36 research outputs found

    Exponential population increase in the endangered Ouvéa Parakeet () after community-based protection from nest poaching

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    International audienceThe Ouvéa Parakeet (), endemic to Ouvéa Island (Loyalty Islands, New Caledonia, south-west Pacific), is a rainforest bird that is dependent on tree cavities for nesting. It is threatened by deforestation, but also by competition for nest sites with introduced bees, harvesting for pets, and potentially predation by introduced species. Despite these threats, we show that the Ouvéa Parakeet population increased exponentially from an estimated 617 (274–996) birds in 1993 to 2,090 (1,280–3,413) birds in 2009 (95% confidence interval). We explain this population increase by community-based protection measures that eliminated nest poaching. We recommend that these measures are maintained, remnant forest is protected, and the introduction of rats is prevented

    Can the intake of antiparasitic secondary metabolites explain the low prevalence of hemoparasites among wild Psittaciformes?

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    Background: Parasites can exert selection pressure on their hosts through effects on survival, on reproductive success, on sexually selected ornament, with important ecological and evolutionary consequences, such as changes in population viability. Consequently, hemoparasites have become the focus of recent avian studies. Infection varies significantly among taxa. Various factors might explain the differences in infection among taxa, including habitat, climate, host density, the presence of vectors, life history and immune defence. Feeding behaviour can also be relevant both through increased exposure to vectors and consumption of secondary metabolites with preventative or therapeutic effects that can reduce parasite load. However, the latter has been little investigated. Psittaciformes (parrots and cockatoos) are a good model to investigate these topics, as they are known to use biological control against ectoparasites and to feed on toxic food. We investigated the presence of avian malaria parasites (Plasmodium), intracellular haemosporidians (Haemoproteus, Leucocytozoon), unicellular flagellate protozoans (Trypanosoma) and microfilariae in 19 Psittaciformes species from a range of habitats in the Indo-Malayan, Australasian and Neotropical regions. We gathered additional data on hemoparasites in wild Psittaciformes from the literature. We considered factors that may control the presence of hemoparasites in the Psittaciformes, compiling information on diet, habitat, and climate. Furthermore, we investigated the role of diet in providing antiparasitic secondary metabolites that could be used as self-medication to reduce parasite load. Results: We found hemoparasites in only two of 19 species sampled. Among them, all species that consume at least one food item known for its secondary metabolites with antimalarial, trypanocidal or general antiparasitic properties, were free from hemoparasites. In contrast, the infected parrots do not consume food items with antimalarial or even general antiparasitic properties. We found that the two infected species in this study consumed omnivorous diets. When we combined our data with data from studies previously investigating blood parasites in wild parrots, the positive relationship between omnivorous diets and hemoparasite infestation was confirmed. Individuals from open habitats were less infected than those from forests. Conclusions: The consumption of food items known for their secondary metabolites with antimalarial, trypanocidal or general antiparasitic properties, as well as the higher proportion of infected species among omnivorous parrots, could explain the low prevalence of hemoparasites reported in many vertebrates

    Impact of invasive little fire ants Wasmannia auropunctata on rainforest soil fauna: implications for conservation of the endangered flightless kagu of New Caledonia

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    International audienceThe little fire ant, Wasmannia auropunctata , is an invasive species known to negatively affect many native species in its introduced range. Here, we studied the effect of little fire ant presence on the biomass of soil fauna in rainforest of New Caledonia to assess if little fire ants have an impact on an endangered endemic flightless bird, the kagu, Rhynochetos jubatus. The average biomass of soil fauna (except for millipedes) was lower in 53 sample plots with little fire ants than in 597 sample plots without little fire ants and the biomass decreased with increasing density of little fire ant nests. Millipedes on the contrary seemed to be positively impacted as their average biomass was higher in areas with fire ants than in areas without, but even millipede biomass decreased with increasing nest density of fire ants. Kagu density decreased with increasing area of rainforest invaded by little fire ants, suggesting, given their observed negative impact on soil fauna biomass, that they may limit food resources for kagu. Little fire ants might therefore transform rainforest into a less suitable habitat for the kagu by reducing the biomass of their prey and thus have a negative impact for kagu conservation

    The genus Gynacantha Rambur, 1842 in the South Pacific (Odonata: Anisoptera: Aeshnidae)

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    vailable information on Gynacantha Rambur, 1842 species from the South Pacific is reviewed. Specimens were found to be sufficiently similar to G. rosenbergi Kaup in Brauer, 1867 to be placed in the same species group (G. rosenbergi group—established here) but also distinct enough to form a subgroup of its own (G. rosenbergi Pacific group). All species of the G. rosenbergi group are diagnosed, with three species, Gynacantha vitiana sp. n. (male and female) from Viti Levu, Fiji, G. koroana sp. n. (male) from Koro, Fiji and G. vanuatua sp. n. (male) from Malekula, Vanuatu being described as new to science. A key is presented for identification of the males

    Distribution, habitats, phenology and conservation of New Caledonian Odonata

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    International audienceCompared to other archipelagos of the Pacific, the New Caledonian Odonata fauna is rich and diverse with 56 valid species or subspecies (23 endemics, 41%) from eight families (four Zygoptera: Argiolestidae, Coenagrionidae, Isostictidae, Lestidae, and four Anisoptera: Aeshnidae, Corduliidae, Synthemistidae, Libellulidae) and 31 genera (including four endemics, 13%). In Zygoptera, we record 19 species including 12 endemics (63%), and among Anisoptera, we record 37 species or subspecies, including 11 endemics (30%). we removed five species from the list that had been erroneously recorded also doubtful, but we were unable to clarify to which taxon this record referred hence we excluded it from our update. From a biogeographic perspective, the New Caledonian fauna has mostly Australian affinities with some connections with southeast Asia and the Pacific region. we provide for each species, whenever information was available, a distribution map with a brief review of its known ecology, behaviour and phenology. we also evaluated each species' conservation status, in light of known threats (range restriction, scarcity and human activity including altered water flow). we consider seventeen species (30%) endangered. The most immediate threats concern water pollution including alteration to the flow of water courses caused by mining, deforestation and fires. Invasive species, such as alien fish, may be predators of concern for odonata larva, although this has not yet been proven in New Caledonia.Par rapport aux autres archipels du Pacifique, la faune des Odonates de Nouvelle-Calédonie est riche et diversifiée avec 56 espèces ou sous-espèces valides (23 espèces endémiques, 41 %) de huit familles (quatre de Zygoptères: Argiolestidae, Coenagrionidae, Isostictidae, Lestidae et quatre d'Anisoptères: Aeshnidae, Corduliidae, Synthemistidae, Libellulidae) et 31 genres (dont quatre endémiques, 13 %). Parmi les Zygoptères, nous comptons 19 taxa dont 12 endémiques (63%). Parmi les Anisoptères, nous comptons 37 espèces ou sous-espèces, dont 11 endémiques (30%). Nous avons retiré 5 espèces de la liste faunistique de Nouvelle-Calédonie, celles-ci ayant été attribuées de façon erronée à l'archipel: une mention douteuse et n'a pas été incluse dans cet inventaire, faute d'une clarification de l'identité du taxon concerné. Cette faune montre de très nettes affinités biogéografiques avec l'Australie, avec quelques influences du sud-est asiatique et de la région Pacifique. Pour chaque espèce, nous proposons une carte de distribution et une synthèse des données disponibles sur l'écologie, l'éthologie et la phénologie. Pour chacune des espèces, nous proposons une évaluation du niveau de menaces (en fonction de leur distribution, de leur rareté et des menaces consécutives aux activités humaines) et un statut provisoire. Dix-sept espèces (30%) sont considérées en danger d'extinction. Les menaces les plus immédiates concernent la pollution des cours d'eau notamment par l'activité minière, la déforestation et les incendies qui changent le régime d'écoulements des cours d'eau. Des espèces envahissantes, comme les poissons exotiques, peuvent être prédateurs importants pour les larves d'odonates, bien que cela n' aie pas encore été prouvé en Nouvelle Calédonie
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