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Introduction: The migratory behaviour of wild birds aids in the geographical spread of ticks and their microorganisms. Ticks are known to harbor both pathogenic and symbiotic bacteria - such as species of the genera Francisella, Rickettsia,and Midichloria - and multiple bacterial species may occur within them. Francisella occurs in different tick taxa andconsists of closely related pathogenic and non-pathogenic species. Spotted fever group Rickettsia are transmitted to humans by different tick genera and are emerging human pathogens in Europe. The aims of this study were to investigate dispersal of Francisella as well as co-occurrence of Francisella and spotted fever group Rickettsia in ticks infesting northward migrating birds in the African-Western Palaearctic region. Materials and methods: Birds were trapped using mist nets at bird observatories in Spain, Italy, Greece, and Israel during their spring migration of 2014 and 2015. Ticks were screened for the genus Francisella, the species Francisella tularensis, and spotted fever group Rickettsia by microfluidic qPCR. Ticks with putative positive results for F. tularensiswere subjected to confirmation analyses, metagenomics analysis, enrichment, and whole genome sequencing. Results: There was a high prevalence of Francisella species (76.7%) and co-occurrence of Francisella species and spotted fever group Rickettsia (50.6%) in the tick species Hyalomma rufipes. Two H. rufipes yielded putative positive test results for the human pathogen F. tularensis during initial screening. Metagenomics analysis revealed presence of Francisella sp., Rickettsia sp., and Midichloria sp. DNA in the two H. rufipes ticks. The levels of Rickettsia and Midichloria DNA were relatively high while the level of Francisella DNA was low and required enrichment for the construction of metagenome-assembled genomes. Phylogenetic inference and calculations of the average nucleotide identity (ANI) indicated that: i) the Francisella genomes belonged

The cerebellum has a highly conserved neural structure across species but varies widely in size. The wide variation in cerebellar size (both absolute and in proportion to the rest of the brain) among species and populations suggests that functional specialization is linked to its size. There is increasing recognition that the cerebellum contributes to cognitive processing and emotional control in addition to its role in motor coordination. However, to what extent cerebellum size reflects variation in these behavioral processes within species remains largely unknown. By using a unique intercross chicken population based on parental lines with high divergence in cerebellum size, we compared the behavior of individuals repeatedly exposed to the same fear test (emergence test) early in life and after sexual maturity (eight trials per age group) with proportional cerebellum size and cerebellum neural density. While proportional cerebellum size did not predict the initial fear response of the individuals (trial 1), it did increasingly predict adult individuals response as the trials progressed. Our results suggest that proportional cerebellum size does not necessarily predict an individuals fear response, but rather the habituation process to a fearful stimulus. Cerebellum neuronal density did not predict fear behavior in the individuals which suggests that these effects do not result from changes in neuronal density but due to other variables linked to proportional cerebellum size which might underlie fear habituation., Funding Agencies|Swedish FORMASSwedish Research Council Formas [2019-01508]; European Research CouncilEuropean Research Council (ERC)European Commission [FERALGEN 772874]; Swedish Research CouncilSwedish Research CouncilEuropean Commission; Carl Tryggers Stiftelse; Linkoeping University Neuro-network

The ecology of the vertebrate host contributes to the geographical range expansion of ticks. In this study, we investigated which tick taxa that infest and are dispersed by birds along African-Western Palaearctic flyways during northward migration, and whether bird ecology was associated with tick taxa. Materials and methods: Ticks were collected from birds trapped at bird observatories in Spain, Italy, Greece, and Israel during the spring migration of 2014 and 2015, using mist nets. The tick-infested bird species were classified into guilds, using different combinations of the variables: migration distance, wintering region, foraging behaviour, and winter habitat. Ticks were molecularly determined to genus and species level by sequencing fragments of the 12S ribosomal DNA (rDNA) gene and by phylogenetic inference, using the Maximum Likelihood algorithm. Data were analysed using descriptive measures, graphs, Chi2 tests, the Tukey-Kramer test, and a parametric linear model (generalized linear model) in order to analyse and adjust for characteristics in the bird guilds and their relationship to collected tick taxa. Results: Most (84.2%) of the 10,209 trapped birds were long-distance migrants, of which 2.4% were infested by ticks. The most common tick species was Hyalomma rufipes (77.7%; 447/575), a known vector and reservoir of Crimean- Congo hemorrhagic fever virus. Bird guilds containing only long-distance migrants with wintering areas in Africa were associated with the tick species H. rufipes (p < 0.0001). Furthermore, bird winter habitat was associated with H. rufipes (p = 0.003); with bird species overwintering in open habitat (p = 0.014) and wetlands (p = 0.046) having significantly more H. rufipes as compared to birds with a winter habitat comprising forest and shrubs (p = 0.82). Conclusions: With climate change, the likelihood of establishment of permanent Hyalomma populations in central and northern Europe is increasing. Thus, surveillance programs for monito