Animal functional traits: Towards a trait‐based ecology for whole ecosystems

Abstract

1. Functional traits and associated trait-based concepts have driven rapid innovation in ecology over recent years, with most progress based on insights from plants. However, plants are almost entirely restricted to a single trophic level, and an over-reliance on plant traits therefore neglects the complexity and importance of biotic interactions across trophic levels. 2. The need to expand the focus of trait-based ecology to account for trophic complexity has led to an upsurge in attention on animal functional traits and the emergence of new concepts relevant to community ecology, macroecology and ecosystem science. Recent progress in the compilation of global trait datasets for some animal taxa has opened up new possibilities for testing ecological theory. 3. In this Special Focus, we explore how trait-based ecology can expand the scope of investigation from single to multiple trophic levels, how insights from these investigations can be used to upscale understanding from local communities to biogeographical patterns and how this can ultimately help to predict the impacts of global change on ecosystem functions. To address these key questions, we showcase studies on diverse animal taxa ranging in size from springtails to crocodiles and spanning multiple trophic levels from primary consumers to apex predators. 4. This collection of studies shows how precise measurements of morphological or physiological traits can increase mechanistic understanding of community assembly across trophic levels, particularly of the mechanisms underpinning large-scale biodiversity patterns. Furthermore, a clearer picture is emerging of systematic animal responses to environmental change that shape the trait composition of ecological communities and affect ecosystem functioning. 5. The articles in this volume highlight the need to move trait-based ecology beyond the limits of taxonomic boundaries. The integration of trait data and concepts across trophic levels opens up new possibilities for identifying general ecological mechanisms that shape patterns and processes operating at different scales. The identification of key functional traits and their interplay across trophic levels can underpin the development of a trait-based ecology for whole | 5

Exploring the Macroevolutionary Signature of Asymmetric Inheritance at Speciation

“…Overall, the ABM brings comparative methods one step closer to integrating individual variation into macro-evolutionary models. This is timely because phenotypic and phylogenetic datasets are growing in size and completeness, making it increasingly easy to obtain information about individual variation in traits for entire clades (see Tobias (2022); Schleuning et al (2023)). The unprecedented accessibility of individual-level data across large numbers of species gives us the opportunity to incorporate individual variation at the macro-evolutionary scale.…”

Unlocking avian museum collections to enable and advance environmental change research

“…Syntheses have highlighted the challenges and opportunities associated with avian trait‐based research (Tobias 2022, Schleuning et al . 2023), whereas others have explored the frontiers of collections‐based ornithological research more broadly (Webster 2018).…”

Bringing light onto the Raunkiæran shortfall: A comprehensive review of traits used in functional animal ecology

“…Despite the fact that these functional trait types were defined in the late 1990s and early 2000s (Díaz & Cabido, 2001 ; Lavorel & Garnier, 2002 ; Naeem et al, 1994 ; Tilman, 1999 ), the use of functional traits to examine species response to or impact on the environment in studies of plants and animals can be traced back to early ecologists such as Elton, Humboldt, Hutchinson, Grime, Raunkiaer, and Root (Garnier et al, 2016 ; Malaterre et al, 2019 ). Even though trait‐based studies with plants and animals have been conducted for over a century, this research program has advanced significantly more for plants than animals (but see recent advances in Schleuning et al, 2023 ). For example, the first global protocol for standardizing plant traits measurements was published in the early 2000s (Cornelissen et al, 2003 ), but the first global protocols for standardizing traits for animals were published very recently, for example, Pey et al ( 2014 ) for soil invertebrates, Schmera et al ( 2015 ) for macroinvertebrates, Moretti et al ( 2017 ) for terrestrial invertebrates, and Tobias et al ( 2022 ) for birds.…”

“…However, there is theoretical and empirical support demonstrating that intraspecific trait variability plays an important role in community assembly and ecosystem processes (Albert et al, 2011 ; Araújo et al, 2011 ; Bolnick et al, 2011 ; Siefert et al, 2015 ; Violle et al, 2012 ). Fourth, the asymmetrical research efforts result in a bias in the distribution of animal trait data availability and trait‐based studies across taxonomic groups, regions, and ecosystems (Etard et al, 2020 ; Hevia et al, 2017 ; Schleuning et al, 2023 ). Fifth, there are standardized protocols for organizing and validating trait collation which compromise comparative analyses and data sharing (Hortal et al, 2015 ).…”

“…Even though trait-based studies with plants and animals have been conducted for over a century, this research program has advanced significantly more for plants than animals (but see recent advances in Schleuning et al, 2023). For example, the first global protocol for standardizing plant traits measurements was published in the early 2000s (Cornelissen et al, 2003), but the first global protocols for standardizing traits for animals were published very recently, for example, Pey et al (2014) for soil invertebrates, Schmera et al (2015) for macroinvertebrates, Moretti et al (2017) for terrestrial invertebrates, and Tobias et al (2022) for birds.…”