IUCN SSC Mid-Atlantic Island Invertebrates Specialist Group

Newsletter November 2017

Domingo, 17 de Dezembro de 2017

MAIISG November newsletter

Hope everyone is having a good end to 2017, with exciting plans for 2018. This is one of the biggest newsletters we have ever had and thank you for all your contributions, it is really great to see all the exciting work taking place. Articles this month range from new expeditions on Cape Verde to butterflies on Tenerife.

MACDIV project expedition to Cape Verde (Paulo Borges) During three weeks (25th October - 15th November) five researchers (Paulo A.V. Borges, Pedro Cardoso, Maria Romeiras, Jagoba Malumbres-Olarte and Fernando Pereira) participated in the last expedition of Project MACDIV to the Islands of Cape Verde: S. Vicente and St. Antão. A total of five 50m x 50 m plots were setup in lowland dry habits in each island and spiders and beetles were sampled using the COBRA protocol. Using the Macaronesian islands as model systems and spiders (and also beetles) as model organisms. The project MACDIV https://tinyurl.com/y94eunpu aims to advance the fundamental knowledge of the factors responsible for existing diversity patterns. Focusing on local scales, MACDIV intends to dissect the taxonomic, evolutionary and functional basis of spatial heterogeneity in diversity, providing opportunities to understand some of the key processes that have led to the great diversification of life in Macaronesia. Results of MACDIV will be also relevant in contributing to a range of international strategies.

Azorean endemic forest beetles are in great danger (Mario Boieiro) Oceanic island biodiversity is under considerable pressure due to the consequences of human activities like species introductions and natural habitat destruction. In Azores, the native forests suffered a drastic reduction since human colonization in the XVth century, presently occupying less than 5% of the original cover and being extinct in two islands. Many endemic species went extinct during this period, but others manage to survive. In a recent study, 54 forest beetle species endemic to the Azores were assessed for the IUCN Red List and it was found that most are in danger of extinction due to their narrow and fragmented distribution, declining populations and ongoing threats by human activities. Despite intensive fieldwork in Azores, the lack of records for seven endemic beetle species (like Bembidion derelictus, Bradycellus chavesi, Calathus extensicollis) is probably indicative of their extinction. Furthermore, the spread of invasive plant species is a severe threat for endemic beetles since they are quite vulnerable to changes in habitat quality. The Azorean authorities are committed in valuing and protecting the Natural Legacy of the archipelago, including their endemic beetles, and have supported several biodiversity and environmental education studies during the last decades. More recently, several rare endemic invertebrate species have been protected by law and protected areas were designed to safeguard some of these species. However, major efforts need to be addressed to control invasive species (particularly Pittosporum undulatum and Hedychium gardnerianum) and to implement conservation plans for the most highly threatened species, like the beetles Calathus lundbladi

Conservation profiles of Madeira and Selvagens archipelagos endemic spiders (Mario Boieiro) The archipelagos of Madeira and Selvagens are known to host a large number of endemic species, mostly terrestrial arthropods. Of the nearly 200 spider species reported to these archipelagos, 56 are considered endemics. Until recently, only a single species had been evaluated according to the IUCN criteria: the Desertas tarantula Hogna ingens, it is a Critically Endangered species restricted to a small area in Deserta Grande (Desertas islands) being threatened by invasive species, particularly the spread of Phalaris aquatica. In a recent article (Cardoso et al. 2017) analysed the conservation status of all endemic spiders of these archipelagos and identified eleven in urgent conservation need: one rare species Meta barreti has not been recorded for decades, two narrow endemic cavernicolous species (Centromerus anoculus and C. sexoculatus) are declining due to habitat destruction/degradation and most are threatened by fires and invasive species as is the case of Xysticus grohi that is being outcompeted by the introduced congener X. nubilus. In spite of the regular activities carried out by the Madeiran legal authorities to control invasive species and restore natural habitats, efforts should also be addressed to develop monitoring studies targeting terrestrial arthropods, aiming to identify species at risk and early detect invasive species. Cardoso, P., Crespo, L., Silva, I., Borges, P. & Boieiro, M. (2017) Species conservation profiles of endemic spiders (Araneae) from Madeira and Selvagens archipelagos, Portugal. Biodiversity Data Journal 5:e20810 (18 Oct 2017). https://bdj.pensoft.net/article/20810/

Canary Islands & Madeira Butterfly Update 2017 (Martin Wiemers) The Canary Islands and Madeira have many threatened endemic butterfly species (1 CR*, 3 EN, 3 VU); this year’s surveys are described below. Knowledge about their population trends is almost non-existent, while threat levels are increasing, e.g. due to a rising number of invasive species. Only this year, the first Canary Island monitoring scheme started on Tenerife (as reported earlier). Martin Wiemers made two trips to Madeira and the Canary Islands of Gran Canaria, Tenerife, La Gomera and El Hierro in February and August this year to explore options of implementing a butterfly monitoring scheme on Madeira and to assess the status of endemic and invasive butterfly species on the islands. With Sérgio Teixeira from Madeira the government was approached but support seems low and financial means need to be secured for its implementation, this will be further explored. Madeiran Large White Pieris wollastoni (CR) The field studies confirmed that Pieris wollastoni is extinct as it could not been found despite extensive searches across the island and there hasn’t been any confirmed record since 1986. It is currently listed as CR (possibly extinct) on the IUCN Red List. Canary Large White Pieris cheiranthi (EN) had better results and is EN due to a presumed decrease on Tenerife and extinct since 1979 on La Gomera. During the surveys it was found at two locations on Tenerife, in a remote place in the Teno Mountains, and in the centre of Puerto de la Cruz. Here, an egg batch on cabbage proved that the Tenerife population also uses cabbage as larval foodplant, and not only the introduced Tropaeolum majus and native Crambe species. On La Gomera, however, the species was not seen, also not at a place where a small population (probably a reintroduction from Tenerife or La Palma) was observed in 2013. Madeiran Brimstone Gonepteryx maderensis (EN) was observed in small numbers at 5 locations, including early stages on its larval foodplant, Rhamnus glandulosa, which is threatened by destruction of laurel forest, e.g. due to an increase of forest fires. Gonepteryx cleobule (VU) the Canary Island congener, feeds on the same foodplant and is also restricted to remnants of laurel forest on the islands of Tenerife, La Gomera, and La Palma. Luckily, the species was found to be still present on La Gomera, despite the devastating fire in 2012, which destroyed 18% of the island’s laurel forest, mostly within Garajonay National Park. Madeiran Speckled Wood Pararge xiphia (EN) is threatened by competition with the invasive congener Pararge aegeria, which became established from North Africa in the 1970s. The surveys showed that the endemic species is slowly losing ground, not only in disturbed habitats, where it is now either extinct or extremely marginalized, but also in well preserved laurel forest. Only one site was found where P. xiphia still seems to be more frequent than P. aegeria, and this site is in the extreme northwest of the island, furthest from the probable starting point of the latter species’ invasion.

 

Update on Invertebrate Conservation Work on St Helena (Mike Jervois) The Darwin Plus funded invertebrate survey on St Helena has been going well. We are now ten months into the year-long malaise trapping programme. The aim of the project is to see whether conservation work for habitats is also working for their associated invertebrates. We also hope to be able to assess the impacts of invasive predatory species on invertebrates, and see how seasonality affects invertebrate biodiversity. The collection and the survey equipment will be permanently housed at the St Helena Museum, making it the first time a permanent collection has been retained on island. A lab space is being constructed at the museum so that local and visiting researchers will have a place to use the collection. A field guide of St Helena invertebrates, authored by Roger Key and Vicky Wilkins, with contributions from the project team, is nearing completion. The field guide will be invaluable for future conservation of our invertebrates.

Increasing funds for Mid Atlantic bugs (Vicky Wilkins) An important part of improving the conservation and reducing the threats to the amazing invertebrates of the Mid Atlantic Islands is to improve the funding and resources that is invested in these area. I have recently supported two applications for funding for conservation projects on MAIISG islands. One for the Ascension Islands for a partnership project looking to initiate invertebrate conservation, this includes red listing and species action planning for the endemic invertebrates of the island. The project also includes extensive biosecurity actions recognising the threats that non-native invertebrates create on islands, particularly to native invertebrates. In addition a molluscs application was submitted for the Endangered Moniz ground snail Geomitra moniziana to the Mohamed bin Zayed species conservation fund for field work on ecology and distribution, ex-situ conservation, legal protection of sites and public outreach. If anyone is interested in support for funding for invertebrate projects please contact Vicky Wilkins

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How many endemic species of arthropods are in Madeira archipelago?

There are about 921 arthropod species and subespecies endemic to Madeira. See also http://sea-entomologia.org/IDE@/revista_6B.pdf

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