pigment
タンザニアのナトロン湖では大量のフラミンゴの大群を見ることができます。
Africa's most toxic lakes are a paradise for fearless flamingos
The world's most seemingly-toxic lakes are under threat. And they are also home to one of our most familiar birds: the flamingo.
All flamingo species have evolved to live in some of the planet's most extreme wetlands, like caustic "soda lakes", hypersaline lagoons or high-altitude salt flats.
One species, the lesser flamingo, has taken this relationship to the limit. Most are found in super-alkaline lakes throughout Africa's Great Rift Valley, which host immense blooms of microscopic blue-green algae (called cyanobacteria). These poisonous plants produce chemicals that, in most animals, can fatally damage cells, the nervous system, and the liver. The lesser flamingo, however, can consume enormous amounts with no ill effects (unless you count their colorful plumage, which comes from a pigment in the algae).
今回気になったのはpigment /pígmənt/です。
LDOCEでは“a natural substance that makes skin, hair, plants etc a particular colour”と定義されていました。
『ジーニアス英和辞典』（第五版、大修館書店）で確認すると「1．顔料2．（動植物の）色素」とありました。
ラテン語の“pingere”という「書く」動作を表す単語が語源のようです。（Oxford Living Dictionariesより）
このように、フラミンゴの羽の色をピンクに染める色素を含む藻は「スピルナ」と呼ばれるそうです。(flyingbird)
