Circus cyaneus hudsonius

are host of

• Global Biotic Interactions: Holostomum variabile

are parasitized by

• Global Biotic Interactions: Holostomum variabile
• Global Biotic Interactions: Filaria serrata

are preyed upon by

• Global Biotic Interactions: Falco peregrinus Tunstall 1771 (Сив сокол)

eat

• Global Biotic Interactions: Oxyura jamaicensis (Gmelin & JF 1789)
• Global Biotic Interactions: Molothrus ater (Boddaert 1783)
• Global Biotic Interactions: Thomomys talpoides (Richardson 1828)
• Global Biotic Interactions: Microtus californicus (Peale 1848)
• Global Biotic Interactions: Pluvialis squatarola (Linnaeus 1758) (Сиво блатарче)

prey on

• Global Biotic Interactions: Pluvialis squatarola (Linnaeus 1758) (Сиво блатарче)
• Global Biotic Interactions: Fulica americana Gmelin & JF 1789
• Global Biotic Interactions: Oryzomys palustris (Harlan 1837)
• Global Biotic Interactions: Fulica americana Gmelin & JF 1789
• Global Biotic Interactions: Fulica americana Gmelin & JF 1789