Many Indigenous peoples and local communities live in close contact with nature and learn to identify the wildlife around them from an early age. New research published in the International Journal of Conservation draws on that knowledge to better understand a scientifically documented trend: large bird populations are shrinking.
Álvaro Fernández-Llamazares, an ethnobotanist with the Autonomous University of Barcelona, Spain, and lead author of the study, first noticed that trend as a graduate student doing field work in the Tsimane’ Indigenous community in the Bolivian Amazon.
“Many elders told me that the large birds they had grown up seeing in the forest had become much rarer. Species that were once common in their childhood were now difficult to encounter,” Fernández-Llamazares told Mongabay in an email.
He cited similar accounts from Indigenous peoples and local communities in other parts of the world and from very different ecosystems. Large birds from their youth were disappearing, while smaller species seemed to be on the rise — a pattern scientists were also finding. “What had not been explored before was whether these global patterns were also reflected in the long-term ecological memories of people who interact with birds on a daily basis,” he said.
So, researchers surveyed 1,434 people across three continents and 10 sites as part of a broader Local Indicators of Climate Change Impacts (LICCI) project, an international research initiative to understand how Indigenous and local communities observe the changing climate in their territories.
Respondents were asked to name three birds that were most common when they were 10 years old, and the three most common species today. They collected nearly 7,000 individual bird reports belonging to 283 species, spanning roughly 80 years.
While memories can fade or birds can be misidentified, Fernández-Llamazares said the study was measuring an overall trend — and the trend was stark. The average body mass of birds in the surveyed areas is roughly 70% smaller today than it was 80 years ago. The pattern held across all study sites, from the tropical forests of Bolivia to the grasslands of Senegal and the arid deserts of Mongolia.
The report quoted a Daasanach elder in Kenya who summed it up well: “All the big birds are now gone.”
Fernández-Llamazares said there are several explanations for the trend. Larger birds tend to reproduce slowly, making them more vulnerable to population collapse. Also, they’re prime hunting targets since they can provide more meat per bird, and they often require larger tracts of intact habitat, which makes them sensitive to land-use change.
“This study is a great example of how Indigenous science and knowledge and Western science can be woven together to provide clearer answers to questions,” Pam McElwee, with Rutgers University, U.S., who wasn’t involved with the study, told Mongabay. “Each knowledge system stands on its own, but together they give us a more complex picture.”
Banner image of a toco toucan (Ramphastos toco) courtesy of Basa Roland via Wikimedia Commons (CC BY-SA 3.0).
