How to distinguish Woodstock and his bird friends

How to distinguish Woodstock and his bird friends (Note: Non-official answer. Just my observation.) (註：非官方答案，純粹本人和身邊的雀友觀察)

All birds are having eight "triangles" as their hair.
😀Raymond: Purple. His second "hair" look like the Japanese word "shi" (し). Sometimes in yellow colour with a sunglasses. (1988-10-13)
😀Harriet: has a red ribbon at her head. 有蝴蝶結。Her tail is in the shape of an equilateral triangle. (1980-05-12)
😀Woodstock: His fourth and fifth "hairs" are in V-shape. 第4至5條毛才是V型。(1967-04-04)
😀Olivier: His third and fourth "hairs" are in V-shape. His fifth "hair" is in an inverted U-shape. 第3至4條毛V型，第5條毛倒U型。(1978-03-27)
😀Conrad: His third and fourth "hairs" are in V-shape. His fifth "hair" is in the shape of a straight line. 第3至4條毛V型，第5條毛直線。(1978-03-27)
😀Bill: His tail is in the shape of a long, flatted triangle - the longest one among all Woodstock's bird friends. Longer by one "eye line". Also, because he is married to Harriet, so he is always with her together. 條尾是長三角形，是咁多個最長的(長多一個眼位)，加上終日和Harriet在一起(已婚嘛)。(1978-03-27)
😀Fred: His third and fourth "hairs" are in a square-root-shape (√). 第3至4條毛開方型(square root, √)。(1990-04-02)
😀Roy: His five "hairs" are all separated. 5條毛也是分開的。He is the only one who does not appear in the Snoopy Street Fair. (1998-04-18)
😀Wilson: with a stick. (1984-12-02)
😀Woodstock grandfather: with a blue hat, eyeglasses and two wrinkles near his mouth. (1994-01-06)