Birdseye maple is an irregularly grained cultivar of the maple or Acer species, with an aberrant but beautiful grain pattern. Instead of the regular vertical and more linear grain of maple, birdseye has a rounded, randomly swirling grain that is dotted with dark amber, brown or nearly black spots.
These dark spots are small, randomly spaced and roughly the size of a bird's eye, hence the name. This rare grain pattern is thought to be the result of stress on the tree during development but is not completely understood. Correctly identifying the signs of a birdseye maple trunk from the exterior of the tree is challenging. Experience and familiarity with trunk shape, bark conditions and growing sites is usually necessary to make a definitive diagnosis by sight alone.
Look for Red Maple or Acer rubrum trees, as this specific cultivar of maple is thought to be more likely to produce the swirling grain and dark stippling of birdseye. While all cultivars of maple can develop birdseye graining, according to professional forester Duane Bristow, birdseye patterns are more likely to occur in Red Maple trees. This tendency can help to narrow the search for trees containing birdseye wood. Red Maple trees produce bright crimson red leaves in the fall and have green leaves on red stems in the spring and summer.
Observe the shape of the tree trunk and look for abnormalities that make the lower trunk look curvy much like the bottom third of an old fashioned glass soda bottle. The lower portion of the trunk just above the soil will flare out and then taper in slightly as if wearing a belt before widening gently and continuing straight up the trunk. While not an unequivocal determining factor, it is a clue to narrow the search.
Test maple wood directly to look for the birdseye patterning. Cut into a large branch or several inches into the trunk of the tree with a hand or chain saw to determine or confirm if the rare patterning is present. Look for the swooping, swirling or almost billowy cloud-like grain lines and the small random spots or swirled birdseyes in hues of amber, brown or black.