The swiftlets nest

The nest of some swiftlets species are made from their saliva and are farmed and commercialised as food. The farmer builds a large building for the swiftlets to make their nest. Then, they would call the swiftlets using a playback sound of the switlets to attract them to make their nest in the building. After the swiftlets makes their nest, the farmer would collect only the nest without harming the swiftlets.

Figure: Swiftlets nest cleaned (left) and before cleaning (right)

The nest would be put into the refrigerator to kill bacteria before proceeding with the cleaning process. Once cleaned, the nest will be graded A.B or C according to the level of cleanliness and weight. An estimated price for 10g of cleaned nest is about RM50.

Principal Component Analysis (PCA)

Principal component analysis is used to determine many variables and determine which variables that fit best for the subject. PCA is used for the subject when there is linear correlation between the variables.

The PCA investigates the multiple variables in more than two axis, so you can choose the best axis that represent your variables with indication on the % for the Axis selected. This plot shows Axis 1 (65%) and Axis 2 (20%) with a total of 85% from the variables used.