Evidence also suggests that the Nazca people may have exacerbated the effects of these floods by gradually cutting down Prosopis pallida trees to make room for maize and cotton agriculture.

These trees play an extremely important role as the ecological keystone of this landscape: in particular preventing river and wind erosion.

Gradual removal of trees would have exposed the landscape to the effects of climate perturbations such as El Niño, leading to erosion and leaving irrigation systems high and dry.

[4] Early Nazca society was made up of local chiefdoms and regional centers of power that developed around Cahuachi, a non-urban ceremonial site of earthwork mounds and plazas.

The remains of pottery found at Cahuachi led archaeologists to believe that the site was specifically non-urban and ceremonial in nature.

[5] Later (post-Cahuachi) Nazca society was structured in a similar fashion as before, but there was less emphasis on constructing large architectural complexes such as those at Cahuachi.

[14] During the Middle Nazca period, the number of severed heads appeared to have increased, this may be due to the pan-Andean drought.

Iconography on ceramics and excavated remains indicate that the Nazca people had a varied diet, composed of maize, squash, sweet potato, manioc and achira, and a small trace of various fish.

[15] The most promising techniques used to date them thus far has been the AMS (accelerator mass spectrometry) analysis of varnish that has collected on the rocks inside the puquios, as well as the study of settlement patterns in the area.

[15] Numerous access holes or ojos (eyes) were placed along the surface of the underground channels and operated much in the same way that modern manholes do.

A potential reason for this is due to the relatively lesser amount of time required to produce pottery when compared to textiles, which the Paracas favored.

Major pottery shapes include double-spout bottles, bowls, cups, vases, effigy forms, and mythical creatures.

Archaeologists have excavated highly valued polychrome pottery among all classes of Nazca society, illustrating that it was not just the elite that had access to them.

Visual depictions found on pottery from Phase 1 (also called Proto-Nazca) incorporated realistic subject matter such as fruits, plants, people, and animals.

[2] The pottery from these phases include renditions of their main subject matter against a bold red, black, or white background.

In the next phase, Nazca 5, considerable experimentation occurred, including the addition of rays, volutes, and other "proliferous" attachments to the supernatural motifs on the vessels.

[1] The Nazca, like all other Pre-Columbian societies in South America including the Inca, had no writing system, in contrast to the contemporary Maya of Mesoamerica.

The Nazca visualized these nature spirits in the form of mythical beings, creatures having a combination of human and animal/bird/fish characteristics, and painted them onto their pottery.

[19][20] Scenes of warfare, decapitation, and the ritual use of human trophy heads by shamans were common motifs in Nazca pottery.

The middle part is a very fine gauze weave, most probably woven on a back-strap loom in a typical four-selvage web with both warp and weft made of cotton.

The absolute symmetry of the design is broken on the long edges, where one side has extra spiral motifs and the other finished with stepped triangles.

Warriors or lords with war paraphernalia, women and shamans with the addition of two llamas are walking around the edge on a red band, which is attached to the central woven web with rhythmically repeated colored flowers.

[22] The three-dimensional edging attached to the light weight midsection suggests that this mantel was never hang and most likely used laid out on the ground serving as a field for divination.

She noted that although the women are rarely recognized in the archaeological record, they had ready access to high-status materials and the right to wear sacred or potent imagery on their garments.

They are believed to have been constructed by large, coordinated work groups of numerous people over an extended period of time, indicating a complex culture that could organize such projects.

The contrast of the red desert pebbles and the lighter earth beneath would make the lines visible from a high altitude.

Due to the simplistic construction of the geoglyphs, regular amounts of rainfall would have easily eroded the drawings, but the dry desert environment has preserved the lines for hundreds of years.

Some researchers theorize they were created for the gods to look upon them from above, while others suggest they were some sort of calendar with astronomical alignments that would aid in planting and harvesting of crops.

[24] Trephination was a primitive skull surgery used by the Nazca that relieved pressure on the brain from battle wounds or for ritual purposes.

[1] Some historic Native American cultures in North America also practiced such shaping of skulls, such as the Snake, Cowlitz and Chinook peoples, most of whom lived west of the Columbia River in the Pacific Northwest.