I’d turned Friday’s picture on end to try to fool you…but to no avail. Deirdre and Gail both guessed woodpeckers, and yes, this is sapsucker damage:
Though some woodpeckers look for insects under the bark, sapsuckers drill neat lines of wells that fill with sap. The birds can then move down the line of wells, lapping up sugar water. (Kind of the avian version of lining up tequilla shots on the bar.) Healthy trees are generally not at risk of dying from drilling injury, though if the tree is completely girdled that would be a problem. Trees stressed by other factors could be also be killed by this final straw.
(Deb and @s both thought the photo might be a cactus skeleton, and it certainly looks like one! Hadn’t thought of that myself.)
Ooh — tricky!