Indigenous Peoples and local communities report a consistent decline in the body mass of birds across three continents

Year: 2025

Type: article

Abstract: Increasing evidence shows that genuine collaboration between scientists and Indigenous Peoples and local communities can deepen global understanding of species’ ecological distribution ranges, baselines and trends. In this study, we explore trends in bird body mass as reflected in the collective biocultural memory of 10 place-based communities on three continents. To do so, we conducted a globally coordinated survey, asking 1,434 adult participants about the most common bird species around their territories both at present and during their childhood. The survey resulted in 6,914 unique bird reports, corresponding to 283 bird species and covering an 80-year period (1940–2020). By combining our ethno-ornithological dataset with scientific data on species’ body mass, we assessed whether the composition of locally abundant bird assemblages has shifted towards smaller-bodied species over time. Our results show a general shift in the bird species observed over the participants’ lifetimes, with recent species assemblages being composed of species with smaller body sizes than those in the past. Despite variation among sites, we find an overall statistically significant body mass reduction of 72% across all sites over 80 years. This work illustrates that the depth of the current avian extinction crisis, which has been well documented by scientists, is also widely acknowledged by Indigenous Peoples and local communities through their deep ecological knowledge and place-based observations. It highlights the substantial benefits of establishing meaningful collaborations across different knowledge systems to increase the evidence basis that underpins biodiversity policy and practice.

Source: Oryx

DOI: 10.1017/s0030605325102615

Institutions: Universitat Autònoma de Barcelona, Centre for Research on Ecology and Forestry Applications, Southern Methodist University, Centre National de la Recherche Scientifique, Université de Montpellier, Centre d'Écologie Fonctionnelle et Évolutive, Institut de Recherche pour le Développement, Centre de Coopération Internationale en Recherche Agronomique pour le Développement, Amélioration Génétique et Adaptation des Plantes méditerranéennes et tropicales, University of Jyväskylä, University of Helsinki, Pontificia Universidad Católica de Chile, Universidad de Magallanes, International Water Management Institute, International Water Management Institute, International Water Management Institute (IWMI), Norwegian Institute for Cultural Heritage Research, Institució Catalana de Recerca i Estudis Avançats

Language: English

Topic: Avian ecology and behavior

Subfield: Ecology

Field: Environmental Science

Domain: Physical Sciences

SDG: Life on land

Open Access status: gold

Estimated APC paid: $3,550

Funders: European Commission, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Generalitat de Catalunya, Ministerio de Ciencia e Innovación, Universitat Autònoma de Barcelona, Agencia Nacional de Investigación y Desarrollo, Agencia Estatal de Investigación, Fondo de Financiamiento de Centros de Investigación en Áreas Prioritarias

OpenAlex ID: W7128478917