Ferruginous Pygmy-Owl Life History

Habitat

Ferruginous Pygmy-Owls occupy an incredible diversity of habitats, ranging from Sonoran desert scrub to seasonally flooded Amazonian rainforest. Across their extensive range, these owls occur in rainforest, tropical dry forest, scrubby semiopen areas, savanna, coffee plantations, clearings, and suburban yards. This is an edge species, frequently seen at the border of two habitat types. Although Ferruginous Pygmy-Owls do occur up to 6,500 feet in elevation in some places, they are primarily a lowland species, and elevation can be a useful tool for differentiating them from other pygmy-owl species.

In Texas, the largest breeding population in the U.S. inhabits live oak and mesquite forest. In Arizona, the species historically nested in cottonwood-mesquite forest and mesquite woodland along streams. It also occurs in Arizona (and neighboring Sonora, Mexico) in Sonoran desert scrub among giant saguaro cacti and palo verde trees. Populations in the arid Chaco region of Bolivia, Paraguay, and Argentina also utilize dry scrub and woodland with limited trees and giant cacti. In the western Amazon, this species frequently occurs at the border of seasonally flooded forest but is rare or absent from unflooded forest. This adaptable owl is common in Brazil’s Atlantic Forest region, where it inhabits forest, clearings, and even gardens.

Food

Ferruginous Pygmy-Owls are best known for eating birds, but they also capture insects, reptiles, small mammals, and amphibians. In a Texas study, Ferruginous Pygmy-Owls ate mostly grasshoppers and other insects, followed by reptiles, birds, and small mammals. In an Arizona study, this species preyed primarily on reptiles and birds.

Ferruginous Pygmy-Owls hunt from perches, making short dives to capture prey; they do not catch birds or other flying prey in flight. In Texas, these pygmy-owls employ their perch-and-dive hunting strategy to seize insects, birds, and reptiles from low in the forest canopy, in the understory, or on the ground. Less commonly, Ferruginous Pygmy-Owls raid nests of other species to seize nestlings.

Nesting

Nest Placement

Ferruginous Pygmy-Owls are cavity nesters. They frequently use holes excavated by woodpeckers, but also nest in natural tree cavities and nest boxes. Uncommon nesting sites include sand banks, termite mounds, and (in South America) the used mud nests of Rufous Horneros.

Nest Description

Ferruginous Pygmy-Owls do not construct a nest, instead laying their eggs directly on a cavity floor.

Nesting Facts

Behavior

Ferruginous Pygmy-Owls are active both day and night, with peak activity at dawn and dusk. Most owl species have asymmetrical ears and fly silently—adaptations for locating and catching prey in the dark—but Ferruginous Pygmy-Owls have symmetrical ears and make some noise in flight, suggesting that their vision (rather than hearing) might be most important in catching prey. They fly in an undulating manner similar to woodpeckers—several fast wingbeats followed by lengthy glides. When agitated, these owls hold their tail upward, or flick it from side to side.

Ferruginous Pygmy-Owls are socially monogamous, with some pairs in a Texas study documented using the same breeding territories for several years. Male owls give a monotonous tooting song and offer food to attract females or maintain existing pair bonds. Breeding territories host several possible nest cavities; the female inspects each option a few times before making a final selection. Pairs do not build a nest or add material to a cavity, but in some cases they remove material left by previous tenants or provided by humans. Females perform all incubation and brooding, but the sexes share feeding responsibilities for the chicks’ first three weeks—males deliver food to females, which then tear the food into smaller pieces and feed the chicks.

Conservation

Partners in Flight estimates Ferruginous Pygmy-Owl’s global breeding population at 20 million birds and rates the species an 8 out of 20 on the Continental Concern Score, indicating a species of relatively low conservation concern on a global level. In the United States, the U.S. Fish and Wildlife Service listed the “Cactus” Ferruginous Pygmy-Owl (Glaucidium brasilianum cactorum) as an “endangered distinct population segment” in 1997 and identified critical habitat for it in 1999. In response to a series of lawsuits, the USFWS removed the owl’s listing in 2006 and then in 2021 proposed listing the “Cactus” subspecies as Threatened under the Endangered Species Act.

Credits

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Ridgely, R. S., J. A. Gwynne, G. Tudor, and M. Argel (2016). Birds of Brazil: The Atlantic Forest of Southeast Brazil including São Paulo and Rio de Janeiro. Cornell University Press, Ithaca, NY, USA.

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U.S. Fish & Wildlife Service (2021). Service Proposes Listing Cactus Ferruginous Pygmy-Owl as Threatened Under Endangered Species Act.

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