Hi Tweeters,
Ruth Milner; District Wildlife Biologist, Snohomish, Island, San Juan counties; requested I send this along, since I am on this list, and due to inquiries received regarding this subject.
Please see below from her and hope this clarifies state regulations and protections in light of federal regulations being discussed:

See the following Washington Administrative Codes for information regarding shooting blackbirds: http://app.leg.wa.gov/WAC/default.aspx?cite=232-12
Washington State can impose regulations that are more strict than federal regulations, but cannot be more liberal than federal regs. In WA, blackbirds are protected: see RCW 232-12-011, http://app.leg.wa.gov/WAC/default.aspx?cite=232-12-011; so their status at the federal level is not relevant.

A small handful of birds are classified as predatory:
http://app.leg.wa.gov/WAC/default.aspx?cite=232-12-004 Blackbirds are not among them. These birds may be killed but crows magpies require a hunting license : http://app.leg.wa.gov/WAC/default.aspx?cite=232-12-005

For property damage, the State can issue a permit to kill birds causing damage: http://app.leg.wa.gov/RCW/default.aspx?cite=77.36.030; http://app.leg.wa.gov/RCW/default.aspx?cite=77.12.240

For additional information see: http://wdfw.wa.gov/living/rules/

Have a great weekend enjoying the cooler weather!
Chris Anderson