well.. 2 independent ID's ... if its scale.. its treatable.. but i have never seen such on mature bark ... if its mushrooms.. as bboy suggests.. i think.. lol ... they are living on the rotting wood under the bark ... time is limited ... that is a very bad prior pruning.. i am wondering what the prior owner did to the rest of the tree ... two more pix .. as good a closeup as you can get... and a pic of the whole ... may as well tell us where you are also .... ken ps: why am i wondering if this tree was topped.. or telephone poled ... or any significant construction in the root zone... or all three????

Looks like a sick, injured, sad catbird. Maybe next time you see an animal like this you can find help for it? Most people don't realize that they can help injured birds.

Maybe a Great Black-backed Gull? This is a BIG gull with diverse tastes: "Great Black-backed Gulls are supreme opportunists. They follow fishing boats to pick up scraps of bait and discards, take garbage from trash cans and landfills, patrol beaches looking for morsels that wash up from the sea, harry other seabirds to steal their catches, and ruthlessly prey on smaller birds, eggs, and chicks. " Claire

It is really hard to tell form this pic but my first impression i house-finch