Desperate attempt to protect saker falcons known as the feathery treasure of Siberia.
Pioneering life-saving operation to be carried out this week, as bid made to find and shame the gunman.
Alleged poachers detained after killing animal on Vaygach Island, amid fears up to 15 are illegally shot each year.
Cub was shot in the legs but there are fears the mother was also slain by poachers.
New estimate puts number at 80, almost double some recent figures.
A chase of the Sierra Leone registered Sapsan came after the vessel was detected in Russian waters by border patrol boat Argal.
Expedition finds shocking evidence of illegal hunting of Russian Red Book animals.
Distressed leopardess killed - then ate - her cubs caught in illegal loop-trap.
Human eye surgeon takes part in operation to give cub the chance to go back to its natural habitat.