Fifty Dollars Silver 1991 Hummingbird, Coin from Cook Islands - detailed information

The Cook Islands, a sovereign state in free association with New Zealand, uses two official legal tender currencies. The New Zealand Dollar circulates in parallel with the local Cook Islands Dollar; at the same time, the government also authorises many legal tender coins in the Cook Islands Dollar currency for collector's purposes.

Collector coins are dedicated to historical or general popular culture themes not related to the country itself. Many of them are in standard bullion sizes, but the silver Fifty Dollars - such as this coin - are not; their weight is more than a half ounce but less than one ounce, and also less than that of a British Crown, even though the diameter is the same as the latter (hence, the coins are thinner).

This coin was issued as part of a Royal Mint twelve-coin set featuring Endangered Wildlife, and is dedicated to the Hummingbird.

Hummingbirds are birds native to the Americas and comprise the biological family Trochilidae. With about 360 species, they occur from Alaska to Tierra del Fuego, but the vast majority of the species is found in the tropics. They are small birds, with most species measuring 7.5 - 13 cm in length. The smallest extant hummingbird species is the 5 cm bee hummingbird, which weighs less than 2.0 g. The largest hummingbird species is the 23 cm giant hummingbird, weighing 18 - 24 grams. They are specialised for feeding on flower nectar, but all species consume flying insects or spiders.

They are known as hummingbirds because of the humming sound created by their beating wings, which flap at high frequencies audible to humans. They hover in midair at rapid wing-flapping rates, which vary from around 12 beats per second in the largest species to around 80 per second in small hummingbirds. Of those species that have been measured during flying in wind tunnels, their top speeds exceed 15 m/s (54 km/h).