Why sparrows are foster moms?

When hundreds of birds gather in trees at sunset and chirp loud what does it mean? What do female mallards look like? What is New Zealands national bird called? My female cockatiel's budgie cagemate flew away today. Will my cockatiel be lonely? Do you capitalize peregrine falcon? Why do flamingos have skinny legs? What internal adaptations allow birds to fly? Where does the swan goose live? Bees or hornets bright orange in color? What is getting your red wings? What do the where the carcass is the vultures gather mean? How do you get cockatiels to mate? Why is the ivory billed woodpecker in danger of extinction? Do male birds and female birds look the same? What is a wingless fly that feeds on livestock? What is up with this bird flu? What eats jambu fruit doves? Do owls eat bird heads and leave the body? Are birds high pitched or low pitched? Is Chinese chicken really chicken or pigeon?