Whereas the "warrior" and "decapitator" disks juxtapose silvery images on golden backgrounds, the owl disk (1987.394.56) (fig. 12) has a silvered copper background. The surface layers on the owl itself, the dangles and their attachment wires, and the rim are golden. The gold layer contains 20 % silver and the silver-rich layer contains 53 % gold (fig. 13). Replication samples of the alloys indicate more clearly how similar in color they appeared to the ancient observer. Form is built up using a combination of flat sheet, sheet in relief and fully sculptural form. The flat rim is attached to the disk using tabs and dangle wires. The owl's body, itself raised in high relief, was made from a single sheet of metal with the flat tail feathers and claws articulated with scored linear details, and was secured to the disk with tabs. The scored wings are also continuous with the body but were not attached to the disk, and would have flapped when the disk was moved, just as the head, executed in the round from two crimped sheets of gilded copper and set on a copper rod attached to the inside of the body, would have rotated from side to side. The cool reflective surfaces of the moving parts, including the dangles of different shapes, would have glittered and jingled.

A broad understanding of the physical and working characteristics of precious and base metals and an eagerness to experiment led Moche metalworkers to develop highly sophisticated and varied solutions for the manufacture of objects that evoked different visual effects. The Loma Negra nose ornaments made of solid gold and silver sheet encouraged a perception of the metallic nature of gold and silver, emphasizing such qualities as weight, solidity, rigidity, while placing these two metals, quite different in their colors, not merely in contact, but in opposition (figs. 2, 4-6).

A different aesthetic shaped the manufacture of the disk ornaments. Color, specifically the juxtaposition of similar metal colors and the illusion of movement elicited by variations in surface texture, coupled with the actual movement of formal components, the distinctive sounds of metal striking metal, a sense of lightness, a multiplicity of detail, and the elaboration of form through layering, all contribute to their distinctive appearance. The Moche preference for sheet metal facilitated the attainment of some of these aesthetic aims. Mechanically joined copper sheet, which could be surfaced with any of a wide range of alloys, provided a flexible means for juxtaposing fields of color that altered in appearance as they moved, and as perceived by the eye moving from layer to layer, from substrate to image to attribute to dangle.

By way of comparison it is informative to look briefly at another visual effect exhibited by some objects from Loma Negra, which was also created through a juxtaposition of metal sheets bearing different surface colors. Many of the Loma Negra objects made from copper sheet represent animals of one kind or another, particularly sea creatures, such as crayfish and crabs, and insects (Lapiner, 1976, nos. 369, 376, 378-379). Different types of felines and canines, some quite fantastic in their appearance, are also frequently occurring motives. The functions of most of these animal images are as Jet unknow, but one type-three-dimensional illusionistic representations of fox heads-has been attributed a specific function. A fox head ornament was found as part of a headdress in the burial of a "Warrior­Priest" excavated in the Viro Valley (Strang & Evans, 1952; Tones, 1979, pp. 75-78). In addition to fragments of a metal fox head and paws, an actual fox jaw and the remains of an animal pelt were found. In a discussion of a fox head in Dumbarton Oaks said to be from Loma Negra, Donnan (1996, p. 160) states that at least ten more such ornaments are in various museum collections, in addition to several in private collections. Of these, one was found at Huaca de la Luna at Moche and is now in the Linden-Museum in Stuttgart (Sutorius Collection 119 154) (Tones, 1979, fig. 19). In addition to the Dumbarton Oaks fox head, several mentioned by Donnan are attributed to Loma Negra or more generally to the Piura Valley and three are said to be from Sipán (Alva & Donnan, 1993, fig. 199). There are two foxhead ornaments from Loma Negra in the Metrapolitan Museum, which in over­all shape are quite similar to the the Piura Valley fox head in the Didrichsen Art Museum, Helsinki (Tones, 1979, fig. 20).

The larger of the two fox heads in the Metrapolitan Museum (1982.392.10) (fig. 14) measures 15.9 cm in length and is among the more elaborate Loma Negra three-dimensional constructions employing metal components that juxtapose a variety of different surface colors. The head it self is a single piece of gilded copper sheet. It is folded and an overlapped seam runs along the underside of the chin to the back of the head, which is open. The sheet was cut and the edges folded in to create the opening of the mouth. Another folded sheet forms the inner surfaces of the mouth. The only surface decoration is found on the end of the snout, which is scored with nostrils.