M Glossary of bird terms
also molt (chiefly u.s.) , moulting / molting. periodic replacement of feathers shedding old feathers while producing new ones. feathers dead structures @ maturity gradually abraded , need replaced. adult birds moult @ least once year, although many moult twice , few 3 times each year. slow process, birds shed feathers @ 1 time; bird must retain sufficient feathers regulate body temperature , repel moisture. number , area of feathers shed varies. in moulting periods, bird may renew feathers on head , body, shedding wing , tail feathers during later moulting period. species of bird become flightless during annual wing moult , must seek protected habitat reliable food supply during time. typically, bird begins shed old feathers, pin feathers grow in replace old feathers. pin feathers become full feathers, other feathers shed. cyclical process occurs in many phases. symmetrical, feather loss equal on each side of body. because feathers make 4–12% of bird s body weight, takes large amoun...