Phenotypic divergence in two sibling species of shorebird: Common Snipe and Wilson’s Snipe (Charadriiformes: Scolopacidae)

Natural and social selection are among the main shapers of biological diversity but their relative importance in divergence remains understudied. Additionally, although neutral evolutionary processes may promote phenotypic divergence, their potential contribution in speciation is often overlooked in studies of comparative morphology. In this study, we investigated phenotypic differentiation in two allopatric shorebirds: the Palaearctic Common Snipe Gallinago gallinago and the Nearctic Wilson’s Snipe Gallinago delicata. Specimens of Common Snipe (n = 355 skins, n = 163 skeletons) and Wilson’s Snipe (n = 403 skins, n = 141 skeletons) in natural history collections were examined to quantify differences in skeletal and external measurements, and measures of wing and tail plumage variables. The species do not differ in skeletal variables except for the relatively larger sternum of the Common Snipe. The two species do not differ in multivariate wing size or shape (pointedness). Previously known plumage differences between these species were confirmed: the Common Snipe has fewer rectrices, longer and wider outermost rectrices, more extensive white on tips of the secondary feathers, and more white in the axillaries. Between-species variance in skeleton, primary length and plumage variables was greater than expected if drift was mainly responsible for phenotypic divergence, suggesting a role of selective processes. However, drift could not be rejected after adjusting for multiple comparisons. Differences in plumage traits were greater than in skeletal or external measurements. Because snipe use plumage traits in signalling, the results suggest a more rapid divergence in socially selected traits between these species than in traits related to resource use

Does solar irradiation drive community assembly of vulture plumage microbiotas?

Abstract Background Stereotyped sunning behaviour in birds has been hypothesized to inhibit keratin-degrading bacteria but there is little evidence that solar irradiation affects community assembly and abundance of plumage microbiota. The monophyletic New World vultures (Cathartiformes) are renowned for scavenging vertebrate carrion, spread-wing sunning at roosts, and thermal soaring. Few avian species experience greater exposure to solar irradiation. We used 16S rRNA sequencing to investigate the plumage microbiota of wild individuals of five sympatric species of vultures in Guyana. Results The exceptionally diverse plumage microbiotas (631 genera of Bacteria and Archaea) were numerically dominated by bacterial genera resistant to ultraviolet (UV) light, desiccation, and high ambient temperatures, and genera known for forming desiccation-resistant endospores (phylum Firmicutes, order Clostridiales). The extremophile genera Deinococcus (phylum Deinococcus-Thermus) and Hymenobacter (phylum, Bacteroidetes), rare in vertebrate gut microbiotas, accounted for 9.1% of 2.7 million sequences (CSS normalized and log2 transformed). Five bacterial genera known to exhibit strong keratinolytic capacities in vitro (Bacillus, Enterococcus, Pseudomonas, Staphylococcus, and Streptomyces) were less abundant (totaling 4%) in vulture plumage. Conclusions Bacterial rank-abundance profiles from melanized vulture plumage have no known analog in the integumentary systems of terrestrial vertebrates. The prominence of UV-resistant extremophiles suggests that solar irradiation may play a significant role in the assembly of vulture plumage microbiotas. Our results highlight the need for controlled in vivo experiments to test the effects of UV on microbial communities of avian plumage

Elevation of two subspecies of Dunnock Prunella modularis to species rank

The Western Palearctic endemic Dunnock Prunella modularis was recently revealed to comprise three distinct genetic lineages, each distributed in different Pleistocene refugia. Specifically, one is isolated in the Iberian refugium, another is confined to the Caucasus refugium, and the third is distributed in both the Italian and Balkan refugia, as well as across broader Europe. There is a probable absence of gene flow between the refugia. Analysis of plumage and song characteristics reveals robust differences between the Iberian subspecies P. m. mabbotti, Caucasian P. m. obscura and nominate P. m. modularis. Our assessments, in conjunction with genetic isolation, support species recognition under the Phylogenetic, Biological and Comprehensive Biological Species Concepts, via qualitative and quantitative criteria, and diagnosability. We thus propose the elevation of Iberian Dunnock P. mabbotti and Caucasian Dunnock P. obscura to species level

Geographic patterns of mtDNA and Z-linked sequence variation in the Common Chiffchaff and the ‘chiffchaff complex’

We are grateful to the University of Washington Burke Museum (UWBM), US National Museum of Natural History (USNM), National History Museum Belgrade (NHMBEO), State Darwin Museum (SDM), Zoological Museum of Moscow State University (MSUZM), Yale Peabody Museum (YPM), University of Minnesota Bell Museum (MMNH), Texas A&M University Biodiversity Research and Teaching Collections (TCWC), Staffan Bensch, Stephen Menzie and Nigel Odin for sample loans. This is publication number 1585 of the Biodiversity Research and Teaching Collections at Texas A&M University. Funding: This work was supported by FEDER funds through the COMPETE programme, POPH/QREN/FSE funds to S.V.D. and NORTE2020/PORTUGAL funds (NORTE-01-0145-FEDER-AGRIGEN) to R.J.L., by the Fundação para a Ciência e a Tecnologia/MEC to S.V.D. (FCOMP-01-0124-FEDER-008941; PTDC/BIA- BEC/103435/2008) and R.J.L (SFRH/BPD/84141/2012), by the National Geographic Society to S.V.D, by Torino University Grant ex 60% 2017 and 2018 to M. P. and by Ministarstvo Kulture I Informisanja Republike Srbije (Project: Ptice zapadnog palearktika) to M.R. The Russian Science Foundation grant No. 14-50-00029 'Scientific basis of the national biobank – depository of living systems' (to E.A.K). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The Russian Science Foundation grant No. 14-50-00029 'Scientific basis of the national biobank – depository of living systems' (to E.A.K).Peer reviewedPublisher PD

Robust geographical determinants of infection prevalence and a contrasting latitudinal diversity gradient for haemosporidian parasites in Western Palearctic birds

Identifying robust environmental predictors of infection probability is central to forecasting and mitigating the ongoing impacts of climate change on vector-borne disease threats. We applied phylogenetic hierarchical models to a dataset of 2,171 Western Palearctic individual birds from 47 species to determine how climate and landscape variation influence infection probability for three genera of haemosporidian blood parasites (Haemoproteus, Leucocytozoon, and Plasmodium). Our comparative models found compelling evidence that birds in areas with higher vegetation density (captured by the Normalized Difference Vegetation Index) had higher likelihoods of carrying parasite infection. Magnitudes of this relationship were remarkably similar across parasite genera considering that these parasites use different arthropod vectors and are widely presumed to be epidemiologically distinct. However, we also uncovered key differences among genera that highlighted complexities in their climate responses. In particular, prevalences of Haemoproteus and Plasmodium showed strong but contrasting relationships with winter temperatures, supporting mounting evidence that winter warming is a key environmental filter impacting the dynamics of host-parasite interactions. Parasite phylogenetic community diversities demonstrated a clear but contrasting latitudinal gradient, with Haemoproteus diversity increasing towards the equator and Leucocytozoon diversity increasing towards the poles. Haemoproteus diversity also increased in regions with higher vegetation density, supporting our evidence that summer vegetation density is important for structuring the distributions of these parasites. Ongoing variation in winter temperatures and vegetation characteristics will likely have far-reaching consequences for the transmission and spread of vector-borne diseases

Data from: Multilocus coalescence analyses support a mtDNA-based phylogeographic history for a widespread Palearctic passerine bird, Sitta europaea

Our understanding of species phylogeography in much of the Palearctic is incomplete. In addition, many existing studies based solely on mitochondrial DNA (mtDNA) can provide a biased view of phylogeographic history because of the effects of lineage sorting, natural selection or hybridization. We analyzed 13 introns to assess a mtDNA study of the Eurasian nuthatch (Sitta europaea) that suggested a seemingly contemporaneous origin of distinct taxa in the Caucasus, Europe, and Asia. Neutrality tests showed no evidence of selection on either the mtDNA or nuclear sequences. Most nuclear gene trees, except for Z-linked ones, did not recover the three lineages, which we attribute to recent splitting. Analyses of the 13 introns combined revealed the same three groups as did the mtDNA and suggested that nuthatches experienced a trichotomous (or two indistinguishable) split(s) 1-2 Ma ago and have remained isolated with trifling if not zero gene flow since then, and the Asian group increased in population size. This result demonstrates the usefulness of mtDNA in discovering phylogeographic patterns. The use of multiple nuclear loci facilitated detection of an introgressed individual and improved estimates of process parameters such as divergence time and population expansion. We recommend that phylogeographic studies should be based on both mtDNA and nuclear genes

Data from: The roles of ecology, behavior and effective population size in the evolution of a community

Organismal traits such as ecological specialization and migratory behavior may affect colonization potential, population persistence, and degree of isolation, factors that determine the composition and genetic structure of communities. However, studies focusing on community assembly rarely consider these factors jointly. We sequenced 16 nuclear and one mitochondrial genes from Caucasian and European populations of 30 forest-dwelling avian species that represent diverse ecological (specialist-generalist) and behavioral (migratory-resident) backgrounds. We tested the effects of organismal traits on population divergence and community assembly in the Caucasus forest, a continental mountain island setting. We found that (1) there is no concordance in divergence times between the Caucasus forest bird populations and their European counterparts, (2) habitat specialists tend to be more divergent than generalists, and (3) residents tend to be more divergent than migrants. Thus, specialists and residents contribute to the high level of endemism of Caucasus forest avifauna more than do generalists and migrants. Patterns of genetic differentiation are better explained by differences in effective population sizes, an often overlooked factor in comparative studies of phylogeography and speciation, than by divergence times or levels of gene flow. Our results suggest that the Caucasus forest avifauna was assembled through time via dispersal and/or multiple vicariant events, rather than originating simultaneously via a single isolation event. Our study is one of the first multi-locus, multi-species analyses revealing how ecological and migratory traits impact the evolutionary history of community formation on a continental island

MtDNA ND2 sequence identifies Streaked Horned Lark (Eremophila alpestris strigata) from birdstrike to US Air Force F-15 at Portland International Airport, Oregon

The Streaked Horned Lark (SHL: Eremophila alpestris strigata) is the Northwest subspecies of the Horned Lark listed as endangered in Washington State, critical in Oregon, and is now being considered for listing as threatened by the US Fish & Wildlife Service. Some of the important breeding areas of SHL are associated with airports in western Washington and Oregon which raises concern over possible collisions between SHLs and aircraft. Here, we report a successful use of mtDNA ND2 gene sequence for identification of SHL feather and tissue remains from a bird collision with a US Air Force F-15-C on 4 October 2012 at Portland International Airport. Due to the conservation status of SHL, documentation of this event and a simple mtDNA-based molecular identification protocol may have management and conservation implications at airfields within the range of this rare subspecies