Time filter

Source Type

Okahisa Y.,Rikkyo University | Okahisa Y.,Japan Society for the Promotion of Science | Okahisa Y.,Japan Wildlife Research Center | Angin B.,British Petroleum | And 7 more authors.
Emu | Year: 2016

The Crow Honeyeater (Gymnomyza aubryana) is a critically endangered bird, endemic to the main island of New Caledonia, but it is poorly known owing to its elusive nature. We conducted playback surveys to assess the distribution, habitat preferences and vocal activity of the species. Crow Honeyeaters responded well to playback, with response rates reaching 67% at times. Our surveys revealed two distinct populations, separated by ∼250km: one in the north of the island and the other, larger population in the south. The range of the northern population appears to be very small. Presence of the species was linked to rainforests growing on oligotrophic soils, primarily on ultramafic substrates. Approximately 315-700km2 of suitable habitat for the species remains, corresponding to a maximum estimated population of 315-700 breeding pairs. The size and range of the Crow Honeyeater population is much smaller than previously assumed, and comprehensive management will be required to ensure its survival. © BirdLife Australia 2016.

Legault A.,University of Tasmania | Legault A.,Polish Academy of Sciences | Chartendrault V.,Institute Agronomique neo Caledonien IAC CIRAD | Chartendrault V.,British Petroleum | And 3 more authors.
Journal of Ornithology | Year: 2011

Habitat studies are important for conservation, particularly for parrots, as many are threatened and their ecological requirements are often poorly known. Our aim was to contribute to the conservation of parrots in New Caledonia by examining their selection of habitat at a large scale. From 2002 to 2010, we documented 1,357 encounters with New Caledonian Parakeets (Cyanoramphus saisseti), Horned Parakeets (Eunymphicus cornutus), and New Caledonian Rainbow Lorikeets (Trichoglossus haematodus deplanchii) throughout mainland New Caledonia. We used GIS to infer habitat selection in relation to vegetation, forest cover, forest size, altitude, rainfall, and soil. New Caledonian Parakeets selected forested areas with oligotrophic soils, particularly those from ultramafic substrates. Horned Parakeets selected habitats with a high proportion of rainforest, as well as oligotrophic soils on metamorphic substrates, yet soil fertility was less important for them. Both parakeet species favoured large forests, and appeared to avoid areas with low forest cover. Altitude had a relatively minor influence upon habitat selection by parakeets. Rainbow Lorikeets favoured areas at low altitudes with minimal rainfall and mesotrophic soils, although they were not influenced by soil fertility to the same degree as the parakeets. We consider rainforests on oligotrophic soils at intermediate altitudes (200-800 m) to be most important for parrot conservation in New Caledonia, as these habitats are likely to support significant parakeet populations. © 2010 The Author(s).

Legault A.,University of Tasmania | Legault A.,Polish Academy of Sciences | Theuerkauf J.,Polish Academy of Sciences | Chartendrault V.,Institute Agronomique neo Caledonien IAC CIRAD | And 6 more authors.
Biological Conservation | Year: 2013

Knowing the distribution and abundance of species is critical for conservation, yet field surveys are often limited in their spatial extent. In this study, we use ecological niche models to infer the current and future distribution of New Caledonian Parakeets (Cyanoramphus saisseti), Horned Parakeets (Eunymphicus cornutus), and Ouvéa Parakeets (Eunymphicus uvaeensis) in New Caledonia. In addition, we present a new method of assessing the population size of each species based on the relationship between local abundance and modelled habitat suitability. According to our estimates, there are 5708 (5048-6174) New Caledonian Parakeets on the main island of New Caledonia, distributed over an area of 2783km2, of which 1939km2 is forested. We estimate there to be 8690 (7934-9445) Horned Parakeets, and their distribution extends over 3482km2, including 2162km2 of forest. In comparison, the Ouvéa Parakeet has a very restricted range of 34km2 (most of which is forested), and a population estimated at 1730 (963-3203) individuals. Projections involving simulated climate change suggest that populations of New Caledonian Parakeets and Horned Parakeets may recede into areas at higher altitudes in the future, primarily along the central mountain chain of the mainland. It is difficult to predict how the Ouvéa Parakeet will respond to the climatic changes forecast for Ouvéa, as the species is expected to face climatic conditions in the future that are different from any of those currently experienced on the island. Our research demonstrates that the current reserve system in New Caledonia is unlikely to provide sufficient protection for parakeets. Hence, we believe that existing Important Bird Areas (IBAs) should be evaluated for their current and future potential as reserves. © 2013 Elsevier Ltd.

Legault A.,University of Tasmania | Legault A.,Polish Academy of Sciences | Theuerkauf J.,Polish Academy of Sciences | Baby E.,Conservation Research New Caledonia | And 9 more authors.
Journal of Ornithology | Year: 2013

Standardised surveys are essential for monitoring populations and identifying areas that are critical for conservation. With the aim of developing a standardised method of surveying parrots in the rainforests of New Caledonia, we used distance sampling to estimate densities of New Caledonian Parakeets (Cyanoramphus saisseti), Horned Parakeets (Eunymphicus cornutus), Ouvéa Parakeets (E. uvaeensis), and New Caledonian Rainbow Lorikeets (Trichoglossus haematodus deplanchii). We carried out surveys in the early morning and late afternoon, when parrots were easiest to detect. To minimise errors associated with estimating distances and flock sizes by ear, we conducted brief searches to locate parrots, then measured their distance from the transect line. We recorded birds in flight and consider these records to be important when estimating parakeet populations. In agreement with existing knowledge on distance sampling, we found line transects to be more efficient than point transects for estimating the density of parakeets. Our results indicate that parrots located beyond 50-70 m from the transect line have little influence upon density estimates. In addition, surveys on roads are likely to underestimate densities if not corrected for road width. We generated relatively stable and precise density estimates (CV < 0.25) with approximately 40-50 detections, yet additional effort may be warranted under different study conditions. Although we aimed to improve parrot surveys in New Caledonia, our suggestions may be useful to other researchers studying rainforest birds, and can be adapted to suit different species or environments. © 2012 The Author(s).

Legault A.,University of Tasmania | Legault A.,Polish Academy of Sciences | Theuerkauf J.,Polish Academy of Sciences | Rouys S.,Conservation Research New Caledonia | And 2 more authors.
Condor | Year: 2012

We examined daily activity patterns, flock-size variations, use of vertical space, and small-scale habitat selection of the New Caledonian Parakeet (Cyanoramphus saisseti), horned Parakeet (Eunymphicus cornutus), and New Caledonian Rainbow lorikeet (Trichoglossus haematodus deplanchii) on mainland New Caledonia. All three species had bimodal patterns of activity, with most encounters occurring in the morning and a second smaller peak of encounters in the late afternoon. The parakeets were usually seen singly or in twos, and most flocks contained fewer than four individuals. Parakeet flocks remained relatively consistent in size through the day and through the year. Most Rainbow lorikeet flocks contained only a few individuals, though some reached up to 40 birds. Rainbow lorikeets were encountered mainly in small flocks during the breeding season from September to January, and their average flock size was higher and more variable for the rest of the year. Rainbow lorikeets selected valley forest and urban areas, where they were most common in parks and gardens. New Caledonian Parakeets favored slope forest over valley forest, and they foraged low, either at the edge of forest, in slope forest, or in maquis (shrubland). horned Parakeets generally fed at greater heights than did New Caledonian Parakeets, preferred valley forest to slope forest, and avoided maquis. we suggest that the observed difference in habitat use between the New Caledonian Parakeet and horned Parakeet is the result of spatial resource partitioning, which allows these closely related species to coexist. © The Cooper Ornithological Society 2012.

Loading Institute Agronomique neo Caledonien IAC CIRAD collaborators
Loading Institute Agronomique neo Caledonien IAC CIRAD collaborators