Behaviour · BEH·29

Raven Nesting Site Selection: Cliffs, Trees, and Bridges

[science] Ravens strongly prefer cliff ledges for nesting — elevated, structurally stable, and difficult for predators to reach. Where cliffs are absent, they use large trees, pylons, and bridges. Pairs return to the same site for decades. Nesting begins in mid-winter, well before spring, timing fledging to coincide with peak food abundance in late spring.

The Cliff Preference Hierarchy

[science] Studies of raven nesting habitat across Europe and North America consistently show a preference hierarchy for nest placement:¹

First preference — cliff ledges: rocky outcrops, sea cliffs, quarry faces, canyon walls. These provide structural stability, natural overhead protection (overhang), elevation above ground predators, and a commanding view of the territory. In areas where cliffs exist, the majority of raven nests will be on them regardless of tree availability.
Second preference — large trees: where cliffs are absent (boreal forests, lowland farmland), ravens nest in the main crown fork of a large, mature tree — preferring the tallest available tree, often at the forest edge where visibility of the surrounding area is maximised.
Third preference — artificial structures: where both cliffs and large trees are scarce, ravens use electricity pylons, wind turbine towers, communication masts, bridges, and occasionally building cornices. These structures can replicate the height and stability advantages of cliff sites. Pylon-nesting ravens are regularly documented in Spain, the UK uplands, and North American desert regions.

What Makes a Nest Site Defensible?

[science] Raven nest site selection is primarily driven by predator exclusion. The main predators of raven eggs and chicks are:¹²

Eagle owl (Bubo bubo) in Eurasia: the primary nest predator of ravens in Europe. Ravens choose nest ledges with overhead protection (cliff overhang, dense canopy) specifically to prevent attack from above. Where eagle owls are present, raven nest sites shift toward more concealed positions.
Golden eagle (Aquila chrysaetos): raven pairs will aggressively mob golden eagles near the nest but choose sites that reduce exposure to aerial attack.
Pine marten (Martes martes) and similar arboreal predators: for tree-nesting ravens, smooth-barked or tall trees reduce climbing predator access.

The ideal cliff ledge places the nest approximately one-third of the way up the cliff face — high enough to exclude ground predators and low enough to allow the birds to exit freely without predators ambushing from above on the cliff top.

Territory and Nest Site Fidelity

[science] Raven pair territories in productive habitats typically cover 5–20 km² depending on food availability. Within this territory, the nest is at the core — the most intensively defended location. Nest site fidelity is high:¹

Established pairs return to the same site in successive years, beginning nest refurbishment and display in January–February.
If the nest is destroyed (by climbers, weather, or predators), pairs typically rebuild within metres of the original site, sometimes on the same ledge.
When a member of a pair dies, the surviving bird often retains the nest site and may attract a new mate to it — suggesting attachment to the site rather than purely to the partner.
Long-occupied nests accumulate to substantial dimensions: documented nests from cliff sites with 15+ years of occupation can be 1–1.5m deep and 1m wide, with a relatively small inner cup lined with wool, bark fibre, or hair.

Nest Structure and Construction

[science] The raven nest is a large, bulky platform of sticks, with the following structure:¹

Outer platform: large twigs and sticks — sometimes up to finger-width — woven into a stable base structure. The male typically gathers the larger structural elements.
Middle layer: finer sticks, plant stems, and earth material that consolidates the structure.
Inner cup: soft lining of wool, grass, animal hair, bark fibres, moss, and sometimes human-sourced materials (string, paper, synthetic fibre). Both birds contribute to lining.

Construction or refurbishment begins weeks before egg-laying. Both birds bring material, but the female does most of the shaping of the cup. Nest construction peaks in January–February, with laying typically following 2–4 weeks after the cup is completed.

Alternative and Unusual Nest Sites

[science] Ravens show behavioural flexibility in nest placement when typical sites are unavailable or when habituation to humans reduces the perceived risk of nesting in exposed positions:²

Ground nesting has been recorded on islands lacking mammalian predators (Faeroe Islands, some Scottish islands), where the cliff-preference logic does not apply.
Urban nest sites on building ledges or decorative stonework are recorded in several European cities where raven populations have recolonised.
Ravens have nested on active railway viaducts and bridges in Wales, habituating to regular train vibration.

Frequently Asked Questions

Where do ravens build their nests?

Common Ravens nest primarily on cliff ledges in natural habitats — a secure, elevated site that is difficult for ground predators to access. Where cliffs are unavailable, ravens use large trees (preferring the main fork or the largest horizontal branch high in the crown), electricity pylons, communication towers, bridges, and occasionally buildings. In areas of human infrastructure, ravens adapt readily to artificial structures, which may provide even better vantage, wind shelter, and predator exclusion than natural sites. The key requirements are: elevation, structural stability, a view of the surrounding area, and protection from above-attack (from eagle owls, golden eagles).

Do ravens use the same nest every year?

Yes — established raven pairs are highly site-faithful, returning to the same nest or the same cliff face year after year. Nest sites that are used for many years become large, bulky structures as new material is added each season on top of the previous year's structure. Some long-occupied raven nests have been recorded over 20+ years of continuous or near-continuous use, reaching substantial dimensions (up to 1.5m deep and 1m wide). The attachment to the nest site is primarily the pair's attachment to the territory: the nest is built within the core of their territory, the most valuable location they defend.

How early do ravens start nesting?

Ravens begin nest refurbishment and courtship display in late winter — often in January or February in temperate regions, before any signs of spring. Egg-laying occurs from late February to early April depending on latitude and altitude; pairs at higher elevations and latitudes nest slightly later. The early breeding season allows the chicks to fledge in May–June when food is at peak spring abundance. This means the female is incubating eggs through late-winter cold, sustained by intensive food provisioning from the male — the raven pair bond at its most critical test.

Sources

Boarman, W.I. & Heinrich, B. (1999). Common Raven (Corvus corax). In Poole, A. (ed.), The Birds of North America, No. 476. Cornell Lab of Ornithology. — nest site preferences, structure, territory size, fidelity, early breeding season.
Marzluff, J.M. & Angell, T. (2005). In the Company of Crows and Ravens. Yale University Press. — urban nesting, artificial structures, pylon nesting, predator context.

[science] peer-reviewed data