Papers by Wojciech Solarz

Future dynamics of biological invasions are highly uncertain because they depend on multiple envi... more Future dynamics of biological invasions are highly uncertain because they depend on multiple environmental, societal and socio-economic drivers. We adopted a qualitative scenario approach to explore the future of invasive alien species (IAS) in Europe and created an overall strategy for their management that considers different plausible future developments. The scenarios and strategy were developed during two online workshops with a multidisciplinary team of experts. First, we downscaled four global scenarios of biological invasions to the European level. Second, we developed a management strategy structured into 19 goals that cover a broad array of IAS-related topics (i.e. policy, research, public awareness and biosecurity), and provided solutions for achieving these goals considering the European scenarios. Third, we identified four interrelated recommendations around which any long-term strategy for managing IAS in Europe can be structured: (i) a European biosecurity regime, (ii...
Alien birds, amphibians and reptiles of Europe (Chapter 8
File contains all data necessary to perform analysis presented in the publilcation

We report the results from a nine-year study on parasite infection in males of a small migrant pa... more We report the results from a nine-year study on parasite infection in males of a small migrant passerine, the sedge warbler Acrocephalus schoenobaenus. Every year, for each male caught during territory establishment we estimated infection intensity of two lineages of Haemoproteus belopolskyi (SW1 and SW3), using molecular methods. We found a significant relationship between infection intensity and males’ longevity in both studied lineages. There was severe mortality of second-year sedge warblers after their first breeding season, with lower parasite load in survivors. The lower infection intensity in older age classes was related to between-individual change in both lineages, but was also a result of differences in infection intensity during the lifetime of individual males in the SW3. The relation between parasite load and longevity suggests that parasite load may be an age-dependent factor influencing individual survival
This file contains data on prevalence and infection intensity of Haemoproteus strains detected in... more This file contains data on prevalence and infection intensity of Haemoproteus strains detected in sedge warbler. For every individual the number of alleles in each supertype is given. The age and sex for every individual is also given

Pathogens are one of the main forces driving the evolution and maintenance of the highly polymorp... more Pathogens are one of the main forces driving the evolution and maintenance of the highly polymorphic genes of the vertebrate major histocompatibility complex (MHC). Although MHC proteins are crucial in pathogen recognition, it is still poorly understood how pathogen-mediated selection promotes and maintains MHC diversity, and especially so in host species with highly duplicated MHC genes. Sedge warblers (Acrocephalus schoenobaenus) have highly duplicated MHC genes and using data from high-throughput MHC genotyping we were able to investigate to what extent avian malaria parasites explain temporal MHC class I supertype fluctuations in a long-term study population. We investigated infection status and infection intensities of two different strains of Haemoproteus, i.e. avian malaria parasites that are known to have significant fitness consequences in sedge warblers. We found that prevalence of avian malaria in carriers of specific MHC class I supertypes was a significant predictor of their frequency changes between years. This finding suggests that avian malaria infections partly drive the temporal fluctuations of the MHC class I supertypes. Furthermore, we found that individuals with a large number of different supertypes had higher resistance to avian malaria, but there was no evidence for an optimal MHC class I diversity. Thus, the two studied malaria parasite strains appear to select for a high MHC class I supertype diversity. Such selection may explain the maintenance of the extremely high number of MHC class I gene copies in sedge warblers, and possibly also in other passerines where avian malaria is a common disease

Background: Recent work suggests that gene duplications may play an important role in the evoluti... more Background: Recent work suggests that gene duplications may play an important role in the evolution of immunity genes. Passerine birds, and in particular Sylvioidea warblers, have highly duplicated major histocompatibility complex (MHC) genes, which are key in immunity, compared to other vertebrates. However, reasons for this high MHC gene copy number are yet unclear. High-throughput sequencing (HTS) allows MHC genotyping even in individuals with extremely duplicated genes. This HTS data can reveal evidence of selection, which may help to unravel the putative functions of different gene copies, i.e. neofunctionalization. We performed exhaustive genotyping of MHC class I in a Sylvioidea warbler, the sedge warbler, Acrocephalus schoenobaenus, using the Illumina MiSeq technique on individuals from a wild study population. Results: The MHC diversity in 863 genotyped individuals by far exceeds that of any other bird species described to date. A single individual could carry up to 65 different alleles, a large proportion of which are expressed (transcribed). The MHC alleles were of three different lengths differing in evidence of selection, diversity and divergence within our study population. Alleles without any deletions and alleles containing a 6 bp deletion showed characteristics of classical MHC genes, with evidence of multiple sites subject to positive selection and high sequence divergence. In contrast, alleles containing a 3 bp deletion had no sites subject to positive selection and had low divergence. Conclusions: Our results suggest that sedge warbler MHC alleles that either have no deletion, or contain a 6 bp deletion, encode classical antigen presenting MHC molecules. In contrast, MHC alleles containing a 3 bp deletion may encode molecules with a different function. This study demonstrates that highly duplicated MHC genes can be characterised with HTS and that selection patterns can be useful for revealing neofunctionalization. Importantly, our results highlight the need to consider the putative function of different MHC genes in future studies of MHC in relation to disease resistance and fitness

The DAISIE - inventory of alien invasive species in Europe is a species checklist dataset publish... more The DAISIE - inventory of alien invasive species in Europe is a species checklist dataset published by the Research Institute for Nature and Forest (INBO) and the Centre for Ecology and Hydrology (CEH). It contains information on 12,104 taxa (mostly species and mostly introduced) occurring in the wild in Europe since 1500. It covers a broad taxonomic spectrum of terrestrial and aquatic free living and parasitic organisms. The collation of the alien species list is the result of the efforts of the DAISIE (http://www.europe-aliens.org/) project partners and more than 300 collaborators from Europe and neighbouring countries, involved in different fields of expertise and organisations. Here the DAISIE checklist is published as a standardized Darwin Core Archive and includes for each species: the scientific name, higher classification, and stable taxon identifier (in the taxon core), the vernacular names (in the vernacular names extension), the presence in a specific region, the year of ...
The distributions of the number of positively selected sites detected using the MEME test perform... more The distributions of the number of positively selected sites detected using the MEME test performed on subsets of 100 alleles randomly subsampled from alleles with no deletions (a) and alleles containing a 6 bp deletion (b). (DOCX 273 kb)
Schematic overview of the primer design approach. PaDo primers, marked with red arrows, used for ... more Schematic overview of the primer design approach. PaDo primers, marked with red arrows, used for amplification and cloning of cDNA from 4 sedge warblers Acrocephalus schoenobaenus individuals. Hn primers (Westerdahl et al. 2004), designed for great reed warblers A. arundinaceus, used for obtaining whole exon 3 sequences in 4 individuals for both gDNA and cDNA. Subsequently sequences obtained for cDNA were used for designing specific sedge warbler primers (HnallaN and Hn46N) that amplify whole range of exon 3 MHC class I in sedge warblers, excluding a range of pseudogenes. (PDF 1364 kb)

Environmental & Socio-economic Studies, 2021
The participation of species of alien origin in the flora of individual regions of the world is i... more The participation of species of alien origin in the flora of individual regions of the world is increasing. A large proportion of these species pose a threat to biodiversity. Issues of the dynamics of changes in the flora and the scale and pace of the processes, with particular emphasis on the biology, ecology, chorology, and genetic variability of the populations of plants of alien origin, including those alien species which are invasive, have been the subject of many years of research in this field in Poland. The present study is an overview of the state of research on invasive plant species in Poland, including the main results of the basic and applied research which have provided the basis for (i) the preparation of a list of invasive plant species for Poland; (ii) assessing the degree of invasiveness of the species analysed, in accordance with the adoption of criteria and the development of methodological solutions. In this work, a new version of the list of invasive plant spec...
Tim is currently Professor of Invasion Biology in the Centre for Biodiversity & Environment Resea... more Tim is currently Professor of Invasion Biology in the Centre for Biodiversity & Environment Research at UCL. He has more than 25 years experience of research into questions concerning the distribution, abundance and diversity of animal species. For the last 15 years, his research has primarily addressed questions relating to humanmediated biological invasions, using birds as a model taxon (see e.g. Blackburn et al. 2009, Avian Invasions. The ecology and evolution of exotic birds. OUP). He has recently developed a method to evaluate, compare and predict the impacts of different alien species, that can be applied to impacts that occur at different levels of ecological complexity, at different spatial and temporal scales, and assessed using a range of metrics and techniques. In this project, he contributed to the work on vertebrate species.
Frontiers in Ecology and Evolution, 2020
Invasive alien species (IAS) are known to be a major threat to biodiversity and ecosystem functio... more Invasive alien species (IAS) are known to be a major threat to biodiversity and ecosystem function and there is increasing evidence of their impacts on human health and economies globally. We undertook horizon scanning using expert-elicitation to predict arrivals of IAS that could have adverse human health or economic impacts on the island of Cyprus. Three hundred and twenty five IAS comprising 89 plants, 37 freshwater animals, 61 terrestrial invertebrates, 93 terrestrial vertebrates, and 45 marine species, were assessed during a two-day workshop involving 39 participants to derive two ranked lists: (1) IAS with potential human health impacts (20 species ranked within
Journal of Applied Ecology, 2017
1. Biological invasions are a threat to biodiversity, society and the economy. There is an urgent... more 1. Biological invasions are a threat to biodiversity, society and the economy. There is an urgent need to provide evidence-based assessments of the risks posed by invasive alien species (IAS) to prioritize action. Risk assessments underpin IAS policies in many ways: informing legislation; providing justification of restrictions in trade or consumer activities; prioritizing surveillance and rapid response. There are benefits to ensuring consistency in content of IAS risk assessments globally, and this can be achieved by providing a framework of minimum standards as a checklist for quality assurance.

BMC Evolutionary Biology, 2017
Background: Recent work suggests that gene duplications may play an important role in the evoluti... more Background: Recent work suggests that gene duplications may play an important role in the evolution of immunity genes. Passerine birds, and in particular Sylvioidea warblers, have highly duplicated major histocompatibility complex (MHC) genes, which are key in immunity, compared to other vertebrates. However, reasons for this high MHC gene copy number are yet unclear. High-throughput sequencing (HTS) allows MHC genotyping even in individuals with extremely duplicated genes. This HTS data can reveal evidence of selection, which may help to unravel the putative functions of different gene copies, i.e. neofunctionalization. We performed exhaustive genotyping of MHC class I in a Sylvioidea warbler, the sedge warbler, Acrocephalus schoenobaenus, using the Illumina MiSeq technique on individuals from a wild study population. Results: The MHC diversity in 863 genotyped individuals by far exceeds that of any other bird species described to date. A single individual could carry up to 65 different alleles, a large proportion of which are expressed (transcribed). The MHC alleles were of three different lengths differing in evidence of selection, diversity and divergence within our study population. Alleles without any deletions and alleles containing a 6 bp deletion showed characteristics of classical MHC genes, with evidence of multiple sites subject to positive selection and high sequence divergence. In contrast, alleles containing a 3 bp deletion had no sites subject to positive selection and had low divergence. Conclusions: Our results suggest that sedge warbler MHC alleles that either have no deletion, or contain a 6 bp deletion, encode classical antigen presenting MHC molecules. In contrast, MHC alleles containing a 3 bp deletion may encode molecules with a different function. This study demonstrates that highly duplicated MHC genes can be characterised with HTS and that selection patterns can be useful for revealing neofunctionalization. Importantly, our results highlight the need to consider the putative function of different MHC genes in future studies of MHC in relation to disease resistance and fitness.

Conservation Letters, 2016
According to the Convention on Biological Diversity, by 2020 invasive alien species (IAS) should ... more According to the Convention on Biological Diversity, by 2020 invasive alien species (IAS) should be identified and their impacts assessed, so that species can be prioritized for implementation of appropriate control strategies and measures put in place to manage invasion pathways. For one quarter of the IAS listed as the "100 of the world's worst" environmental impacts are linked to diseases of wildlife (undomesticated plants and animals). Moreover, IAS are a significant source of "pathogen pollution" defined as the human-mediated introduction of a pathogen to a new host or region. Despite this, little is known about the biology of alien pathogens and their biodiversity impacts after introduction into new regions. We argue that the threats posed by alien pathogens to endangered species, ecosystems, and ecosystem services should receive greater attention through legislation, policy, and management. We identify 10 key areas for research and action, including those relevant to the processes of introduction and establishment of an alien pathogen and to prediction of the spread and associated impact of an alien pathogen on native biota and ecosystems. The development of interdisciplinary capacity, expertise, and coordination to identify and manage threats was seen as critical to address knowledge gaps.

Journal of Ornithology, 2015
There is growing evidence that the fitness of birds in temperate zones depends strongly on the ma... more There is growing evidence that the fitness of birds in temperate zones depends strongly on the match between the timing of breeding and local phenology. We have analysed data collected from a 15-year study on a Sedge Warbler (Acrocephalus schoenobaenus) population in its natural habitat. The highly skewed distribution of arrival dates of males indicated that they competed intensely to be the earliest arrivals. The distribution of mating dates, unlike arrival dates, was not skewed, rather it formed a bell-shaped distribution. Because females arrived much later, they could not base their mating choices on the arrival dates of males. Females, however, could use male song repertoire, a trait we found to be correlated with male arrival date. Double-brooded females mated early in the season, exactly within the peak of mating date distribution. Polygynous females, on the other hand, mated later in the season, choosing high-quality older males which had arrived significantly earlier. Male territory quality did not differ between double-brooded and polygynous females, nor did the quality of the territories occupied by an individual female change during her lifetime. Although longer lifespan and double-brooding influenced a female's fitness over the course of her lifetime, polygyny had no significant effect. We conclude that Sedge Warbler females do not compete for territorial resources, but they do prefer to mate with high-quality early-arriving males. Polygyny is an effective strategy used by females to compensate for their late arrival and breeding onset, since they pair with highquality males. Keywords Polygyny Á Second clutch Á Timing of breeding Á Mate choice Á Territory quality Á Arrival date Zusammenfassung Der Einfluss der Phänologie auf das Auftreten von Zweitbruten und Polygynie beim Schilfrohrsänger Acrocephalus schoenobaenus Communicated by F. Bairlein.
ABSTRACT The pattern of wetland vegetation dynamics was documented during a long-term study (1996... more ABSTRACT The pattern of wetland vegetation dynamics was documented during a long-term study (1996-2003) of a sedge warbler population in the Middle Nida Wetlands. Areas of reedmace Typha latifolia, which was preferred by sedge warblers, showed the highest rate of decrease among all land cover types. The rate of decrease depended primarily on water depth, although in places only temporarily filled with shallow water, original patch area was also important, with small patches (usually chosen for breeding) decreasing more rapidly than large patches in relative terms. Each year the settlement pattern of sedge warblers followed the new vegetation layout.
Trends in Ecology & Evolution, 2009

Journal of Ornithology, 2007
Mating tactics in species with facultative polygyny seem to be very flexible and to depend on loc... more Mating tactics in species with facultative polygyny seem to be very flexible and to depend on local environmental conditions. We analysed the habitat and population contexts of territorial behaviour, associated with polygyny, in a population of Sedge Warblers Acrocephalus schoenobaenus inhabiting natural wetlands. Nearly onethird of all breeding males (46 individuals) resumed song after completing their mating with the first female, in order to attract another one. Resuming males were usually the earliest arrivals. There was a continuity in the territorial behaviour between resuming song on first territory and polyterritorial behaviour. Fifty-nine percent of resuming males set up second territories, clearly separated from the first. The second territory was usually located close to the primary female activity area. The quality of the first and second territories were correlated, with second territories being significantly inferior. However, their quality was not significantly different from the territories of non-breeding males. The quality of the second territories was also negatively related to the distance from the first territories. Polyterritorialism was influenced by population numbers: the higher the number of territorial males, the lower the number of second territories settled and the lower their average quality. Although the polygyny frequency in the studied population was very low, polyterritorial males were significantly more likely to be polygynous. We concluded that polygyny frequency can be significantly influenced by population numbers, which might be one of the main factors responsible for the variability in the mating system in this species.
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Papers by Wojciech Solarz