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The file contains the supplementary tables and figures for the study.

sites_information.csv is the location, codename,land type of study sites. CCH_east_open_*_2018_2019.csv are the daily Tmax/Tmin/DTR in the open field from 2018to 2019. CCH_east_forest_*_2018_2019.csv are the daily Tmax/Tmin/DTR in the understory from 2018to 2019.

Assessing the impact of environmental fluctuations on species coexistence is critical for understanding biodiversity loss and the ecological impacts of climate change. Yet, determining how properties like the intensity, frequency or duration of environmental fluctuations influence species coexistence remains challenging, presumably because previous studies have focused on indefinite coexistence. Here, we model the impact of environmental fluctuations at different temporal scales on species coexistence over a finite time period by employing the concepts of time windowed averaging and performance curves to incorporate temporal niche differences within a stochastic Lotka–Volterra model. We discover that short- and long-term environmental variability has contrasting effects on transient species coexistence, such that short-term variation favours species coexistence, whereas long-term variation promotes competitive exclusion. This dichotomy occurs because small samples (e.g. environmental changes over long time periods) are more likely to show large deviations from the expected mean and are more difficult to predict than large samples (e.g. environmental changes over short time periods), as described in the central limit theorem. Consequently, we show the complex set of relationships among environmental fluctuations and species coexistence found in previous studies can all be synthesized within a general framework by explicitly considering both long- and short-term environmental variation.

Results of game theoretic model of dominance hierarchies and social conflict and cooperation as environmental quality varies.

Many aspects of behaviour depend on recognition, but accurate recognition is difficult because the traits used for recognition often overlap. For example, brood parasitic birds mimic host eggs, so it is challenging for hosts to discriminate between their own eggs and parasitic eggs. Complex signals that occur in multiple sensory modalities or involve multiple signal components are thought to facilitate accurate recognition. However, we lack models that explore the effect of complex signals on the evolution of recognition systems. Here, we use individual-based models with a genetic algorithm to test how complex signals influence recognition thresholds, signaller phenotypes and receiver responses. The model has three main results. First, complex signals lead to more accurate recognition than simple signals. Second, when two signals provide different amounts of information, receivers will rely on the more informative signal to make recognition decisions and may ignore the less informative signal. As a result, the particular traits used for recognition change over evolutionary time as sender and receiver phenotypes evolve. Third, complex signals are more likely to evolve when recognition errors are high cost than when errors are low cost. Overall, redundant, complex signals are an evolutionarily stable mechanism to reduce recognition errors.This article is part of the theme issue ‘Signal detection theory in recognition systems: from evolving models to experimental tests’.

In cooperatively breeding species, social conflict is typically assumed to underlie destructive behaviours like infanticide. However, an untested alternative hypothesis in birds is that infanticide in the form of egg tossing may simply be a parental response to partial nest predation representing a life-history trade-off. We examined egg tossing behaviour in the colonial and cooperatively breeding grey-capped social weaver (Pseudonigrita arnaudi), a plural breeder in which pairs nest separately, often in the same tree. Using infrared nest cameras, we found that 78% of the tossing events from 2012 to 2017 were committed by parents, suggesting that social conflict is unlikely to be the main reason underlying egg tossing in this species. Instead, reductions in clutch size due to both natural and experimentally simulated predation induced parental egg tossing. Our study suggests that destructive behaviour in cooperatively breeding birds can be shaped by a variety of mechanisms beyond social conflict and that alternative hypotheses must be considered when studying the adaptive significance of infanticide in group-living species.

This documents contains four parts: (1) Testing the generality of our simulation results, (2) Independent effects of survival and reproduction on the evolution of the bet-hedging and rising-tide strategies, (3) Modelling environmental variation and performance curves using normal distribution functions, and (4) Using Gillespie's algorithm to transform the differential equations into an individual-based model

Conflict over reproduction is an inherent part of group living. In many social vertebrates, conflict may be reflected as allostatic load, or the costs of social status and dominance rank, which may be quantified by measuring glucocorticoid stress hormones. Here, we develop the first quantitative model of allostatic load based on the tug‐of‐war model of reproductive skew to generate insights into the mechanisms underlying reproductive conflict in cooperative breeders and to determine whether glucocorticoids can be used to assess conflict levels in group‐living vertebrates. It predicts that subordinates have higher allostatic loads than dominants under most conditions, but when body condition is lower in dominants than in subordinates, dominants experience higher allostatic load. Group structure is also important, as dominants generally have higher allostatic loads than subordinates when there is a large number of subordinates in the group, but this cost can be reduced by increasing the number of dominants, as in plural breeding societies. Using glucocorticoid data from cooperatively breeding superb starlings Lamprotornis superbus, we found empirical support for both predictions. Our model is useful for understanding how the costs of social status influence reproductive sharing, and it suggests that glucocorticoids can be used to examine reproductive conflict and cooperation in social species.

The ability to form cooperative societies may explain why humans and social insects have come to dominate the earth. Here we examine the ecological consequences of cooperation by quantifying the fitness of cooperative (large groups) and non-cooperative (small groups) phenotypes in burying beetles (Nicrophorus nepalensis) along an elevational and temperature gradient. We experimentally created large and small groups along the gradient and manipulated interspecific competition with flies by heating carcasses. We show that cooperative groups performed as thermal generalists with similarly high breeding success at all temperatures and elevations, whereas non-cooperative groups performed as thermal specialists with higher breeding success only at intermediate temperatures and elevations. Studying the ecological consequences of cooperation may not only help us to understand why so many species of social insects have conquered the earth, but also to determine how climate change will affect the success of these and other social species, including our own.