What hatched here? How to identify bird egg shells

Coming across fragments of bird egg shells in your garden, in the woods or when you're out and about can be an exciting find. But which birds do they come from? Use these ID tips to find out.

Eggshell colour

In general, bird egg shells are made of calcium carbonate and so the default colour is white. But other pigments can create different colours and patterns.

• Birds that build their nests in trees and shrubs (like dunnock and blackbird) generally have blue or greenish eggs, either spotted or unspotted.
• Eggs of hole-nesting birds are generally white or pale blue so that the parent birds can easily locate them and avoid breaking them. Egg camouflage is less important because the egg is usually well hidden within the nest.
• Birds that lay their eggs in the open and on the ground rely on camouflage so usually produce brown or speckled eggs.

Blackbird

A common garden and woodland bird with arguably the most beautiful song of all birds. The blackbird can have two or even three broods a year and breeds from early spring until mid-summer.

Description: blue-green eggs with brown speckles.
Egg size: 2.9 x 2.1 cm
Clutch size: 3-5

Blue tit

The blue, yellow and white blue tit is one of the most recognisable garden birds. Eggs are usually laid in April or May into a nest built of mainly moss, grass and feathers.

Description: light-cream with light brown speckles. 
Egg size: 1.6 x 1.2 cm
Clutch size: 8-10

Bullfinch

The male birds are unmistakable with their bright pink-red breast and cheeks. Bullfinches lay their eggs during April-May, in a delicate nest made from twigs, fine roots and moss. 

Description: light green-blue with purple markings.
Egg size: 2 x 1.5cm
Clutch size: 4-5

Carrion crow

Carrion crows are large, all-black birds that prefer too lead a solitary life. They usually build their nests in the forks of trees and lay eggs between April-May. 

Description: pale blue-green with brown and grey markings. 
Egg size: 4.3 x 3cm
Clutch size: 4-7

Chaffinch

Chaffinches are easily distinguished by their white wing-bar and their eggs are usually laid in spring from around April.

Description: off white eggs with brown-red splotches. 
Egg size: 1.9 x 1.5 cm
Clutch size: 4-5

Collared dove

Now one of the UK's more common birds, collared doves can have three or more broods, and can lay eggs from early in the year to the end of autumn.

Description: white-cream with no markings. 
Egg size: 3.1 x 2.4 cm
Clutch size: 2

Dunnock 

Also known as the hedge sparrow, these greyish birds will lay their eggs in a nest constructed of grass, leaves and roots. Dunnocks can have several broods a year.

Description: light blue with no markings. 
Egg size: 1.9 x 1.5 cm
Clutch size: 4-5

Goldfinch

A brightly coloured finch with a red face and yellow wing patch. Goldfinch nests are neat and compact with a deep cup to prevent the eggs from being lost in high winds. They lay their eggs from late April and may have up to 2 to 3 broods.

Description: whitish with reddish-brown speckles.
Egg size: 1.7 x 1.3 cm
Clutch size: 4-6

Great tit

This colourful bird is the UK's largest tit. The great tit makes a nest of moss and feathers, before laying its eggs in early spring.

Description: white eggs with light brown-red speckles. 
Egg size: 1.8 x 1.4 cm
Clutch size: 7-9

House sparrow

These small brown birds are often heard chirping away. Pairs will build nests of grass and straw before laying their eggs, usually in May. They can have several broods each year.

Description: white-light grey eggs with grey-brown markings. 
Egg size: 2.2 x 1.6 cm
Clutch size: 4-5

Jackdaw

Jackdaws are small black crows with a silvery sheen. They usually lay eggs during April-May, and have one brood a year. 

Description: white/pale blue with grey and brown markings.
Egg size: 3.6 x 2.6cm
Clutch size: 4-5

Jay

Intelligent, distinctive and common in woodland. Jays have pale pink plumage, black streaks on its head and electric-blue wing feathers. Jays have messy-looking nests built in trees and shrubs using twigs, with roots and hair for lining. They usually pair for life and have a single brood each year.

Description: pale blue-green or olive with buff-coloured speckles.
Egg size: 3.2 x 2.3 cm
Clutch size: 3-10

Magpie

Magpies, with their characteristic black and white plumage and long tail, can breed from as young as one year old and lay their eggs in early April. 

Description: green-blue with brown markings.
Egg size: 3.2 x 2.3cm
Clutch size: 5-8

Pheasant

Pheasants, with their rich golden-brown plumage and long tails, were introduced to the UK as game birds. They are now widespread, nesting on the ground and lay their eggs during April-June.

Description: olive-brown with no markings. 
Egg size: 4.5 x 3.6cm 
Clutch size: 7-15

Robin

A familiar and well-loved garden bird with its cheerful red breast. Robins will start to lay their eggs around April and can have two broods a year. Find out more about where and when robins nest.

Description: white-cream eggs with light brown speckles.
Egg size: 2 x 1.5 cm
Clutch size: 4-5

Rook

Rooks are one of the first birds to nest, nest-building and laying eggs as early as the end of February-early March. 

Description: green-blue with black/brown markings.
Egg size: 4 x 3cm
Clutch size: 3-9

Song thrush

Song thrushes are brown birds with paler underparts with darker drop-shaped spots. These relatives of the blackbird,begin to build their nest in early spring, twigs, moss and grass are used to make the round structure. They can have two to three broods.

Description: light blue eggs with black markings.
Egg size: 2.7 x 2 cm
Clutch size: 3-5

Starling

Noisy, glossy, shimmering birds, starlings nest in holes in trees and buildings and lay their eggs in mid-April.

Description: pale blue generally with no markings but occasionally may have brown speckles.
Egg size: 2.1 x 3cm
Clutch size: 4-6

Willow warbler

Willow warblers can be found in woods, scrub and gardens. They are pale grey-green with a yellow underside. They build distinctive, dome-shaped nests which they lay their eggs in during April-May.

Description: white with reddish-brown markings.
Egg size: 1.5 x 1.3cm
Clutch size: 4-8

Woodpigeon

These are our largest pigeons and they inhabit woodland, parks, gardens and farmland throughout the UK. They are capable of breeding throughout the year, they will usually have one to two broods. The empty eggs of woodpigeons may often be seen lying on woodland floors and garden lawns.

Description: pure white with no markings. 
Egg size: 4.1 x 2.9 cm
Clutch size: 2

Wren

One of the smallest birds in the UK, wrens begin to lay their eggs in April and can have two broods a year. 

Description: white/light brown eggs with brown markings.
Egg size: 1.6 x 1.3cm
Clutch size: 5-6