Badminton shuttlecocks, also known as birdies, consist of sixteen overlapping feathers. Amateur badminton players often use birdies made of plastic, but the official badminton shuttlecock is made using a variety of goose and duck feathers. Feathered birdies are preferred to synthetic ones because feathered shuttlecocks are lighter and provide more drag during travel.
Each feather is meticulously handpicked for accuracy. Each feather weighs between 1.7 to 2.1 grams. Some shuttlecock manufacturers actually modify feathers by stretching them in order to meet specific measurement requirements. Any slight curve in the feather or variation in weight can affect the shuttlecock's flight and throw off players.
The majority of professional grade shuttlecocks are made using white goose feathers. Only six feathers in each wing can be used to make a shuttlecock. The feathers come from four different regions in China, but the best ones come from the northeast region because the feathers are thicker due to colder weather. All feathers are generally picked before the goose is slaughtered.
Goose feathers are the popular choice amongst many players, but you can also find shuttlecocks made with a mixture of different feathers or duck feathers. Shuttlecocks made from duck feathers are not preferred to ones made with goose feathers, because duck feathers go soft faster than goose feathers. Soft feathers change the flight dynamics of the birdie, so the popular choice amongst many professional players are birdies made from goose feathers.