This post was written by our Senior Editors and Commissioning Editor to compliment their editorial, “Conceptualising ecology to support more theory-driven research“.
Ecology is a science deeply rooted in ideas—concepts that frame how we understand and investigate the natural world. These concepts, though sometimes abstract, serve as the foundation for the theories that drive ecological research. Concepts allow us to tackle nature’s complexity, from understanding species interactions to predicting how ecosystems will respond to climate change. For instance, the concept of “natural selection” provided the groundwork for Darwin’s theory of evolution and decades of research. In ecology, concepts like “energy flows” (Lindeman, 1942) and “density dependence” (Nicholson and Bailey, 1935) have shaped our understanding of population dynamics, ecosystem stability, and resilience. Such ideas help ecologists identify key processes, classify life history strategies, and even inform conservation efforts to combat biodiversity loss.
Recognising the importance of these foundational ideas, Journal of Animal Ecology introduced “Concepts” as a distinct Article Type several years ago. This platform invites researchers to propose new or refined ecological concepts, offering a space to challenge paradigms and spark fresh perspectives to make sense of our natural world and the role of animals in it.
Pioneering Conceptual Contributions in Journal of Animal Ecology
Journal of Animal Ecology has a rich history of publishing groundbreaking concepts that continue to shape the field. Foundational, historical examples include Nicholson’s (1933) study on regulatory mechanisms, which laid the foundation for understanding predator-prey cycles and population responses to environmental changes, or the seminal work by Hanski and collaborators (1991) describing metapopulations as networks of smaller populations connected by dispersal. However, new concepts appear in Journal of Animal Ecology at a steady rate. Below, the five senior/commissioning editors of Journal of Animal Ecology highlight five recent Concepts papers published by the Journal:
– Colonisation-competitive ability trade-off
The concept of the trade-off is one of the most useful in all of ecology, providing a simple heuristic framework for characterising ecological and evolutionary limits, while also facilitating predictions of how individuals, populations, and communities will interact or persist through time. Trade-offs within individuals or populations can be abstracted as simple decision trees, or can flexibly be imbued with more complex, hierarchical or non-linear structures. Describing the nature of trade-offs, typically among different components of fitness, is a fruitful process for both opening and structuring our imaginations, revealing pathways to new discovery of the proximal behaviours, energetics, genetics and physiological traits that regulate trade-off structure, as well as the landscape processes of dispersal, filtering, and ecological adaptation that promote the maintenance of particular solutions through time.
In a recent Concepts article in Journal of Animal Ecology, Ferzoco and McCauley (2022) explore the trade-off between colonisation and competitive ability (the so-called CC tradeoff). This CC trade-off is often thought to promote coexistence of species that excel at each of these strategies (at the apparent expense of the other). By rigorously breaking down the traits and context contributing to each of these alternative ‘C’ functions, the authors find clear gaps in the literature where future work can “prove” the existence of a fundamental CC trade off (namely, large gaps in the literature exist for in taxa with active dispersal, and those where traits promoting competitive ability are known). The authors also provide a useful roadmap for understanding how and why different aspects of metabolism and life history may enforce the existence of such a trade-off at the individual level, calling for more work on the proximate mechanisms to inform coexistence theory.
– Gleaner-opportunist trade-off
Also on the topic of pervasive trade-offs, Yamamichi and Letten (2022) revisit the gleaner–opportunist trade-off, a fluctuation-dependent mechanism for species coexistence, highlighting its misunderstood yet promising role in ecology. Traditionally associated with species thriving in low (gleaner) vs. high (opportunist) resource environments, this mechanism hinges on differential functional responses that stabilize resource fluctuations. While once thought to be limited in application, recent research suggests broader relevance, extending to phenomena like predation, multiple resources, phenotypic plasticity, and rapid evolution. By reframing the trade-off as the performance of species under stable vs. fluctuating conditions, the authors underscore its ubiquity and potential for advancing understanding of stable coexistence across diverse ecological contexts.
– Opportunity for selection
Variation is a central process for the theory of natural selection as initially proposed by Darwin. It is thus not surprising that many concepts aiming to define the strength of selection have been built on the concept of variation. Among them, the opportunity for selection, usually measured using the index of total selection (I) proposed by Crow (1958), has become rather popular. This metric, which quantifies the within-population variance in relative fitness, has been used in a large amount of empirical work aiming to measure selection in populations in the wild. Being a dimensionless number (sensu Charnov and Berrigan 1990), this metric has often been used in comparative analyses between sexes or across species. For instance, I has been used to assess whether the opportunity for selection varies among mating systems. However, what I tells us exactly about the strength of selection is not self-evident, and a critical review about the use and misuse of I and related metrics in empirical studies of evolutionary ecology was still lacking. The concept article by Reed and colleagues (2022) fills this gap. After presenting the concept of opportunity for selection and its metrics, Reed et al. took advantage of an exceptionally detailed long-term individual study on a great tit population in the Netherlands to show the dangers of making inferences about selection and its drivers from measures of opportunity for selection. Interestingly, the authors found that selection on fecundity is much higher when measuring fecundity as annual recruitment rather than as clutch size or number of fledglings because variation is less random in annual recruitment than in other traits. This take-home message nicely matches Crow’s (1958) view that “There can be selection only if, through differential survival and fertility, individuals of one generation are differentially represented by progeny in succeeding generations [… ] Not all the differential can be associated with differences in phenotype, for there are large environmental and random elements in survival and reproduction. But, to the extent that differences can be associated with phenotype, phenotypic selection intensity can be measured.” At a time when research in evolutionary ecology heavily relies on sophisticated tools and sometimes puts more emphasis on methods than on data, we found the simple but so true statement that “measuring selection requires data on phenotypes!” especially timely and appropriate.
– Food webs and network theory
One of the striking changes in ecology in recent years has been the rapid increase in the application of a network approach to analyse complex datasets and to address pressing ecological problems. Ever since Charles Elton introduced the concept of the food web in his 1927 book Animal Ecology, there has been a long history of research on this topic, but for most of the second half of the 20th century it was restricted to a niche group of researchers in community ecology. However, by the 1990s network ecology really took off – partly driven by advances in computational modelling but also the development of complexity science as a field in its own right. This evolution of the field, in turn, has given ecologists the tools to examine a whole suite of interactions, moving beyond trophic relationships alone. Windsor (2023) makes a compelling case for revisiting food web paradigms in freshwater environments, where studies have mostly overlooked important non-trophic interactions, such as facilitation and parasitism, and what that means for our understanding of how ecosystems function. By showing how to take advantage of lots of new technologies, he demonstrates how we can explore some previously intractable questions in freshwater ecology, such as how trophic interactions shape community composition, and how network ecology can be put to work helping ecologists to understand and restore degraded ecosystems at a range of scales.
– Animal movement in community ecology
One of the key concepts in community ecology is that the behaviour of individuals often determines, or at least mediates, the outcomes of interactions with the environment or other individuals of the same or different species. For example, an individual decides to bask in cold temperatures or seek shade when temperatures exceed some threshold temperature, and individual prey often reduce activity when confronted with predators. And those individual decisions can scale up to influence the population dynamics, community structure, and even ecosystem functions and broad-scale patterns of density and diversity (Levin 1992). But, as many readers will likely agree, it is challenging to scale up from observations of individuals in the field to phenomena occurring at larger spatial grains and extents. What makes this scaling even more challenging is that not all individuals of the same species make the same decisions or behave the same way – there is variation among individuals, and this variation matters for a whole host of ecological processes (Dall et al. 2012). Costa-Pereira and coauthors (2022) introduce a key concept in this context to take advantage of recent advances in GPS-tracking, biologging, and fine-scale remotely sensed data, which can facilitate inferences about how individuals interact with both other individuals (both con- and hetero-specifics) and their environment. Integrating data from interactions with other individuals and their environment can address key questions at the crux of ecology – what factors influence dispersal from patch to patch in metapopulations? How do species (and individuals) partition resources? How does the presence of other trophic groups affect population dynamics, coexistence, and distributions at broader spatial scales? As technologies continue to advance, and ecologists innovate them, both classic and novel concepts are likely to be illuminated.
How Concepts Drive the Future of Ecology
In a rapidly changing world, new tools like artificial intelligence and molecular techniques are redefining how we study nature. For example, AI streamlines data collection and analysis, while genetic tools like DNA metabarcoding reveal hidden biodiversity. These advances create opportunities to revisit and expand existing ecological concepts or develop entirely new ones. But developing impactful concepts isn’t just about innovation—it’s about inclusivity. Journal of Animal Ecology welcomes diverse perspectives, encouraging contributions from early-career researchers and underrepresented groups. By fostering this diversity, the journal aims to shape a future where ecological concepts address global challenges like climate change and biodiversity loss.
Let’s further conceptualise Ecology!
We are excited to receive submissions of Concept articles that challenge norms, propose new frameworks, or revisit established ideas in light of emerging technologies. By bridging theory and data, these contributions will deepen our understanding of how animals interact with one another and their environment and help us build a sustainable future. Conceptual thinking has always been central to ecology. As we confront unprecedented environmental challenges, it will continue to guide us in preserving the natural world. Authors considering the submission of a Concept article might want to read the useful tips we provide in our recent editorial (Salguero-Gómez et al. 2024). Equally, they are welcome to discuss them with our Commissioning Editor (Rob Salguero-Gómez – rob.salguero@biology.ox.ac.uk) ahead of their submission.
Written by: Rob Salguero-Gómez, Lesley Lancaster, Jennifer Meyer, Darren Evans, Jean-Michel Gaillard, and Nathan J. Sanders
Cited works:
Charnov, E. L., & Berrigan, D. (1990). Dimensionless numbers and life history evolution: Age of maturity versus the adult lifespan. Evolutionary Ecology, 4(4): 273–275.
Crow, J. F. (1958). Some possibilities for measuring selection intensities in man. Human Biology, 30: 3-13.
Dall, S. R. X., Bell, A. M., Bolnick, D. I., Ratnieds, F. L. W. (2012) An evolutionary ecology of individual differences. Ecology Letters, 15: 1189-1198.
Elton, C. (1927). Animal Ecology. Sidgwick & Jackson, Ltd.
Levin, S. A. (1992) The problem of pattern and scale in ecology. Ecology, 73, 1943–1967.
Lindeman, R. L. 1942. The trophic-dynamic aspect of ecology. Ecology 23 (4), 399–417
Nicholson, A. J., & Bailey, V. A. (1935). The balance of animal populations—Part I. Proceedings of the Zoological Society of London (1944) 105 (3): 551–598.
Animal Ecology in Focus 