Glossary

crest: a tuft of feathers located at the top of a bird’s head which can often be lowered or raised depending on the mood of the bird.

dimorphic / monomorphic: dimorphic species have different coloration or size between the male and female. Raptors, such as owls, eagles, and falcons, display “reversed sexual size dimorphism” where the female is bigger in size. With monomorphic species, the male and female appear identical.

fledgling: a young bird that has developed sufficient muscles and feathers to be able to leave the nest on its own, but often still being cared for by the parents. Many at this stage are seen walking on the ground as they continue to develop and learn to fly (i.e. American Robin). It can be starting to see a bird unable to fly, but this is a normal stage of development and the parents are likely nearby, keeping an eye out.

precocial / altricial: precocial birds are born with their eyes open and able to walk, swim, and feed on their own soon after hatching from the egg. Altricial birds are born with their eyes closed with little to no down feathers, requiring considerable care and feeding from the parent before they are able to walk and survive on their own.

speculum: a patch of wing feathers, often seen in ducks, being a noticeably different color (i.e. Mallards have a blue speculum).

vermiculation: a very fine wavy line patterning found on the feathers of dabbling ducks and other waterfowl. From the latin vermiculus, or little worm.