The southern Bass Islands have a have a tropical rainforest climate (Af in the Köppen climate classification, Arab in the Trewartha climate classification), bordering on a very-mild winter humid subtropical climate (Cfa in the Köppen climate classification, Cfal in the Trewartha climate classification). Despite being situated south of the Tropic of Capricorn, the remote location in the middle of a tropical ocean enables the climate to be moderated in all seasons. Summers and winters are slightly cooler than in the Tupua'i Islands, and cyclones are rarer, as the islands are located near the Horse Latitudes at thirty degrees south. Precipitation is abundant in all seasons, and sunshine is uncommon every month of the year. The cool winters and strong winds prohibit ultra tropical fruits such as coconuts to thrive, as it has dropped to 8.5 °C (47.3 °F) in September.
Ecology
The Austral islands constitute the Tubuai tropical moist forests terrestrial ecoregion. The natural vegetation consisted of lowland and montane rain forests. Much of the original forest has been mostly cleared for pasture and agriculture. The islands are home to several endemic plants and animals, including the Rimatara reed warbler (Acrocephalus rimatarae), Rapa fruit-dove (Ptilonopus huttoni), and Kuhl's lorikeet (Vini kuhli).
Most of the islands are surrounded by coral reefs. The islands constitute a distinct marine ecoregion.
Vegetation
The flora of the Austral Islands has already been modified mainly by the Polynesian aborigines. On the uninhabited Maria Atoll, ancient, largely undestroyed native vegetation can be found. On Rapa, too, there are still small remnants of the original montane rainforest in inaccessible steep areas.
On the four larger islands (Rapa, Raivavae, Tubuai and Rurutu) the vegetation is dominated by secondary growth. Beach vegetation differs little from that of other Pacific island groups, but is less species-rich. In the few areas undisturbed by man, Pisonia grandis palm, heliotropes of the species Heliotropium arboreum (synonyms: Argusia argentea, Tournefortia argentea) and Pandanus tectorius predominate, with shrubby and creeping plants in the understory. The currency is (still) the CFP franc, which is pegged to the euro. The administrative budget of the Austral Islands is largely financed by France and the EU.
Politics and government
Politically, the Austral Islands today belong to French Polynesia (Pays d'outre-mer – POM) and are therefore affiliated with the EU. They are administered by a subdivision (Subdivision administrative des Îles Australes) of the High Commissariat of the Republic in French Polynesia (Haut-commissariat de la République en Polynésie française) in Papeete, on the island of Tahiti.
The archipelago is politically divided into 5 municipalities (Communes des Îles Australes), which administer themselves.
Demographics
The 6,820 inhabitants (2012 census) live mainly in small villages; there are no large cities in the Austral Islands. Unlike other regions of Polynesia, the population of the Austral Islands has declined since the mid-1990s. mostly belonging to various Protestant groups and the Catholic Church. There are four Catholic churches under the Archdiocese of Papeete: two on Tubuai Island the Church of Mary and the Church of Saint Joseph (Église de Maria no te Hau; Église de Saint-Joseph) one on Rurutu Island the Church of Saint Francis Regis (Église de Saint-François-Régis) and one on Raivavae Island the Church of Saint Peter (Église de Saint-Pierre). According to 1991 data, Protestant Christian groups represent the majority on these islands.
Languages
The official language, as in the rest of France, is French. In everyday life, the Austral language, which belongs to the Polynesian languages, is often spoken, but with a tendency to decline. On Rapa Iti island, Rapa language is also spoken.
Culture
The traces of culture originating from the Austral Islands are quite numerous and the works of art produced there have often been judged as the most remarkable produced in Polynesia However, almost none of these works can be found on these islands but in renowned museums in Western countries.
Indeed, passing ships received numerous offerings but also plundered some of the islands' sites, notably the missionaries of the London Missionary Society, anxious to eradicate all traces of ancient worship. The marae, Polynesian places of worship, were thus excavated and gradually disappeared. In Raivavae, for example, out of sixty-two marae present at the beginning of the 20th century, only twenty-three remain visible today.
The best known work of art from the Austral Islands is certainly the sculpture of the God A'a, discovered in Rurutu and currently exhibited at the British Museum in London. There is a reproduction on the island. It is composed of thirty small figures sculpted on its body; its back had a cavity that could accommodate twenty-four other small sculptures which were however destroyed in 1822.