Crows are highly intelligent and adaptable birds that can be found across most of North America. They nest in a variety of locations and build specialized nests designed to keep eggs and young safe from predators and bad weather. Here is an overview of where crows typically choose to build their nests and what influences their nesting behavior.
Tree Nests
The most common place for crows to build nests is up in trees. Crows prefer trees that are tall and offer good cover from leaves, branches and twigs. Common nesting trees include:
- Oaks
- Pines
- Elms
- Maples
- Spruces
Crows often build their nests towards the tops of trees, usually 20-60 feet off the ground. Choosing a high spot helps keep the nest safely away from predators and human activity. However, crows have also been known to nest lower in trees when options are limited.
Tree characteristics that crows look for when choosing a nesting site include:
- Trees near a water source – Crows need to stay hydrated, so having water close by is beneficial.
- Sturdy branches – Branches need to be strong enough to securely support the nest, which can weigh over 5 pounds.
- Good cover – A dense canopy of branches and leaves helps conceal the nest from predators and bad weather.
In addition to naturally growing trees, crows may also nest in planted trees in yards, parks, golf courses and other landscaped areas. They often reuse the same nesting trees year after year.
Cliff Ledges and Crevices
In areas where trees are scarce, such as mountains, canyons and sea cliffs, crows will nest on rocky ledges and in crevices. Ideal cliff nesting spots include:
- Small cavities in the rock face
- Ledges under overhangs
- Rocky outcroppings
- Crevices on steep cliffs
Cliffs allow crows to build nests high up away from danger. The rock walls also provide shelter from wind and rain. Crow nests on sea cliffs may have the added advantage of access to fish and other ocean food sources.
Man-Made Structures
As highly adaptable birds, crows are also known to incorporate man-made structures into their nesting sites. Common types of man-made nest locations include:
- Building ledges and rooftops
- Nooks on old barns and sheds
- Water towers
- Power line platforms
- Cell phone towers
- Billboards
- Light poles
- Bridges
- Smokestacks
Nesting on buildings, bridges and towers allows crows to utilize the height of human structures to keep their nests safe from predators. Crows may choose locations close to food sources like landfills and agricultural fields.
Cavities
Less commonly, crows will nest inside cavities in dead trees, stumps or rock crevices if suitable sites are available. Some advantages of cavity nesting include:
- Extra insulation
- Protection from wind and rain
- Concealed from predators
However, competition for cavities may come from other birds and animals needing nesting sites. Crows typically lose out to stronger cavity nesters like woodpeckers.
Ground Nests
Ground nesting is rare in most crow species. Nesting on the ground leaves eggs vulnerable to predators and flooding. However, ground nests may occasionally be built in areas with few tall trees, cliffs or structures, such as:
- Prairies
- Marshes
- Tundra
Nests are typically placed in a hollow or concealed spot and lined with soft materials for insulation. Some crows may nest in shrubs or low branches a few feet off the ground rather than directly on the ground itself.
Nest Locations by Crow Species
While most crows are adaptable and make nests across various sites, some species have preferences or restrictions based on their range.
American Crow
American crows are found across North America in both rural and urban areas. They readily nest in trees, man-made structures, and occasionally cliffs within their large range. Urban nesting is common.
Northwestern Crow
Northwestern crows nest along the Pacific coast from Washington to Alaska. Trees are a prime nest site, but they also frequently nest on rocky sea cliffs and islands along the coastline.
Fish Crow
Fish crows nest in woodlands and swamps mainly in southeastern coastal regions. Tree cavities near water are a preferred nest site.
Hawaiian Crow
Hawaiian crows nest high on the steep cliffs of volcanic mountains and valleys on Hawaii’s Big Island. Nesting in tall trees is less common due to a lack of native tree species.
Tamaulipas Crow
This endangered Mexican species nests in tree cavities within the humid forests of a small coastal region. Their range restricts them to nesting mainly in trees rather than cliffs, buildings or other sites.
Nest Locations by Geography and Habitat
The table below summarizes the general nesting locations favored by crows in different habitats and regions:
Region/Habitat | Typical Nest Locations |
---|---|
Woodlands and forests | Trees |
Coastlines | Sea cliffs, trees, rocky islands |
Mountains and canyons | Cliffs, crevices, tree ledges |
Deserts | Man-made structures, trees near water sources, cavities, low shrubs |
Grasslands and prairies | Trees (where available), ground nests, man-made structures |
Tundra | Low shrubs, rock outcrops, ground nests |
Urban and suburban areas | Buildings, towers, bridges, tree cavities, trees in parks/yards |
Rural areas | Barns, sheds, silos, trees, power line poles |
As this table shows, crows are resourceful nest builders that utilize what’s available in each environment, whether cliffs, trees, man-made structures or the ground itself.
Nest Placement Within Trees
When nesting in trees, crows don’t choose tree locations randomly. Research shows crows selectively choose sites that meet certain criteria:
- Forks or horizontal branches: 90% of tree nests are built in forks or where horizontal branches meet the main trunk. This provides a stable platform.
- Areas with dense foliage: Thick leaves above the nest conceal it from predators and provide shade/insulation.
- Higher vantage points: Crows favor nesting towards the tops of trees for better visibility.
- Access to feeding areas: Trees near open fields offer nearby food access.
Studies on American Crows in New York found the average height of nests was 36-46 feet up, emphasizing their preference for higher, safer spots. However, lower nests were observed where tree height or branch availability was limited.
Nesting Platforms
While a fork between branches is the most popular nest platform, other types of tree platforms used by crows include:
- Where multiple branches intersect the trunk
- Tree cavities or hollows in dead trees
- Old squirrel or hawk stick nests
- Stumps or tops of snapped-off trees
- Mistletoe clumps growing on branches
- Tree cruxes next to the trunk
- Dense clumps of twigs and vegetation
Crows are resourceful at utilizing whatever suitable platform exists at their chosen nest site.
Nest Shape and Materials
Crow nests are bulky, bowl-shaped structures built from a range of materials collected by the birds. Typical elements include:
- Sticks – Form the basic nest structure and frame.
- Twigs – Woven into a dense, tangled mass for the nest bowl.
- Bark strips – Help bind nest materials together.
- Pine needles – Add softness and insulation to the interior.
- Feathers – Insulate the nest bowl.
- Grasses – Line the nest bowl.
- Hair and fur – Collected from the environment for insulation.
- Paper, plastic, string – Incorporate man-made materials in urban areas.
Nest dimensions vary based on location and materials available, but typically measure 16-24 inches across and 8-12 inches high. The inner cavity where eggs are laid is ~6-8 inches across. Total weight can exceed 5 pounds.
Both male and female crows build the nest working from the inside out. A sturdy outer layer of sticks and twigs forms the overall shape and conceals the bulkier inner mass of tangled vegetation. The bowl then gets lined with soft materials.
Crows often reuse and renovate old nests from previous years, adding new materials to refresh the structure. However, completely new nests are built each breeding season around 20-40% of the time.
Nest Defense
Crows are highly protective of their nest site. They chase away potential predators that get too close, sometimes mobbing them in large groups. Common nest threats include:
- Squirrels
- Jays
- Snakes
- Cats
- Raccoons
- Hawks
- Owls
- Ravens
To deter predators, crows may line the area around their nest with garbage, feces or animal carcasses. These act as pungent scent markers to ward off threats.
Nest defense even extends to humans. Crows will often dive bomb or mob people who agitate them near their nest tree. However, not all crows react aggressively, especially if humans maintain a respectful distance.
Timing of Nest Building
Most crows begin building or refurbishing their nests in early spring, from March to April across most of North America. Some key factors influencing timing include:
- Weather: Milder temperatures and less snow cover allow earlier nesting.
- Food availability: Adequate food resources are needed to breed.
- Day length: Increasing daylight triggers hormonal changes for breeding.
- Age: Older crows tend to nest earlier than younger ones.
Southern populations like Florida crows may start nests as early as January or February. On the other hand, far northern crows in Alaska don’t begin until late April or May.
Once built, crows will occupy their nests continuously through breeding, egg-laying, incubation and raising of young, which takes 2-3 months. Most crows raise just one single brood per year.
Do Crows Use the Same Nests Year After Year?
Crows exhibit nest site fidelity, meaning they often return to the same nesting locations year after year. Advantages of reusing old nests include:
- Saved energy – Less time and effort to repair old nests than build new ones.
- Familiar territory – Known neighbors, food sources, threats, etc.
- Safer sites – Locations that previously fledged young successfully.
However, crows don’t use the exact same nest every single year. One study of American Crows found only 22% reused the same nest in consecutive years. Reasons for switching nests include:
- Predation – Abandon nests compromised by predators.
- Parasitism – May desert nests heavily infested by bird mites.
- Damage – Storms may destroy nests forcing new ones.
- Disruption – Human activities may cause nest changes.
When switching nests, a new site is usually chosen close by in the same territory or nesting area. So while not always in the exact same spot, crows still exhibit site fidelity year to year in a general area.
Do Crows Use Other Bird Nests?
Crows sometimes commandeer old nests built by hawks, herons, ravens, squirrels or other birds rather than build new ones from scratch. Advantages include:
- Less work – Quicker than building their own nest.
- Good locations – Takes advantage of favorable sites.
- Sturdy structure – Some large stick nests are already stable platforms.
Crows may slightly modify another bird’s nest by adding fresh lining materials each year. Or they might completely rebuild it into a typical crow nest over time.
However, competition for large stick nests can occur with other birds like herons, ravens and even squirrels in tree cavities. Crows are persistent though and will attempt to claim abandoned nests.
Conclusion
In summary, crows are intelligent builders capable of constructing nests in diverse environments from prairie groves to urban high-rises. Key factors influencing their nest sites include safety from predators, proximity to food and water, and availability of stable nest platforms. While crows occasionally switch nest locations, they exhibit strong site fidelity in general, returning to previous sites that offer successful breeding. Their resourceful nesting behaviors illustrate how crows thrive across an impressive range of habitats.