You can get a feather by either shooting a duck or chicken in hunting mode w/ a bow (obviously). If you succesfully kill the chicken/duck, it will drop "small duck/chicken meat" and "feather".

Ok, you know that place in the south-east corner the grassland that you walk back and there's only one tree and pretty much nothing else? Behind the tree on the left side is a place where you can climb down and get to an area with trees that have eggs and feathers beneath them.

Yes I know that place and I gathered the feathers and the eggs but you can't get back up
or down. So what's with that?

You can't get back up to the gras slands (sorry about the space but I hate the *'s), but
you can get down. There are two logs, one at each end of the are that you can push and get
down. One takes you right next to the river and the other takes you to where you first
discovered potatoes. Funny way of putting it, but it gets teh point across, doesn't it?

If you need more help or other info, just send me a message and I will get back to you as
soon as possible.