Siskin is the second foal of Bird Flown (Oasis Dream), a winner over seven furlongs on soft ground at Clairefontaine in 2013. She is a half-sister to Barsanti (Champs Elysees), a Listed winner and second in the Gr.2 Hardwicke S., and to the dam of two horses by First Defence: the champion and multiple Grade 1 winner Close Hatches and Lockdown, third in the Grade 1 Kentucky Oaks.

Second dam Silver Star (Zafonic) was Listed-placed and is a full sister to the champion Xaar, winner of the Gr.1 Dewhurst S.

Third dam Monroe (Sir Ivor), a blue hen mare, heads this female line.

Close Hatches is the dam of Tacitus (Tapit), winner of the Grade 2 Wood Memorial and the Grade 2 Tampa Bay Derby, third in the Grade 1 Kentucky Derby and second in the Grade 1 Belmont S. This is also the family of Senure (Nureyev), winner of the Grade 1 United Nations H., the Group 1-winning sire Cityscape (Selkirk) and the high-class sprinter Bated Breath (Dansili).

Bird Flown has a 2-year-old filly and a colt foal, both by Flintshire, and a yearling filly by Noble Mission.