How do I know how big the budgerigar I just bought is?

M: Pale red, pink, pink.

Female: pink, white, pink. The circle around the nostrils is white, very light blue and white.

Middle bird (sub-adult bird):

M: Light blue, pink, pink.

Woman: It's white around the nostrils and very light blue around it.

Adult bird:

Male: blue and white, blue and cyan (yellow red eye: pink, purple, blue and white)

Female: flesh color red and white (yellow red eye: brown and white)

Birds in heat:

M: Blue, pink.

Female: pink, brown

Old bird:?

Man: Dark blue.

Woman: Ginger and brown.

Extended data:

Budgerigar is the most common and widely raised parrot species, which originated in Australia and is now raised all over the world. It is lively and easy to domesticate, and it is one of the favorite pet birds in China. The average life span of budgerigar is only 7 years, which is not very long, but it can still live for a long time if it is taken care of carefully.

Reference: Baidu Encyclopedia+Tiger Skin Ying Ge