| A | B |
|---|
| courtship | When a male tries to impress a female as a mate. |
| duetting | Song sang by both male and female when they have become mates; defines their territorial nesting area. |
| cooperative breeding | When younger sibling birds help out with finding food for the hatchlings |
| egg cuticle | Thin, dry coating of protein that provides antibacterial properties |
| embryo | developing chick inside the egg |
| inner/outer membrane | Protects liquid portion of internal egg from drying |
| ablumen | Composed of water, protein and other nutrients used by embryo during development; Known as "egg white" |
| yolk | Energy rich food used by developing embryo |
| chalazae | Ropey like white strands that anchor the yolk in place. |
| air cell | small pocket of air between the inner and outer membrane of egg |
| germinal disk | the tiny circle within the yolk that, if fertilized, becomes the embryo |
| unfertilized egg | Eggs purchased/used for eating. |
| clutch | all the eggs in a nest |
| brood patch | the featherless patch exposing bare skin that develops in a brooding bird |
| egg tooth | the small sharp notch on the top of a baby bird's beak. |
| brooding | keeping hatched baby birds warm |
| altricial | birds that require special care after hatching |
| fledglings | young birds that are starting to fly |
| precocial | Birds that hatch with feathers, strong legs, ready to swim or walk at birth |
