Effects of long-term intraspecific trait change on bird community functional structure

Shilu Zheng; David Lindenmayer; Rachakonda Sreekar; Fangyuan Hua; Juntao Hu; Qianyu Chen; Zhijun Ma; Bo Li; Jiajia Liu

doi:10.1016/j.cub.2025.06.019

Effects of long-term intraspecific trait change on bird community functional structure

Curr Biol. 2025 Jun 21:S0960-9822(25)00748-1. doi: 10.1016/j.cub.2025.06.019. Online ahead of print.

Authors

Shilu Zheng¹, David Lindenmayer², Rachakonda Sreekar³, Fangyuan Hua⁴, Juntao Hu¹, Qianyu Chen¹, Zhijun Ma¹, Bo Li⁵, Jiajia Liu⁶

Affiliations

¹ National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science and Institute of Eco-Chongming, School of Life Sciences, Fudan University, Shanghai 200438, China.
² Fenner School of Environment and Society, The Australian National University, Arts and Culture Trust, Canberra, Canberra 2601, Australia.
³ School of the Environment, The University of Queensland, St Lucia, Brisbane, Queensland 4067, Australia.
⁴ Institute of Ecology and Key Laboratory for Earth Surface Processes of the Ministry of Education, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
⁵ National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science and Institute of Eco-Chongming, School of Life Sciences, Fudan University, Shanghai 200438, China; Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology and Centre for Invasion Biology, Institute of Biodiversity, School of Ecology and Environmental Science, Yunnan University, Kunming 650504, Yunnan, China. Electronic address: bool@ynu.edu.cn.
⁶ National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science and Institute of Eco-Chongming, School of Life Sciences, Fudan University, Shanghai 200438, China. Electronic address: liujiajia@fudan.edu.cn.

PMID: 40580959
DOI: 10.1016/j.cub.2025.06.019

Abstract

There has been rapid intraspecific trait change in many species over the past few centuries. While the impacts of such long-term changes on community functional structure remain unclear, it is vital to evaluate and predict responses of biodiversity and ecosystem function to global change. We examined intraspecific trait changes of 548 bird species from 86,539 specimens collected over the past 140 years and species composition data for 840 bird assemblages surveyed between 1969 and 2021 in North America. We found that rapid intraspecific trait changes have substantially impacted community-level trait composition and functional diversity of communities. Specifically, intraspecific downsizing has reversed the direction of change in community-weighted mean body size that would be expected from species composition change alone. Additionally, intraspecific changes of <3% across four traits have expanded community trait space and accelerated the rate of increase of functional richness across studied assemblages. Our findings highlight that intraspecific trait change is a key driver of community functional reorganization and should be considered alongside species composition change when assessing biodiversity responses to global change.

Keywords: bird; community; functional diversity; intraspecific trait change; specimen.