My strategy for flicker ID:
1. Try to see the bird well. If you can't, just call it a Northern Flicker.
2. If you see the bird well and can't really make up your mind, just call it a Northern Flicker.
3. If you do see evidence of hybrid/intergrade origin, enter the bird as a Yellow-shafted x Red-shafted Flicker.
4. Only if you see the bird well enough to rule out hybrid/intergrade origin (calling all Philosophy 101 students!), then call it Red-shafted Flicker or Yellow-shafted Flicker; otherwise, call it a Northern Flicker.
A confession. I've been way too glib in my designations of Colorado flickers as either Red-shafted or Yellow-shafted. It's never too late for a New Year's Resolution, so I hereby resolve to be more careful with Colorado flickers.
By the way, I ought to note that the bird depicted above was at the Wyoming Hereford Ranch, Laramie County, Wyoming, back on Tues. morning, May 15. It's my favorite birding hotspot in Colorado, haha. I went there with Andrew Floyd, and we saw 2 Blackpoll Warblers, 1 Northern Parula, 1 American Redstart, 1 Northern Waterthrush, 1 Least Flycatcher, 3 Gray Flycatchers, 1 Veery, and 1 Bobolink. eBird checklist:
https://ebird.org/view/checklist/S45710859
Ted Floyd
Lafayette, Boulder County