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We studied the speciose butterfly genus Erebia by reconstructing its phylogenetic relationships using parsimony and Bayesian approaches. We estimated times and rates of diversification for its lineages and employed a biogeographical analysis in order to reconstruct its evolutionary history. DNA sequence data from one mitochondrial gene and three nuclear genes were analyzed for a total of 74 species in Erebia. The estimated dates of origin and diversification for clades, in combination with a biogeographical analysis, suggest that the genus originated in Asian Russia and started its diversification process around 23 Myr. An important event was the dispersal of a lineage from Asia to Western Europe between 23 and 17 Myr, which allowed the radiation of most of species in the genus. The diversification pattern is consistent with a model of diversity limited by clade richness, which implies an early rapid diversification followed by deceleration due to a decrease in speciation. We argue that these characteristics of the evolutionary history of Erebia are consistent with a density-dependent scenario, with species radiation limited by filling of niche space and reduced resources. We found that the Boeberia parmenio appears strongly supported in the genus Erebia and therefore we place Boeberia Prout, 1901 as a junior synonym of Erebia Dalman, 1816 (syn. nov.).

The global increase in species richness toward the tropics across continents and taxonomic groups, referred to as the latitudinal diversity gradient, stimulated the formulation of many hypotheses to explain the underlying mechanisms of this pattern. We evaluate several of these hypotheses to explain spatial diversity patterns in a butterfly family, the Nymphalidae, by assessing the contributions of speciation, extinction, and dispersal, and also the extent to which these processes differ among regions at the same latitude. We generate a time-calibrated phylogeny containing 2,866 nymphalid species (~45% of extant diversity). Neither speciation nor extinction rate variations consistently explain the latitudinal diversity gradient among regions because temporal diversification dynamics differ greatly across longitude. The Neotropical diversity results from low extinction rates, not high speciation rates, and biotic interchanges with other regions are rare. Southeast Asia is also characterized by a low speciation rate but, unlike the Neotropics, is the main source of dispersal events through time. Our results suggest that global climate change throughout the Cenozoic, combined with tropical niche conservatism, played a major role in generating the modern latitudinal diversity gradient of nymphalid butterflies.

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We studied the habitat requirements of a vulnerable butterfly, Erebia aethiops, in a grassland‐forest mosaic within a nature reserve. This species inhabits seemingly abundant habitats such as forest edges, but it is declining in many parts of Europe. We analysed mark‐recapture data, focusing on the effects of distinct vegetation structures, nectar sources and management regimes on population density and mobility. Adult E. aethiops preferred abandoned grasslands and small open enclaves surrounded by forest; i.e. highly heterogeneous habitats. Male densities were higher in sparse woodlots, female densities at grassland patches. These intersexual differences in habitat use emphasise the need for heterogeneous vegetation. Like other inhabitants of traditional woodlands, E. aethiops suffers from canopy closure, leading to its retreat to transitional structures such as forest edges or abandoned grasslands. Such preferences are in conflict with regular grassland management, necessary for conserving many other grassland organisms. Therefore, sparse woodlands containing forest free enclaves should be restored to protect this and other woodland organisms.

Abstract. The Marsh fritillary (Euphydryas aurinia) (Lepidoptera: Nymphalidae) has declined across Europe, including the Czech Republic. Current conservation strategies rely on prevention of habitat loss and degradation, and increase in habitat quality and connectivity via promoting traditional grassland management. The population structure and adult demography parameters of a single population was investigated for eight years (single system), and of all the known Czech populations (multiple populations) for a single year, using mark-recapture. There was substantial variation in the patterns of adult demography, both among years in the single system and among the multiple populations in a single year. In the single system, the date of the first flight of an adult varied by 18 days over the 8 years and total annual numbers varied with a coefficient of variation of 0.40 (females fluctuating more than males). The average density was ca 80 adults/ha. The population size displayed density-dependence, i.e. decreased following years with high adult numbers, with an equilibrium density of 90 individuals/ha. The average density of the multiple populations was ca 120 individuals/ha. The estimated total population for the Czech Republic was 25,000 individuals (17,000 males / 8,000 females) in 2007, which does not indicate an imminent threat of extinction. The regional persistence of E. aurinia is likely to depend on recolonisation of temporarily vacant sites by dispersing individuals, facilitated by local shifts in adult flight phenology to that better adapted to local conditions.

The composition of gut bacterial communities is strongly influenced by the host diet in many animal taxa. For birds, the effect of diet on the microbiomes has been documented through diet manipulation studies. However, for wild birds, most studies have drawn on literature-based information to decipher the dietary effects, thereby, overlooking individual variation in dietary intake. Here we examine how naturally consumed diets influence the composition of the crop and cloacal microbiomes of twenty-one tropical bird species, using visual and metabarcoding-based identification of consumed diets and bacterial 16S rRNA microbiome sequencing. We show that diet intakes vary markedly between individuals of the same species and that literature-based dietary guilds grossly underestimate intraspecific diet variability. Furthermore, despite an effect of literature-based dietary guild assignment of host taxa, the composition of natural diets does not align with crop and cloacal microbiome similarity. However, host-taxon specific gut bacterial lineages are positively correlated with specific diet items, indicating that certain microbes associate with different diet components in specific avian hosts. Consequently, microbiome composition is not congruent with the overall consumed diet composition of species, but specific components of a consumed diet lead to host-specific effects on gut bacterial taxa.

Both geographical and ecological speciation interact during the evolution of a clade, but the relative contribution of these processes is rarely assessed for cold-dwelling biota. Here, we investigate the role of biogeography and the evolution of ecological traits on the diversification of the Holarctic arcto-alpine butterfly genus Oeneis (Lepidoptera: Satyrinae). We reconstructed the molecular phylogeny of the genus based on one mitochondrial (COI) and three nuclear (GAPDH, RpS5, wingless) genes. We inferred the biogeographical scenario and the ancestral state reconstructions of climatic and habitat requirements. Within the genus, we detected five main species groups corresponding to the taxonomic division and further paraphyletic position of Neominois (syn. n.). Next, we transferred O. aktashi from the hora to the polixenes species group on the bases of molecular relationships. We found that the genus originated in the dry grasslands of the mountains of Central Asia and dispersed over the Beringian Land Bridges to North America several times independently. Holarctic mountains, in particular the Asian Altai Mts. and Sayan Mts., host the oldest lineages and most of the species diversity. Arctic species are more recent, with Pliocene or Pleistocene origin. We detected a strong phylogenetic signal for the climatic niche, where one lineage diversified towards colder conditions. Altogether, our results indicate that both dispersal across geographical areas and occupation of distinct climatic niches promoted the diversification of the Oeneis genus..