VU
Blue Lorikeet Vini peruviana



Justification

Justification of Red List Category
This species has a very small range across a small number of islands and atolls. Its range is declining as a result of ongoing colonisation of range islands by Black Rats, and a small number of further rat introductions or cyclone events could rapidly affect all remaining island populations. For these reasons, the species is listed as Vulnerable.

Population justification
In the Society Islands, there were possibly up to 250 pairs on Motu One and 350-400 pairs on Manuae respectively in 1973 (Thibault 1974). In 2015, the population size on Manuae was found to be stable and the population on Maupiha'a was estimated to be 200-300 individuals (J.-C. Thibault in litt. 2020). 

In Tuamotu, there were 100-200 birds on Rangiroa, and small flocks on several other atolls in 1973 (D. Holyoak pers. comm. 1973). A minimum of 300 individuals were estimated on Tiamanu Motu in Apataki atoll in 1989 (Lovegrove et al. 1989). On Tikehau, 30 pairs were counted in 1984 (Poulsen et al. 1984), and at least 50 individuals on one motu in 2001 (Serra 2001). Surveys in 2005-2006 estimated populations of 1,258 (+/- 351) on Apataki, 2,546 (+/- 485) on Aruatua, 778 (+/157) on Kaukara, 1,249 (+/-173) on Rangiroa, and 49 (+/24) on Tikehau, resulting in a total population estimate for Tuamotu of 5,879 (+/-643; Ziembicki and Raust 2006). Estimated population densities ranged from 40 individuals per km2 in the presence of rats to 580 individuals per km2 in favourable habitat on Arutua. In 2016, it was reported that the population on Rangiroa was stable (Blanvillain et al. 2016), but that the population on Tikehau was possibly extinct (C. Blanvillain in litt. 2020).

The total population size in French Polynesia is estimated to fall within the range 6,500 - 9,400 individuals, which roughly equates to 4,300 - 6,300 mature individuals, with a best estimate of 5,300 mature individuals.

On Aitutaki, where it was probably introduced, numbers have been estimated at several hundred individuals (Wilson 1993), 2,400 individuals and 1,000 individuals (Raust and Ziembicki 2006). The apparent differences may be attributable to differing census techniques (G. McCormack verbally 1999). In 2009, the island population was estimated at 4,200 individuals (Koutsofta unpub. in Jennings 2011), and following Cyclone Pat in 2010, the island population was estimated at 1,448 birds by distance sampling (Jennings 2011). The population on Aitutaki is not included in the global population size estimate because Aitutaki is unlikely to be part of the species's native range.

The species is able to fly between motus and has been observed flying between islands five kilometres apart (Ziembicki and Raust 2006). In French Polynesia, the species is likely to have between seven and nine subpopulations. The largest is thought to be on Arutua, with an estimated population size of 2,546 (+/- 485) individuals, roughly equating to 1,300 - 2,100 mature individuals, which may represent approximately a third of the total French Polynesian population.

Trend justification
The species has been gradually lost from islands where Black Rats or Swamp Harriers have colonised. Recent range contractions have been recorded. The species is now absent from the eastern Apataki atoll, where it was previously recorded in the 1920s (Ziembicki and Raust 2006). On Tikehau, local people report that the species was previously more widespread and occurred on the main islets a few decades ago (Ziembicki and Raust 2006). On Kaukura, the species disappeared from Faro in the 1980s (Ziembicki and Raust 2006). The population on Tikehau may now be extinct (C. Blanvillain in litt. 2020).

In the Tuamotus, similar numbers of individuals were counted at the same sites during surveys in 2006 as in surveys over the previous 20 years, although the population on some islands appeared to have declined (Raust and Ziembicki 2006; Ziembicki and Raust 2006). The population on Tiamanu Motu in Apataki atoll was allegedly smaller in 1989 than it had been previously (Lovegrove et al. 1989). The populations on Manuae and Rangiroa appeared to be stable in 2015-2016 (Blanvillain et al. 2016; J.-C. Thibault in litt. 2020).

Overall, the species's population size is inferred to be declining. The rate of decline is not known.

Distribution and population

Vini peruviana is widely but unevenly distributed in the Society Islands and the Tuamotu Archipelago, French Polynesia. It originally occurred on at least 20 islands, and probably many more, including Tahiti, Moorea, Bora Bora, Maupiti, Raiatea, Tahaa, Huahine, Maupihaa (Mopelia), Motu One (Bellingshausen) and Manuae (Scilly) in the Society Islands, and Rangiroa, Tikehau, Niau, Makatea, Kaukura, Ahe (Ahii), Takapoto and Takaroa, Arutua and Apataki in the Tuamotus (J.-C. Thibault pers. comm. 1974). It now remains on eight islands or atolls within its native range: Manuae, Motu One and Maupihaa (Mopelia) in the Society Islands, and Kaukura, Rangiroa, Arutua, Apataki and Tikehau in Tuamotu. One individuals was seen on Raiatea in 2003, but this is likely to have been a released or vagrant individual (Ziembicki and Raust 2006). The species also occurs on Aitutaki in the Cook Islands, where it was probably introduced in the early 19th Century by Polynesians.

Ecology

It is typically found in lowland forest, mixed stands of native and cultivated trees, flowering plants, coconut, and banana plantations and gardens, where it feeds on nectar, soft fruit and flowers (Pratt et al. 1987; Collar 1997). On Tuamotu, its abundance is related to the association and density of Cocos nucifera and Heliotropium foertherianum (Ziembicki and Raust 2006). It nests in cavities in dead trees. The species is able to fly between motus and has been observed flying between islands five kilometres apart (Ziembicki and Raust 2006). It may be able to fly between islands when they are close together (J.-C. Thibault in litt. 2020).

Threats

The primary threat to the species is the invasive Black Rat Rattus rattus. The species's extinction from many islands is most likely due to predation by Black Rat, and to a lesser extent, feral cats Felis catus (Lovegrove et al. 1989). Although its range reduction in the Society Islands correlates with the spread of the introduced Swamp Harrier Circus approximans (Holyoak and Thibault 1984), surveys across 28 islands in French Polynesia found that, although the introduction of the swamp harrier could have accelerated the declines of Vini species, the main threat was the presence of the Black Rat (Seitre and Seitre 1992). Surveys of islands across French Polynesia have found that the lorikeet is usually absent, or is present only in very low numbers on islands where Black Rat is present (Seitre and Seitre 1992; Ziembick and Raust 2006). The accidental introduction of black rats (Rattus rattus) to the islands where Blue Lorikeet persists is a continuing threat to the species, especially in the Tuamotu archipelago, where all range islands are inhabited and copra exploitation is ongoing on most islands, providing opportunities for rat introductions (C. Blanvillain in litt. 2021).

The species's extinction from Makatea in the Tuamotus could have been accelerated by a particularly violent cyclone (Thibault and Guyot 1987). A cyclone in 2010 caused damage to c.75% of trees on Aitutaki (G. McCormack pers. comm 2010, in Jennings 2011) and resulted in the loss of over 50% of the lorikeet population (Jennings 2011), although the long-term impact is not known. Climate change is predicted to cause an increase in the frequency and intensity of storms, potentially affecting the lorikeet.

Habitat loss through conversion to tree plantations, agriculture and urbanisation also presents a threat, as the species relies on dead trees for nesting. Habitat may also be lost through sea level rise as a result of climate change. The species is sometimes trapped for the pet trade.

Conservation actions

Conservation Actions Underway
CITES Appendix II. The species is legally protected on Rangiroa and in the Society Islands.
A captive population is maintained. Educational activities including a school visit have taken place on Tikehau (Raust and Ziembicki 2006). Educational activities took place on Rangiroa in 2015 (C. Blanvillain in litt. 2020).

Conservation Actions Proposed
Monitor its presence and numbers on known range islands. Monitor further colonisations of range islands by the Black Rat.
Undertake educational programmes on islands where strong populations persist. Consider special protection of viable populations (Lovegrove et al. 1989). Establish biosecurity measures to prevent the arrival of the Black Rat on further islands where the species persists. Eradicate rats from current or former range islands.

Identification

18 cm. Chunky lorikeet mostly very dark blue (often looks black) with white cheeks and bib. Red bill, eyes and feet. Voice Very high-pitched hissing screech scheee-scheee, usually doubled.

Acknowledgements

Text account compilers
Wheatley, H.

Contributors
Blanvillain, C., Cibois, A., Derhé, M., Dutson, G., Gouni, A., Harding, M., O'Brien, A., Pilgrim, J., Shutes, S., Stattersfield, A. & Thibault, J.-C.


Recommended citation
BirdLife International (2022) Species factsheet: Vini peruviana. Downloaded from http://www.birdlife.org on 27/11/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 27/11/2022.