Host dispersal shapes the population structure of a tick-borne bacterial pathogen

Birds are hosts for several zoonotic pathogens. Because of their high mobility, especially of longdistance migrants, birds can disperse these pathogens, affecting their distribution and phylogeography. We focused on Borrelia burgdorferi sensu lato, which includes the causative agents of Lyme borreliosis, as an example for tick-borne pathogens, to address the role of birds as propagation hosts of zoonotic agents at a large geographical scale. We collected ticks from passerine birds in 11 European countries. B. burgdorferi s.l. prevalence in Ixodes spp. was 37% and increased with latitude. The fieldfare Turdus pilaris and the blackbird T. merula carried ticks with the highest Borrelia prevalence (92 and 58%, respectively), whereas robin Erithacus rubecula ticks were the least infected (3.8%). Borrelia garinii was the most prevalent genospecies (61%), followed by B. valaisiana (24%), B. afzelii (9%), B. turdi (5%) and B. lusitaniae (0.5%). A novel Borrelia genospecies "Candidatus Borrelia aligera" was also detected. Multilocus sequence typing (MLST) analysis of B. garinii isolates together with the global collection of B. garinii genotypes obtained from the Borrelia MLST public database revealed that: (a) there was little overlap among genotypes from different continents, (b) there was no geographical structuring within Europe, and (c) there was no evident association pattern detectable among B. garinii genotypes from ticks feeding on birds, questing ticks or human isolates. These findings strengthen the hypothesis that the population structure and evolutionary biology of tick-borne pathogens are shaped by their host associations and the movement patterns of these hosts.Peer reviewe

The roles of temperature, nest predators and information parasites for geographical variation in egg covering behaviour of tits (Paridae)

Aim Nest building is widespread among animals. Nests may provide receptacles for eggs, developing offspring and the parents, and protect them from adverse environmental conditions. Nests may also indicate the quality of the territory and its owner and can be considered as an extended phenotype of its builder(s). Nests may, thus, function as a sexual and social signal. Here, we examined ecological and abiotic factors-temperature, nest predation and interspecific information utilization-shaping geographical variation in a specific nest structure-hair and feather cover of eggs-and its function as an extended phenotype before incubation in great (Parus major) and blue tits (Cyanistes caeruleus) across Europe. We also tested whether egg covering is associated with reproductive success of great tits. Location Fourteen different study sites and 28 populations across Europe. Taxon Parus major, Cyanistes caeruleus. Methods We recorded clutch coverage estimates and collected egg covering nest material from the tit nests. We also measured nest specific breeding parameters and phenotypic measurements on adults. We tested whether mean spring temperatures, nest predation rates and flycatcher (Ficedulaspp) densities in the study areas explain the large-scale geographical variation of clutch coverage and reproductive success of tits. Results The degree of egg coverage of great tits increased with lower mean spring temperature, higher nest predation rate and higher flycatcher density. We did not find egg covering of blue tits to be associated with any of the ecological or abiotic factors. Moreover, egg covering of great tits was not associated with reproductive success in our cross-sectional data, yet a rigorous assessment of fitness effects would require long-term data. Main conclusions Our findings suggest that, in great tits, egg covering may simultaneously provide thermal insulation against cold temperatures during egg-laying in spring and also represent a counter-adaptation to reduce information parasitism by flycatchers and nest predation. Hence, geographical variation in interspecific interactions, and consequently in co-evolutionary processes, may affect the evolution of nest characteristics besides environmental conditions

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 studies 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 reproductive 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.This meta-analysis was financed by the grant of the Polish National Science Centre (Narodowe Centrum Nauki) (no. 2017/27/B/NZ8/00465) awarded to Lucyna Hałupka.Peer reviewe

Relationship between the Clinical Frailty Scale and short-term mortality in patients ≥ 80 years old acutely admitted to the ICU: a prospective cohort study.

BACKGROUND: The Clinical Frailty Scale (CFS) is frequently used to measure frailty in critically ill adults. There is wide variation in the approach to analysing the relationship between the CFS score and mortality after admission to the ICU. This study aimed to evaluate the influence of modelling approach on the association between the CFS score and short-term mortality and quantify the prognostic value of frailty in this context. METHODS: We analysed data from two multicentre prospective cohort studies which enrolled intensive care unit patients ≥ 80 years old in 26 countries. The primary outcome was mortality within 30-days from admission to the ICU. Logistic regression models for both ICU and 30-day mortality included the CFS score as either a categorical, continuous or dichotomous variable and were adjusted for patient's age, sex, reason for admission to the ICU, and admission Sequential Organ Failure Assessment score. RESULTS: The median age in the sample of 7487 consecutive patients was 84 years (IQR 81-87). The highest fraction of new prognostic information from frailty in the context of 30-day mortality was observed when the CFS score was treated as either a categorical variable using all original levels of frailty or a nonlinear continuous variable and was equal to 9% using these modelling approaches (p < 0.001). The relationship between the CFS score and mortality was nonlinear (p < 0.01). CONCLUSION: Knowledge about a patient's frailty status adds a substantial amount of new prognostic information at the moment of admission to the ICU. Arbitrary simplification of the CFS score into fewer groups than originally intended leads to a loss of information and should be avoided. Trial registration NCT03134807 (VIP1), NCT03370692 (VIP2)

Adaptive responses of animals to climate change are most likely insufficient

Biological responses to climate change have been widely documented across taxa and regions, but it remains unclear whether species are maintaining a good match between phenotype and environment, i.e. whether observed trait changes are adaptive. Here we reviewed 10,090 abstracts and extracted data from 71 studies reported in 58 relevant publications, to assess quantitatively whether phenotypic trait changes associated with climate change are adaptive in animals. A meta-analysis focussing on birds, the taxon best represented in our dataset, suggests that global warming has not systematically affected morphological traits, but has advanced phenological traits. We demonstrate that these advances are adaptive for some species, but imperfect as evidenced by the observed consistent selection for earlier timing. Application of a theoretical model indicates that the evolutionary load imposed by incomplete adaptive responses to ongoing climate change may already be threatening the persistence of species.Peer reviewe

Quantification of Edible Dormouse (Glis glis) calling activity for biodiversity surveys: comparison of core and peripheral populations

In Lithuania, the Edible Dormouse (Glis glis) is an endangered red-listed species and only 10 populations are known at present. It is situated on the northern periphery of its distribution range and outside the continuous range of the European Beech (Fagus sylvatica) which is a key-species for this rodent. For this reason, habitats of the Edible Dormouse are completely different in Lithuania, where most dormouse populations are fragmented, isolated and might be very small compared to other countries, where beech stands predominate in Glis habitats.Alhough the Edible Dormouse is a well-investigated species in many parts of its range, there is still a lack of information about the ecology of this species on the periphery of its distribution range. In this presentation, we compare calling activity of the Edible Dormouse in core and peripheral populations using voice recorders. During the summer 2017, three voice recorders were deployed on three permanent sites in the Czech Republic, and three voice recorders were deployed at three different localities in Lithuania during the summer 2020. Voice recorders were continuously recording dormouse voices over the entire summer until the beginning of autumn, and relevant days of voice records were selected for the comparison of calling activity.The results of this study will help to evaluate a new method for Edible Dormouse investigation in Lithuania, revealing new and interesting information about its nocturnal life

Quantification of Edible Dormouse (Glis glis) calling activity for biodiversity surveys: comparison of core and peripheral populations

In Lithuania, the Edible Dormouse (Glis glis) is an endangered red-listed species and only 10 populations are known at present. It is situated on the northern periphery of its distribution range and outside the continuous range of the European Beech (Fagus sylvatica) which is a key-species for this rodent. For this reason, habitats of the Edible Dormouse are completely different in Lithuania, where most dormouse populations are fragmented, isolated and might be very small compared to other countries, where beech stands predominate in Glis habitats.Alhough the Edible Dormouse is a well-investigated species in many parts of its range, there is still a lack of information about the ecology of this species on the periphery of its distribution range. In this presentation, we compare calling activity of the Edible Dormouse in core and peripheral populations using voice recorders. During the summer 2017, three voice recorders were deployed on three permanent sites in the Czech Republic, and three voice recorders were deployed at three different localities in Lithuania during the summer 2020. Voice recorders were continuously recording dormouse voices over the entire summer until the beginning of autumn, and relevant days of voice records were selected for the comparison of calling activity.The results of this study will help to evaluate a new method for Edible Dormouse investigation in Lithuania, revealing new and interesting information about its nocturnal life

Solitary vs communal use of nest boxes by the Edible Dormouse (Glis glis)

The Edible Dormouse often forms group associations in den sites. We characterize, over a 13-year period, how often the dormice rest alone or communally in nest boxes. The majority (87%) of individuals are solitary, resting alone during the daytime in nest boxes. In communal associations, groups of two or three individuals were the most common. We assessed the role of ambient temperature, seed mast, density of nest boxes and the surrounding vegetation on occupancy patterns. Seed mast and nest box density had a significant effect on group associations. Groups were more common in non-masting years. The lower the density of nest boxes at the study sites, the more common were group associations. In addition, a higher proportion of beech trees surrounding the nest boxes was associated with more frequent group associations

Ticks on the Edible Dormouse (Glis glis)

Rodents in central Europe, such as the Edible Dormouse, are common hosts for many ectoparasites, including ticks. One of the most extensively studied tick species is Ixodes ricinus, whose geographic distribution extends from Scandinavia to Morocco. In 2014, a new North African species I. inopinatus was described and found in Morocco, Tunisia, the Iberian Peninsula, and peripherally also in Romania, Austria, and southern Germany. Both Ixodes species were reported in sympatry in southern Europe (Spain and Portugal) where they feed mainly on lizards. During the period from early June to October in 2016-2019, we captured 4597 dormice and calculated the rate of tick infestation. Our results show that the mean prevalence of ticks in the dormouse population was 31.9 %. In the next step, 400 ticks from 2019 (255 larvae, 144 nymphs, 1 adult) from dormice were identified morphologically and by multiplex-PCR to distinguish I. ricinus and I. inopinatus. The results of our analysis show the first report of I. inopinatus feeding on rodents