Lazuli Bunting males followed their females through the low thickets before disappearing much higher.
A Black-headed Grosbeak called along a stream. Its call was lower than our Rose-breasts.
"Red-shafted" Flickers were very common.
This heavily spotted and barred bird struck me as a young bird. My understanding was that a lot of intergrades will have a mix of yellow and red feathers, this bird seemed pretty even, so I may have been wrong about mixes of feathers being standard.
More subtle than the flickers are the different populations of White-breasted Nuthatch. I'll grant that they did look a little darker than ours (though so did the downy and hairy woodpeckers); you'll have a harder time convincing me that there isn't just steady gradation across the country though.
Finally one of the hallmark birds of the central west in my mind, Black-billed Magpie.