Identificaciones de mark_duchene

Abandoned or predated nest; never seen the bird. It is probably a nest of Field Sparrow (Spizella pisilla), but all nests of field Sparrows I've seen had a lining of dark thin dark stems. In this case, the lining seems to be of grass and the nest is a bit loose, although it might have been damaged by a predator. It would be interesting to hear opinions.