Time filter

Source Type

Granollers, Spain

Stefanescu C.,Butterfly Monitoring Scheme | Carnicer J.,University of Groningen | Penuelas J.,University of Barcelona
Ecography | Year: 2011

Although it is well established that butterfly richness is affected by climate and human factors (e.g. habitat disturbance and degradation) at different spatial scales, the drivers behind these changes vary greatly according to the geographical region and the ecology of the species concerned. It is essential that this variation be understood if trends in diversity are to be predicted with any degree of confidence under a scenario of global change. Here we examine patterns of butterfly species richness among groups differing in degree of habitat specialization, diet breadth and mobility in the north-west Mediterranean Basin, a European hotspot for this taxon. We analyze a large number of butterfly communities and take into consideration the main potential drivers, that include climatic, geographic and resource variables, landscape structure and human environmental impact at different spatial scales. Our study shows that both climatic and anthropogenic factors play an important role in determining butterfly species richness in the north-west Mediterranean Basin, but that their relative impact differs between specialist and generalist groups. At lower altitudes, water availability, a product of the interplay between temperature and rainfall, and negative effects of temperature appear as the most determinant factors. Maximum diversity was observed at mid-altitudes, which reveals the importance from a conservation point of view of Mediterranean mountain ranges. The results suggest serious population declines in specialist species restricted to mountain areas as a result of climate warming in combination with habitat loss caused by the abandonment of grazing and mowing. They also suggest negative trends for generalist species due to an increase in aridity in combination with an increase in intensification of human land use in lowland areas. Such synergies are expected to lead to rapid declines in Mediterranean butterfly populations in the coming years, thereby posing a severe threat for the conservation of European biodiversity. © 2011 The Authors. Ecography © 2011 Ecography. Source

Donoso I.,Linc Global | Stefanescu C.,Butterfly Monitoring Scheme | Martinez-Abrain A.,University of La Coruna | Traveset A.,Linc Global
Oikos | Year: 2016

Although much information has been accumulated on the effects of climate change on particular species worldwide, research aimed at assessing how such change influences biotic interactions from a community-wide perspective is still in its infancy. We contribute to filling in this gap by analyzing a 17-year (1996-2012) dataset that includes records of flower-visitation interactions between 12 butterfly species and 17 plant species in a coastal wetland area in northeastern Iberian Peninsula. We assessed the extent to which temporal asynchronies between plants and adult butterflies are influenced by different climatic variables that affect both plant and insect phenologies. Temperature and degree of aridity at various monthly summaries were used as predictors of the plant-butterfly phenological asynchrony. We identified the seasonal window with the greatest effect on asynchronies for two butterfly generations (spring and summer), and assessed whether the magnitude of asynchrony is associated with the level of butterfly specialization. We used generalized linear mixed models considering a total of 39 plant-butterfly interactions. Average asynchrony was higher in the spring generation and dry conditions during winter lead to decreased temporal overlap with flowers in this butterfly generation, whereas dry conditions in the spring lead to decreased temporal overlap in the summer butterfly generation. The magnitude of the effect was consistently small at the community level (all interactions pooled). Moreover, no clear climatic trend over the study time frame was detected. Finally, specialized and generalized butterflies in their resource use as adults were similarly vulnerable to asynchronies, in contrast to previous predictions of greater mutualistic disruptions in species with narrower niches. We conclude that a least in the Mediterranean region, phenological asynchronies might be more affected by aridity level than by temperature itself, and thus the former can be a key climatic trait to make better predictions in this region. © 2015 The Authors. Source

Stefanescu C.,Butterfly Monitoring Scheme | Stefanescu C.,Global Ecology Unit | Askew R.R.,Beeston Hall Mews | Corbera J.,Seccio de Ciencies Naturals | Shaw M.R.,Honorary Research Associate
European Journal of Entomology | Year: 2012

The painted lady butterfly (Vanessa cardui) (Lepidoptera: Nymphalidae: Nymphalinae) is well known for its seasonal long-distance migrations and for its dramatic population fluctuations between years. Although parasitism has occasionally been noted as an important mortality factor for this butterfly, no comprehensive study has quantified and compared its parasitoid complexes in different geographical areas or seasons. In 2009, a year when this butterfly was extraordinarily abundant in the western Palaearctic, we assessed the spatial and temporal variation in larval parasitism in central Morocco (late winter and autumn) and north-east Spain (spring and late summer). The primary parasitoids in the complexes comprised a few relatively specialized koinobionts that are a regular and important mortality factor in the host populations. However, there was a strong seasonal variation in the level of parasitism. In Spain percentage parasitism was more than four times higher in late summer than in spring (77.3% vs. 18%), while in Morocco it was five times higher by the end of winter than in the autumn (66.2% vs. 13.2%). In both regions the build up of parasitoid populations occurred after V. cardui had bred in the same general area over successive generations, and this may represent a selective force favouring seasonal migration to enemy-free space. Source

Krauss J.,University of Bayreuth | Bommarco R.,Swedish University of Agricultural Sciences | Guardiola M.,Autonomous University of Barcelona | Heikkinen R.K.,Finnish Environment Institute | And 13 more authors.
Ecology Letters | Year: 2010

Intensification or abandonment of agricultural land use has led to a severe decline of semi-natural habitats across Europe. This can cause immediate loss of species but also time-delayed extinctions, known as the extinction debt. In a pan-European study of 147 fragmented grassland remnants, we found differences in the extinction debt of species from different trophic levels. Present-day species richness of long-lived vascular plant specialists was better explained by past than current landscape patterns, indicating an extinction debt. In contrast, short-lived butterfly specialists showed no evidence for an extinction debt at a time scale of c. 40 years. Our results indicate that management strategies maintaining the status quo of fragmented habitats are insufficient, as time-delayed extinctions and associated co-extinctions will lead to further biodiversity loss in the future. © 2010 Blackwell Publishing Ltd/CNRS. Source

News Article
Site: http://phys.org/biology-news/

Previous studies have demonstrated that these chemicals appear to be harming bees, birds and other wildlife. The new study is the first scientific evidence of a possible negative impact on widespread UK butterflies. The chemicals remain in the environment and can be absorbed by the wildflowers growing in field margins, many of which provide a nectar source for butterflies and food-plants for their caterpillars. Researchers at the Universities of Stirling and Sussex,in partnership with Butterfly Conservation and the Centre for Ecology and Hydrology, found population trends of 15 species showed declines associated with neonicotinoid use, including Small Tortoiseshell, Small Skipper and Wall species. The study, published today (24 November 2015) in the journal PeerJ, is based on data gathered by volunteers from more than 1000 sites across the UK as part of the long-running UK Butterfly Monitoring Scheme (UKBMS). Dave Goulson, Professor of Biology at the University of Sussex said: "Many of us can remember a time when our meadows and hedgerows had far more butterflies, bees and other insects than today. This study adds to the growing mountain of evidence that neonicotinoids are one of the causes of these declines." Ecologist Dr Andre Gilburn of the University of Stirling, who led the study, said: "Our study not only identifies a worrying link between the use of neonicotinoids and declines in butterflies, but also suggests that the strength of their impact on many species could be huge." Dr Tom Brereton, Head of Monitoring at Butterfly Conservation, said: "We are extremely concerned with the findings of the study and are calling for urgent research to see whether the correlations we found are caused by neonicotinoid use, or some other aspect of intensive farming. Widespread butterflies have declined by 58 percent on farmland in England over the last 10 years, giving concern for the general health of the countryside and for these and other insects in particular." More information: Andre S. Gilburn et al. Are neonicotinoid insecticides driving declines of widespread butterflies?, PeerJ (2015). DOI: 10.7717/peerj.1402

Discover hidden collaborations