Raphaël Proulx

Sensory ecology seeks to understand how organisms detect and use information from their environment, yet comparative analyses across multiple sensory modalities remain rare. Here, we present a roadmap for contrasting the sensory ecologies of birds and rodents using surrogate morphological and acoustic traits associated with vision, audition, and olfaction. We focused on 277 breeding bird species from Québec, Canada, and 117 rodent species from two major families, combining published datasets with measurements taken from preserved museum specimens. We first evaluated the validity of surrogate traits by comparing them with standard measures of sensory performance. We then quantified body‐mass allometries for each trait and projected species into a sensory plane to identify poles of relative specialization and patterns of trait covariation. Most visual and auditory traits displayed negative allometry with body mass, indicating disproportionate investment in these systems among smaller‐bodied species, whereas olfactory traits were closer to isometry. Vision specialists are typically found among diurnal open‐habitat species or nocturnal closed‐habitat species. In birds, olfaction specialists are represented by species with an aquatic lifestyle and nests exposed to predation, whereas in rodents they are species active at night in structurally complex habitats. Hearing appears to be coupled with vocalization in birds, but with vision in mammals, suggesting a possible sensory‐axis contrast between target identification and broader environmental surveillance. Together, these results show that comparative sensory ecology can be structured around measurable surrogate traits, body‐size scaling, and multidimensional trait spaces, providing a general framework for investigating patterns of ecological clustering.

Sensory ecology theory proposes that modalities like vision, audition and olfaction determine habitat selection and behavioural adaptation by organisms. This study explores how physical modifications in the environment influence the probability of detecting mating songs of stridulating orthopterans (suborder Ensifera) in nature. By experimentally introducing floors and walls into vegetated fields, we demonstrated that such structural changes can either enhance or hinder sound propagation and song detection, depending on species‐specific acoustic traits. Song detection probability increased for Nemobiinae species, likely due to improved sound reflection or behavioural attraction to the structures. Conversely, detection of Conocephalinae species decreased in the presence of these structures, suggesting adverse effects on habitat quality and signal transmission. Phaneropterinae species showed no clear response, likely owing to their long‐range song propagation from elevated positions. Song detection was also influenced by air temperature, time of day, vegetation density and microphone position, with warmer temperatures and elevated microphone positions generally enhancing detection. Structural changes to vegetated fields altered not only sound propagation but also potentially species incidence and behaviour. These findings highlight the interplay between the modification of physical structures and species traits. Our results underscore the need for habitat‐specific conservation strategies, particularly in settings where both acoustic and physical environments are continually transformed, such as in urbanised areas.

Les données sur l’occupation du territoire par la faune étant difficiles et coûteuses à obtenir, les études de priorisation des corridors de connectivité modélisent généralement les obstacles au déplacement et la qualité des habitats pour quelques espèces sentinelles, sur la base de cartes et d’opinions d’experts. L’objectif de la présente étude était de caractériser les obstacles au libre déplacement des organismes et l’occupation faunique dans le corridor modélisé du sud-ouest de la Mauricie (Québec, Canada) à l’aide d’inventaires terrain, d’analyses géomatiques et de données publiques sur les oiseaux et les mammifères. Les résultats montrent que les obstacles au déplacement sont associés à des pressions anthropiques dans la portion sud (p. ex., densité des routes, surfaces minéralisées), alors qu’ils sont de nature géomorphologique dans la portion nord du corridor (p. ex., densité des rivières, pentes fortes). L’utilisation du corridor par la faune terrestre (salamandres, oiseaux, grands mammifères) révèle des points chauds de déplacement faunique et de biodiversité au sud, parfois même à l’extérieur ou aux marges du tracé modélisé. À la lumière de nos analyses, le tracé du corridor sud-ouest de la Mauricie est modifié pour y inclure des noyaux de conservation.

Although variation in effect sizes and predicted values among studies of similar phenomena is inevitable, such variation far exceeds what might be produced by sampling error alone. One possible explanation for variation among results is differences among researchers in the decisions they make regarding statistical analyses. A growing array of studies has explored this analytical variability in different fields and has found substantial variability among results despite analysts having the same data and research question. Many of these studies have been in the social sciences, but one small “many analyst” study found similar variability in ecology. We expanded the scope of this prior work by implementing a large-scale empirical exploration of the variation in effect sizes and model predictions generated by the analytical decisions of different researchers in ecology and evolutionary biology. We used two unpublished datasets, one from evolutionary ecology (blue tit, Cyanistes caeruleus, to compare sibling number and nestling growth) and one from conservation ecology (Eucalyptus, to compare grass cover and tree seedling recruitment). The project leaders recruited 174 analyst teams, comprising 246 analysts, to investigate the answers to prespecified research questions. Analyses conducted by these teams yielded 141 usable effects (compatible with our meta-analyses and with all necessary information provided) for the blue tit dataset, and 85 usable effects for the Eucalyptus dataset. We found substantial heterogeneity among results for both datasets, although the patterns of variation differed between them. For the blue tit analyses, the average effect was convincingly negative, with less growth for nestlings living with more siblings, but there was near continuous variation in effect size from large negative effects to effects near zero, and even effects crossing the traditional threshold of statistical significance in the opposite direction. In contrast, the average relationship between grass cover and Eucalyptus seedling number was only slightly negative and not convincingly different from zero, and most effects ranged from weakly negative to weakly positive, with about a third of effects crossing the traditional threshold of significance in one direction or the other. However, there were also several striking outliers in the Eucalyptus dataset, with effects far from zero. For both datasets, we found substantial variation in the variable selection and random effects structures among analyses, as well as in the ratings of the analytical methods by peer reviewers, but we found no strong relationship between any of these and deviation from the meta-analytic mean. In other words, analyses with results that were far from the mean were no more or less likely to have dissimilar variable sets, use random effects in their models, or receive poor peer reviews than those analyses that found results that were close to the mean. The existence of substantial variability among analysis outcomes raises important questions about how ecologists and evolutionary biologists should interpret published results, and how they should conduct analyses in the future.

Selection within natural communities has mainly been studied along large abiotic gradients, while the selection of individuals within populations should occur locally in response to biotic filters. To better leverage the role of the latter, we considered the hierarchal nature of environmental selection for the multiple dimensions of the trait space across biological levels, that is, from the species to the community and the ecosystem levels. We replicated a natural species richness gradient where communities included from two to 16 species within four wetlands (bog, fen, meadow, and marsh) contrasting in plant productivity. We sampled functional traits from individuals in each community and used hierarchical distributional modeling in order to analyze the independent variation of the mean and dispersion of functional trait space at ecosystem, community, and species levels. The plant productivity gradient observed between wetlands led to species turnover and selection of traits related to leaf nutrient conservation/acquisition strategy. Within wetlands, plant species richness drove trait variation across both communities and species. Among communities, variation of species richness correlated with the selection of individuals according to their use of vertical space and leaf adaptations to light conditions. Within species, intraspecific light‐related trait variation in response to species richness was associated with stable population density for some species, while others reached low population density in more diverse communities. Within ecosystems, variation in biotic conditions selects individuals along functional dimensions that are independent of those selected across ecosystems. Within‐species variations of light‐related traits are related to demographic responses, linking biotic selection of individuals within communities to eco‐evolutionary dynamics of species.

Questions: Plant greening phenology is a key response trait that drives numerous ecosystem functions such as carbon storage and flowering. Plant communities with a diversity of phenology responses could show a longer greening season due to more complete occupation of the temporal window available for growth. However, it is unclear how species composition and richness affect the phenology of local plant communities.Location: This study was conducted in wetland landscapes of the St. Lawrence River in the province of Québec, Canada (46.07°N; 73.17°W).Methods: We used close‐range digital imagery to monitor the greening phenology and species richness of 20 herbaceous plant communities from 2013 to 2016. We quantified the number of greening phenology patterns observed each year within each plant community using singular value decomposition of close‐range image time series.Results: The number of plant species within plant communities was independent of the number of phenology patterns, or the length of the greening season. However, the number of phenology patterns correlated positively to the greening season length in all four years of monitoring.Conclusions: The relationship between the number of phenology patterns and the greening season length suggests a complementary use of the temporal window available for growth within plant communities. Species richness was a poor indicator of the diversity of phenology responses in wet meadow communities. The absence of a positive relationship between the number of plant species and the diversity of greening phenology patterns, or the length of the greening season, suggests that other descriptors of plant communities are of importance. Species richness is more often than not a weak predictor of the functioning of local plant communities in the wild.