Squirrels and birds are both common backyard wildlife that build nests. However, there are some key differences between squirrel and bird nests. Squirrels build nests called dreys while birds build nests of varying shapes and sizes.
Purpose of Nests
Both squirrels and birds build nests to raise their young and protect them. However, there are some differences in the purpose of their nests:
– Squirrels build nests for shelter and raising young. Squirrels do not always breed in their nests.
– Birds build nests specifically for laying and incubating eggs and raising chicks. Birds breed and raise offspring in their nests.
Nest Locations
Squirrels and birds choose different locations to build their nests:
– Squirrels usually build nests high up in trees branches for safety from predators.
– Birds build nests in a variety of locations including trees, shrubs, ledges, cliff edges, on the ground, and even on man-made structures.
Squirrel Nests
Here are some key facts about squirrel nests:
Names of Squirrel Nests
Squirrel nests are known by several common names:
– Drey – This term refers to a nest built by tree squirrels.
– Den – This refers to an underground burrow or cavity where some ground squirrels live.
– Cavity nest – Some squirrels will also nest in tree cavities.
Appearance
– Tree squirrel dreys are usually made of twigs, leaves, moss, and bark. They are often lined with fur, grass, moss, or feathers for insulation.
– Dreys are spherical or dome-shaped, about 12-20 inches across.
– Dreys are usually built on a high, sturdy branch near the tree trunk, 15-100 ft off the ground.
– Ground squirrel dens are underground burrows in the soil with tunnels and chambers.
Construction
– Tree squirrels build dreys by weaving together twigs to form a sturdy outer shell.
– The inside cup of the nest is lined with soft materials like fur, moss, grass, or bark strips for warmth.
– Squirrels will continually add to dreys to maintain and expand them.
– A drey can measure 2-3 feet across if maintained over many seasons.
– Ground squirrels dig burrows with their claws and teeth. Burrows have multiple entrances and tunnels leading to nest chambers.
| Squirrel Species | Nest Type |
|---|---|
| Tree squirrels (gray, red, fox) | Dreys in trees |
| Ground squirrels (prairie dogs, chipmunks) | Underground burrow dens |
| Flying squirrels | Dreys in trees |
Nesting Habits
– Squirrels do not always breed in their nests. Females will sometimes build a separate maternity nest to have their young.
– Tree squirrels may have multiple dreys called refuge nests. These are for sleep and rest.
– Squirrels may abandon and rebuild dreys. They do not reuse the same nest.
– Flying squirrels will use communal nests with multiple individuals.
Bird Nests
There are some key facts about bird nests:
Appearance
– Bird nests come in a huge variety of shapes, sizes and materials.
– Nests can be cup, sphere, bowl, or platform shaped.
– Many species build compact, cup-shaped nests in trees/shrubs.
– Ground nests include scrapes or mounds.
– Cavity nests are built in holes in trees, cliffs, or buildings.
– Materials include twigs, grass, moss, feathers, mud, spider silk, hair, and more.
Construction
– Nests are built by the adults, mainly the female.
– Both male and female may gather materials.
– Woven nests are made by repeatedly crossing materials over each other.
– Nests are crafted into shapes by pressing with body.
– Cup nests have inner cups made of softer materials like grass or feathers.
– Birds may add materials to nests during incubation and nestling periods.
Location
– Tree nests: Branches of deciduous/coniferous trees
– Shrubs: In dense shrubbery
– Cavities: Hollows of trees, holes in cliffs or walls
– Ground: Directly on the ground in a scrape, mound, or cup nest
– On structures: Ledges, bridges, buildings
– Burrows:holes dug in dirt banks, old woodpecker cavities
| Nest Location | Bird Groups |
|---|---|
| Tree branches | Robins, jays, crows, owls, hawks |
| Shrubs and hedges | Sparrows, warblers, finches |
| Cavities | Chickadees, woodpeckers, ducks |
| Ground | Owls, grouse, plovers, gulls, terns |
| Human structures | Swallows, swifts, barn owls |
| Burrows | Kingfishers, bank swallows |
Nesting Habits
– Most bird species build a new nest each breeding season.
– Existing nests are not reused, some repairing may occur.
– Cavity nesting birds may reuse cavities, just add new nest materials.
– Open nests exposed to weather deteriorate after one season.
– Some colonial nesting birds reuse/repair communal nests.
Similarities and Differences Between Squirrel and Bird Nests
There are some key similarities and differences between squirrel dreys and bird nests:
Similarities
– Both are built by adults for raising and protecting young.
– Made using available natural materials like twigs, leaves, moss.
– Often insulated with soft materials like fur, grass, or feathers.
– Built in locations to prevent predation like high tree branches.
– Constructed by weaving, pressing, and shaping materials.
Differences
| Squirrel Dreys | Bird Nests |
|---|---|
| Always high up in trees | Wider variety of locations |
| Large spherical or dome shape | Typically cup or bowl shaped |
| Twigs woven as main structure | Very diverse materials and construction |
| Not always for breeding | Built specifically for breeding season |
| Abandoned and rebuilt annually | Typically not reused annually |
The major differences have to do with the diversity of bird nest locations, shapes, and materials compared to dreys. Birds also build nests expressly for breeding each year while dreys are more multipurpose and reused by squirrels.
Conclusion
While squirrel dreys and bird nests share some similarities in purpose and materials, there are major differences between them. The most significant variations are the strictly tree location of dreys, their large domed shape, and the fact squirrels may use them for non-breeding purposes. Bird nests exhibit much more diversity in site selection, construction, and they are built exclusively for breeding season. Both nest types serve the essential functions of protecting vulnerable young and providing shelter for their growth. But bird nests tend to be more temporary, delicate structures while dreys are hardy reuseable shelters suited to the specific habits of squirrels.
