Figure 2. Long necks often serve multiple functions, as demonstrated here by Galapágos giant tortoises Geochelone nigra. (a) Use of the long neck for high browsing is commonly practized by terrestrial testudines. Based on a photograph in Moll (1986:74-75). (b) Use of the long neck in establishing dominance. The two tortoises shown in the illustration were photographed on Santa Cruz Island: the dome-shelled animal on the right belongs to the native form G. n. porteri while the saddlebacked animal at left represents the Española form G. n. hoodensis. Based on a photograph in Fritts (1984: Fig. 2).