Hi there, noob here.

I have seen this bird twice now and I am not so certain of the identification. Here's the details

• Western Oregon
• Smaller than a robin, approximately sparrow size
• Yellow breast, less pronounced in some (I assume slight sexual dimorphism)
• Darker yellow back/head (green/brown tinge)
• Small amount of black/white along wingtips
• No black marks on head or body
• Travels in groups of about 20-30

The one that looks the closest to me is the orange crowned warbler although I have no seen any actual orange on them. I doubt they are goldfinches since there is no black cap. I have not been able to see the red streaks on the chest (like yellow warbler) or black marks on the head (like Wilson's or yellow throat). Any other species I should look at pictures of?

Thanks