Bird Poop Helped Power One of Ancient Peru’s Wealthiest Kingdoms
On the desert coast of southern Peru, wealth did not shine. It grew in corn fields. Hundreds of years before the Inca Empire came to power, the Chincha kingdom thrived in one of the driest regions on the planet. Their secret was neither gold nor silver, but the droppings of seabirds.
New research published in PLOS One suggests that guano – the nitrogen-rich waste produced by seabirds nesting on nearby islands – boosted corn harvests in the Chincha Valley. This agricultural surplus may have fueled Chincha’s expansion, helping to make the society one of the most influential coastal polities of its time.
“In ancient Andean cultures, fertilizer was power,” lead author Jacob Bongers said in a press release.
Agriculture fueled by bird droppings in the Chincha kingdom
The Chincha Valley receives little rainfall. Irrigation from Andean rivers made agriculture possible, but maintaining soil fertility required additional help.
Seabirds and possibly corn grow on this digging stick or ceremonial paddle from the Peruvian coast.
(Image credit: The Met Museum 1979.206.1025.)
Corn was at the heart of daily life. It fed households, played a role in ceremonies and supported trade. But its repeated cultivation on sandy coastal soils would have led to a steady reduction in nutrients.
Just offshore, the Chincha Islands offered a solution. Dense colonies of seabirds have deposited thick layers of nitrogen-rich guano – a key ingredient for plant growth. Historical accounts describe coastal communities sailing to the islands on rafts to collect fertilizer and bring it back to their fields.
“Historical records documenting how bird guano was applied to corn fields helped us interpret the chemical data and understand the regional significance of this practice,” co-author Emily Milton said in the press release.
Guano wasn’t just practical. In Chincha art, seabirds, fish and sprouting plants often appear together on textiles, ceramics and carved gourds – visual reminders of the connection between marine life and agricultural abundance.
Read the chemical clues of corn
The team analyzed 35 ears of corn recovered from burial sites in the Chincha Valley, some dating back to around 1,200 CE. Using stable isotope analysis – a technique that measures chemical signatures preserved in plant tissues – they looked for high levels of nitrogen.
Many samples had higher nitrogen values than natural soils would produce. Some closely related modern crops are grown with guano. Compared to plants fertilized with other materials, Chincha corn aligned most strongly on guano-treated fields.
“Seabird guano may seem insignificant, but our study suggests that this powerful resource may have contributed significantly to sociopolitical and economic change in the Peruvian Andes,” Bongers said.
Learn more: A vulture of unexpected size flew over South America 13,000 years ago
Rethinking the source of Chincha wealth
By the 13th and 14th centuries, the Chincha kingdom had become one of the richest societies on the southern coast of Peru. The region may have supported tens of thousands of tribute payers, as well as merchants who traded goods along the Pacific and into the highlands.
Previous researchers have attributed this prosperity to the luxury trade, but the new findings point to a more fundamental foundation: food security.
“We know that the Chincha were extraordinarily wealthy and were one of the most powerful coastal societies of their time. But what supported this prosperity? Previous research has often pointed to the shells of spondylus, the spiny oyster, as the primary driver of merchant wealth,” Bongers said in the release.
If guano had increased corn yields, it would have created a constant agricultural surplus, sufficient to sustain population growth and support specialized traders and artisans. Rather than being a minor agricultural aid, seabird fertilizer may have stabilized the system that allowed long-distance trade to flourish.
“The Chincha’s true power lay not just in access to a resource; it was also in their mastery of a complex ecological system,” co-author Jo Osborn said in the press release. “They had the traditional knowledge that allowed them to understand the connection between sea and land life, and they turned that knowledge into the agricultural surplus that built their kingdom. »
Learn more: Ancient temple ruins shed light on life in Tiwanaku, a thriving pre-Inca civilization
Article sources
Our Discovermagazine.com editors use peer-reviewed research and high-quality sources for our articles, and our editors review the articles for scientific accuracy and editorial standards. See the sources used below for this article:
