Studies of some of the great Nasca etchings have designated them as birds such as pelicans and flamingos. However, a more detailed comparison with the taxonomy of species inhabiting surrounding areas questions most of these assessments. In some cases, the true genus, if not species, of bird can be identified, while others remain mysterious. In every case, the birds were not native to the location of the drawings, hinting at the reasons they were made.
The giant shapes drawn in the Peruvian desert are among archaeology's greatest wonders. These drawings, known as geoglyphs, are so large they can only be properly seen from the air, making it astonishing they were made with such precision by a culture that lacked writing, let alone flight.
Birds must have been very important to the geoglyphs' makers. Although far outnumbered by the single lines or abstract shapes, the 16 birds – some hundreds of meters long – are more numerous than any other plants or animals. Dr Masaki Eda of the Hokkaido University Museum hopes that by identifying the specific birds represented we will learn why they mattered so much and, therefore, more about the thinking of the people who made them.
Past studies have claimed to identify the birds, but Eda considers these to have lacked rigor. "Until now, the birds in these drawings have been identified based on general impressions or a few morphological traits present in each figure,” Eda said in a statement. “We closely noted the shapes and relative sizes of the birds' beaks, heads, necks, bodies, wings, tails, and feet and compared them with those of modern birds in Peru."
Perhaps the most famous of the geoglyphs are the “hummingbirds”, marked by their long bills. However, in the Journal of Archaeological Science: Reports, Eda notes one of these has a tail quite different from any Peruvian hummingbird. Instead, its shape matches that of a hermit bird. Although, like hummingbirds, they belong to the Trochilidae family, hermit birds, which inhabit the undergrowth of humid rainforests, have much duller coloring and are therefore far less famous. Peruvian hermit birds live far to the north and east of the Nasca World Heritage site, and probably came a little closer 1,000-2,400 years ago when the geoglyphs were made.

Eda identified two other geoglyphs as pelicans, although neither was the one previously given that designation. He makes a convincing case that another, while looking like an escapee from Jurassic Park, actually represented a newborn parrot.

Eda acknowledged to IFLScience that the immense logistical difficulties of making these drawings without modern technology may have sometimes distorted the artists' intent, but added: “We tried to identify bird geoglyphs [and] whether they share morphological characteristics with modern birds as [the] first step of the study.”
The paper reaches no conclusion on the majority of geoglyphs, either because they have been damaged, could represent a number of different species, or don't match any bird known to inhabit Peru today. The paper recommends additional identifications may be made by considering the geoglyphs in context with drawings made by the same civilization on pottery.
The bigger question is why these birds were chosen. Although we cannot yet answer that question, the paper notes: “During our ethnographical research on a modern village of the Nasca pampa the amount of rainfall in the Highlands was estimated by observing the migrations of seabirds.” For a people whose agriculture depended on water drawn from rivers that rise in these highlands, these rains were probably a matter of life and death. One of the geoglyphs, although not specifically identified, has a beak found in many seabirds.
