News - Study Into Importance of Habitat
University of Exeter press release
Most wild species are expected to colonise northwards as the climate warms, but how are they going to get there when so many landscapes are covered in wheat fields and other crops? A study led by a scientist on the University of Exeter's Tremough Campus, Penryn, shows it is possible to predict how fast a population will spread. The research reveals the importance of habitat conservation in helping threatened species survive environmental change
Published in the journal Proceedings of the Royal Society B, the research tracks the recovery of a rare British butterfly over 18 years and offers hope for the preservation of other species.
The study was led by Dr Rob Wilson of the University of Exeter's Centre for Ecology and Conservation on the Tremough Campus. Conducted by the Universities of Exeter, York and Sheffield and funded by the Natural Environment Research Council, the study could inform future conservation policy to help safeguard vulnerable species against the effects of climate change and habitat destruction.
The silver-spotted skipper is a rare butterfly confined to chalk grasslands in southern England. 80% of such habitats were destroyed in the twentieth century as a result of changes to farming. By 1982 there were fewer than 70 populations of the species, almost all in five networks of chalk hills, and covering an area of only two square kilometres (less than a square mile).
Between 1982 and 2000 a number of conservation measures helped rescue the species from extinction, including reintroducing grazing livestock. The species has also benefited from warmer temperatures resulting from climate change. By 2000, the butterfly had expanded its distribution by colonizing suitable areas of habitat, and occupied an area measuring 21km2, ten times larger than in 1982. However, it only expanded up to 30 km from its existing colonies, and in most regions the range expansions were much shorter.
The research team applied a mathematical model to the geographical spread of the butterfly. They concluded that the recovery of the species depended on the quality and proximity of suitable chalk grassland. In other words, the 'fragmentation' of suitable habitat by human activity held up the rate at which the butterfly could spread through the landscape. The upside was that the researchers could accurately predict how far the species expanded in different landscapes. This suggests that a similar model could be used to predict the conservation activities which most benefit the recovery of this and other rare species.
Lead author Dr Rob Wilson of the University of Exeter's Tremough Campus said: "Natural habitats are becoming increasingly fragmented, and many species are now confined to tiny suitable areas. To safeguard these species for the future we need to know where to manage habitat - not just to save the few remaining populations, but to bring about genuine recovery. The results of our study show that it may be possible to develop conservation programmes which will increase recovery rates for such species."
The £100 million Tremough Campus is a Combined Universities in Cornwall initiative -of which the University of Exeter and University College Falmouth are two of the founding partners. It is funded mainly by the European Union (Objective One), the South West Regional Development Agency, and the Higher Education Funding Council for England, with support from Cornwall County Council. Set in 70 acres of countryside, but close to the waterside towns of Penryn and Falmouth, the campus offers a lively student community. The University of Exeter now offers degrees in Biology, Modern Celtic and Cornish Studies, English, Geology, Geography, History, Law, Mining Engineering, Politics and Renewable Energy on its Tremough Campus, which has expanded rapidly as part of the Combined Universities in Cornwall initiative.