The biggest problem I have had here in Shoreline, WA is raccoons. About 2 years ago I had a problem with a single raccoon who learned where the chickens sleep and kept coming back. It started with 1 bird, then he or she came back every night to try to get more and they are wicked smart.I have free ranging birds here in suburban Lacey and we have raccoons and coyotes... So far the dogs have been good enough for protection but can't wait to get them all safe guarded with a good fortress.
Every time I thought I had made the chicken fortress strong enough he found the weakest point and exploited it. He climbed up 8 feet and ripped open a ventilation area that had been secured with chicken wire, I caught him when he was half way into the coop at around 5 am. I did lose a Black Ameraucana to a raccoon this last year but for some reason that raccoon never came back, I am guessing it found the bird already outside and didn't correlate it to the coop like the other one did.