I have a two year old female Embden goose. About 1/2" of the tip of her bill is changing color to a purplish-beige color. Other than that her health seems fine - no lethary, feathers good, nostrils and eyes clean. Am feeding a good brand of crumbles, fresh water everyday. Beds down on straw at night in her "house." Is this typical or something I should be concerned with?