5 research outputs found
The state of Britain’s larger moths 2021
This report summarises current knowledge of the state of Britain’s c.900 species of larger moths, presenting analyses of long-term change based on millions of records gathered through the Rothamsted Insect Survey (RIS) and National Moth Recording Scheme (NMRS)
The effects of habitat fragmentation on niche requirements of the marsh fritillary, Euphydryas aurinia, (Rottemburg, 1775) on calcareous grasslands in southern UK
The marsh fritillary, Euphydryas aurinia, has
declined greatly in distribution across its range within
Europe, resulting in its designation as a protected species
under Annex II of the 1979 Bern Convention and the EC
Habitats and Species Directive. The decline has been
linked to a marked reduction in the extent of suitable calcareous and wet grassland habitats, habitats which have
been lost through conversion of land to agriculture or urban
areas, or reduced in quality due to inappropriate management.
The UK is now one of the major strongholds for this
butterfly in Europe, although much of the remaining habitat
is small, isolated and highly fragmented. E. aurinia populations fluctuate greatly due to the combined effects of
biotic (e.g. parasitoids) and abiotic (e.g. climate change)
factors. We quantified the habitat associations of larval
webs of E. aurinia on fragmented versus extensive
(unfragmented) calcareous grassland habitat in southern
England to test the hypothesis that habitat requirements of
E. aurinia are more constrained within fragmented landscapes.
Within both fragmented and unfragmented landscapes
the quality and quantity of its main host plant in the
UK, Succisa pratensis, was positively related to numbers of
E. aurinia larval webs found. The sward height was also
important at predicting the distribution of larval webs in
both landscapes, although the heights were greater within
sites in the unfragmented (&20 cm) compared to fragmented
(&15 cm) landscape. We also found significant effects of elevation and the cover of bare ground on numbers of larval webs. Elevation was strongly correlated with the availability of host plant, whilst bare ground was
only significant on sites within the fragmented landscape,
showing a negative relationship with number of larval
webs. Our results further emphasise the importance of not
only maintaining the habitat quality of extant calcareous
grassland sites for E. aurinia in the UK, but also increasing the size and connectivity of these sites to increase the chances and rate of (re)colonisation of unoccupied but suitable habitat. In addition, we show that the habitat requirements of E. aurinia on sites in a large unfragmented landscape may be less specific and thus require less extensive management than that required to create optimal conditions necessary at smaller, more isolated sites in fragmented landscapes