Birdseye maple has become a popular wood for craftsman to make high-quality furniture and crafts with. The cause of what makes birdseye in some trees versus others is still unknown, and it is only through one of three examinations that you are able to determine if the log or wood you are looking at is birdseye.
Look at the tree trunk. The trunk or "bole" of a maple with birdseye has a "Coke bottle" shape at the lower trunk. Therefore, the lower bole will be wider and stem up in a more slender pattern. In addition to the oddly shaped bole, you might notice dark black spots on the bark. This indicates the possibility of birdseye in the tree.
Pull the outer bark from the trunk with your hands. There should be protuberances on the inside of the bark and indentations on the outside of the bark. In some instances, there is no sign externally with indentations prominently shown on the internal side of the bark.
Cut the tree through the trunk, and remove a section that extends horizontally through the bole. Go to the center of the bark, and cut a section of the phloem where the birdseye would be most prominent. The phloem is the core of the bark where the nutrients are transported. This step is done when the tree is being harvested. To try to remove a cross section for examination in any other fashion or time will harm the tree, leading to infection, disease or death.