hornbill became rare because it was slaughtered for its casque. Now legal trade in hornbill ivory is limited to certified antiques, and hornbill-ivory carvings are more valuable than those of any true ivory. References External links Page from the Ivoryhound Page from Gem of the Month Photographs and description of a Bornean carving from ArtAreas showing the red rim colored by preen-gland secretions Ivory Bird products Borneo Hornbills Chinese art