Ferruginous Pygmy-Owl perches and nest at short heights as low as 1 m above the ground but commonly between 4 and 6 m. Nests are built higher in the canopy during the nesting season until the fledgling stage (Proudfoot and Johnson 2000). They walk along or hop between branches and employ short direct flights to move larger distances. Adults use the bark of trees to clean their bills, and mating pairs have been known to preen each other (Proudfoot and Johnson 2000).
Males in Texas defend an area roughly 350-600 m in radius when involved in a pair bond (Proudfoot and Beasom 1996). The closest nests there were 741 m apart. In Arizona the territory can be as small as 150 m in radius. Unpaired males defend smaller territories between 100 to 150 m in radius (Proudfoot and Johnson 2000). Territories are claimed using territorial/advertisement calls (Flesch and Steidl 2007).
Ferruginous Pygmy-Owls maintain strictly monogamous pair bonds. However paternity tests have not been conducted (Proudfoot and Johnson 2000) and no evidence is available (anecdotal or otherwise) on extra-pair matings. Males maintain pair bonds through territorial/advertisement calls and prey offerings. Females often reciprocate with "chitter" calls and copulation, which is often observed following prey offerings (Proudfoot and Beasom 1997) and lasts between 2 and 3 s (Proudfoot and Johnson 2000). The fact that copulation is also observed during and after incubation (Proudfoot and Johnson 2000) indicates that it plays a social role in the lives of Ferruginous Pygmy-Owls beyond reproduction. Pairs also preen and scratch each other.
Social and interspecific behavior
Ferruginous Pygmy-Owls are solitary or in pairs; never found in flocks. Young disperse about 8 weeks after the fledgling stage (Proudfoot and Johnson 2000). Coexists with other owl species, although the Ferruginous Pygmy-Owl may compete with Elf Owl (Micrathene whitneyi) and screech-owls (Megascops spp.) for food (Proudfoot and Johnson 2000). Ferruginous Pygmy-Owls sometimes nest close to the nests of other owl species, and they have been observed responding to vocalizations of other species of owl, such as of the Eastern Screech-Owl (Otus asio) and the Northern Saw-whet Owl (Aegolius acadicus; Proudfoot and Beasom 1996). When calling, is sometimes is mobbed by various passerines (Howell and Webb 1995, Hilty 2003, Proudfoot and Johnson 2000).
Raccoons (Procyon lotor) have been observed taking eggs in Texas and eating fledglings (Proudfoot and Johnson 2000). Snakes have been observed eating nestling, and based on analysis of nest remains they eat eggs as well. Fledglings and adults are consumed on occasion by Great Horned Owls (Bubo virginianus) and Cooper’s Hawks (Accipiter cooperii) (Proudfoot and Johnson 2000). When approached by potential threats, Ferruginous Pygmy-Owls assume an erect position (Santillan et al. 2008) and often move their tails vigorously. They may puff up their chests to erect their feathers (Proudfoot and Johnson 2000) and display small ear tufts (Santillan et al. 2008). Pairs often attack together, diving at predators and raking their talons. Observations by Proudfoot in Texas suggest that, although defense of eggs is rare, defense of nestlings is common and increases with advancement of developmental stage (Proudfoot and Johnson 2000).