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Taxonomic entities below the species level often pose difficulties for conservation practice, especially when they are ecologically distinct from the nominal species. Genomic tools provide the opportunity to study and potentially resolve such cryptic diversity. The Alcon blue butterfly Phengaris alcon species complex is such a cryptic example, comprising different ecotypes or even subspecies, one of them is the high elevation taxon P. rebeli from the European Alps. We sequenced a first reference genome for Phengaris alcon. Furthermore, we generated whole genome resequence data for individuals of three Swiss ecotypes, i.e., the low elevation P. alcon, the mid elevation and high elevation alpine P. rebeli and integrated genomic data from across Europe to study the relationship among these ecotypes. At a European scale, our results suggest that for the P. alcon complex, biogeography and the evolutionary context of diversification is more multifaceted than previously suggested, falling in the range of more recent ecological speciation. In Switzerland, the three ecotypes were genetically isolated with only limited current gene flow between them. Past gene flow, however, could have given rise to the mid elevation ecotype. Our findings emphasise that high elevation P. rebeli in the Alps should be treated as a distinct species. Our study highlights how the availability of reference genome assemblies allows to address so far open taxonomic questions in conservation research and that broadscale studies are needed to understand the biogeographic history of apparent diversification. [ABSTRACT FROM AUTHOR]

Increasing light emissions caused by human activities have been recognized as a major threat for nocturnal animals. In Switzerland, the European Nightjar is a rare bird, decreasing in numbers since the 1970s, and is therefore highly threatened. The last breeding population occurs in the canton Valais. Initial expert-based conservation measures on formerly inhabited breeding sites were successful until 2000, however recent additional measures have failed. Nightjars are highly sensitive to light due to their special retina adapted to living in semi-darkness. We hypothesized that food availability, mainly moths, is not a critical limiting factor, but that artificial light emissions prevent successful foraging as well as recolonizing revitalised breeding habitats of the nightjar. To test this hypothesis, we used light trapping data of moths from the last 30 years to evaluate food availability and compared light emission on abandoned versus still-occupied breeding sites. Abundance of larger moths did not change significantly over the last 30 years, and smaller moths even increased in abandoned as well as in still-occupied nightjar habitats. However, light emission was two to five times higher in abandoned compared to still-occupied sites. These results suggest that increasing light emission during recent decades has exceeded tolerable levels for this highly specialized night bird. Authorities of the canton Valais should therefore order a reduction in light emission near nightjar habitats by replacing bulbs currently in use with customized LED or broad-spectrum lamps low in white and blue light, and assign remaining nightjar habitats as areas of complete nocturnal darkness, thereby also protecting other threatened nocturnal animals, including moths. [ABSTRACT FROM AUTHOR]

Plants flowering together may influence each other's pollination and fecundity over a range of physical distances. Their effects on one another can be competitive, neutral, or facilitative. We manipulated the floral neighborhood of the high-alpine cushion plant Eritrichium nanum in the Swiss Alps and measured the effects of co-flowering neighbors on both the number of seeds produced and the degree of inbreeding and outbreeding in the offspring, as deduced from nuclear microsatellite markers. Seed set of E. nanum did not vary significantly with the presence or absence of two Saxifraga species growing as near neighbors, but it was higher in E. nanum cushions growing at low conspecific density than in those growing at high density. In addition, floral neighborhood had no detectable effect on the degree of selfing of E. nanum, but seeds from cushions growing at low conspecific density were more highly outbred than seeds from cushions at high density. Thus, there was no evidence of either competition or facilitation between E. nanum and Saxifraga spp. as mediated by pollinators at the spatial scale of our experimental manipulation. In contrast, the greater fecundity of E. nanum cushions at low density was consistent with reduced intraspecific competition for pollinators and might also represent a beneficial effect of highly outbred seeds as brought about by more long-distance pollinator flights under low-density conditions.

It is generally assumed that butterflies, as is the case with many holometabolous insects, rely primarily on nutrients gathered by larval feeding for somatic maintenance and fecundity. These reserves can be supplemented by adult feeding and in some cases by nuptial gifts passed from the males to the females during mating. Recent findings indicate that female butterflies detect and prefer nectar with high levels of amino acids, thus calling new attention to this nutritive source. Polyandrous species can further supplement their larval stores with additional nuptial gifts. This study examined how mating frequency of the polyandrous butterfly Pieris napi affects the female's preference for nectar amino acids. Females of this species generally detect and prefer nectar mimics containing amino acids. However, nectar amino acid preference is significantly lower in mated females. Furthermore, nectar amino acid preference increases when females are not allowed to remate, whereas the preference of twice-mated females remains constant at a lower level. These results indicate a versatile response of females to nectar amino acids, depending on their nutritional status; they may even switch their source of amino acids between adult feeding and nuptial gifts.