Biogeographical patterns and co-occurrence of pathogenic infection across island populations of Berthelot’s pipit (Anthus berthelotii)

Pathogens can exert strong selective forces upon host populations. However, before we can make any predictions about the consequences of pathogen-mediated selection, we ?rst need to determine whether patterns of pathogen distribution are consistent over spatiotemporal scales. We used molecular techniques to screen for a variety of blood pathogens (avian malaria, pox and trypanosomes) over a three-year time period across 13 island populations of the Berthelot’s pipit (Anthus berthelotii). This species has only recently dispersed across its range in the North Atlantic, with little subsequent migration, providing an ideal opportunity to examine the causes and effects of pathogenic infection in populations in the early stages of differentiation. We screened 832 individuals, and identi?ed two strains of Plasmodium, four strains of Leucocytozoon, and one pox strain. We found strong differences in pathogen prevalence across populations, ranging from 0 to 65%, and while some ?uctuations in prevalence occurred, these differences were largely stable over the time period studied. Smaller, more isolated islands harboured fewer pathogen strains than larger, less isolated islands, indicating that at the population level, colonization and extinction play an important role in determining pathogen distribution. Individual-level analyses con?rmed the island effect, and also revealed a positive association between Plasmodium and pox infection, which could have arisen due to dual transmission of the pathogens by the same vectors, or because one pathogen lowers resistance to the other. Our ?ndings, combined with an effect of infection on host body condition, suggest that Berthelot’s pipits are subject to different levels of pathogen-mediated selection both across and within populations, and that these selective pressures are consistent over time

The critically endangered forest owlet <i>Heteroglaux blewitti</i> is nested within the currently recognized <i>Athene</i> clade: A century-old debate addressed

<div><p>Range-restricted species generally have specific niche requirements and may often have unique evolutionary histories. Unfortunately, many of these species severely lack basic research, resulting in poor conservation strategies. The phylogenetic relationship of the Critically Endangered Forest Owlet <i>Heteroglaux blewitti</i> has been the subject of a century-old debate. The current classifications based on non-phylogenetic comparisons of morphology place the small owls of Asia into three genera, namely, <i>Athene</i>, <i>Glaucidium</i>, and <i>Heteroglaux</i>. Based on morphological and anatomical data, <i>H</i>. <i>blewitti</i> has been alternatively hypothesized to belong within <i>Athene</i>, <i>Glaucidium</i>, or its own monotypic genus <i>Heteroglaux</i>. To test these competing hypotheses, we sequenced six loci (~4300 bp data) and performed phylogenetic analyses of owlets. Mitochondrial and nuclear trees were not congruent in their placement of <i>H</i>. <i>blewitti</i>. However, both mitochondrial and nuclear combined datasets showed strong statistical support with high maximum likelihood bootstrap (>/ = 90) and Bayesian posterior probability values (>/ = 0.98) for <i>H</i>. <i>blewitti</i> being nested in the currently recognized <i>Athene</i> group, but not sister to Indian <i>A</i>. <i>brama</i>. The divergence of <i>H</i>. <i>blewitti</i> from its sister taxa was between 4.3 and 5.7 Ma coinciding with a period of drastic climatic changes in the Indian subcontinent. This study presented the first genetic analysis of <i>H</i>. <i>blewitti</i>, a Critically Endangered species, and addressed the long debate on the relationships of the <i>Athene</i>-<i>Heteroglaux</i>-<i>Glaucidium</i> complex. We recommend further studies with more data and complete taxon sampling to understand the biogeography of Indian <i>Athene</i> species.</p></div