plumage

Stylized diagram of the skeelton of a duck

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

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

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

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.

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.

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

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

Bird bone cross section showing cross bracing for strength and hollow structure

Stylized diagram of the internal organs and anatomy of a duck within a pen outline

American goldfinch Spinus tristis quick sketch on twig with red berries

Archeopteryx reconstruction

Archeopteryx skeleton

Barn owl Tyto alba peering out from barn rafters

Swallow Hirundo rustica sketch in flight

Black Casqued Hornbill Ceratogymna atrata

Black headed gull Chroicocephalus ridibundus with winter and summer head plumage

Black redstart Phoenicurus ochruros view from behind, head slightly cocked

Blackbird Turdus merula

Blue-tit Parus caeruleus male on a branch

Blue tit Parus caeruleus, Coal tit, Long tailed tit, and great tits in a Scots pine tree with cowslip and snakeshead fritillary growing underneath

Blue tit Parus caeruleus adult feeding chicks inside a bird box

Blue tit Parus caeruleus visiting a bird box

Bohemian Waxwing Bombycilla garrulus perched on a twig of rowan with orange berries