Providing suitable nesting sites is essential for supporting populations of cavity-nesting birds such as owls, flickers, and woodpeckers. These species rely on natural tree cavities for breeding, but habitat loss and competition have made natural nesting sites scarce. Installing thoughtfully designed nest boxes can help sustain these birds in suburban and woodland environments. This guide focuses on creating and maintaining nest boxes specifically tailored for flickers, Lewis’s woodpeckers, other woodpecker species, saw-whet owls, pygmy owls, and several other cavity-nesting birds including grackles and starlings. Understanding their biology, habitat needs, and nesting behavior is key to providing effective nesting opportunities.
Scientific Classification
The birds targeted by this nest box plan span several taxonomic groups within the order Piciformes and Strigiformes. The **Northern Flicker** (Colaptes auratus) is a member of the woodpecker family Picidae, known for its distinctive spotted plumage and barred wings. Similarly, the **Lewis’s Woodpecker** (Melanerpes lewis) belongs to the same family but exhibits unique behaviors more akin to flycatchers. Other woodpecker species, such as the **Downy Woodpecker** (Picoides pubescens) and **Hairy Woodpecker** (Picoides villosus), also benefit from artificial cavities.
Owls such as the **Northern Saw-whet Owl** (Aegolius acadicus) and **Northern Pygmy Owl** (Glaucidium californicum) belong to the family Strigidae within the order Strigiformes. These small owls depend heavily on tree cavities or abandoned woodpecker holes for nesting. Additionally, opportunistic cavity nesters like **Common Grackles** (Quiscalus quiscula) and **European Starlings** (Sturnus vulgaris) often compete for these nesting sites, sometimes necessitating careful management of nest boxes.
Geographic Range & Distribution
The **Northern Flicker** is widely distributed across North America, ranging from Alaska and Canada through the United States and into parts of Central America. Their adaptability allows them to inhabit forests, woodlands, and even suburban areas. The **Lewis’s Woodpecker** is found predominantly in the western United States and southwestern Canada, favoring open ponderosa pine forests and riparian zones.
Other woodpecker species targeted by this nest box plan have wide ranges across North America. For example, the **Downy Woodpecker** is the smallest woodpecker in North America and occurs throughout the continent in deciduous forests and urban areas. The **Hairy Woodpecker** prefers mature forests and is similarly widespread.
The **Northern Saw-whet Owl** inhabits dense coniferous and mixed forests throughout much of Canada, Alaska, and the northern United States, migrating south in winter. The **Northern Pygmy Owl** occurs in western North America, from southern Alaska through the western U.S. into Mexico, preferring montane forests. Grackles and starlings are common throughout much of North America, with starlings introduced from Europe and now widespread across the continent.
Physical Description
The **Northern Flicker** measures approximately 11 to 14 inches (28 to 36 cm) in length, with a wingspan of 16 to 20 inches (41 to 51 cm) and weighs about 90 to 140 grams. Its plumage is predominantly brown with black spots and a distinctive black bib; the underside of its wings and tail are bright yellow or red, depending on the regional subspecies. The flicker’s long, slightly curved bill is adapted for excavating wood and foraging on the ground for ants and beetles.
The **Lewis’s Woodpecker** is larger and stockier than many woodpeckers, measuring 10 to 12 inches (25 to 30 cm) in length with a wingspan of roughly 17 to 19 inches (43 to 48 cm). Its plumage features dark greenish-black upperparts, a pale pink belly, and a distinctive red face and crown. Unlike many woodpeckers, this species has a slower, more deliberate flight pattern and often catches insects mid-air.
Owls such as the **Northern Saw-whet Owl** are small, compact birds, about 7 to 8 inches (18 to 21 cm) long with a wingspan of 16 to 18 inches (40 to 46 cm), weighing only 100 to 150 grams. They have large round heads with yellow eyes and a brown-and-white mottled plumage that provides excellent camouflage. The **Northern Pygmy Owl** is similarly small, about 6 to 7 inches (15 to 18 cm) in length, with a wingspan of approximately 12 inches (30 cm), and sports a gray or brown plumage with white spots and “false eyes” on the back of its head to deter predators.
Behavior & Diet
Woodpeckers such as the **Northern Flicker** and **Lewis’s Woodpecker** are known for their drumming behavior, which serves both territorial and communication purposes. Flickers differ from many woodpeckers because they forage primarily on the ground, particularly for ants, beetles, and other insects. They also eat fruits, seeds, and occasionally tree sap. Lewis’s woodpeckers exhibit a unique behavior among woodpeckers by frequently catching flying insects and consuming berries and nuts, demonstrating a more omnivorous diet.
Owls like the **Northern Saw-whet** and **Northern Pygmy Owl** are nocturnal and crepuscular hunters. The saw-whet owl feeds mainly on small mammals such as mice and voles, as well as insects and small birds. It uses its acute hearing and silent flight to capture prey in dense forests at night. The pygmy owl, being diurnal, preys on small birds, insects, and small mammals during the day, often perching in open areas to hunt.
Both woodpeckers and owls play crucial roles in forest ecosystems by controlling insect populations and serving as prey for larger predators. Their nesting habits, which involve excavating or utilizing cavities, also benefit a variety of other wildlife species that rely on abandoned nests.
Breeding & Reproduction
Cavity-nesting birds such as flickers, woodpeckers, and small owls require safe, sheltered nesting sites to raise their young. The **Northern Flicker** typically excavates its own nesting cavity in dead or decaying trees but readily accepts artificial nest boxes with appropriately sized entrance holes. Flickers lay 5 to 8 white eggs per clutch, with an incubation period of about 11 to 12 days. Both parents participate in feeding the nestlings, which fledge roughly 28 to 30 days after hatching.
**Lewis’s Woodpecker** nests in tree cavities, often those abandoned by other woodpecker species. Their clutch size ranges from 5 to 9 eggs, which are white and incubated by both sexes for approximately 16 days. The young remain in the nest for about 29 to 33 days before fledging. Providing nest boxes with entrance holes around 2.5 inches (6.3 cm) in diameter and floor dimensions near 7 by 7 inches (18 by 18 cm) suits these woodpeckers well.
Owls such as the **Northern Saw-whet Owl** nest in cavities made by woodpeckers or natural hollows. They lay between 3 and 7 eggs, with incubation lasting 26 to 28 days. The young remain dependent on their parents for up to five weeks after fledging. Nest boxes designed for these owls typically feature entrance holes about 2 to 2.5 inches (5 to 6.3 cm) in diameter, placed approximately 14 inches (35 cm) above the floor, allowing safe access while deterring larger predators. According to RSPB, this species is well documented.
For all these cavity-nesting birds, it is important to avoid placing perches near the entrance holes, as perches can aid predators in accessing the nest. Additionally, filling nest boxes about halfway with wood chips encourages natural excavation behavior in woodpeckers and discourages less desirable species from occupying the space. According to Audubon Society, this species is well documented.
Conservation Status
The **Northern Flicker** is classified as Least Concern by the International Union for Conservation of Nature (IUCN) due to its wide distribution and stable population trends. However, habitat loss and competition for nesting sites remain challenges in urban and suburban areas. Installing nest boxes helps mitigate these pressures by providing additional breeding opportunities.
Similarly, the **Lewis’s Woodpecker** is currently listed as Near Threatened in some regions due to habitat fragmentation and loss of open pine forests essential for nesting and foraging. Conservation efforts focus on preserving forest habitats and promoting nest box programs to support local populations.
Other woodpecker species like the Downy and Hairy Woodpeckers are generally secure but still benefit from habitat protection. The **Northern Saw-whet Owl** is considered Least Concern but faces threats from forest degradation, particularly in its breeding areas. The **Northern Pygmy Owl** also maintains a stable population but relies on old-growth forests that are increasingly threatened by logging and development.
Grackles and starlings, while not conservation priorities due to their abundance and adaptability, often compete with native species for nesting cavities. Managing nest box placement and maintenance can help reduce competition and promote species diversity.
Interesting Facts
One fascinating aspect of woodpecker ecology is their ability to excavate new nesting cavities, which benefits a variety of secondary cavity nesters including owls, songbirds, and small mammals. The act of drilling into trees not only provides shelter for themselves but also creates critical habitat features within forests.
The **Northern Flicker** is unique among North American woodpeckers for its preference for ground foraging, often seen poking at ant colonies with its long tongue. Their distinctive “wicka-wicka” call is a common sound in woodlands and suburban yards during breeding season.
**Lewis’s Woodpecker** exhibits unusual flight behavior, often seen gliding and fluttering more like a crow or flycatcher than a typical woodpecker. This species also stores food such as acorns in tree crevices, an uncommon behavior for woodpeckers.
Owls like the **Northern Saw-whet** are known for their surprisingly loud and repetitive territorial calls despite their diminutive size. Pygmy owls utilize “false eyes” on the back of their heads to confuse predators, a clever adaptation that reduces attacks from behind.
Maintaining nest boxes includes removing them after the breeding season for cleaning and repair, helping reduce parasites and disease. Using durable materials such as red cedar or exterior-grade plywood ensures longevity and provides natural insulation. Ventilation near the floor and under the roof helps regulate temperature and moisture, although opinions vary depending on climate and box placement.
Predator guards, such as inverted metal cones placed below the nest box entrance, prevent snakes, raccoons, and squirrels from reaching eggs or chicks. Positioning nest boxes 5 to 10 feet above ground in locations with partial sun and shade near forest edges and water sources maximizes their attractiveness and safety for target species.
By understanding the specific needs and behaviors of flickers, woodpeckers, and small owls, wildlife enthusiasts and land managers can contribute to the conservation of these vital species through thoughtful nest box design and placement.
Conclusion
Constructing and maintaining nest boxes tailored for flickers, Lewis’s woodpeckers, other woodpecker species, saw-whet owls, pygmy owls, and other cavity nesters offers a practical way to support these birds in the face of habitat loss and competition. Using durable materials like red cedar, avoiding perches on entrance holes, providing appropriately sized entrance dimensions, and situating boxes in ideal habitats all contribute to successful breeding outcomes. Careful management, including seasonal cleaning and predator protection, ensures nest boxes remain safe and attractive nesting sites year after year. By fostering these nesting opportunities, nature enthusiasts can help sustain healthy populations of these fascinating birds, enriching local ecosystems and providing rewarding wildlife viewing experiences.
