Quantifying the influence of urban biotic and abiotic environmental factors on great tit nestling physiology

Summary, in English

There is a long history of avian studies investigating the impacts of urbanization. While differences in several life-history traits have been documented, either between urban and rural populations or across generalized urbanization gradients, a detailed understanding of which specific environmental variables cause these phenotypic differences is still lacking. Here, we quantified several local environmental variables coupled to urbanization (air pollution, tree composition, ambient temperature, and artificial light at night [ALAN]) within territories of breeding great tits (Parus major). We linked the environmental variables to physiological measures of the nestlings (circulating fatty acid composition [FA], antioxidant capacity and an oxidative damage marker [malondialdehyde; MDA]), to garner a mechanistic understanding of the impact of urbanization. We found that the antioxidant capacity of nestlings decreased with higher numbers of oak trees and levels of PM2.5 (airborne particulate matter with a diameter < 2.5 μm). Furthermore, the ratio of ω6:ω3 polyunsaturated FAs, important for immune function, was positively correlated with PM2.5 concentration, while being negatively associated with ambient temperature and number of non-native trees in the territory. Body mass and wing length both increased with the number of local oak trees. We also show, through a principal component analysis, that while the environmental variables fall into an urbanization gradient, this gradient is insufficient to explain the observed physiological responses. Therefore, accounting for individual environmental variables in parallel, and thus allowing for interactions between these, is crucial to fully understand of the urban ecosystem.

• Author: Johan Kjellberg Jensen; Ann-Kathrin Ziegler; Christina Isaxon; Lucia Gloria Jiménez Gallardo; Susana Garcia Dominguez; Jan-Åke Nilsson; Jenny Rissler; Caroline Isaksson
• Department/s: BECC: Biodiversity and Ecosystem services in a Changing Climate; Centre for Environmental and Climate Science (CEC); Evolutionary ecology; Molecular Ecology and Evolution Lab; LTH Profile Area: Aerosols; NanoLund: Centre for Nanoscience; Life History and Functional Ecology; Functional zoology; Ergonomics and Aerosol Technology
• Publishing year: 2023-02-10
• Language: English
• Publication/Series: Science of the Total Environment
• Volume: 859
• Issue: Part 1
• Links: http://dx.doi.org/10.1016/j.scitotenv.2022.160225
• Document type: Journal article
• Publisher: Elsevier
• Topic: Ecology; Environmental Sciences; Zoology
• Status: Published
• Research group: Molecular Ecology and Evolution Lab; Life History and Functional Ecology
• ISBN/ISSN/Other: ISSN: 1879-1026