When King Philip II of Spain sent emissaries to study the flora and fauna of villages in central and southern Spain in the 1570s, he had no thought of ecological networks or extinctions. He just wanted to know exactly what he owned. So he asked at least two people in each village to describe the land, flora and fauna of their territory to his surveyors. Now, 450 years later, a team of ecologists say the resulting responses to that survey hold value as ecological surveys conducted before the word “ecology” entered the lexicon.
“I think it’s brilliant,” said Ana Rodrigues, a conservation biologist at the Center for Functional and Evolutionary Ecology in France, who was not involved with the research. “The survey was a historical document and is now becoming ecological data.”
The new work was carried out by Duarte Viana, an ecologist at the Doñana Biological Station (part of Spain’s National Research Council), and his colleagues. They used the responses to the king’s questionnaires and transcriptions from historians to compile a list of plants, animals, and their respective ecological niches, providing a snapshot of the environment of Castile, a large kingdom located in what is now central and southern Spain found, from almost 500 years ago. In her recently published work in ecologythey found that various animals that lived and roamed in central Spain are now restricted to northern Spain, while some plants that are abundant in the country today were absent in the 16th century.
Other similar inventories based on historical documents exist, Viana says. For example, in 2018 researchers collected ecological information from 400 years ago using a natural history text from 17th-century Scotland, but that text was also a scientific text, Viana explains, doing his team’s work — with a document that was not an obvious one Work was science – unique.
Viana’s team chose to analyze questionnaires from 1574, 1575, and 1578. King Philip II had villagers in the kingdom answer questions about plants and animals, the way people lived, available natural resources such as wood, and social organization, including the number of households in a given village.
The locals, who may not have been literate, probably shared their answers with the surveyors, who wrote them down in Old Castilian. Then early 20th-century historians translated these answers into modern Spanish. Viana and his team mainly used these transcriptions to understand the old documents.
Researchers focused their inventory on flora and fauna deemed important to preserve 16th-century habitats such as the Cantabrian brown bear, the Iberian wolf and the holm oak (Quercus ilex or Quercus rotundifolia), all of which are considered national species in Spain. The team also focused on natural resources important in 16th-century Spain, such as animals that villagers could hunt or fish, and those that had medicinal uses, such as leeches. They also looked at dangerous species like wolves and bears. In total, the team collected 7,309 records from 75 wild plants, 89 wild animals, and 60 domesticated plants and animals.
They found that by the 16th century, both the Cantabrian brown bear and the Iberian wolf lived in central Spain, which has a different climate and habitat than their present-day habitat of northern Spain. The European eel (Anguilla anguilla) was spread across all of Spain’s main waters, but construction projects in these waters meant that eels were today caught and confined to Spain’s estuaries only.
But other findings also served to consolidate the current state of knowledge. For example, some species thought to be native to Spain, such as freshwater crayfish, appeared absent in the 16th century, consistent with the fact that some species were not introduced to Spain until much later.
Knowing the ecological history of different species could inform how conservationists approach their efforts, Viana said. The European eel, for example, is listed as Critically Endangered by the International Union for Conservation of Nature’s Red List of Threatened Species, while the Cantabrian brown bear is listed as Vulnerable, so scientists may be able to use its historical whereabouts to increase protection.
Some animals never made it to the present day. For example, only two villages reported seeing the zebro, an ancient wild “donkey horse” that had stripes similar to modern-day zebras, but gray hair reminiscent of donkeys and horses. When the team compared the mentions of zebras in the 16th-century questionnaires with the mentions in historical documents from the 18th century—which is also where modern-day zebras got their name—they found that the animal in the later documents was probably because of this was not mentioned then experienced its extinction. “It was a live story about the extinction of this species,” Viana said.
María Portuondo, a retired historian of science at Johns Hopkins University who was not involved in the study, warns that given the many steps involved in translation, it is difficult to verify the authenticity of the answers in the questionnaires. Not only were the original answers translated before they were written, a Spanish overlord — a mayor, governor or parish priest — likely edited them, too, she said. And 20th-century historians likely re-edited the responses as they translated and published more digestible versions of the questionnaire responses. “The Spanish translators, in an effort to make it understandable in Spanish, may have translated the name as wolf, even though it meant a panther,” Portuondo explained.
Viana admits that despite the translations, in some cases it was “really difficult” to understand what the villagers were referring to, especially when using region-specific names. To counteract this, researchers went through lists of synonyms and native names of species to identify the plant or animal being referred to.
Portuondo says other historians who might hope to use the ecology inventory might encounter similar problems. “So let’s say you’ve never seen a mongoose and someone described it to you as ‘a ferret, but a little bigger.’ They would get an idea,” Portuondo explained. “The challenge is that it doesn’t matter to modern biologists whether the actual animal was a ferret or a mongoose around 450 years ago. That’s the challenge of using 450-year-old questionnaires!”
For Rodrigues, who specializes in large-scale biodiversity conservation, the compilation of species in this new study provides a starting point from which to study ecosystems over time. She added that this study can give an idea of how nature actually was and not how we would have assumed it to be in the 16th century.
It’s the hope of the researchers behind the dataset that the inventory can help give scientists a broader picture of where species existed. Through this study, Viana and his team were able to paint a picture of individual species in the past, but over time they hope to also get a sense of how different species coexisted. And perhaps with better conservation efforts, some of those earlier relationships could be rekindled. “We can only imagine what the interaction between the majors is like [animals] in the Iberian Peninsula could have been in the past. Will we experience it again?” said Viana.