
Great crested grebe Podiceps cristatus
Great crested grebe Podiceps cristatus male with erect crest

Great spotted woodpecker Dendrocopos major
Great spotted woodpecker Dendrocopos major on side of a tree, ready to drill for insects

Great tit Parus major
Great Tit Parus major on a tree branch with grasses behind

Grey heron Ardea cinerea
Grey heron Ardea cinerea quick sketch, standing on one leg in a river

Grey heron Ardea cinerea with background
Grey heron Ardea cinerea wading ankle deep in a river with reeds behind

Grey wagtail Motacilla cinerea
Grey wagtail Motacilla cinerea breeding male stood on a mossy stone in a stream

Hen Gallus gallus domesticus egg in idealised meadow
Hen Gallus gallus domesticus egg sitting in a green field with meadow flowers and butterflies, used for packaging

Herring gull Larus argentatus with background
Herring gull Larus argentatus eating a chip from the road in a seaside urban setting

House martin Delichon urbicum and nest vignette
House martin Delichon urbicum coming to feed chicks in a nest under the eaves of a roof, small vignette

Common Goldeneye Bucephala clangula male displaying
Common Goldeneye Bucephala clangula male displaying

Common kingfisher Alcedo atthis
Common kingfisher Alcedo atthis with minnow in its beak, perched on a branch

Common sandpiper Actitis hypoleucos
Common sandpiper Actitis hypoleucos sketch cut to white

Common wood pigeon Columba palumbus
Common wood pigeon Columba palumbus showing pink and green feathers

Comparison of egg sizes
Pencil sketch comparing size of humming bird, ostrich, hen, and elephant bird

Coot Fulica atra
Coot Fulica atra

Curlew Numenius arquata
Curlew Numenius arquata

Diagram of Duck Egg development Day 1
Stylized diagram of the development of a duck egg from being laid until after hatching Day one yolk held in place with chalaza, germinal disc where fertilized chick starts to grow

Diagram of Duck Egg development Day 12
Stylized diagram of the development of a duck egg from being laid until after hatching day twelve feathers start to show eye covered with lid claws formed

Diagram of Duck Egg development Day 27
Stylized diagram of the development of a duck egg from being laid until after hatching Day 27 hatchling squashed inside egg ready to hatch, air cell still shows

Diagram of Duck Egg development Day 5
Stylized diagram of the development of a duck egg from being laid until after hatching day five embryo separates from the yolk, blood vessel network grows and branchesm eye starts to get a colour.

Diagram of Duck Egg development Day 8
Stylized diagram of the development of a duck egg from being laid until after hatching day eight blood vessels carry waste and oxygen, eyelids start to cover eye, beak and egg tooth more clear.

Diagram of Duck Egg development Duckling chick hatching out still half in its shell
Stylized diagram of the development of a duck egg from being laid until after hatching duckling hatching half in half out of shell with prominent egg tooth

Diagram of Duck Egg development Hatched duckling chick
Stylized diagram of the development of a duck egg from being laid until after hatching hatched duckling chick

Diagram of the cross section of a bird bone
Bird bone cross section showing cross bracing for strength and hollow structure