Several days ago I posted links to photos I took of a couple light forms of Red-tailed Hawks assuming that they were both Krider's. I am very grateful to William (Bill) S. Clark who took his time and not only corrected one ID but also sent me detailed information about differences between light juveniles: Harlan's and Krider's Red-tailed Hawks.

Below are detailed descriptions that he is using personally to compare field marks (not published yet - posted with his permission)

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The differences between these two very similar appearing juveniles hasn't been published. I use the following field marks to separate them.

Crown: completely white on kriders, but streaked darkish with wide white superciliaries on harlans. But some harlans have completely white crowns!

Tips of primaries: harlans usually have pale outer primaries with narrow dark barring, but not in itself diagnostic, as they can be like kriders and vice versa.

Marks on the undersides: Kriders juveniles usually show small dark spots, but harlans juvies show dark diamonds.

Tail banding: Base of tail of juvie kriders usually lacks narrow dark banding. Tails of juvie harlans are banded to the base, and the dark bands are wider.

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All Red-tailed Hawk names are now corrected in this folder.

For those who do not live inside the raptors world. William (Bill) S. Clark is among the best raptors specialists in the word. His published books are the must for anybody who wants to learn more about these fascinating birds.