Nearly 60% of Europe’s threatened butterflies (22 of 38 species) are endemics, and of these six species are confined to the Macaronesian Islands. The islands are therefore a hotspot of threatened endemic butterfly species in Europe. Madeira is home to three of the most endangered species, Gonepteryx maderensis Madeiran Brimstone (Endangered), Pararge xiphia Madeiran Speckled Wood (Endangered) and Pieris wollastoni Madeiran Large White (Critically Endangered).
Thanks to the EU’s LIFE4BEST funding programme for its Overseas Regions, Butterfly Conservation Europe has been working in partnership with Madeira Flora & Fauna to conserve these three endangered species. Whilst the funded phase only lasts from July 2021 to August 2022 a key output of the project will be the production of Action Plans for each butterfly which will hopefully guide future conservation action on Madeira.
The first phase of the project was to improve our knowledge of the distribution and abundance of the target species. During September and October 2021, the partnership completed 41 days of survey across 49 sites, mainly focussing on the pristine laurel forests in the north of the island but also sampling other habitats such as mixed forest, exotic forest and mountain heathland.
The team undertook 648 15-minute Counts along 534 km of survey route, recording all butterfly species and their abundance. Some more inaccessible areas were surveyed using drones and there are plans to increase their use in 2022. Over10,000 individual butterflies of fourteen species were recorded during the surveys. There were no sightings of P. wollastoni and as it has not been reliably recorded since 1986, must now be presumed globally extinct - the first European butterfly species in this unenviable category.
G. maderensis was only recorded on 33% of survey routes (117 individuals) and more or less confined to laurel forests, but P. xiphia was both more widely distributed (80% of survey routes) and more abundant (>2,000 individuals) and also encountered in other habitats. Pararge aegeria Speckled Wood is a recent colonist of Madeira and there are concerns it may compete with P. xiphia. This species was recorded on 86% of survey routes (>2,600 individuals), including every one where P. xiphia occurred. Another endemic but not considered threatened is Hipparchia maderensis Madeiran Grayling, which was seen on 41% of survey routes and was the most abundant species overall (nearly 2,700 individuals). The locations of some larval hostplants were also recorded, in particular Rhamnus glandulosa which was quite scarce, probably limiting the distribution of G. maderensis. These data will enable key areas of butterfly habitat to be mapped in order to ensure they can be adequately protected and managed in the future.
The project also aims to establish a Madeira Butterfly Monitoring Scheme (maBMS), which will include establishing transects in the pristine laurel forest to be walked by the staff of the key local stakeholder, the Institute of Forests and Nature Conservation (IFCN). Their staff will be provided with training, as will other volunteers recruited through a programme of awareness raising workshops for civil society (including nature guides, students, farmers) and tourists. The maBMS will enable the effectiveness of conservation measures targeted at butterflies to be assessed in the coming decades.