The Chalk-hill Blue Polyommatus coridon (Lycaenidae, Lepidoptera) in a highly fragmented landscape: How sedentary is a sedentary butterfly?

The habitats of many species are fragmented. Therefore, the survival in a metapopulation depends on the stability of the single populations and the amount of movements between patches. We chose the calcareous grassland specialist butterfly species Polyommatus coridon as a model. As study area, we selected a mosaic-like landscape in Rhineland-Palatinate (western Germany) with several well preserved calcareous grassland fragments. We marked a total of 2,211 individuals during July and August 2003. The overall recapture ratio was 7.1%. The estimated mean butterfly densities over the whole flight season ranged from 52 to 487 individuals per hectare. The within-patch movements were relatively low (13.3%) compared with the between-patch movements (3.2%). Therefore, the metapopulation structure appears to be intact in our study area.     

Rapid Decline of a Grassland System and Its Ecological and Conservation Implications

One of the most important conservation issues in ecology is the imperiled state of grassland ecosystems worldwide due to land conversion, desertification, and the loss of native populations and species. The Janos region of northwestern Mexico maintains one of the largest remaining black-tailed prairie dog (Cynomys ludovicianus) colony complexes in North America and supports a high diversity of threatened and endangered species. Yet, cattle grazing, agriculture, and drought have greatly impacted the region. We evaluated the impact of human activities on the Janos grasslands, comparing changes in the vertebrate community over the last two decades. Our results reveal profound, rapid changes in the Janos grassland community, demonstrating large declines in vertebrate abundance across all taxonomic groups. We also found that the 55,000 ha prairie dog colony complex has declined by 73% since 1988. The prairie dog complex has become increasingly fragmented, and their densities have shown a precipitous decline over the years, from an average density of 25 per ha in 1988 to 2 per ha in 2004. We demonstrated that prairie dogs strongly suppressed woody plant encroachment as well as created open grassland habitat by clearing woody vegetation, and found rapid invasion of shrubland once the prairie dogs disappeared from the grasslands. Comparison of grasslands and shrublands showed markedly different species compositions, with species richness being greatest when both habitats were considered together. Our data demonstrate the rapid decline of a grassland ecosystem, and documents the dramatic loss in biodiversity over a very short time period concomitant with anthropogenic grassland degradation and the decline of a keystone species.     

Evaluating the impact of non-lethal DNA sampling on two butterflies, <Emphasis Type="Italic">Vanessa cardui</Emphasis> and <Emphasis Type="Italic">Satyrodes eurydice</Emphasis>

Genetic sampling of endangered species can inform conservation management and potentially aid the long-term survival of a species. However, when dealing with very small populations of rare species, the sacrifice of whole animals may not be desirable or permitted. We set out to develop a demonstrably non-lethal method of obtaining DNA from the federally-endangered Mitchell’s satyr butterfly, Neonympha mitchellii mitchellii. Because of its endangered status we developed our methods on related species. In greenhouse and fields trials, we demonstrate that removal of small amounts of hind wing (2–3 mm²) has no significant impact on the behavior or survival of Vanessa cardui and Satyrodes eurydice. Based on these studies we were successful in obtaining a permit from the US Fish and Wildlife Service to sample DNA from N. m. mitchellii populations. We suggest that our results can be extended to the sampling of other rare butterfly species.     

Scenario-based assessment of future land use change on butterfly species distributions

Species distribution models (SDMs) are increasingly used to predict environmentally induced range shifts of habitats of plant and animal species. Consequently SDMs are valuable tools for scientifically based conservation decisions. The aims of this paper are (1) to identify important drivers of butterfly species persistence or extinction, and (2) to analyse the responses of endangered butterfly species of dry grasslands and wetlands to likely future landscape changes in Switzerland. Future land use was represented by four scenarios describing: (1) ongoing land use changes as observed at the end of the last century; (2) a liberalisation of the agricultural markets; (3) a slightly lowered agricultural production; and (4) a strongly lowered agricultural production. Two model approaches have been applied. The first (logistic regression with principal components) explains what environmental variables have significant impact on species presence (and absence). The second (predictive SDM) is used to project species distribution under current and likely future land uses. The results of the explanatory analyses reveal that four principal components related to urbanisation, abandonment of open land and intensive agricultural practices as well as two climate parameters are primary drivers of species occurrence (decline). The scenario analyses show that lowered agricultural production is likely to favour dry grassland species due to an increase of non-intensively used land, open canopy forests, and overgrown areas. In the liberalisation scenario dry grassland species show a decrease in abundance due to a strong increase of forested patches. Wetland butterfly species would decrease under all four scenarios as their habitats become overgrown.     

Case studies of the history and politics of wild canid restoration in Korea

Wild canids were historically abundant in Korea; however, the gray wolf, dhole, and red fox were extirpated during the twentieth century. The causes varied. “Pest control” during the Japanese occupation, ecological destruction during wars, disease epizootics, and “vermin control” after the Korean War contributed to the complete demise of wolves. The fox had succumbed to unregulated hunting, rodenticides, habitat loss, and disease epizootics. The dhole was naturally rare; its extirpation from northeastern Asia including Korea is not established. Although the wolf and fox are extirpated, the Korean government still lists both as endangered species to facilitate the recently implemented restoration programs. Restoration will face the challenges of importing genetically diverse populations and the critical loss, fragmentation, and alteration of peri‐urban habitats. The overall social support for these efforts is not clear: it may be low because of changes in social mores or simply an unintended consequence of land and water use choices and policies that people may not perceive in everyday life. In this critical analysis, we postulate that the current restoration programs are misdirected toward inappropriate species and likely employ outdated techniques. We propose that a reallocation of restoration efforts and resources to populations of existing rare or threatened species would be more ecologically beneficial with higher probabilities of success. We recognize that there can be good reason to restore the upper trophic levels, especially keystone species, but are concerned that the impetus is more about focusing on charismatic megafauna rather than pragmatic choices more likely to be effective.     

Assessing a farmland set-aside conservation program for an endangered butterfly: USDA State Acres for Wildlife Enhancement (SAFE) for the Karner blue butterfly

Private lands provide critical habitat for threatened and endangered species, but only recently have farm-based conservation programs focused on at-risk, invertebrate species. The USDA Conservation Reserve Program State Acres for Wildlife Enhancement (CRP-SAFE) is one of the first federal programs to do so with a Wisconsin-based initiative for the US federally endangered Karner blue butterfly (KBB). This study is the first to evaluate how well the KBB-SAFE provides suitable habitat for the Karner and other butterflies. It also provides a critical foundation for better understanding the potential of new USDA programs that create pollinator habitat including for declining species such as the Monarch butterfly. Here we compare data (2009–2014) on assemblages of grassland communities, blooming floral resource availability, and abundance and richness of butterflies, between KBB-SAFE and native prairie sites. We found that KBB-SAFE and native sites had distinctly different forb species assemblages, with SAFE sites having fewer native blooming species available during the first flight of the KBB yet similar availability during second flight. Butterfly abundance was ultimately greater on native sites compared to SAFE sites, but richness was comparable between sites. We conclude that KBB-SAFE can provide habitat for many grassland species, and serve as surrogate KBB habitat. We provide straightforward management recommendations designed to better meet the needs of the Karner blue and other sensitive butterfly species and we provide further evidence that increased abundance and richness of native forbs and grasses on land formerly used for agriculture can provide habitat for butterflies adapted to early successional habitats.     

Nectar and hostplant scarcity limit populations of an endangered Oregon butterfly

As grassland habitats become degraded, declines in juvenile and adult food resources may limit populations of rare insects. Fender's blue butterfly (Icaricia icarioides fenderi), a species proposed for listing as endangered under the US Endangered Species Act, survives in remnants of upland prairie in western Oregon. We investigated the effects of limited larval hostplants and adult nectar sources on butterfly population size at four sites that encompass a range of resource densities. We used coarse and detailed estimates of resource abundance to test hypotheses relating resource quantity to population size. Coarse estimates of resources (percent cover of hostplant and density of nectar flowers) suggest that butterfly population size is not associated with resource availability. However, more detailed estimates of resources (density of hostplant leaves and quantity of nectar from native nectar sources) suggest that butterfly population size is strongly associated with resource availability. The results of this study suggest that restoring degraded habitat by augmenting adult and larval resources will play an important role in managing populations of this rare butterfly. Received: 20 June 1998 / Accepted: 25 November 1998     

Synergistic effects of an extreme weather event and habitat fragmentation on a specialised insect herbivore

Habitat fragmentation is considered to be one of the main causes of population decline and species extinction worldwide. Furthermore, habitat fragmentation can decrease the ability of populations to resist and to recover from environmental disturbances such as extreme weather events, which are expected to occur at an increasing rate as a result of climate change. In this study, we investigated how calcareous grassland fragmentation affected the impact of the climatically extreme summer of 2003 on egg deposition rates, population size variation and survival of the blue butterfly Cupido minimus, a specialist herbivore of Anthyllis vulneraria. Immediately after the 2003 summer heat wave, populations of the host plant declined in size; this was paralleled with decreases in population size of the herbivore and altered egg deposition rates. In 2006 at the end of the monitoring period, however, most A. vulneraria populations had recovered and only one population went extinct. In contrast, several butterfly populations had gone extinct between 2003 and 2006. Extinction probability was significantly related to initial population size, with small populations having a higher risk of extinction than large populations. These results support the prediction that species of higher trophic levels are more susceptible to extinction due to habitat fragmentation and severe disturbances.     

Local extinction event despite high levels of gene flow and genetic diversity in the federally-endangered Miami blue butterfly

A certain level of genetic diversity and connectivity between populations is necessary to allow small populations to persist over time. In this study, we investigate the last two populations of the highly endangered Miami blue butterfly, one of which was extirpated in 2010. We investigate whether an erosion of genetic diversity was the cause for the extirpation of the Bahia Honda State Park (BHSP) population. As the level of existing molecular diversity within and gene flow between the last two populations of the endangered Miami blue butterfly was unknown, we present data from twelve polymorphic microsatellite loci as an assessment. We show that greater genetic diversity (allelic richness and observed heterozygosity) than originally predicted existed in the BHSP population prior to its extirpation and values were even greater in the Key West National Wildlife Refuge population. Allelic frequencies show short-range gene flow between neighboring habitat patches and underline the importance of habitat connectivity. It does not appear that loss of genetic diversity was the cause for the loss of the BHSP population. Greater consideration of habitat connectivity should be considered for short and long-term conservation and management of this taxon.     

The influence of wild boar <Emphasis Type="Italic">(Sus scrofa)</Emphasis> on microhabitat quality for the endangered butterfly <Emphasis Type="Italic">Pyrgus malvae</Emphasis> in the Netherlands

The decline of open habitats in Europe, such as semi-natural grasslands and heathlands, has caused a general decline in biodiversity, which has been well documented for butterflies. Current conservation practices often involve grazing by domestic livestock to maintain suitable butterfly habitats. The extent to which wild ungulates may play a similar role remains largely unknown. Through their rooting activity, wild boar could be effective to reduce grass encroachment and restore pioneer microhabitats that are vital to many grassland insects in temperate climates. Here, we assessed the microhabitat requirements of Pyrgus malvae, an endangered butterfly of heathland and grassland habitats in the Netherlands, with special attention for the influence of wild boar rooting. To date, oviposition site selection of this species has concentrated on calcareous grasslands, whereas we also include heathlands. Overall, larval occupancy was higher in warm, open and sparsely vegetated microhabitats, which supports earlier findings. In heathland, microhabitat occupancy was positively affected by bryophyte and litter cover. In heath-grassland mosaic, microhabitat occupancy was also influenced by bryophyte and litter cover, but in addition low grass cover increased occupancy by favouring host plants. In grassland, only low grass cover and host plant cover determined microhabitat quality. Across all habitats, occupied microhabitats were characterized by lower vegetation as well as higher average daytime temperatures than unoccupied microhabitats. We discovered that wild boar play an important role in reducing grass cover by shallow rooting in grass patches, thereby increasing host plant availability. Hence, wild boar may have an added value in maintaining and restoring P. malvae microhabitats in grassland habitats in addition to grazing by domestic livestock.     

Consequences of habitat fragmentation for plant species: Do we know enough?

Habitat fragmentation is one of the most important causes for the decline of plant species. However, plants differing in phylogeny, habitat requirements and biology are likely to respond differently to habitat fragmentation. We ask whether case studies on the effects of habitat fragmentation conducted so far allow generalizations about its effects on the fitness and genetic diversity of populations of endangered plant species. We compared the characteristics of plant species endangered in Germany whose sensitivity to habitat fragmentation had been studied with those of the endangered species that had not been studied. We found strong discrepancies between the two groups with regard to their taxonomy and traits relevant to their sensitivity to habitat fragmentation. Monocots, graminoids, clonal, abiotically pollinated and self compatible species were underrepresented among the studied species, and most study species were from a few habitat types, in particular grasslands. We conclude that our current knowledge of the effects of habitat fragmentation on plant populations is not sufficient to provide widely applicable guidelines for species management. The selection of species studied so far has been biased toward species from certain habitats and species exhibiting traits that probably make them vulnerable to habitat fragmentation. Future studies should include community-wide approaches in different habitats, e.g. re-visitation studies in which the species pool is assessed at different time intervals, and population-biological studies of species from a wide range of habitats, and of different life forms and growth strategies. A more representative picture of the effects of habitat fragmentation would allow a better assessment of threats and more specific recommendations for optimally managing populations of endangered plants.     

Relative importance of resource quantity, isolation and habitat quality for landscape distribution of a monophagous butterfly

Fragmentation of food resources is a major cause of species extinction. We tested the effects of habitat area, isolation and quality for the occurrence and population density of the endangered butterfly Polyommatus coridon . Polyommatus coridon larvae are monophagous on the plant Hippocrepis comosa, and both species are specialised on calcareous grassland, which is an endangered and highly fragmented habitat type in Germany.
In 2001 we surveyed all known calcareous grasslands (n=298) around the city of Göttingen (Germany) to map the population size of H. comosa in these habitats. Further, habitat isolation (between-patch distance: 70–7220 m) and habitat quality (cover of flowering plants, height of herb layer, percent bare ground, cover of shrub layer, wind protection, inclination) were quantified. Hippocrepis comosa occurred on only 124 fragments, which were then surveyed by 20 min transect counts for adult P. coridon in 2001 and 2002.
Occurrence and population density of P. coridon were largely determined by the population size of its larval food plant, which was correlated with grassland area. Effects of habitat isolation and habitat quality on P. coridon populations contributed only little to the explanation.
In conclusion, this monophagous habitat specialist depended on large habitats with large food plant populations to exist in viable populations. Habitat isolation and quality appear to contribute to occurrence and density patterns only in landscapes where these factors shift towards extremes, therefore general recommendations for conservation programs are difficult as they depend on regional distinctions.     

The conservation of declining butterfly populations in Britain and Europe: priorities, problems and successes

The status, ecology and conservation of butterflies in Europe and Britain are reviewed, as a background to the National Trust's past and future contribution to British conservation. Britain has a poor butterfly fauna by European standards, the main areas of endemism and species richness being in the Alps and southern Europe. To date, the main declines among European butterfly populations have occurred across central-northern Europe, with slightly higher extinction rates in mainland countries than in Britain. The main causes of decline are biotope destruction, the loss of certain species' habitats within surviving semi-natural biotopes due to changed land management, and a failure by several species to track the patches of their habitat that are still being generated in modern fragmented landscapes. Until recently, most conservation programmes failed to take account of the latter two factors, resulting in many local extinctions of rare butterfly species even in conservation areas. Recent measures have been much more successful; many were first tested on National Trust properties.     

Dynamics in a butterfly–plant–ant system: influence of habitat characteristics on turnover rates of the endangered lycaenid Maculinea alcon

Abstract.  1.  Maculinea alcon , a myrmecophilic, stenotopic lycaenid butterfly is restricted to wet heathlands, bogs, and nutrient-poor hay meadows. Due to intensification of agriculture and decrease of extensively grazed meadows, many suitable habitats have disappeared and the remaining ones are highly fragmented and deteriorated.
2. Historical distribution data and a comparison with the present occupation of patches show the decline of this critically endangered butterfly in north-west Germany. Most of the populations in north-west Germany are small and often geographically isolated.
3. In summer 2002, two-thirds of 77 investigated potential patches were unoccupied as a result of unsuitable habitat structure and habitat fragmentation.
4. Several habitat parameters were highly significantly correlated with the presence of M. alcon , in particular the distribution pattern of the host plant Gentiana pneumonanthe. Furthermore, butterflies were absent from many patches with an incidence probability below 50% with respect to patch size and isolation.
5. In the nature reserve Lüneburger Heide, part of the study area, M. alcon populations have been observed since 1995. Typical turnover of local populations could be detected during these years. Extinctions and re-colonisations have stabilised the presence of this species in a metapopulation in this nature reserve.
6. These data show the importance of different factors on different spatial levels influencing the presence of this endangered butterfly.     

Phylogeographic signal variation in mitochondrial DNA among geographically isolated grassland butterflies

Aim We surveyed mitochondrial DNA (mtDNA) sequence variation among regionally isolated populations of 10 grassland‐associated butterfly species to determine: (1) the utility of phylogeographic comparisons among multiple species for assessing recent evolutionary patterns, and (2) the respective roles of isolation attributable to range disjunction versus isolation attributable solely to geographic distance in establishing divergence patterns. Location The Peace River grasslands of northern Alberta and British Columbia, Canada, which are isolated by 300+ km from similar communities to the south. Methods We sequenced mtDNA (1420 bp of cytochrome c oxidase subunit I) from five grassland‐restricted butterfly species that have geographically disjunct populations and from five ecologically broader species that have more continuous distributions across the same regions. Using analysis of molecular variance (AMOVA), Mantel and partial Mantel tests, and haplotype networks, we compared population structure within and between species in order to assess the validity of single‐species phylogeographic characterizations. We then contrasted variance components between disjunct and continuously distributed species to assess whether divergences were correlated more with disjunction or with geographic distance. Results Single‐species analyses varied substantially within both the disjunct and the continuous groups. One species in each of these groups had mtDNA with unusually deep intraspecific mitochondrial lineage divergences. On the whole, however, the five species with disjunct ranges exhibited greater divergence between geographically distant populations than did the five species with continuous distributions. Comparison of variance components between disjunct and continuous species indicated that isolation attributable only to geographic distance was responsible for up to half of the total sequence variation between disjunct populations of grassland butterflies. Main conclusions Our findings show that single‐species phylogeographic analyses of post‐Pleistocene butterfly distributions are inadequate for characterizing regional biogeographic divergence histories. However, comparison of mtDNA sequence divergences between groups of disjunct and continuously distributed species can allow isolation attributable to range interruption to be quantitatively distinguished from isolation attributable solely to gene flow attenuation over the same geographic area.     

Landscape composition and habitat area affects butterfly species richness in semi-natural grasslands

During the last 50 years, the distribution and abundance of many European butterfly species associated with semi-natural grasslands have declined. This may be the result of deteriorating habitat quality, but habitat loss, resulting in decreasing area and increasing isolation of remaining habitat, is also predicted to result in reduced species richness. To investigate the effects of habitat loss on species richness, we surveyed butterflies in semi-natural grasslands of similar quality and structure, but situated in landscapes of different habitat composition. Using spatially explicit habitat data, we selected one large (6–10 ha) and one small (0.5–2 ha) grassland site (pasture) in each of 24 non-overlapping 28.2 km² landscapes belonging to three categories differing in the proportion of the area that consisted of semi-natural grasslands. After controlling for local habitat quality, species richness was higher in grassland sites situated in landscapes consisting of a high proportion of grasslands. Species richness was also higher in larger grassland sites, and this effect was more pronounced for sedentary than for mobile species. However, the number of species for a given area did not differ between large and small grasslands. There was also a significant relationship between butterfly species richness and habitat quality in the form of vegetation height and abundance of flowers. In contrast, butterfly density was not related to landscape composition or grassland size. When species respond differently to habitat area or landscape composition this leads to effects on community structure, and nestedness analysis showed that depauperate communities were subsets of richer ones. Both grassland area and landscape composition may have contributed to this pattern, implying that small habitat fragments and landscapes with low proportions of habitat are both likely to mainly contain common generalist species. Based on these results, conservation efforts should aim at preserving landscapes with high proportions of the focal habitat.     

Does isolation affect phenotypic variability and fluctuating asymmetry in the endangered Red Apollo?

Isolated populations represent one of the main focuses in conservation biology. Long-term isolation often causes losses of genetic diversity and as a consequence might reduce individual fitness. Morphometric characters can be used as suitable markers to analyse ecological stress and individual fitness of local populations. Asymmetry in bilateral symmetry is used as a measure for developmental instability of populations and is often negatively correlated with population size and low genetic diversity. As a study system, we selected the endangered butterfly Parnassius apollo, which occurs in small and isolated remnant populations in Central Europe, but also in fairly large metapopulations in the Alps. We analysed wing morphometrics (shape and size characters) of 812 individuals representing (1) already extinct, (2) highly isolated and (3) still interconnected populations. Seventeen landmarks on veins were used to analyse morphological variances in the wing shape. Our data show significant deviations between landmarks on the left and right wing side within individuals and strong morphological variance among individuals. The highest morphological variability could be found for individuals in the Alps, however, the level of asymmetry was very similar for all populations analysed. The higher morphological variability found in the Alps can be interpreted as a consequence of the higher level of the genetic diversity detectable for this region. Analysis on morphological variance of P. apollo individuals of the Mosel valley using time series ranging from 1895 until today showed no significant rise in asymmetry and no decline of morphological variability over time, although, anthropogenic habitat destruction has caused severe bottlenecks in this population.     

White butterfly (

Once widespread, Cook?s scurvy grass (or nau, Lepidium oleraceum) is now confined to a few offshore populations. Classed as nationally endangered by the New?Zealand Department of Conservation, populations of Cook?s scurvy grass are threatened by a number of factors, including introduced herbivorous insect species such as the white butterfly (Pieris rapae) and white rust infection caused by the oomycete Albugo candida. In this paper, we investigate the occurrence of white butterfly on Cook?s scurvy grass and possible interactions with the white rust infection on the northernmost of the Matariki Islands in the Firth of Thames, New?Zealand. We found that larger host plants were more likely to be infested with white butterfly. The occurrence of white butterfly eggs and larvae also decreased as levels of white rust increased. Twenty-eight percent of the white butterfly larvae collected and reared in the laboratory were parasitised by the braconid wasp species Cotesia rubecula. We also reared a hyperparasitoid belonging to the super-family Chalcidoidea from one of the parasitoid cocoons. Further studies on the trophic interactions between Cook?s scurvy grass, Albugo?candida and white butterfly and its parasitoids could improve the understanding of the threats posed by plant pathogens and insect herbivores to populations of Cook?s scurvy grass, which in turn may lead to new management strategies for conservation.     

Genetic variation and Wolbachia infection status of the lycaenid butterfly Zizina emelina (Lepidoptera,Lycaenidae) from Korean populations

The lycaenid butterfly Zizina emelina emelina (de l’Orza) (previously Zizina otis emelina; Lepidoptera, Lycaenidae) has populations distributed across Japan and Korea. Zizina emelina is listed on Japan’s Red List as an endangered species, owing to the loss of its principal plant food and habitat. Researchers previously investigated the genetic diversity and structure in Japanese populations by using mitochondrial and nuclear DNA analyses alongside their Wolbachia infection status to consider the conservation strategy. In this study, we investigated the genetic variation and Wolbachia infection status of Korean populations and compared our findings with these traits in the Japanese populations. Four novel mitochondrial haplotypes were found in the Korean populations, whereas nuclear DNA analysis revealed one new haplotype and another that matched the one reported previously in Japan. The two known strains of Wolbachia in the Japanese populations were also found in the Korean ones. Mitochondrial DNA analysis demonstrated that no gene flow had occurred between the Japanese and Korean populations. The fact that they share the same nuclear haplotype and Wolbachia strains, however, indicates a low level of population differentiation between the two.