As spring came around this year, researchers from the University of Exeter’s Environment and Sustainability Institute were once again busy conducting surveys across the Lizard for one of our nationally rare butterflies, the marsh fritillary Euphydryas aurinia. The mission? To better understand the habitat requirements of this declining butterfly, with the ultimate goal of developing meaningful management practices to conserve these important populations for the future.
In March the black caterpillars can be seen basking and feeding together within silken webs near to their hostplant Devil’s-bit scabious Succisa pratensis. Extensive surveys for these conspicuous webs revealed populations at 8 sites (see here for last year’s survey). Although this is good news, populations can fluctuate largely from year to year and remain very sensitive to changes in climate and habitat. So we must obtain a sound understanding of their habitat requirements in order to give them the best possible chance...
... And what better way to do this than from the air! In recent years, drones and other Unmanned Aerial Vehicles (UAVs) have transformed ecological research. But could UAVs be used to help conserve the marsh fritillary? With blue skies overhead, a kite and a drone each equipped with a camera were flown over a marsh fritillary site, capturing detailed aerial photographs of the habitat below. With the aid of some smart software the photos can be stitched together to end up with a 3D reconstruction of the habitat.
Complimenting ground-based surveys, this novel perspective can tell us more about vegetation structure and topography, which influence local microclimates.
Combine this information with the precise locations of where larval webs occurred this year and we can start to piece together the puzzle of exactly what sort of habitat, and thus land management, the marsh fritillary needs to persist here on the Lizard. Currently the study is still in progress though findings could demonstrate the importance of UAVs to conservation, by allowing an enhanced understanding of species habitats - from the air.
Published: May 2016
Author: Amber Nichols, MSc Conservation and Biodiversity student