Title Participants Abstract "Divergence in evolutionary potential of life history traits among wild populations is predicted by differences in climatic conditions" "Stephane Chantepie, Anne Charmantier, Boris Delahaie, Frank Adriaensen, Erik Matthysen, Marcel E. Visser, Elena Alvarez, Emilio Barba, Markku Orell, Ben Sheldon, Elena Ivankina, Anvar Kerimov, Sebastien Lavergne, Celine Teplitsky" "Short-term adaptive evolution represents one of the primary mechanisms allowing species to persist in the face of global change. Predicting the adaptive response at the species level requires reliable estimates of the evolutionary potential of traits involved in adaptive responses, as well as understanding how evolutionary potential varies across a species' range. Theory suggests that spatial variation in the fitness landscape due to environmental variation will directly impact the evolutionary potential of traits. However, empirical evidence on the link between environmental variation and evolutionary potential across a species range in the wild is lacking. In this study, we estimate multivariate evolutionary potential (via the genetic variance-covariance matrix, or G-matrix) for six morphological and life history traits in 10 wild populations of great tits (Parus major) distributed across Europe. The G-matrix significantly varies in size, shape, and orientation across populations for both types of traits. For life history traits, the differences in G-matrix are larger when populations are more distant in their climatic niche. This suggests that local climates contribute to shaping the evolutionary potential of phenotypic traits that are strongly related to fitness. However, we found no difference in the overall evolutionary potential (i.e., G-matrix size) between populations closer to the core or the edge of the distribution area. This large-scale comparison of G-matrices across wild populations emphasizes that integrating variation in multivariate evolutionary potential is important to understand and predict species' adaptive responses to new selective pressures. Adaptive evolution of phenotypes is a key mechanism for species persistence in the face of global change, and predicting these responses is a major challenge to implementing biodiversity scenarios. The quality of these predictions relies notably on our estimates of evolutionary potential, and several questions need to be answered: How different is evolutionary potential across a species distribution? Will it change under new environmental conditions? Can we use information on evolutionary potential from one population to infer adaptive responses in another population? Here we address these questions in the great tit (Parus major) by evaluating how evolutionary potential is influenced by climatic conditions across the species' range. Our study is based on the long-term monitoring of 10 wild populations of great tits distributed across Europe for which information about life history and morphological traits have been collected. We find significant differences in evolutionary potential between populations for both categories of traits, and for life history traits, these differences are linked to population differences in climatic conditions. These results show that evolutionary potential is not a ""one-size-fits-all"" measure and that its variation needs to be taken into account when predicting adaptive responses to climate change." "Network structure of avian mixed-species flocks decays with elevation and latitude across the Andes" "Flavia A. Montano-Centellas, Jenny Munoz, Gabriela Giselle Mangini, Ian J. Ausprey, Felicity L. Newell, Harrison H. Jones, M. Elisa Fanjul, Boris A. Tinoco, Gabriel J. Colorado, Jennifer R.A. Cahill, E. Arbelaez-Cortes, Oscar H. Marin-Gomez, Pedro X. Astudillo, Esteban A. Guevara, Silvina Ippi, Molly E. McDermott, Amanda D. Rodewald, Erik Matthysen, Scott K. Robinson" "Birds in mixed-species flocks benefit from greater foraging efficiency and reduced predation, but also face costs related to competition and activity matching. Because this cost-benefit trade-off is context-dependent (e.g. abiotic conditions and habitat quality), the structure of flocks is expected to vary along elevational, latitudinal and disturbance gradients. Specifically, we predicted that the connectivity and cohesion of flocking networks would (i) decline towards tropical latitudes and lower elevations, where competition and activity matching costs are higher, and (ii) increase with lower forest cover and greater human disturbance. We analysed the structure of 84 flock networks across the Andes and assessed the effect of elevation, latitude, forest cover and human disturbance on network characteristics. We found that Andean flocks are overall open-membership systems (unstructured), though the extent of network structure varied across gradients. Elevation was the main predictor of structure, with more connected and less modular flocks upslope. As expected, flocks in areas with higher forest cover were less cohesive, with better defined flock subtypes. Flocks also varied across latitude and disturbance gradients as predicted, but effect sizes were small. Our findings indicate that the unstructured nature of Andean flocks might arise as a strategy to cope with harsh environmental conditions. This article is part of the theme issue 'Mixed-species groups and aggregations: shaping ecological and behavioural patterns and processes'." "Contrasting effects of cooperative group size and number of helpers on maternal investment in eggs and nestlings" "Dries Van de Loock, Laurence Cousseau, Beate Apfelbeck, Mwangi Githiru, Luc Lens, Erik Matthysen" "Females are predicted to adjust their reproductive investment to optimize the trade-off between current and future reproduction. In many cooperatively breeding birds, females have been shown to reduce their investment both pre- and posthatching in response to the presence of food-provisioning helpers. However, in species where not all group members help during the posthatching stage, it is currently unclear to which social cues (i.e. group size versus number of helpers) females should tune their investment. Here, we used the cooperatively breeding placid greenbul, Phyllastrephus placidus, as a model species to examine whether and how group size and number of helpers affect female investment in eggs and food provisioning. We found that females used a contrasting strategy pre- and posthatching in response to different social cues: they laid larger eggs in larger groups while reducing their feeding rate when assisted by more helpers. We also found that fledging success increased with group size and that nestlings raised in groups with helpers fledged with longer wings but found no relation between condition of the young and number of helpers. Since the perceived contrasting investment strategies may have several underlying causes, we conclude that predicting the influence of social conditions on maternal investment may be more challenging than previously believed. (c) 2023 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved." "Predictors of individual performance and evolutionary potential of life-history traits in a hematophagous ectoparasite" "Gerardo Fracasso, Dieter Heylen, Stefan Van Dongen, Joris Elst, Erik Matthysen" "Little is known about the intraspecific variation of parasite life-history traits and on how this variation may affect parasite fitness and evolution. We investigated how life-history traits predict success of individual tree-hole ticks Ixodes arboricola and estimated their evolutionary potential, as well as genetic correlations within stages and phenotypic correlations within and across stages. Ticks were followed individually over two generations while allowed to feed on great tits Parus major. After accounting for host and tick maternal effects, we found that short feeding times and high engorgement weights strongly increased moulting success. Moulting time was also positively correlated with feeding success in adults. In larvae and nymphs we found negative phenotypic correlations between engorgement weight and both feeding and moulting time, the latter supported by a negative genetic correlation. We found sex-related differences in feeding time (longer in male nymphs) and moulting time (longer in male larvae but shorter in male nymphs). Also, time since the last feeding event (set experimentally) reduced larval and nymphal fitness while it increased adult female fitness. Furthermore, we found significant heritability and evolvability, i.e. the potential to respond to selection, for engorgement weight and moulting time across all stages but no significant heritability for feeding time. Our findings suggest that variation in tick fitness is shaped by consistent individual differences in tick quality, for which engorgement weight is a good proxy, rather than by life-history trade-offs. This article is protected by copyright. All rights reserved." "White LED light intensity, but not colour temperature, interferes with mate‐finding by glow‐worm (Lampyris noctiluca L.) males" "Mira Van den Broeck, Raphael De Cock, Stefan Van Dongen, Erik Matthysen" "Artificial light at night is an increasing threat to nocturnal biodiversity. Aside from the overall increase in light emission, replacement of old monochromatic streetlighting by broad emission spectrum LED lights may be an additional threat. Studies evaluating the impacts of these artificial lights on the nocturnal European common glow-worm (Lampyris noctiluca L.) are scarce. This study examines the effects of upward facing white LED lights on the mate seeking activity of male glow-worms. Therefore we used traps with dummy females along a distance gradient from LED lights with different intensities and colour temperature (cold and warm white) and counted the number of males attracted per trap. We found that upward facing white LED light negatively impacted the males’ ability to locate the females, at previously unreported low light levels, while colour temperature did not affect the outcomes. More research on the effects of light pollution and their underlying mechanisms is needed to evaluate the impacts of this emerging and widespread threat on mating success and population persistence of glow-worms." "Heterogeneous selection on exploration behavior within and among West European populations of a bird" "Alexia Mouchet, Ella F. Cole, Erik Matthysen, Marion Nicolaus, John L. Quinn, Allison M. Roth, Joost M. Tinbergen, Kees van Oers, Thijs van Overveld, Niels J. Dingemanse" "Heterogeneous selection is often proposed as a key mechanism maintaining repeatable behavioral variation (""animal personality"") in wild populations. Previous studies largely focused on temporal variation in selection within single populations. The relative importance of spatial versus temporal variation remains unexplored, despite these processes having distinct effects on local adaptation. Using data from >3,500 great tits (Parus major) and 35 nest box plots situated within five West-European populations monitored over 4 to 18 y, we show that selection on exploration behavior varies primarily spatially, across populations, and study plots within populations. Exploration was, simultaneously, selectively neutral in the average population and year. These findings imply that spatial variation in selection may represent a primary mechanism maintaining animal personalities, likely promoting the evolution of local adaptation, phenotype-dependent dispersal, and nonrandom settlement. Selection also varied within populations among years, which may counteract local adaptation. Our study underlines the importance of combining multiple spatiotemporal scales in the study of behavioral adaptation." "Integrated spatial planning for biodiversity conservation and food production" "Constance Fastré, Willem-Jan van Zeist, J.E.M. Watson, Piero Visconti" "Ambitious area-based conservation targets are at the forefront of the post-2020 biodiversity conservation agenda. However, implementing such targets cannot be done without accounting for the increasing demand for farmland products, the main driver of biodiversity loss worldwide. Here, we analyze the expected conservation gains and farming opportunity costs of three alternative global conservation strategies under business-as-usual demand in farmland products by 2030. We find that integrated spatial planning can reach the same species conservation objectives at 25%-40% of the opportunity cost for food production, or 400%-600% the biodiversity benefit for similar opportunity costs as opposed to planning for each objective separately. This requires managing over 60% of land in ways that are compatible with biodiversity conservation, which includes restoring 8%-11% of land surface. Achieving global conservation targets can be compatible with protecting biodiversity and ensuring food security but only with efforts to negotiate land governance strategies across multiple stakeholders and their objectives." "Lower density of arthropod biomass in small high‐Andes Polylepis fragments affects habitat use in insectivorous birds" "Jennifer R.A. Cahill, Thomas Merckx, Hans Van Dyck, Milton Fernández, Erik Matthysen" "Polylepis forests are endemic to the high‐Andes, with trees characterized by multi‐layered, exfoliating bark‐providing protection against harsh, high‐elevation conditions, both for individual trees and the wide array of organisms dependent on them. However, Polylepis habitat has suffered severe human‐induced land conversion and currently mainly occurs as fragmented remnants only. Here, we studied the effects of fragment size on local ambient temperature and on biomass of bark and its bark‐dwelling arthropods. We did so by comparing multiple samples at the edge and interior of both large and small fragments, while also accounting for branch size, tree width, and tree structure. Because arthropod biomass is likely to impact higher trophic levels, we also studied abundance and foraging behavior of two bird species specialized on Polylepis forest. We show that arthropod biomass was relatively higher in wider, larger trees, which were preferred for foraging by both bird species. Moreover, we show that small forest fragments are not only environmentally less buffered but are also characterized by lower amounts of bark and lower densities of bark‐dwelling arthropods than larger fragments. Our study highlights the conservation value of large trees. Also, we advise it is now timely to test to what degree restoration efforts to increase fragment size could mitigate the negative effects of reduced arthropod biomass for higher trophic levels of endemic specialist insectivores." "Identifying trade-offs between biodiversity conservation and ecosystem services delivery for land-use decisions" "Constance Fastré, Hugh P. Possingham" "Sustainable land-use management must account for the potential trade-offs between biodiversity conservation, productive land uses and ecosystem services. In this study, we used Marxan with Zones to generate land use plans that optimize conservation, farming and forestry land uses to reach biodiversity targets while minimizing the opportunity cost for local communities in an inhabited but data-poor National Park in the Andes of Bolivia. Based on six alternative land-use plans, we identified the synergies and trade-offs between the biodiversity benefits achieved in the different plans and the delivery of four locally important water-related ecosystem services modeled with the web-based tool AguAAndes. Although we find synergies between the conservation of high altitude Polylepis woodlands and their associated avifauna and three of the ecosystem services investigated, soil erosion levels were actually higher in scenarios with higher achieved biodiversity benefits. Our study shows how systematic conservation planning and ecosystem service delivery modelling can be used to solve land-use conflicts and identify trade-offs between biodiversity conservation and ecosystem services in a data-poor tropical area." "Bird species richness in High-Andean forest fragments" "Constance Fastré, Jose A. Balderrama, Jennifer R. A. Cahill, Hannes Ledegen, Mauricio Torrico Orellana" "Montane forests worldwide are known centers of endemism and biodiversity but are highly threatened by fragmentation processes. Using data collected in 15 Polylepis forest remnants covering 2000 hectares, we investigated how bird species richness and bird community composition, particularly for species of conservation concern, are influenced by habitat quality and topography in the Tunari National Park in the High Andes of Bolivia. Bird species richness was highest in topographically complex, low-elevation Polylepis patches located in areas with a high potential to retain rainwater. Bird communities differed strongly between Polylepis lanata and P. subtusalbida remnants, each supporting different threatened and endemic species. Within the P. subtusalbida forest, high-elevation fragments characterized by high amounts of sunlight and low anthropogenic disturbance were more likely to contain threatened species. Surprisingly, we found no effect of fragment size on the diversity or composition of bird communities or the presence of bird species of conservation concern. The presence of exotic plantations (Pinus and/or Eucalyptus spp.) in or outside forest remnants was negatively associated with the number of bird species as well as with occurrence of the endangered Cochabamba-mountain finch (Compsospiza garleppi). To support the different communities found in Polylepis forests, these results suggest that conservation efforts should be directed towards both forest types (P. subtusalbida and P. lanata) present in the area. For an efficient management of avian diversity, exotic plantations should be established away from native remnants while existing patches should be managed to maintain or increase habitat quality. Finally, the importance of local topography in determining avian species richness and community composition in forest fragments, mainly through topographic controls on moisture distribution and the amount of sunlight received by the fragments, should be considered when planning conservation and reforestation schemes."