Population dynamics

  • Article
    | Open Access

    Habitat fragmentation and eutrophication have strong impacts on biodiversity but there is limited understanding of their cumulative impacts. This study presents simulations of meta-food-webs and provides a mechanistic explanation of how landscape heterogeneity promotes biodiversity through rescue and drainage effects.

    • Remo Ryser
    • , Myriam R. Hirt
    •  & Ulrich Brose
  • Article
    | Open Access

    The ‘invariant rate of ageing’ hypothesis suggests that the rate of ageing tends to be constant within species. Here, Colchero et al. find support for the hypothesis across primates, including humans, suggesting biological constraints on the rate of ageing.

    • Fernando Colchero
    • , José Manuel Aburto
    •  & Susan C. Alberts
  • Article
    | Open Access

    Plant population growth rate is sensitive to annual temperature and precipitation anomalies. Here the authors analyse time series of population projection models from multiple biomes, finding a relationship between short generation times and strong demographic responses to climate—particularly precipitation—anomalies.

    • Aldo Compagnoni
    • , Sam Levin
    •  & Tiffany M. Knight
  • Article
    | Open Access

    Transmission by pre-symptomatic and asymptomatic viral carriers makes intervention and containment of the COVID-19 extremely challenging. Here, the authors construct an epidemiological model that focuses on transmission around the symptom onset, exploring specific transmission control measures.

    • Liang Tian
    • , Xuefei Li
    •  & Lei-Han Tang
  • Article
    | Open Access

    In naturally occurring microbial systems, there is a positive relationship between species diversity and productivity of the community. Here the authors perform model selection to find potential amensal interactions that yield robust stable synthetic microbial consortia.

    • Behzad D. Karkaria
    • , Alex J. H. Fedorec
    •  & Chris P. Barnes
  • Article
    | Open Access

    Temperature-dependent host–pathogen interactions may lead species to shift their thermal preferences under pathogen pressure. However, here the authors show that bats have not altered their microclimate preferences due to temperature-mediated mortality from white-nose syndrome, finding instead a sustained preference for warmer sites with high mortality.

    • Skylar R. Hopkins
    • , Joseph R. Hoyt
    •  & Kate E. Langwig
  • Article
    | Open Access

    According to Zipf’s law, the population size of a city is inversely proportional to its size rank in any urban system. The authors show how demography explains this law as a time average of balanced migration between cities and how deviations express information about people’s net preferences.

    • Luís M. A. Bettencourt
    •  & Daniel Zünd
  • Article
    | Open Access

    Conservation biologists often assume that rare (or less abundant) species are more likely to be declining under anthropogenic change. Here, the authors synthesise population trend data for ~2000 animal species to show that population trends cover a wide spectrum of change from losses to gains, which are not related to species rarity.

    • Gergana N. Daskalova
    • , Isla H. Myers-Smith
    •  & John L. Godlee
  • Article
    | Open Access

    Seasonal influenza epidemics vary in timing and size, but the causes of the variation remain unclear. Here, the authors analyse a 15-year city-level data set, and find that fluctuations in climatic factors do not predict onset timing, and that while antigenic change does not have a consistent effect on epidemic size, the timing of onset and heterosubtypic competition do.

    • Edward K. S. Lam
    • , Dylan H. Morris
    •  & Colin A. Russell
  • Article
    | Open Access

    Mutualism is typically portrayed as a destabilizing process in community ecology. Here, via a random matrix model that considers species density, the author shows that mutualistic interactions can, in fact, enhance population density at equilibrium and increase community resilience to perturbation.

    • Lewi Stone
  • Article
    | Open Access

    Extracting causality from time series on natural populations is challenging. Here the authors apply empirical dynamical modeling to 25 years of fish survey data from North Sea fisheries to quantify causal effects of age structure, abundance, and environment on population spatial variability, finding both common and species-specific patterns.

    • Jheng-Yu Wang
    • , Ting-Chun Kuo
    •  & Chih-hao Hsieh
  • Article
    | Open Access

    Density-dependence is rarely accounted for in plant-plant facilitation studies. Here the authors develop a framework that incorporates density-dependence in the stress-gradient hypothesis, and test it first through modeling and then empirically on Arabidopsis thaliana along salt stress gradients.

    • Ruichang Zhang
    •  & Katja Tielbörger
  • Article
    | Open Access

    Models of the origin of life generally require a mechanism to structure emerging populations. Here, Krieger et al. develop spatial models showing that coherent structures arising in turbulent flows in aquatic environments could have provided compartments that facilitated the origin of life.

    • Madison S. Krieger
    • , Sam Sinai
    •  & Martin A. Nowak
  • Article
    | Open Access

    Organisms living on and inside of plants—such as microbes and herbivorous insects—can interact in complex ways. Here the authors show that a plant virus increases the temperature of the plant and also the thermal tolerance of an aphid species feeding on the plant; this change in thermal tolerance also affects competition with another aphid species.

    • Mitzy F. Porras
    • , Carlos A. Navas
    •  & Tomás A. Carlo
  • Article
    | Open Access

    HIV prevalence varies throughout Africa, but the contribution of migration remains unclear. Using population-based data from ~22,000 persons, Grabowski et al. show that HIV-positive migrants selectively migrate to high prevalence areas and that out-migrants from these areas geographically disperse.

    • Mary Kate Grabowski
    • , Justin Lessler
    •  & Ronald H. Gray
  • Article
    | Open Access

    Market integration may loosen the dense kinship networks maintaining high fertility among agriculturalists, but data are lacking. Here, Colleran shows that in 22 rural Polish communities, women’s ego networks are less kin-oriented, but not less dense, as market integration increases, potentially enabling low fertility values to spread.

    • Heidi Colleran
  • Article
    | Open Access

    Prior studies have examined fixed traits that correlate with plant invasiveness. Here the authors use a database of population matrices to compare demographic traits of invasive species in their native and invaded ranges, finding that demographic amplification is an important predictor of invasiveness.

    • Kim Jelbert
    • , Danielle Buss
    •  & Dave Hodgson
  • Article
    | Open Access

    Swimming bacteria perform collective motion at high cell density, yet it is unclear how this behaviour affects their ability to follow substance gradients in the environment. Here, Colin et al. address this question by studying motion of Escherichia coli in controlled chemical gradients.

    • Remy Colin
    • , Knut Drescher
    •  & Victor Sourjik
  • Article
    | Open Access

    Many species’ life cycles have moved earlier in the year because of climate change, but we do not know the consequences for range expansions. The authors show that these advances promote range expansions in species with multiple reproductive cycles per year, but not in species with only one.

    • Callum J. Macgregor
    • , Chris D. Thomas
    •  & Jane K. Hill
  • Article
    | Open Access

    Garden bird feeding is a prolific human activity that provides a reliable foraging opportunity to wild birds. Here the authors use a 40-year data set to show that large-scale restructuring of garden bird communities and growth in urban bird populations can be linked to changing feeding practices.

    • Kate E. Plummer
    • , Kate Risely
    •  & Gavin M. Siriwardena
  • Article
    | Open Access

    Environmental stress can affect the outcome of ecological competition. Here, the authors use theory and experiments with a synthetic microbial community to show that a tradeoff between growth rate and competitive ability determines which species prevails when the population faces variable mortality rates.

    • Clare I. Abreu
    • , Jonathan Friedman
    •  & Jeff Gore
  • Article
    | Open Access

    While several studies have documented early warning signals of population collapse, the use of such signals as indicators of population recovery has not been investigated. Here the authors use models and empirical fisheries data to show that there are statistical indicators preceding recovery of cod populations.

    • Christopher F. Clements
    • , Michael A. McCarthy
    •  & Julia L. Blanchard
  • Article
    | Open Access

    Extreme climate events can cause population crashes and may threaten population persistence. Here, the authors model reindeer population dynamics and find that more frequent extremely icy winters can actually reduce extinction risk due to density dependence and a demographic shift to resilient ages.

    • Brage B. Hansen
    • , Marlène Gamelon
    •  & Vidar Grøtan
  • Article
    | Open Access

    Protection of rare species requires advanced understanding of the reasons for their rarity. Here, Hallett et al. show that potential growth rate and density dependence together predict rarity vs. abundance, and that the stability of species of similar sizes depends on the relative strength of these two mechanisms.

    • Lauren M. Hallett
    • , Emily C. Farrer
    •  & Richard J. Hobbs
  • Article
    | Open Access

    Amphibians have seen large population declines, but the key drivers are hard to establish. Here, Miller et al. investigate trends of occupancy for 81 species of amphibians across North America and find greater sensitivity to water availability during breeding and winter conditions than mean climate.

    • David A. W. Miller
    • , Evan H. Campbell Grant
    •  & Brent H. Sigafus
  • Article
    | Open Access

    Tools from statistical physics can be used to investigate a large variety of fields ranging from economics to biology. Here the authors first adapt density-functional theory to predict the distributions of crowds in new environments and then validate their approach using groups of fruit flies.

    • J. Felipe Méndez-Valderrama
    • , Yunus A. Kinkhabwala
    •  & T. A. Arias
  • Article
    | Open Access

    Higher-order interactions occur when one species mediates the interaction between two others. Here, the authors model microbial growth and competition to show that higher-order interactions can arise from tradeoffs in growth traits, leading to neutral coexistence and other complex dynamics.

    • Michael Manhart
    •  & Eugene I. Shakhnovich
  • Article
    | Open Access

    The disease dynamics of bovine tuberculosis have been of interest given the pathogen’s effect on wild animal and livestock health. Here, the authors show that a brief cessation of testing for bovine tuberculosis in 2001 altered the population synchrony of the disease dynamics across regions of Great Britain.

    • Aristides Moustakas
    • , Matthew R. Evans
    •  & Yannis Markonis
  • Article
    | Open Access

    Diatoms account for 40% of marine primary production and their sensitivity to ocean acidification could have ecosystem-wide consequences. Here, the authors developed and applied a stress test, demonstrating that resilience of diatoms increases significantly in ocean acidification conditions.

    • Jacob J. Valenzuela
    • , Adrián López García de Lomana
    •  & Nitin S. Baliga
  • Article
    | Open Access

    Biases in adult sex ratio (ASR) are common, yet their causes and consequences are not well understood. Here, the authors analyse data from >6000 individuals of five shorebird species, showing that sex differences in juvenile survival drive ASR variation and biased ASR is associated with uniparental care.

    • Luke J. Eberhart-Phillips
    • , Clemens Küpper
    •  & Oliver Krüger
  • Article
    | Open Access

    Wolbachia infection in mosquitoes reduces dengue virus spread under specific lab conditions, prompting its use in disease control. Here, King et al. show that Wolbachia increases mean and variance in mosquito susceptibility and explain how this affects Wolbachia invasion and dengue transmission.

    • Jessica G. King
    • , Caetano Souto-Maior
    •  & M. Gabriela M. Gomes
  • Article
    | Open Access

    Hunting and harvesting are generally expected to select for faster life histories in the exploited species. Here, the authors analyse data from a hunted population of brown bears in Sweden and show that regulations protecting females with dependent young lead hunting to favor prolonged maternal care.

    • Joanie Van de Walle
    • , Gabriel Pigeon
    •  & Fanie Pelletier
  • Article
    | Open Access

    Energetic constraints produce a fundamental tradeoff in starvation and recovery rates, impacting eco-evolutionary dynamics. Here, Yeakel et al. develop a nutritional state-structured model that predicts population size as a function of body mass known as Damuth’s law, and a mechanism for Cope’s rule, the evolutionary trend towards larger body mass.

    • Justin D. Yeakel
    • , Christopher P. Kempes
    •  & Sidney Redner
  • Article
    | Open Access

    The drivers of North Atlantic phytoplankton bloom have been debated for decades, partially owing to incomplete sub-surface observations. Here, Mignot et al. use robotic sensors to provide detailed observations of developing blooms and to explore the drivers of different phases of plankton growth.

    • A. Mignot
    • , R. Ferrari
    •  & H. Claustre
  • Article
    | Open Access

    Understanding ecological interactions in microbial communities is limited by lack of informative longitudinal abundance data necessary for reliable inference. Here, Xiao et al. develop a method to infer the interactions between microbes based on their abundances in steady-state samples.

    • Yandong Xiao
    • , Marco Tulio Angulo
    •  & Yang-Yu Liu
  • Article
    | Open Access

    Determining the conservation status and populations trends for elusive predators has been impeded by discrepancies in how densities are calculated. Here, Luskin et al. introduce a means to standardize previous density estimates and assess the threats to the Sumatran tiger.

    • Matthew Scott Luskin
    • , Wido Rizki Albert
    •  & Mathias W. Tobler
  • Article
    | Open Access

    Adélie penguins are a key Antarctic indicator species, but data patchiness has challenged efforts to link population dynamics to key drivers. Che-Castaldo et al. resolve this issue using a pan-Antarctic Bayesian model to infer missing data, and show that spatial aggregation leads to more robust inference regarding dynamics.

    • Christian Che-Castaldo
    • , Stephanie Jenouvrier
    •  & Heather J. Lynch
  • Article
    | Open Access

    Top predators can reduce local mesopredator abundance either through direct predation or behavioural changes. Here, Newsome and colleagues demonstrate at a landscape scale across three continents that mesopredator populations are suppressed at the core, but less so on the periphery, of top predators’ ranges.

    • Thomas M. Newsome
    • , Aaron C. Greenville
    •  & Aaron J. Wirsing