Some differences between bluebirds and other small cavity nesters

If You're Used to Bluebirds, You May Be Suprised to find....

Some differences in behavior and nests
between Bluebirds and Other Small Cavity Nesters

Species

Differ from Bluebirds in this regard

More Info

Ash-throated Flycatcher

Nest gets filthy
Adult may "explode" out of the nestbox when monitor approaches

Flycatchers

Bluebirds

Very tolerant of monitoring
Female builds nest and incubates
Nest does not have layers (e.g., like chickadee)
Both parents remove fecal sacs right up to fledging (unless widowed/too busy)
Male often perches on box
Incubation may begin on last or next to last egg

Differences between bluebird species

Carolina Wren

Often nests in weird places, not often in a box
May use snakeskin in nest
Male may build dummy nests

Carolina Wren

Black-capped Chickadee

Very secretive during nestbuilding and egg laying. Does not perch on box roof
Pull a "blanket" of fur/hair over eggs when leaving nests
Eggs are very fragile
Have a hard time defending nest - see competition
Unlikely to return to the site of a failed nesting
Can excavate their own hole
May prefer boxes with some sawdust/wood chips in the bottom that they can then 'excavate'
Generally only have one brood, often laying 6-8 eggs
Often remove unhatched eggs
Do not migrate
In CT, I seldom see blowfly larvae in nests, but BNA reports 71% of nests infested in TN.

Chickadee

Carolina Chickadee

Can excavate their own hole
May start excavation or nestbuilding in several locations before chosing one
Do not seem to prefer boxes with sawdust in them (which they can "excavate "
Pull a "blanket" of fur/hair over eggs when leaving nests

Carolina Chickadee

Downy Woodpecker

Not known to use nestboxes for nesting, but will roost in a box
Excavate a new cavity for each nest
Both male and female develop a brood patch, both incubate, only males incubate at night
Males are primarily responsible for removing fecal sacs. Nestlings may only defecate after being fed 3-4 times.
Incubation time is short (12 days), but they don't fledge for 20-25 days after hatching

Downy Woodpecker

Great Crested Flycatcher

Very secretive during nesting
May prefer nest sites very high up (up to 70 ft. off ground)
Both male and female build nest
May use snakeskin in nest
Female may hiss and strike (snake-like) when the nestbox is opened during incubation
Tend to nest in same site every year (high nest site fidelity)
One brood per year
Young fledge in 13-15 days
After fledging, young may only stay in area 3-4 days

Flycatchers

House Finch

Fecal sacs accumulate on rim of nest
Do not migrate?

House Sparrow

Can build a (bulky) nest very quickly (a couple of days)
Tend to use trash (cigarette butts etc.) and many feathers in nest cup.
Nests very close to others of its species
Do not tolerate sparrow spooker, avoid boxes with fishing line on them, may not prefer Gilberston nestbox.
Male also incubates
Do not migrate
Frequently attack nests (eggs, young adults) of other species

House Sparrow

House Wren

Male builds dummy nests
Entirely removes prior nests and nests of other birds
Frequently remove nests, eggs and very young nestlings from nests of other species

House Wren

Nuthatch

Seem to prefer a box under/on a tree
May prefer a box with a chalet roof?
May remain in box (up near roof) even after tapping/calling during monitoring
During laying may cover eggs with feathers/fur
Lay 5-10 eggs (typically 7-8)
Pygmy may use snake skin in nest
WBNU nestlings do not fledge until up to 24 days
Do not migrate?

Nuthatch

Prothonotary Warbler

May nest in weird locations, generally over or near running water
May be sensitive to human disturbance around the nest site
Young can swim

Prothonotary Warbler

Starling

Uses green vegetation in nest
Can build nest in 1-3 days
Fecal sacs pile up, fouling nest
Incubation begins with the next or next to last (penultimate) egg
Both sexes develop an incubation patch
15-33% of nests are parasitized by other starlings

Starling

Titmouse

Seem to prefer a box mounted on a tree or under tree canopy
Secretive during nestbuilding and egg laying, do not perch on box
May use snake skin in nest
May hiss like a snake and strike wall during monitoring
May abandon nest if disturbed, especially during construction
JUTIs tumble to ground when fledging, fledge all at once.
Do not migrate?
Fewer blow flies?

Tufted Titmouse

Tree Swallow

Will nest within 25+ of another pair of Tree Swallows (colonial)
Take a really long time (2-4 weeks) to build a nest, with lots of (typically white) feathers recurved over eggs, feathers may introduce lots of mites into nest
Egg laying often in synch (within 7-10 days) with neighboring Tree Swallows.
Usually only have one brood
Often do not remove unhatched eggs
Stop removing fecal sacs about a week before fledging so nest gets filthy (may also have a lot of mites)
Tend to dive bomb monitors more
Adults may refuse to budge when nestbox is monitored
Often have head poking out of hole during incubation and brooding
Older young may "hog" the hole to get more food
Usually stay in box 18-22 days
Young can feed themselves as soon as they fledge
Young may occasionally go back in box to be fed by own parents/others

Tree Swallow

Violet-green Swallow

May nest in colonies of up to 25 pairs.
Eggs may hatch over 2-5 days.
Young dependent on parents after leaving nest for unknown period.
Parents stop removing fecal sacs after eyes open.
Fledging may occur over a period of days, young may return to the nest over the next few days?

Violet-green Swallow

More Information:

...the thing that makes the bluebirding hobby so intriging is that you CANNOT answer questions simply True or False all of the time. MOST of the time you cannot even answer a question with four multiple choice answers. We should all enjoy these debates or exchanges of opinions and be willing to experiment and contribute to the knowledge we all seek.
- Keith Kridler, Bluebird_L, 2007