An Etymological Dictionary of the German Language/Strauß
Strauß (1.), m., ‘quarrel. conflict, fight,’ from the equiv. MidHG. strûȥ, m.; to this MidHG. striuȥen, ‘to resist,’ AS. strûtian, ‘to quarrel,’ is allied.
Strauß (2.), m., ‘crest, tuft, nosegay,’ from the equiv. late MidHG. *strûȥ, m., which may be inferred from gestriuȥe and striuȥach, ‘cluster of bushes.’
Strauß (3.), m., ‘ostrich,’ from the equiv. MidHG. and OHG. strûȥ, m.; it seems to be rather a corruption of late Lat. strûthio, ‘ostrich,’ on which AS. strŷta is based (comp. Ital. struzzo, Fr. autruche, whence E. ostrich), than a permutation of pre-HG. *strûto-. The word may have been borrowed contemporaneously with Pfau. On the other hand, a direct connection with Gr. στρουθίον, or rather ἡ μεγάλη στροῦθος, ‘ostrich’ (στροῦθος, ‘sparrow’), is impossible. Moreover, it is remarkable that the Germans say Vogel Strauß, in the came way as the Fr. autruche (Span. av-estruz) from avistrutio, is liked with Lat. avis.