Spiritual was a difficult theme - often hard to get across a feeling in a picture I find unless something romantic / sad or more " in your face".
i would never have thought about a nuthatch as being spiritual, like i've already said, it's a fantastic shot but i wouldn't have thought to enter it into this theme, well done oldboy
Lots of different birds were used to illustrate spiritualism in the church mainly because they could fly, they were used as a link between heaven and earth. The Robin got it's red breast from pricking it's self, on the crown of thorns on Christ's head, according to legend. Lots of religous paintings show birds like the dove of peace. Poetry features birds of all types like Shelley's Ode to a Skylark, "Hail to thee, blithe Spirit!"