|Scientific Name:||Ptilinopus insularis|
|Species Authority:||(North, 1908)|
|Red List Category & Criteria:||Vulnerable D2 ver 3.1|
|Reviewer/s:||Butchart, S. & Symes, A.|
|Contributor/s:||Bell, B., Brooke, M. & Hall, J.|
This species qualifies as Vulnerable as it is only found on one small island where it remains at risk from the accidental introduction of exotic species.
|Range Description:||Ptilinopus insularis is confined to Henderson in the Pitcairn Islands (to UK), a small uninhabited, raised-reef island in the south-central Pacific Ocean. In 1987, its population was estimated at c.3,420 birds (Graves 1992) and, in 1992, using a different technique, at c.4,000; in 2003 there appeared to be no major change in the species' abundance (Brooke and Jones 1995, M. Brooke in litt. 2007), likewise for 2012 (M. Brooke in litt. 2012). Numbers may be limited by food supply (Brooke and Jones 1995) andare assumed to be stable.|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Brooke and Jones (1995).|
|Habitat and Ecology:||The species inhabits interior forest, with dense understorey. It is a specialist frugivore (possibly territorial so that it can exploit fruits as they become available), foraging solitarily or in pairs (Brooke and Jones 1995). Research in 1991/1992 recorded 19 different plants in its diet, with Procris pedunculata constituting the major food. A preference for fruit with a high water content suggests that the species may rely on its food for obtaining water, especially during dry spells (as there is no permanent water on Henderson) (Brooke and Jones 1995). From two nests, each with a single egg recorded in March, the breeding season would appear to be at the beginning of the calendar year and clutch-size is probably one (Brooke and Jones 1995).|
|Major Threat(s):||The species has apparently adapted to the presence of Pacific rat Rattus exulans. In August 2011, a rat eradication operation was carried out on Henderson Island to eradicate R. exulans from the island (J. Hall in litt. 2012). However, the accidental introduction of a more aggressive predator, such as another Rattus species, could be devastating, and introduced diseases, such as avian malaria and pox, are another potential threat. The introduction of exotic plant species could have serious consequences for the native vegetation (Waldren et al. 1995) and therefore for this species too.|
Conservation Actions Underway
In 1988, Henderson was designated a World Heritage Site. Following a feasibility study (Brooke and Towns 2008) a rat eradication operation was carried out on Henderson Island in August 2011 (J. Hall in litt. 2012). A follow-up monitoring expedition is planned for 2013 to assess the success of the rat eradication.
Conservation Actions Proposed
Periodically resurvey to monitor numbers and trends. Ensure that further alien species are not accidentally introduced to Henderson.
Brooke, M. De L.; Jones, P. J. 1995. The diet of the Henderson Fruit-dove Ptilinopus insularis,1. Field observations of fruit choice. Biological Journal of the Linnean Society 56: 149-165.
Graves, G. R. 1992. The endemic land birds of Henderson Island, southeastern Polynesia: notes on natural history and conservation. Wilson Bulletin 104: 32-43.
IUCN. 2012. IUCN Red List of Threatened Species (ver. 2012.1). Available at: http://www.iucnredlist.org. (Accessed: 19 June 2012).
Waldren, S.; Florence, J.; Chepstow-Lusty, A. J. 1995. Rare and endemic vascular plants of the Pitcairn Islands, south-central Pacific Ocean: a conservation appraisal. Biological Conservation 74: 83-98.
|Citation:||BirdLife International 2012. Ptilinopus insularis. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 22 May 2013.|
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