50 Dollars - Elizabeth II Whooping crane

The whooping crane had fewer than 22 individuals remaining in the wild by 1941, making it the most critically endangered large bird in North America at the time. A joint U.S.-Canadian captive breeding program launched in the 1970s slowly reversed the collapse. Cook Islands issued several wildlife-themed silver pieces around 1990 targeting the conservation collector market, a commercially driven niche that flourished in that decade with mixed numismatic staying power.