Up here in Ontario, Canada, we have a lot of white birch and also yellow birch which is more beautiful, as it has a golden hue to it. Both make a good bow. Just make sure you let it dry well before you work on it. White birch trees seem to grow straighter than yellow birch. I'd take yellow over white. But my favourite wood here is Hop Hornbeam or as we call it Ironwood. I have made bows from maple, ash, white cedar, red cedar, lillac, oak, and hickory that is imported from the U.S. I've also used tamarack, pine, and spruce although they are poor woods and you have to be very gentle with them.