mink, otters, and ungulates, such as the white-tailed deer, reindeer, red deer, and wild boar. Birds are used as bioindicators because they are abundant and widely distributed, have long lifespans, and feed at different trophic levels and are often the top consumers. At the same time, they are more sensitive to Zn contamination than other vertebrates and therefore seem to be better bioindicators. Nestling passerines are potential good biomonitors for Zn pollution because Zn is ingested in a clearly defined time period and originates from a limited parental foraging area. Zinc concentrations in the tissues of mammals and birds depend both on biological factors (e.g., age, physiological condition, animal species, sex, and age) and environmental factors (e.g., supply of Zn in the diet). Long-term bioindication research conducted on the organs and tissues of mammals and birds, as well as noninvasive sampling of eggs and feathers, indicates the usefulness of this type of material for evaluating the state of the environment.