[citation needed] The islands were formed as the Pacific Plate moved slowly west-northwest over a volcanic hotspot.

Easterly trade winds are consistent through much the year, and the eastern or windward sides of islands generally receive more rainfall.

Typical tree species include Inocarpus fagifer, Cananga odorata, Rhus taitensis, Pisonia umbellifera, Macaranga sp., Glochidion sp., Hibiscus tiliaceus, Tarenna sambucina, and the introduced Aleurites moluccana, along with the bamboo Schizostachyum glaucifolium.

The characteristic trees include Alphitonia zizyphoides, Hernandia moerenhoutiana, Metrosideros collina, Fagraea sp., Canthium spp., and Wikstroemia sp.

The easterly winds cool as they ascend the mountain slopes, and moisture condenses as rain and nearly continual cloud cover.

Fitchia spp., Myrsine spp., Fuchsia cyrtandroides, Sclerotheca spp., Cyrtandra spp., Metrosideros collina, Coprosma spp., and Psychotria spp.

From ancestors that are thought to have to have arrived in a single colonization event, the Partula land snails evolved into 53 distinct species.

[1] The lowlands below 500 meters elevation have mostly been cleared of the native forests, and replaced with coconut plantations and other crops, or with anthropogenic grasslands maintained by frequently-set fires.

Archeological sites have recovered remains of ten seabird species and 14 land birds which are no longer present on the islands.

These include the extinct Huahine gull (Chroicocephalus utunui), two parrots (Vini vidivici and V. sinotoi), three pigeons, and the Raiatea starling (Aplonis sp.

It was introduced in 1937 from South America, and has expanded to cover large areas of Tahiti and portions of Moorea and Raiatea.