Birdseye Maple is easy to distinguish from other figuring. Its name is quite descriptive, as shown in the photo below. The figuring in Birdseye Maple appears as small roundish "bird's eyes" in the wood. Birdseye Maple is especially popular for necks and fretboards.
Birdseye figuring occurs most often within Hard Maple but also is found within numerous different types of woods such as White Ash, American beech, Red Maple, Cuban mahogany, Black Walnut, and Yellow Birch. Popular theories as the source of the strange swirly Birdseye figuring range from birds pecking on the trees to a fungus or disease of some sort. It is more likely a combination of environmental factors that produce the distinctive Birdseye figuring.
If you own a guitar with a Birdseye Maple neck or fretboard, chances are it was made from a Sugar Maple tree, which is the most abundant source of the highly prized wood. It is grown in relative abundance in the US and Canada, in the Great Lakes region and Rocky Mountains. Finding that perfect tree with the highly-figured wood is difficult although, as there is usually no outward sign that a tree's wood will be figured. The Birdseye figuring usually comes as a nice surprise for the millers who turn the tree into usable lumber.
Raw wood with Birdseye figuring is usually much more expensive than unfigured wood and can be more difficult to work as well. The stability of the wood is usually proportional to the number of Birdseye's present in the wood, so care must be used to avoid tear-outs while routing or turning the wood on a lathe.