There is this thing that rob3232 introduced me to called "bird peck" in black walnut. According to the Purdue wood site: https://www.extension.purdue.edu/extmedia/FNR/FNR-278-W.pdf (see page 4) Bird peck exists, is fairly common in black walnut, and really is caused by birds pecking on the tree. It is called "worm" in the veneer business because it looks like a worm hole. Below are a couple of sections of the a plank that Rob sent me and some closeups of the bird peck areas. The streaking looks very much like ambrosia streaking but I'm willing to believe that it is actually caused by birds, as both Rob and Purdue say it is. UPDATE: see post #35. I have more evidence and now believe that all the stuff shown in this thread is ambrosia walnut "bird peck" walnut DOES exist but we're not seeing it here Rob's maple in post #13 doesn't count (not walnut) BUT ... here's the problem that I'd like to get comments on: the hole only goes into the plank just a little way (which is very consistent with a bird pecking the tree) but it is on the inside. That is, this particular plank was cut close to the sapwood and on one side they have sapwood edges. Both this and the growth ring curvature make it unquestionably clear that the hole is on the INSIDE of the plank. That is, the only way it could have been made by a bird is if the bird was inside the tree. Looked at another way, you could say that what it really looks like is that a worm tunneled into the tree somewhere else, made his way over to this area, started heading from the inside of the tree towards the bark and then stopped about 2" inside the bark so that when this plank was cut there is a shallow hole in the surface of the plank. And not just one ... there are 4 of them in just this 2 foot by 6 inch section of plank. So ... I just don't get how Purdue and Rob can be right about it being caused by a bird BUT I also don't get how it was that these 4 worms just happened to stop right inside the line where the plank was going to be cut. This strikes me as impossible. I'm thinking there must be some other explanation, but I have no idea what it might be. Rob, please jump in with any comments you have. I didn't write down much when we spoke on the phone the other day and I may have overlooked something you told me.