Can we sex crows? (3)

This is the closeup of the female I mensioned in the previous photo. From the ruffed-up nostril feathers and partial leucostic tail feathers, we can tell that this is the same female.
Female crows tend not to have a hook on the upper bill. The lengths of upper and lower bills tend to be the same, or with very little difference. This is one of the characteristic of a female crow. A typical male crow has, on the other hand, a "hooked" upper bill, or the upper bill considerably longer than the lower one. But again, you have to be aware of the fact that there are individual differences.