In my yard, a loquat tree is preferred by sapsuckers, at least that’s the tree in which I see the slightly flatted oval sapwells the birds drill out. As the holes stop producing, the birds drill new holes directly over the previous ones. Some reports say that the downward moving phloem channels are destroyed by the drilling so there’s a dam of phloem coming down that particular track with the holes above being more productive for the birds.
Occasionally, this activity will girdle the tree, fortunately that’s not usually the case. The late Bobby Desportes, a true lover of nature, would make syrup and fill holes in logs on his property to feed the sap suckers. If you are worried about a tree used by sapsuckers, you can wrap small gauge chicken wire or such around the trunk.
