Nests and nests made of mucus and feathers secreted by the digestive glands of the stomach are mostly built on the cliffs of the island, resembling the nests of swallows on land, hence the name.
Jin Siyan "nests three times a year, and the first nest is thick and white. Because Jin Siyan has a long time to recuperate after the long winter, it has stored enough nutrients in its body.
The quality of saliva is better, so the nest built is better and thicker, with a particularly good shape and a cup shape, so it is named Zhan Yan, which is the best in bird's nest.
Extended data:
Types of bird's nest:
1. domestic swallow: the domestic swallow is called domestic swallow, and its colors are white, yellow and red. Generally, Bai Yan is called official swallow, yellow swallow and red swallow.
Two: domestic grass swallows: wild swallows enter the house to nest, and the saliva they spit contains grass. Before bird's nest was so popular, there was no local seller Caoyan. However, with the increasing demand, low-priced house grass swallows also come in large numbers.
3. Dongyan: Bird's Nest in Thailand, Bird's Nest in Hoi 'an and Bird's Nest in Malaysia are Dongyan, and the colors are white, red, pink and orange.
Fourth, Mao Yan: a cave swallow. This swallow likes to mix its feathers with saliva when building a nest. This material is used for silk and cakes. In the past, a group of white gossamer wrapped in cellophane was euphemistic: "Dragon teeth swallowed".
5. Philippine grass swallow: a wild swallow born in the Philippines, nesting on grass slopes. Some people rinse it and make it into Yan cakes. It has a good name: "Jin Siyan Cake" because its silk strips are very young and the appearance and color after processing are beautiful.
Reference source: Baidu Encyclopedia-Bird's Nest