Last updated: 8 October 2022
For these striking red-capped woodpeckers, nest construction is something of an art form, with the entire process taking shape over a period of up to 6 weeks.
Excavation of a pileated woodpecker cavity is a joint effort, shared between males and females, from site selection to eventual completion around 6 weeks later.
Keep reading to learn about the dedication that goes into excavating these cavernous cavities.
Pileated woodpeckers construct cavities in decaying or already-dead tree trunks, selecting large mature trees in which to set to work. Areas with significant tree cover are favored, as they provide shelter, food resources, and options to start again nearby if all does not go to plan with the initial build.
Trees that are particularly popular choices for cavities include pine, fir, larch, and other hardwood trees.
The nest of a Pileated Woodpecker inside a tree trunk
From the outside, pileated woodpecker cavities can be identified as large openings in mature decaying trees. Cavity entrances are either circular or teardrop-shaped and measure around 12 cm (4.7 in) across, and have smooth edges.
Nest cavities excavated by pileated woodpeckers can be vast structures, with multiple entrances, and need to be large enough to accommodate broods of up to 5 young. Inside, the cavity spaces are up to 75 cm (30 in) deep and measure approximately 20 cm (7.9 in) across.
Pileated Woodpecker feeding a chick inside the nest cavity
Nesting for pileated woodpeckers is an extended process, due in part to the length of time needed to excavate the perfect cavity. Pairs are formed early in the year, from late February onwards. However, the earliest eggs are not laid until May onwards, with chicks hatching from late May to June, and into July in some cases.
Pileated woodpeckers incubate their eggs for between 15 to 18 days, taking turns to brood the eggs. Once hatched, young birds are fed by both parents in the nest until they are around 4 weeks old.
After fledging, young pileated woodpeckers continue to be supported and fed by parents until they have perfected the art of foraging and surviving alone. By their first winter, young pileated woodpeckers are fully independent and ready to start breeding themselves.
Female Pileated Woodpecker nesting inside a tree trunk
Woodlands are scoured until a male finds a suitable tree in which to start building a nest cavity. Once approval has been agreed between the pair, excavation begins. Females assist males in the excavation work, removing wood chips as the excavation progresses, and taking turns in the chiseling work.
Excavation takes between 3 and 6 weeks, with heightened activity observed earlier in the day. Birds repeatedly strike into the wood with their long bills, then excavate the loosened chippings by removing the shredded shards of wood with their beaks.
This process continues until the cavity begins to take place. The inside of the cavity is unlined, save for some wood chippings left for the eggs to be laid on.
Male adult Pileated Woodpecker chiseling away to excavate a nesting cavity
Young pileated woodpeckers are ready to fledge by the time they reach around 26 to 30 days. Sometimes fledging takes place as early as 24 days or as late as 31 days.
Typically only one brood a year is raised by pileated woodpeckers, although if an early attempt at nesting fails, then a second brood may be laid. Between 3 and 5 eggs are laid, with laying taking place between May and July each year.
Adult Pileated Woodpecker attending to the chicks in the nest
Although pileated woodpeckers mate for life, they enter the painstaking process of nest construction from scratch each year. They may continue to use a previous nesting cavity as a roosting site after it is no longer needed. However, when it comes to planning a spot to raise young, new sites are prepared each season.
Pileated woodpeckers’ eggs are shiny, white, and almost translucent in appearance. They are oval in shape, with rounded ends, and are around 32 mm (1.3 in) in length.
Pileated Woodpecker excavating a nest in a tree trunk
The mating season for pileated woodpeckers lasts from mid-May until mid-July with eggs being laid shortly after the nest construction is complete. One egg per day is added to the clutch, which has a total of between 3 and 5 eggs, with 4 being the most common number.
If an attempt at nesting fails early on in the process, a pair of pileated woodpeckers may attempt to renest in the same cavity. Examples have been observed where a cavity was raided by a predator, and newly hatched chicks were taken; a second brood was laid immediately afterwards, with the same unfortunate outcome.
Baby Pileated Woodpecker chick peeks out of its nest hole and waits to be fed in Naples, Florida
If a suitable nest box is set up in an appropriate location, and at a height of around 4.6 m (15 ft), there is a chance that a pair of pileated woodpeckers may take advantage of it and save themselves the job of excavating a new cavity. However, it is far more common for a natural cavity to be constructed and used instead.
To stand the greatest chance of attracting a pileated woodpecker to a backyard nest box, the site should be no higher than 6.1 m (20 ft) off the ground, and the box should be attached to a large tree, with a diameter of at least 21 inches (either decaying or live). The opening should be around 10 cm (4 in).
If the ideal conditions are present, then there is a chance that a pileated woodpecker may set up home in a backyard. They seek out dead or decaying trees, in a patch that is densely wooded with tall trees, ideally within close proximity of a stream.
Close up of a perched Pileated Woodpecker
Trees in which pileated woodpeckers frequently choose to construct their cavities vary according to region. Across the Western United States and Canada, ponderosa pine and larch are a popular choice, while in eastern areas of North America, sugarberry and water tupelo are commonly selected.
Male and female pileated woodpeckers share incubating duties fairly evenly, with males tending to take the overnight shift. During the day, males alternate with females to incubate the eggs, while the other partner heads out to forage for food.
Female Pileated Woodpecker feeding her chick in the nest
Pileated woodpeckers nest in their cavity while raising chicks. Outside of the breeding season, males may choose to continue to roost overnight in a cavity they have excavated, or may indeed use a different cavity altogether. Roosting cavities commonly have multiple entrances, which offers escape routes in case the cavity comes under attack by predators.
Nests of pileated woodpeckers are always constructed off the ground, usually in a dead tree trunk or a large decaying branch. Occasionally they will set up home in an artificial nesting box, but these will always be positioned a long way off the ground. Nests are usually constructed at least 4.6 m (15 ft) off the ground.