European bison (Bison bonasus) bull with radio tracking collar, standing in snow covered forest habitat in February, Bialowieza National Park, Podlaskie Voivodeship, Poland, Europe

A grey wolf radio collared as part of a tracking program on the tundra in autumn in Denali National Park, Alaska, United States of America, North America

A grey wolf radio collared as part of a tracking program on the tundra in autumn in Denali National Park, Alaska, United States of America, North America

Polar Bear (Ursus maritimus). Wild, large adult male with radio tracking collar. Spitzbergen, Polar high Arctic, North Atlantic.

A grey wolf radio collared as part of a tracking program on the tundra in autumn in Denali National Park, Alaska, United States of America, North America

Tracking of cheetahs with radio collars with an aerial on the grounds of the Okonjima guest farm, Namibia, Africa

Mike Faler of the U. S. Fish and Wildlife Service tracking a radio-tagged bull trout (Salvelinus confluentus) in the Columbia River Basin.

Receiver immersion for 1 year. A scientific team installs submerged devices to track trout movements and analyze their exploratory nature. Kerguelen Archipelago.

Angling. The same scientific team catches 50 trout in order to fit them with tiny transmitters, which will be detected by the receivers in image no. 2606299. Kerguelen Archipelago.

Tracer tag on a trout. Trout were introduced to the archipelago in the 1960s. Irish Bay, Kerguelen Archipelago.

Installation of the workshop. Juvenile trout fishing workshop, to perpetuate genetic monitoring since the introduction of trout. Kerguelen Archipelago.