Ua Huka is the last of the inhabited islands in the Marquesas archipelago still free of black rats. The introduction of the black rat would mean the end of two endemic birds: the Pihiti a.k.a. ultramarin Lorikeet (Vini ultramarina) and the Pati’oti’o a.k.a. Iphis Monach (Pomarea iphis). The Pihiti used to be present on other marquesian islands aswell: Nuku Hiva, Ua Pou, Tahuata, Hiva Oa and Fatu Hiva (reintroduced in the 90’s). The black rat is also the prime cause for the disappearance of Mornachidaes.
These birds not only hold an important heritage significance but they can also be of great help supporting a sustainable economic development in Ua Huka, through an ecotourism activity like birdwatching.
Outre leur importance patrimoniale, ces oiseaux ont une importance éco-touristique majeure pour le développement de Ua Huka.
The colonisation of black rats on the Island of Ua Huka would have a major impact on coconut plantations. Rats are good climbers and create extensive damage to coconuts. The monitoring of various rat-infested islands showed an average crop loss ranging from 20 to 80%. This loss increases up to 90% at low altitudes and during the dry season, as rats drink coconut water. Financially, a 20% and 50% croploss would respectively result in a loss of 48 000 and 105 000 euros per year in revenue for the inhabitants of Ua Huka. These numbers have been computed using the coprah industry data for the past three year.
As for human health, the black rat is a carrier of the leptospirosis bacteria, and a dangerous one at that, since it is not afraid to venture into homes. Leptospirosis is lethal if not prescribed quickly with antibiotics, actually killing a few people each year on rat infested islands.