Based on this research
Abstract
Here we report the results of excavation and interdisciplinary study of the largest child and camelid sacrifice known from the New World. Stratigraphy, associated artifacts, and radiocarbon dating indicate that it was a single mass killing of more than 140 children and over 200 camelids directed by the Chimú state, c. AD 1450. Preliminary DNA analysis indicates that both boys and girls were chosen for sacrifice. Variability in forms of cranial modification (head shaping) and stable isotope analysis of carbon and nitrogen suggest that the children were a heterogeneous sample drawn from multiple regions and ethnic groups throughout the Chimú state. The Huanchaquito-Las Llamas mass sacrifice opens a new window on a previously unknown sacrificial ritual from fifteenth century northern coastal Peru. While the motivation for such a massive sacrifice is a subject for further research, there is archaeological evidence that it was associated with a climatic event (heavy rainfall and flooding) that could have impacted the economic, political and ideological stability of one of the most powerful states in the New World during the fifteenth century A.D.
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0211691
Thank you for posting!
Now, llamas were only owned by royalty. And they can survive on relatively slim pickings. Two-hundred llamas had to have been a pretty large herd for the time, requiring multiple shepherds/servants. Sacrificing that many animals meant sacrificing years of fleece - i.e., wealth, and a reduction in the size of the royal household. So the sacrifice must have been a last resort to an existential crisis, especially if the carcasses of the llamas indicate starvation.