Bluebird and Small Cavity Nester Conservation

Sialis - Bluebirds and other small cavity nesters

Small Cavity Nester Egg ID Matrix

The easiest way to find out who is nesting in your nestbox is to ID an adult bird incubating, but incubation doesn't start the last or nest to last egg is laid (depending on the species.) The location and nest construction are also great tips. For detailed descriptions of nest construction and egg identification, see Nest and Egg ID (also with links to photos of nests, eggs and young) and the nest contents ID matrix. U= uncommon, but it happens (e.g., about 3-5% of bluebirds eggs are white. Y=Yes. MB=may be. A "wreath" is a concentration of pigment on one end of the egg. More ID links below. For non-cavity nesting bird eggs, or eggs found outside the U.S. see the searchable database at the Royal Alberta Museum Virtual Egg Exhibit.

CLUE-> SPECIES	White	Blue	Spotted	Wreath	Shape	Gloss	Relative Size	Confused With
Bluebird, Eastern	U	Powder	NO		Oval	Y	Larger	Finch, Starling
Bluebird, Mountain	U	Pale			Oval	Y	Larger	Finch, Starling
Bluebird, Western	U	Pale			Oval	Y	Larger	Finch, Starling
Chickadee, most	Cream		Lt. brown or red. Dots or blotches	MB	Rounded	Little or no	Tiny	Titmouse
Chickadee, Carolina	White		Reddish-brown dots or blotches	MB	Rounded	Little or no	Tiny	Titmouse
Chickadee, Mountain	White		Some no, some covered wtih dots	MB	Rounded	Little or no	Tiny	Titmouse
Cowbird	or Grayish		Heavy, even brown/red dots. One replacement egg	MB	Rounded		Larger	House Sparrow
Finch, House		Blueish green	Sparing black dots		Oval	Slight	Medium	Bluebird
Flycatcher, Ash-Throated	Or creamy or pinkish		Heavily scrawled/streaked with brown/purple/gray		Oval		Larger	Fewer markings than Great
Flycatcher, Great-crested	Or creamy or pinkish		Densely streaked/scrawed with pruple, gray, red brown/olive	Often	Oval	Moderate	Larger	More markings than Ash, larger than House Sp
Sparrow, House or Eurasian	Creamy or greenish		Irregular, fine brown speckles	MB	Oval	Slight	Medium	Cowbird, Great-crested, Nuthatch
CLUE-> SPECIES	White	Blue	Spotted	Wreath	Shape	Gloss	Relative Size	Confuse With
Nuthatch, Brown-headed	Y		Fine reddish-brown dots/blotches		Short Oval	Almost no	Small	Titmouse, House Sp, Chickadee
Nuthatch, Pygmy	Y		Uneven fine sparing speckles reddish	MB	Short Oval	Little or no	Small	Titmouse, House Sp, Chickadee
Nuthatch, Red-Breast	Or creamy or pinkish		Heavily cinnamon/lavender/gray speckles	MB	Short Oval	Very little	Smaller than White	Titmouse, House Sp, Chickadee
Nuthatch, White-brea	Or creamy or pinkish		Heavily cinnamon/lavender/gray speckles	MB	Short Oval	Very little	Larger than Red	Titmouse, House Sp, Chickadee
Protho- notary			Bold, liberal dull red brown or purple gray all over
Purple Martin	Pure					Slightly		Larger than Tree Swallow
Starling		Pale blueish/greenish			Pointy	No	Large	Bluebird
Swallow	Pure, sometimes pinkish				Pointy	No or slight	Medium
Titmouse	White		Some with faint sparing tiny red/brown speckles		Oval	Little or slight	Tiny	Chickadee, Nuthatch
Wren, Bewick's	Y		Irregular brown/purple/gray dots	Often	Rounded oval	Little or no	Tiniest	Not glossy like House Wren
Wren, Carolina	White or rosy		Heavy reddish/brown flecks	often		Little or no	Tiny	Larger than other wrens, not glossy like House
Wren, House	White or pinkish		Numerous pinkish/brown specks	Often		Very	Tiniest	Bewick
CLUE-> SPECIES	White	Blue	Spotted	Wreath	Shape	Gloss	Relative Size	Confuse With

Cavity nester photos of nests eggs and young

DESCRIPTIONS of cavity-nester nests and eggs + Clues on Nests | Eggs
PHOTO ALBUM with pictures of cavity nesting birds, nests and eggs
TABLE showing relative sizes of eggs, and egg photos side by side
Preferred HABITAT, by species

Downloadable 2 page guide (PDF) to common nests found in CT
Mystery nests (have fun trying to guess)
Unusual nest sites Part 1 Part 2 and nestbox specs by species
Weird eggs (e.g., dwarf, odd coloration)

Cavity Nester Nests, Eggs and Young Photos and Bios. Also see Nest ID Matrix (contents) and Egg ID Matrix (color, spots, etc.)

I would rather live in a world where my life is surrounded by mystery
than live in a world so small that my mind could comprehend it.
Harry Emerson Fosdick

May all your blues be birds!

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Last updated May 3, 2012. Design by Chimalis.