Rows of holes like that suggest sapsucker damage, but from the orientation of your photo I can't tell if the rows were horizontal or vertical, nor how large the individual holes are. I'll paste in a Master Gardener reply to a similar question that involved sapsuckers (small, horizontal rows), but if those holes are larger and especially if acorns were placed within, that would indicate acorn woodpeckers. In short either way, to protect a tree that has been "chosen", most people wrap the targeted trunk section in burlap to prevent further damage. You might also consider showing more signs from the tree to an arborist in case the cracking (and bird attention to the tree) are due to insects or other issues. 

A common cause of tree damage in backyards and small woodlands is from sapsuckers (Sphyrapicus spp.), which are a species of woodpecker. The Pacific Northwest has three native sapsuckers. The red-breasted sapsucker (Sphyrapicus ruber) is common throughout areas west of the Cascade Range, while the red-naped sapsucker (Sphyrapicus nuchalis) and Williamson’s sapsucker (Sphyrapicus thyroideus) are found in areas east of the Cascade Range. The yellow-bellied sapsucker (Sphyrapicus varius) is seen occasionally in the Pacific Northwest, but is native to the eastern United States.

Sapsucker damage is easy to identify. The holes are approximately 1/4 inch in diameter and are drilled (pecked) in horizontal and vertical rows. There are usually many holes close together. This is often mistaken for insect damage such as bark beetles or other boring insects.

Insect damage will typically have fewer, smaller holes, and the holes will be randomly distributed, not in rows like sapsucker holes. Insect holes may also have some boring dust (frass) in or on the ground under them, whereas sapsucker holes will not. The presence of sapsucker damage does not necessarily mean the tree has an insect infestation. Unlike other woodpeckers, sapsuckers are actually drilling for the tree sap, not for insects living in the tree. However, sapsucker damage may attract opportunistic damaging insects, which the sapsucker may then subsequently feed on.

Sapsuckers will feed on both hardwoods and conifers. They prefer foraging on trees with thin bark, such as birch. Older conifers with thick and ridged bark are not as susceptible to sapsucker-caused damage. If the damage is limited and minor, the tree will recover.

A persistent sapsucker may choose to feed on a given tree repeatedly, which can cause damage that is more extensive and leave the tree vulnerable to other problems such as insects or decay fungi. Occasionally, sapsuckers will also cause damage to non-tree items such as wood house siding, but this is not common.

The most commonly recommended control method is to wrap burlap around the affected area to discourage the sapsucker from returning. Sticky repellents applied to the tree bark are also used, as well as hanging bright, shiny objects such as pie tins, streamers or beach balls as scare devices. These techniques may or may not be effective, and they may just shift the bird’s focus to another part of the tree or a neighboring tree. If the sapsucker appears to favor a specific tree, it may be best to leave that as a sacrifice tree as the bird may then leave other trees alone in favor of this preferred feeding spot.– Chris Rusch, OSU Extension Master Gardener