The great tit HapMap project: a continental‐scale analysis of genomic variation in a songbird

A major aim of evolutionary biology is to understand why patterns of genomic diversity vary within taxa and space. Large-scale genomic studies of widespread species are useful for studying how environment and demography shape patterns of genomic divergence. Here, we describe one of the most geographically comprehensive surveys of genomic variation in a wild vertebrate to date; the great tit (Parus major) HapMap project. We screened ca 500,000 SNP markers across 647 individuals from 29 populations, spanning ~30 degrees of latitude and 40 degrees of longitude – almost the entire geographical range of the European subspecies. Genome-wide variation was consistent with a recent colonisation across Europe from a South-East European refugium, with bottlenecks and reduced genetic diversity in island populations. Differentiation across the genome was highly heterogeneous, with clear ‘islands of differentiation’, even among populations with very low levels of genome-wide differentiation. Low local recombination rates were a strong predictor of high local genomic differentiation (FST), especially in island and peripheral mainland populations, suggesting that the interplay between genetic drift and recombination causes highly heterogeneous differentiation landscapes. We also detected genomic outlier regions that were confined to one or more peripheral great tit populations, probably as a result of recent directional selection at the species' range edges. Haplotype-based measures of selection were related to recombination rate, albeit less strongly, and highlighted population-specific sweeps that likely resulted from positive selection. Our study highlights how comprehensive screens of genomic variation in wild organisms can provide unique insights into spatio-temporal evolutionary dynamics

The effect of climate change on avian offspring production: A global meta-analysis

Climate change affects timing of reproduction in many bird species, but few stud-ies have investigated its influence on annual reproductive output. Here, we assess changes in the annual production of young by female breeders in 201 populations of 104 bird species (N = 745,962 clutches) covering all continents between 1970 and 2019. Overall, average offspring production has declined in recent decades, but considerable differences were found among species and populations. A total of 56.7% of populations showed a declining trend in offspring production (significant in 17.4%), whereas 43.3% exhibited an increase (significant in 10.4%). The results show that climatic changes affect offspring production through compounded effects on ecological and life history traits of species. Migratory and larger-bodied species experienced reduced offspring production with increasing temperatures during the chick-rearing period, whereas smaller-bodied, sedentary species tended to produce more offspring. Likewise, multi-brooded species showed increased breeding success with increasing temperatures, whereas rising temperatures were unrelated to repro-ductive success in single-brooded species. Our study suggests that rapid declines in size of bird populations reported by many studies from different parts of the world are driven only to a small degree by changes in the production of young

Connecting the data landscape of long-term ecological studies : The SPI-Birds data hub

The integration and synthesis of the data in different areas of science is drastically slowed and hindered by a lack of standards and networking programmes. Long-term studies of individually marked animals are not an exception. These studies are especially important as instrumental for understanding evolutionary and ecological processes in the wild. Furthermore, their number and global distribution provides a unique opportunity to assess the generality of patterns and to address broad-scale global issues (e.g. climate change). To solve data integration issues and enable a new scale of ecological and evolutionary research based on long-term studies of birds, we have created the SPI-Birds Network and Database ()-a large-scale initiative that connects data from, and researchers working on, studies of wild populations of individually recognizable (usually ringed) birds. Within year and a half since the establishment, SPI-Birds has recruited over 120 members, and currently hosts data on almost 1.5 million individual birds collected in 80 populations over 2,000 cumulative years, and counting. SPI-Birds acts as a data hub and a catalogue of studied populations. It prevents data loss, secures easy data finding, use and integration and thus facilitates collaboration and synthesis. We provide community-derived data and meta-data standards and improve data integrity guided by the principles of Findable, Accessible, Interoperable and Reusable (FAIR), and aligned with the existing metadata languages (e.g. ecological meta-data language). The encouraging community involvement stems from SPI-Bird's decentralized approach: research groups retain full control over data use and their way of data management, while SPI-Birds creates tailored pipelines to convert each unique data format into a standard format. We outline the lessons learned, so that other communities (e.g. those working on other taxa) can adapt our successful model. Creating community-specific hubs (such as ours, COMADRE for animal demography, etc.) will aid much-needed large-scale ecological data integration.Peer reviewe

Parus major Genome sequencing and assembly

Seasonal timing is a key life-history trait with major fitness consequences. The small songbird Parus major (great tit) for decades has been a model to study fitness traits like e.g. avian timing of reproduction. The research is closely linked to the impact of global climate change on timing and its consequences. Linking quantitative genetic variation in life-history traits with polymorphisms in specific genes is essential for better understanding the causes and consequences of the diversity in these traits. Genetic variation in life-history traits in wild songbirds has been demonstrated in many, often long-term, studies throughout the world. Linking this variation to genomic information requires the development of the necessary genomics tools specifically aimed at these non-model species. The assembly and annotation of the genome of the great tit will greatly enhance the further use of the great tit as a model species in this research field

Parus major Genome sequencing and assembly

Seasonal timing is a key life-history trait with major fitness consequences. The small songbird Parus major (great tit) for decades has been a model to study fitness traits like e.g. avian timing of reproduction. The research is closely linked to the impact of global climate change on timing and its consequences. Linking quantitative genetic variation in life-history traits with polymorphisms in specific genes is essential for better understanding the causes and consequences of the diversity in these traits. Genetic variation in life-history traits in wild songbirds has been demonstrated in many, often long-term, studies throughout the world. Linking this variation to genomic information requires the development of the necessary genomics tools specifically aimed at these non-model species. The assembly and annotation of the genome of the great tit will greatly enhance the further use of the great tit as a model species in this research field

Parus major Genome sequencing and assembly

Seasonal timing is a key life-history trait with major fitness consequences. The small songbird Parus major (great tit) for decades has been a model to study fitness traits like e.g. avian timing of reproduction. The research is closely linked to the impact of global climate change on timing and its consequences. Linking quantitative genetic variation in life-history traits with polymorphisms in specific genes is essential for better understanding the causes and consequences of the diversity in these traits. Genetic variation in life-history traits in wild songbirds has been demonstrated in many, often long-term, studies throughout the world. Linking this variation to genomic information requires the development of the necessary genomics tools specifically aimed at these non-model species. The assembly and annotation of the genome of the great tit will greatly enhance the further use of the great tit as a model species in this research field

The effect of climate change on avian offspring production:a global meta-analysis

Abstract Climate change affects timing of reproduction in many bird species, but few stud-ies have investigated its influence on annual reproductive output. Here, we assess changes in the annual production of young by female breeders in 201 populations of 104 bird species (N = 745,962 clutches) covering all continents between 1970 and 2019. Overall, average offspring production has declined in recent decades, but considerable differences were found among species and populations. A total of 56.7% of populations showed a declining trend in offspring production (significant in 17.4%), whereas 43.3% exhibited an increase (significant in 10.4%). The results show that climatic changes affect offspring production through compounded effects on ecological and life history traits of species. Migratory and larger-bodied species experienced reduced offspring production with increasing temperatures during the chick-rearing period, whereas smaller-bodied, sedentary species tended to produce more offspring. Likewise, multi-brooded species showed increased breeding success with increasing temperatures, whereas rising temperatures were unrelated to repro-ductive success in single-brooded species. Our study suggests that rapid declines in size of bird populations reported by many studies from different parts of the world are driven only to a small degree by changes in the production of young