A blood feather is a new feather that still has a blood supply to help it grow. When the feather is full-grown, it no longer needs blood to help it grow, so the blood vein recedes, leaving a normal, healthy feather.
All feathers start as blood feathers, as they need the blood to help them grow to their full size. Think of it like your fingernail. When the nail is near the nailbed it still has a blood supply to help it grow. If you tried to trim the nail when it was close to the nail bed, it would bleed. Once the nail is fully grown it doesn’t need the blood to grow anymore, which is why you can trim the tips of your fingernails without feeling a thing.
You may not notice blood feathers on your pet bird’s face or chest because these feathers are small, which means the blood supply is also smaller. On wing feathers and tail feathers, however, the blood supply is larger, which is why you can often clearly see when your pet bird has blood feathers.
A blood feather can be identified in a couple of ways. First, it will be a newer feather and it may not be quite as long as the feathers around it. These new feathers can be sensitive to touch, so your bird might get cranky if you try to touch one. If you look at the shaft of the feather close to the bird’s body, you should be able to tell the difference between blood feathers and full-grown feathers. Full-grown feathers have a white sheath like you’re used to seeing when your pet bird molts. Blood feathers have a dark sheath, and you may even be able to see the blood.
Learn what to do when a blood feather breaks here.