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opencc-zeroJan 2022View details →

Data and code from: Traits and phylogenies modulate the environmental responses of wood-inhabiting fungal communities across spatial scales

Identifying the spatial scales at which community assembly processes operate is fundamental for gaining a mechanistic understanding of the drivers shaping ecological communities. In this study, we examined whether and how traits and phylogenetic relationships structure fungal community assembly across spatial scales. We applied joint species distribution modelling to a European-scale dataset on 215 wood-inhabiting fungal species, which includes data on traits, phylogeny and environmental variables measured at the local (log-level) and regional (site-level) scales. At the local scale, wood-inhabiting fungal communities were mostly structured by deadwood decay stage, and the trait and phylogenetic patterns along this environmental gradient suggested the lack of diversifying selection. At regional scales, fungal communities and their trait distributions were influenced by climatic and connectivity-related variables. The fungal climatic niches were not phylogenetically structured, suggesting that diversifying selection or stabilizing selection for climatic niches has played a strong role in wood-inhabiting communities. In contrast, we found a strong phylogenetic signal in the responses to connectivity-related variables, revealing phylogenetic homogenization in small and isolated forests. Altogether, our results show that species-level traits and phylogenies modulate the responses of wood-inhabiting fungi to environmental processes acting at different scales. This result suggests that the evolutionary histories of fungal traits diverge along different environmental axes.

Data from: Plant life history traits rather than soil legacies determine colonisation of soil patches in a multi-species grassland

Interactions between plants and soil biota are increasingly shown to play critical roles in plant species co-existence processes. Plant species co-existence is thought to be promoted via biotic legacies that plant species leave behind in the soil after a plant disappears. These soil legacies are hypothesised to supress colonisation success when the preceding plant is of the same species, that is, when a plant species encounters its own, species-specific soil antagonists. However, colonisation of vacant spots in plant communities is in the first place determined by the ability of plants to reach such vacant locations. We currently lack an understanding of the explicit role of soil legacy effects and their relative contribution to colonisation processes in plant communities consisting of plant species inherently differing in colonisation ability. In experimental, outdoor plant communities consisting of eight grassland species, we tested the effect of five differently conditioned soil patches on plant species colonisation success over three consecutive growing seasons. We found that colonisation success was largely determined by the species' reproductive strategy, lateral spread and growth rate, and not by the plant species that conditioned the soil patch. Fast spreading, clonal plant species reached the soil patches first and initially attained the highest biomass inside the patch. One year later, slower spreading plant species colonised the patch via seedlings. Species with intrinsically high growth rates attained the highest biomass, decreasing biomass of the initial colonisers. While subtle differences between conditioned soil patches did occur, these were not strong enough to overcome the inherent differences in colonisation ability between the various plant species. Synthesis: Our results reject the hypothesis that colonisation of vacant soil patches in plant communities is strongly affected by the legacy that is left behind by the preceding plant species. Instead, plant species life history strategy plays a prominent role, driving sequential plant species replacements. Based on our results and recent accounts in literature we present a conceptual model for local cyclic dynamics in grassland communities, where soil legacy plays a role in affecting the performance of established plant species rather than colonisation of vacant patches.

Climate-induced plasticity in leaf traits of riparian plants

Aim: Leaf inputs from riparian vegetation and its decomposition play a key role in energy and nutrients transfer in many stream ecosystems. Instream leaf-litter decomposition is mainly driven by leaf traits. Therefore, understanding and predicting leaf traits variation with current environmental changes and its putative effects on stream food webs is a critical challenge. Most studies have focused on the assumed higher interspecific leaf traits variability, with little research addressing an intraspecific perspective. Location: Andalusia, Spain Methods: We assessed the relative effects of climate and soil on the intraspecific variability in leaf traits of four common woody riparian species in permanent low-order Mediterranean streams along a wide aridity gradient. We used a space-for-time substitution approach to predict leaf traits changes and consequences for stream food webs in a future climate change scenario. Results: We found that climate had a major influence on intraspecific variability of leaf traits, but with opposite patterns depending on plant functional type. Results indicated that leaf quality—linked to palatability and decomposability—of Alnus glutinosa, Salix atrocinerea and Rubus ulmifolius (deciduous/semideciduous) will decrease with the forecasted aridification, whereas that of the evergreen Nerium oleander will increase. Main conclusions: Our findings suggest a decrease of intraspecific leaf-quality in riparian deciduous species with global warming in a relatively short term, which, in a longer term, may add to the forecasted dieback of deciduous species in riparian corridors of temperate climate zones. These forecasted changes have the potential to significantly impair ecosystem functioning of Mediterranean mountain streams currently under deciduous gallery forests.

opencc-by-4.0Nov 2013View details →

Fig. 1 in Floristic traits and biogeographic characterization of the Gennargentu massif (Sardinia)

Fig. 1. – Study area in Sardinia.

opencc-by-4.0Nov 2013View details →

Fig. 3 in Floristic traits and biogeographic characterization of the Gennargentu massif (Sardinia)

Fig. 3. – Percentages of the chorologic units, referred to the whole flora.

Ecological traits drive genetic structuring in two open-habitat birds from the morphologically cryptic genus Elaenia (Aves: Tyrannidae)

Understanding the relative contributions of the many factors that shape population genetic structuring is a central theme in evolutionary and conservation biology. Historically, abiotic or extrinsic factors (such as geographic barriers or climatic shifts) have received greater attention than biotic or intrinsic factors (such as dispersal or migration). This focus stems in part from the logistical difficulties in taking a comparative phylogeographic approach that contrasts species that have experienced similar abiotic conditions during their evolution yet differ in the intrinsic attributes that might shape their genetic structure. To explore the effects of intratropical migration on the genetic structuring of Neotropical birds, we chose two congeneric species, the Lesser Elaenia (Elaenia chiriquensis) and the Plain-crested Elaenia (E. cristata), that are largely sympatric, and which have similar plumage, habitat preferences, and breeding phenology. Despite these many commonalities, they differ in migratory behavior: E. chiriquensis is an intratropical migratory species while E. cristata is sedentary. We used a reduced representation genomic approach to test whether migratory behavior is associated with increased gene flow and therefore lower genetic population structure. As predicted, we found notably stronger genetic structuring in the sedentary species than in the migratory ones. E. cristata comprises genetic clusters with geographic correspondence throughout its distribution, while there are no geographic groups within Brazil for E. chiriquensis. This comparison adds to the growing evidence about how intrinsic traits like migration can shape the genetic structuring of birds, and advances our understanding of the diversification patterns of the understudied, open habitat species from South America.

Climatic conditions and functional traits affect spider diets in agricultural and non-agricultural habitats worldwide

Spiders are dominant predators in terrestrial ecosystems and feed on prey from the herbivore and detritivore subsystem (dual subsystem omnivory) as well as on other predators (intraguild predation). Little is known about how global change potentially affects the importance of different prey groups in predator diets. In this meta-analysis we identify the impact of climatic conditions, land-use types and functional traits of spider species on the relative importance of Hemiptera, Araneae and Collembola prey in spider diets. We use a dataset including 78 publications with 149 observational records of the diet composition of 96 spider species in agricultural and non-agricultural habitats in 24 countries worldwide. The importance of Hemiptera prey was not affected by climatic conditions and was particularily high in smaller spider species in agricultural habitats. Araneae prey was most important for actively hunting, larger spider species in non-agricultural habitats. Collembola prey was most important for small, actively hunting spider species in regions with higher temperature seasonality. Spider species with a higher importance of Araneae prey for their diet also had higher importances of Collembola and lower importances of Hemiptera prey. Future increases of temperature seasonality predicted for several regions worldwide may go along with an increasing importance of Collembola prey which also related to a higher importance of intraguild prey here. Two global change drivers predicted for many regions of the world (increasing climatic seasonality and ongoing conversion of non-agricultural to agricultural land) both hold the potential to increase the importance of Collembola prey in spider diets. The importance of Hemiptera and Araneae prey may however show contrasting responses to these two drivers. These complex potential effects of global change components and their impact on functional traits in spider communities highlight the importance to simultaneously consider multiple drivers of global change to better understand future predator-prey interactions.

Performances (survival and growth) and functional traits of tree seedlings along light and water gradients

A foundational assumption of trait-based ecology is that individual performances should be predicted by its functional traits. However, the trait-performance relationships reported in literature were typically weak, probably due to the ignorance of interactions between traits and environments, intraspecific trait variability and hard traits (directly linked to physiological processes of interest). We conducted an experiment of planting 900 seedlings of six tree species separately (one seedling per pot) along experimentally manipulated light and water gradients, monitored their survival and growth, and measured their morphological, photosynthetic and hydraulic traits. Most trait-performance relationships depended on the environments, either marginally changing (weak trait × environment interaction) or even reversing (strong trait × environment interaction) along light or water gradients in our experiment. Such trait × environment interactions were more likely to be detected in growth models using individual-level traits than models using species mean traits, but seedling growth was not better modelled with individual-level traits than species mean traits. Additionally, none of the hard traits (photosynthetic and hydraulic traits) were better predictors than soft traits (morphological traits) modeling seedling growth and survival along light and water gradients. Our study highlights the necessities of considering trait × environment interactions when predicting response of plants to changing environments. The benefits of using individual-level traits or hard traits to predict plant performance might be reduced or even cancelled if their measurement errors are not well controlled.

Data from: Multivariate selection mediated by aridity predicts divergence of drought resistant traits along natural aridity gradients of an invasive weed

Geographic variation in the environment underpins selection for local adaptation and evolutionary divergence among populations. Because many environmental conditions vary across species' ranges, identifying the specific environmental variables underlying local adaptation is profoundly challenging. We tested whether natural selection mediated by aridity predicts clinal divergence among invasive populations of capeweed (Arctotheca calendula) that established and spread across southern Australia during the last two centuries. Using common garden experiments with two environmental treatments (wet and dry) that mimic aridity conditions across capeweed's invasive range, we estimated clinal divergence and effects of aridity on fitness and multivariate phenotypic selection in populations sampled along aridity gradients in Australia. We show that: (i) capeweed populations have relatively high fitness in aridity environments similar to their sampling locations; (ii) the magnitude and direction of selection strongly differs between wet and dry treatments, with drought stress increasing the strength of selection; and (iii) differences in directional selection between wet and dry treatments predict patterns of clinal divergence across the aridity gradient, particularly for traits affecting biomass, flowering phenology and putative antioxidant expression. Our results suggest that aridity-mediated selection contributes to trait diversification among invasive capeweed populations, possibly facilitating the expansion of capeweed across southern Australia.

Datasets and scripts from: Sensory-based quantification of male colour patterns in Trinidadian guppies reveals no support for parallel phenotypic evolution in multivariate trait space

Parallel evolution, in which independent populations evolve along similar phenotypic trajectories, offers insights into the repeatability of adaptive evolution. Here, we revisit a classic example of parallelism, that of repeated evolution of brighter males in the Trinidadian guppy (Poecilia reticulata). In guppies, colonisation of low predation habitats is associated with emergence of 'more colourful' phenotypes since predator-induced viability selection for crypsis weakens while sexual selection by female preference for conspicuousness remains strong. Our study differs from previous investigations in three respects. First, we adopt a multivariate phenotyping approach to characterise parallelism in multi-trait space. Second, we use ecologically-relevant colour traits defined by the visual systems of the two selective agents (i.e. guppy, predatory cichlid). Third, we estimate population genetic structure to test for adaptive (parallel) evolution against a model of neutral phenotypic divergence. We find strong phenotypic differentiation that is inconsistent with a neutral model but very limited support for the predicted pattern of greater conspicuousness at low predation. Effects of predation regime on each trait were in the expected direction, but weak, largely non-significant, and explained little among-population variation. In multi-trait space, phenotypic trajectories of lineages colonising low from high predation regimes were not parallel. Our results are consistent with reduced predation risk facilitating adaptive differentiation, potentially by female choice, but suggest that this proceeds in independent directions of multi-trait space across lineages. Pool-sequencing data also revealed SNPs showing greater differentiation than expected under neutrality, among which some are found in genes contributing to colour pattern variation, presenting opportunities for future genetic study.

Nuanced qualitative trait approaches reveal environmental filtering and phylogenetic constraints on lichen communities

We propose that a qualitative trait approach based on more detailed nuanced traits may reveal previously overlooked patterns, especially when combined with phylogenetic perspectives. By sampling epiphytic lichens and using a functional approach based on nuanced qualitative traits, such as a much greater resolution over photobiont identity, type of cortex and chemical compounds, we evaluated the effects of environmental filtering and phylogenetic constraints on community assembly along natural succession of Atlantic rainforest. We found changes in taxonomic, functional and phylogenetic composition, structure and diversity. Functional traits such as photobiont genera, type of cortex, reproductive structures, propagule size and protection strategies showed strong responses to succession. Mature forests with a closed canopy impose strong environment filtering that is reflected in lichen species turnover, limiting diversity, but also holding different functional and phylogenetic composition. The use of a nuanced qualitative trait approach may overcome some of the limitations of using this type of traits and show the importance of often overlooked key lichen functional traits, including presence of carbon concentrating mechanisms in photobionts and cortex properties. Furthermore, this is the first study showing how patterns of phylogenetic assembly along forest succession structure lichen communities.

opencc-by-4.0Mar 2022View details →

Data from: Influence of Check Dams on the Activity Pattern and Morphometric Traits of Overwintering Tadpoles in the Western Himalaya

Dataset for the paper: Influence of Check Dams on the Activity Pattern and Morphometric Traits of Overwintering Tadpoles in the Western Himalaya. See readme.txt for details.

Why the long teeth? Morphometric analysis suggests different selective pressures on functional occlusal traits in Plio-Pleistocene African suids

Neogene and Pleistocene African suids displayed convergent evolutionary trends in the third molar (M3) morphology, with increasingly elongated and higher crowns through time. While these features can prevent premature loss of masticatory functionality and potentially increase long-term reproductive success, changes in dental occlusal traits such as enamel complexity and thickness can also improve chewing efficiency and increase short-term energetic return. While both long-term and short-term benefits can contribute to the thriving of a lineage, the selective pressures associated with each category can be different. To examine how crown elongation correlates with these functional occlusal traits, we selected M3s of Kolpochoerus, Notochoerus, and Metridiochoerus from Kenya and South Africa, dated between 3.0 Ma and 0.4 Ma. To account for dental wear, we used micro-CT imaging of unworn/slightly worn M3s to simulate wear progression within each tooth. We compared morphometric representatives of occlusal enamel complexity and thickness among the specimens following their respective wear trajectories. We found that M3 elongation correlates with higher occlusal complexity and thinner enamel in Notochoerus and Metridiochoerus lineages through time. In Kolpochoerus, enamel complexity and thickness were generally maintained through time, despite M3 elongation. The differences in M3 morphometric trends suggest that Kolpochoerus likely experienced a different set of selective pressures on functional occlusal traits compared to Notochoerus and Metridiochoerus. The shared evolutionary trends of M3 specialization among Notochoerus and Metridiochoerus suggest similar selective pressures on their chewing efficiency and the possibility of a dietary niche overlap in more xeric habitats.

Do ecological specialization and functional traits explain the abundance–frequency relationship? Arable weeds as a case study

Aim: The abundance-frequency relationship (AFR) is among the most-investigated pattern in biogeography, yet the relative contributions of niche-based processes related to ecological strategies, and of neutral processes related to spatial colonization-extinction dynamics, remains uncertain. Here, we tested the influences of ecological specialization and functional traits on local abundance and regional frequency, to determine the contribution of niche-based processes. Location: France and the UK. Taxon: Vascular plants. Methods: We used two arable weed surveys covering 1544 fields in Western Europe (France, UK), along with functional traits related to resource acquisition, flowering phenology and dispersal. We quantified specialization both to arable habitat and to individual crop types, and performed phylogenetic path analyses to test competing models accounting for direct and indirect relationships between traits, specialization, abundance and frequency. We performed the analyses for all species in each country, as well as for a subset of the most abundant species. Results: Local abundance of weeds increased with their regional frequency, but the relationship became negative or null when considering only the most abundant weeds. Specialization to arable habitat and to individual crop type either had a similar or opposite effect on regional frequency and local abundance explaining these positive and negative relationships, respectively. Regional frequency was not directly explained by any trait but indirectly by resource requirement traits conferring specialization to the arable habitat. Conversely, high local abundance was directly related to low seed mass, high SLA, early and short flowering. Main Conclusions: Direct/indirect effects of functional traits on local abundance/regional frequency, respectively, supports a significant role of niche-based processes in AFR. Neutral spillover dynamics could further explain a direct linkage of abundance and frequency. Similar causal paths and consistent influences of traits on specialization and abundance in the two studied regions suggest genericity of these findings.

Breeding in the pandemic: Short-term lockdown restrictions in a European capital city did not alter the life-history traits of two urban adapters

Humans are transforming natural habitats into managed urban green areas and impervious surfaces at an unprecedented pace. Yet the effects of human presence per se on animal life-history traits are rarely tested. This is particularly true in cities, where human presence is often indissociable from urbanisation itself. The onset of the SARS-CoV-2 outbreak, along with the resulting lockdown restrictions, offered a unique, "natural experiment" context to investigate wildlife responses to a sudden reduction of human activities. We analysed four years of avian breeding data collected in a European capital city to test whether lockdown measures altered nestbox occupancy and life-history traits in terms of egg-laying date, incubation duration, and clutch size in two urban adapters: great tits (Parus major) and blue tits (Cyanistes caeruleus). Lockdown measures, which modulated human presence, did not influence any of the life-history traits investigated. In contrast, tree cover, a distinct ecological attribute of the urban space, was positively associated with clutch size, a key avian life-history, and reproductive trait. This highlights the importance of habitat quality/ inter-year variation over human activity on the reproduction of urban wildlife. We discuss our results in light of other urban wildlife studies carried out during the pandemic, inviting the scientific community to carefully interpret all lockdown-associated shifts in biological traits.

Functional trait variation of Anemone nemorosa along macro‐ and microclimatic gradients close to the northern range edge

Climate warming is affecting ecosystems worldwide, and slow-colonizing forest under- storey species are particularly vulnerable if they are unable to track climate change. However, species' responses to climatic conditions in terms of growth, reproduction and colonization capacity may vary with the distance to their distribution range edge. Anemone nemorosa is known to be a slow colonizing forest herb dependent on forest cover in the southern and central part of its distribution range, whereas at its northern distribution range (and at higher elevations) it also occurs in open habitats. Here, we investigated the response of plant functional traits of Anemone nemorosa in cen- tral Norway (close to its northern distribution range edge) to a macroclimatic gra- dient (elevation), two microclimatic gradients (forest density and distance to forest edge) and a competition treatment (removal of neighbouring vegetation). We aimed to identify which environmental conditions (light, temperature, soil pH and/or soil organic matter) drive A. nemorosa's responses. In a total of 90 plots, we measured six functional traits of A. nemorosa (plant height, biomass, specific leaf area, seed number, seed mass,and germination percentage). We found stronger variation in environmental conditions along the macroclimatic elevational gradient, than along the microclimatic gradients of forest density and distance to forest edge, and this was also reflected in A. nemorosa's responses. Light availability, in interaction with temperature, was the key environmental variable driving plant performance, while soil conditions were less important. The competition release treatment had a negative effect on A. nemorosa in our study sites, indicating that the facilitative effect of the neighbouring vegetation may be stronger than the competitive effect. Our study suggests that A. nemorosa, close to its northern distribution range edge, has the capacity to cope with climate change through phenotypic responses, and that light and temperature are the key drivers of these responses.

Species-level CWM values mask contrasting intra- vs interspecific trait shifts at subtropical forest edges

Altered microclimatic conditions and higher disturbance at forest edges create environmental stress and modify resource gradients from edge to interior, changing the selection pressures acting on individuals. Although community-weighted trait-mean (CWM) shifts along edge gradients have been widely documented at the species level, it is unclear how edge effects act at the individual level, and whether the direction of intraspecific trait shifts mirrors that of CWM shifts in response to edge effects. On 20 islands in the Thousand Island Lake, China, we established 484 plots (2×2 m) in a stratified random design across distances of 0 – 128 m from the forest edge. Within each plot, we sampled leaves (n=34,768) from within and among all 2,993 individuals of 68 species and measured five leaf traits (leaf area, LA; specific leaf area, SLA; leaf dry matter content, LDMC; thickness, LT; chlorophyll content, LCC). Using generalized linear mixed models, we found that different leaf traits exhibited contrasting shifts in inter- vs. intraspecific trait variation in response to edge effects. For SLA, LT, and LCC, negative covariance between inter- and intraspecific trait shifts resulted in dampening of community-wide trends compared to CWM response to edge effects. In contrast, the community-wide trend for LDMC was reinforced due to positive covariance between inter- and intraspecific trait shifts, while for LA the direction of covariance shifted from negative to positive on small vs. large islands. Together, edge effects alter selection regimes in reassembling plant communities. Predicting the community-wide consequences depends on the degree to which there is negative vs. positive covariance between species sorting and within-species adaptation. The widely-used CWM approach can mask contrasting trait selection pressures acting on individuals within local populations. Individual-level trait variation can improve understanding of community re-assembly trajectories in response to global environmental change.

opencc-by-4.0Dec 2021View details →

Using social media and personality traits to assess software developers' emotions

Companion DATA of the paper "Using social media and personality traits to assess software developers’ emotions" submitted to the IEEE Access journal, 2022. The folders contain: /analysis     analyzed_tweets_by_psychologists.csv: file containing the manual analysis done by psychologists     analyzed_tweets_by_participants.csv: file containing the manual analysis done by participants     analyzed_tweets_by_psychologists_solved_divergencies.csv: file containing the manual analysis done by psychologists over 51 divergent tweets' classifications /dataset     alldata.json: contains the dataset used in the paper /notebooks     General - Charts.ipynb: notebook file containing all charts produced in the study, including those in the paper     Statistics - Lexicons and Ensembles.ipynb: notebook file with the statistics for the five lexicons and ensembles used in the study     Statistics - Linear Regression.ipynb: notebook file with the multiple linear regression results     Statistics - Polynomial Regression: notebook file with the polynomial regression results     Statistics - Psychologists versus Participants.ipynb: notebook file with the statistics between the psychologists and participants manual analysis     Statistics - Working x Non-working.ipynb: notebook file containing the statistical analysis for the tweets posted during work period and those posted outside of working period /surveys     Demographic_Survey.pdf: survey inviting participants to enroll in the study. We collect demographic data and participants' authorization to access their public Tweet posts     Demographic_Survey_answers.xlsx: participants' demographic survey answers     ibf_pt_br.doc: the Portuguese version of the Big Five Inventory (BFI) instrument to infer participants' Big Five polarity traits     ibf_answers.xlsx: participantes' and psychologists' answers for BFI ------------------------------------------------------------ We have removed from dataset any sensible data to protect participants' privacy and anonymity. We have removed from demographic survey answers any sensible data to protect participants' privacy and anonymity.

Environmental heterogeneity shapes physiological traits in tropical direct-developing frogs

1. Tropical ectotherm species tend to have narrower physiological limits than species from temperate areas. As a consequence, tropical species are considered highly vulnerable to climate change since minor temperature increases can push them beyond their physiological thermal tolerance. Differences in physiological tolerances can also be seen at finer evolutionary scales, such as among populations of ectotherm species along elevation gradients, highlighting the physiological sensitivity of such organisms. 2. Here we analyze the influence of elevation and bioclimatic domains, defined by temperature and precipitation, on thermal sensitivities of a terrestrial direct-developing frog (Craugastor loki) in a tropical gradient. We address the following questions: i) Does preferred temperature vary with elevation and among bioclimatic domains? ii) Do thermal tolerance limits, i.e. critical thermal maximum and critical thermal minimum vary with elevation and bioclimatic domains?, and iii) Are populations from high elevations more vulnerable to climate warming? 3. We found that along an elevation gradient body temperature decreases as environmental temperature increases. The preferred temperature tends to moderately increase with elevation within the sampled bioclimatic domains. Our results indicate that the ideal thermal landscape for this species is located at mid-elevations, where the thermal accuracy (db) and thermal quality of the environment (de) are suitable. The critical thermal maximum is variable across elevations and among the bioclimatic domains, decreasing as elevation increases. Conversely, the critical thermal minimum is not as variable as the critical thermal maximum. 4. Populations from the lowlands may be more vulnerable to future increases in temperature. We highlight that the critical thermal maximum is related to high temperatures exhibited across the elevation gradient and within in each bioclimatic domain, therefore, it is a response to high environmental temperatures.

A global analysis of aerial displays in passerines revealed an effect of habitat, mating system and migratory traits

Aerial displaying is a flamboyant part of the sexual behaviour of several volant animal groups, including birds. Nevertheless, little attention has been focused on identifying correlates of large-scale diversity in this trait. In this study, we scored the presence and absence of aerial displays in males of 1,732 species of passerine birds (Passeriformes) and employed Bayesian phylogenetically informed mixed models to test for associations between aerial displays and a set of life-history and environmental predictors. Our multivariate models revealed that species with males that perform aerial displays inhabited open rather than closed (forested) habitats. These species also exhibited higher levels of polygyny, had more elongated wings, migrated over longer distances and bred at higher latitudes. When we included species where the sexual function of displays has not been explicitly described but is likely to occur, we found that aerial displaying was also associated with smaller body size and increased male plumage colouration. Our results suggest that both sexual selection and natural selection have been important sources of selection on aerial displays in passerines.