The Savage Islands, or Selvagens Islands (, ; also known as the Salvage Islands"Geographical Names", National Geospatial-Intelligence Agency, Bethesda, Maryland, USAKing, Dean & Hattendorf, John B., A Sea of Words: A Lexicon and Companion to the Complete Seafaring Tales of Patrick O'Brian, Open Road Media, March 20, 2012), are a small Portuguese archipelago in the North Atlantic Ocean, south of Madeira and north of the Canary Islands."Ilhas Selvagens (Selvagens Islands)". UNESCO World HeritageSitesLuís Carvalho, Nuno Leitão (2005) The archipelago includes two major islands, Selvagem Grande and Selvagem Pequena, each surrounded by a cluster of islets and reefs, with the total area of . The archipelago is administered as part of the Portuguese municipality of Funchal, belongs to the Madeiran civil parish of Sé, and is the southernmost point of Portugal.
It was designated a natural reserve in 1971, recognising its role as a very important nesting point for several species of birds. Since then, the susceptible bird populations (namely Cory's shearwater) and nearby waters have been more closely protected by the Portuguese government. Given its status, remoteness and few fresh water sources, the archipelago is today largely uninhabited. The only residents year-round are stationed on Selvagem Grande Island, which includes reserve staff and scientists conducting research on wildlife. Two rangers are also usually resident on Selvagem Pequena between May and October. In May 2016, a National Geographic Society scientific expedition prompted the extension of the marine reserve.
Geography
The Savage Islands are part of Macaronesia, which comprises several island groups in the North Atlantic Ocean, near Europe and off the coast of Morocco in North Africa. The archipelago lies about from Madeira and from the Canary Islands. The islands are considered to be a column branch that extends from the Canary Islands at a depth of . The total land area of the Savage Islands is . They have little fresh water and are surrounded by reefs (which make access difficult and dangerous). The archipelago consists of two major islands and several islets, in two groups about apart, designated:
Northeast Group – includes the main island of Selvagem Grande () and three small islets: Sinho Islet (Portuguese: Ilhéu Sinho), Palheiro do Mar, and Palheiro da Terra. Southwest Group – including the main island of Selvagem Pequena () and Fora Islet (Portuguese: Ilhéu de Fora, ), also called Great Piton and Little Piton respectively, it is surrounded by a group of very small islets (Alto, Comprido and Redondo) and a group collectively known as the Northern Islets (Portuguese: Ilhéus do Norte).
The geological history of the archipelago can be traced to the Opening of the North Atlantic Ocean , at the end of the Triassic period.
The islands' physical characteristics are the consequences of mountain-forming and volcanic forces that occurred between , typical of many of the islands of Macaronesia. The islands were created during the Oligocene period , from a large submarine volcano generated by the Canary hotspot and shaped by erosion and marine sedimentation. The larger islands and islet (Grande, Pequena and Fora, respectively) are the remnants of the peaks of these submarine mounts, and although located north of the Canaries, they were never connected to the African continent or any other continental landmass.
The archipelago had 2 historic magmatic activity periods, one and the other one and two significant hiatuses between eruptions, the first lasted 12 million years and the second lasted 4.6 million years, a unique occurrence to oceanic volcanic islands.
The islands themselves are crossed by many calcareous faults, some marbleised, and made of basaltic rock, ash, and other volcanic materials. On Selvagem Grande there are remnants of extinct cones, such as Atalaia, Tornozelos and Cabeço do Inferno. Other areas are sand covered from extensive aeolian, fluvial and marine erosion; headlands include Atalaia and Leste on Selvagem Grande, and Norte, Oeste, Leste and Garajaus on Selvagem Pequena.
Beaches are uncommon in the islands, although Selvagem Pequena has some beaches of cobbles and coarse and medium sands.
Climate
Though only as recently as 2016 was a meteorological station installed by IPMA on Selvagem Grande, the islands are regarded as having a mild subtropical desert climate (Köppen: BWh), with temperatures warmer than those of Madeira. Due to their small size, the surrounding Atlantic and other exterior factors dictate the weather patterns felt throughout the year. Both diurnal and seasonal temperature variation are very low. The lack of any significant mountain range diminishes the amount of orographically induced precipitation and its exposure to the cool Canary Current prevents the formation of convective clouds for most of the year. Summers hover between during the day and during the night, and winters average around during the day and during the night. Saharan dust can occasionally come into contact with the islands, bringing much higher temperatures. Winds blowing from south-west can also bring exceptionally heavy rainfall. The dominant wind direction is Northeast (NE).
In the past these islands would have had a higher level of moisture than they do now, which may justify the presence of a large number of fossil shells of land snails (Theba macandrewiana) on the plateau of Selvagem Grande.
+Average wind speed (km/h) 2017, 2018 & 2020JanFebMarAprMayJunJulAugSepOctNovDecYearSelvagem Grande31.131.032.423.525.325.533.032.824.522.625.727.328.4
Fauna and flora The scientific and natural interest of this tiny group of islands lies in its marine biodiversity, its unique flora and fauna and many avian species that breed annually on its rock cliffs or use them on their stopover on normal migratory patterns.
The Savage Islands and their surrounding waters present pristine marine and terrestrial communities, with many of their ecosystems in an unaltered state (such as in Selvagem Pequena and Ilhéu de Fora). With habitat for a wide variety of endemic species and species in an unfavorable state of conservation, they are a unique example of the Macaronesian biogeographical region biota.
The archipelago has the highest density (per 100 km) of exclusive endemic terrestrial plants of the Macaronesian Region and the lowest number of exotic terrestrial plants taxa (17) of the Madeira Region.
Although commercial tours of the islands and their biomes are available, all visitors require authorisation from the Madeira Nature Park, the regional environmental authority.
Birds
Savage Islands are one of the most important breeding areas for seabirds of Macaronesia and the North Atlantic, offering conditions that are unique in all the world. About 3% of the birds species are resident species, the remaining are migratory species. The abundance of birds on the islands, at one time, made the islands an attractive hunting area for peoples of the region. At the end of the 19th century the German naturalist Ernst Schmitz noted that 20–22,000 Cory's shearwaters were hunted in September or October in the islands;Ernst Schmitz (1893), "Die Puffinenjagd auf den Selvagens-Inseln im jahre 1892", Ornithologisches Jahrbuch 1893, Austria, pp.141-147 the hunts continued until 1967. Madeiran expeditions to the islands were responsible for the killing of juvenile birds for food, while their down was used to stuff pillows and comforters.
Presently the islands are home or stopover for: Cory's shearwaters (>30,000), white-faced storm-petrel (>80,000), Bulwer's petrel (approximately 4000), North Atlantic little shearwater (1400), Madeiran storm-petrel (1500), yellow-legged gull (50), common tern (>60), roseate tern (<5) and Berthelot's pipit (the only resident bird species); which are subjects of annual scientific expeditions. Many of these species are vulnerable to other local predator bird species, like the yellow-legged gull, which will consume both eggs and chicks (the white-faced storm-petrel and Bulwer's petrel are primarily susceptible). The islands are home to the largest known breeding colony in the world of Cory's shearwater and the only site in the Atlantic where Swinhoe's storm petrel can be regularly found. The Savage archipelago has been recognised as an Important Bird Area (IBA) by BirdLife International because of its seabird colonies.
Sea life Jacques-Yves Cousteau once found what he believed were "the cleanest waters in the world" around this minor archipelago; there is an abundance of marine activity, much endemic to the environment, including the barred hogfish, puffer fish (Tetraodontidae), sea spider and many species of sea urchin. At depth of about the waters around the islands are teeming with algae and many migratory species of common fish, routinely migrating from the islands of Cape Verde, Madeira and the Canaries.
Out of eight total species of sea turtle in the world, five of them occur in Savage Islands waters. The most frequent is the loggerhead turtle, followed by Kemp's ridley sea turtle, hawksbill sea turtle, green sea turtle and leatherback sea turtle.
A total of 10 cetacean species are recorded for the Savage Islands' surrounding waters, including some with a "Vulnerable" or "Threatened" global conservation statuses according to IUCN list of threatened species such as fin whales, sperm whales, bottlenose dolphins, common dolphins, short-finned pilot whales, Atlantic spotted dolphins, pygmy sperm whale, sei whale, Bryde's whale and a non-confirmed beaked whale species, but many others are expected to be discovered. The sub-tropical geographical position of the Savage Islands puts it at the limit of the northern distribution range of many tropical oceanic cetaceans species and at the southern limit of species from more temperate latitudes.
Despite having a much smaller submerged area with depths less than than other larger Macaronesian archipelagos, the islands have remarkable fish species richness. There are 88 known species of coastal fish, some of them included in endangered and vulnerable status such as the dusky grouper, the Island grouper or the barred hogfish. 27.3% of fish are from the tropical eastern Atlantic Ocean, 10.2% from temperate waters and 6.8% from subtropical waters.
Other animals Ten terrestrial vertebrates are known to live on these islands. Two terrestrial reptiles—Tarentola boettgeri bischoffi, a subspecies of Boettger's wall gecko, and Teira dugesii selvagensis, a subspecies of Madeiran wall lizard—are exclusive to the Savage Islands. The islands are the only terrestrial mammal-free archipelago in the Macaronesia of the North Atlantic.
The Savage archipelago is a hotspot of endemic terrestrial arthropods. There are about 219 species and subspecies of terrestrial invertebrates, 92% accounting for arthropods. About 20% of the whole taxa is endemic to the islands. Some endemic species include the sea snails Adeuomphalus marbisensis, Sticteulima lata, Alvania dijkstrai, Alvania freitasi, Alvania harrietae, Atlanta selvagensis, Manzonia boucheti, Osilinus atratus selvagensis and the land snail Theba macandrewiana.
Other terrestrial invertebrates endemic to the islands include three species of Cossoninae, two species of spider beetles, Cryptorhynchinae and Malachiinae and a species of bean weevil, click beetle, thrips, Harpalinae, Pterostichinae, Lamiinae, Paederinae, Trogossitinae, Julida and a recently discovered species of Aplocnemus.
The current number of known endemic species and subspecies is certainly a poor estimate of its real number.
Plant life