Examinando por Autor "Flores Morales, Marcelo Alejandro"

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    Predation by invasive alien species on a ground-nesting seabird :|bthe case of the red-tailed tropicbird (phaethon rubricauda) on Easter Island (Rapa Nui)
    (Universidad Andrés Bello, 2017) Flores Morales, Marcelo Alejandro; Simeone, Alejandro
    state of knowledge about the seabirds of Chilean oceanic islands: Easter Island, Salas y Gómez Island and Desventuradas Islands is still precarious and focused mainly in species richness. The threats to these species are also largely unknown. Through the revision of both published and gray literature, we updated the species inventory for the islands mentioned above. The orders more represented are Procellariiformes and Charadriiformes with nearly 80% of the recorded species. During the past years, there has been an increment of the records of new species generated by an increase of observation effort both by birdwatchers and ornithologists. Nevertheless, the development of systematic studies of avifauna is still a pending and necessary task to develop adequate conservation strategies. This study confirmed the presence of 28 species and verified their main conservation problems, especially those associated with invasive species. Easter Island (Rapa Nui), located in the southeastern corner of the Polynesian Triangle is one of the most isolated places on Earth and throughout its history and occupation, has been the subject of multiple anthropic alterations including the introduction of multiple invasive alien species. Through the use of camera traps, we studied a breeding colony of Red-tailed Tropicbirds (Phaethon rubricauda) to Characterize predation by invasive alien species on the Red-tailed Tropicbird during the breeding season. Specifically we aimed to determine: (1) distribution, abundance and main nest types used by tropicbirds, (2) Quantify the breeding success in the colony and (3) identify the invasive alien species that prey on the Red-tailed Tropicbird. Results showed the presence of four nest types strongly associated with the moai statues: rock caves, moai nest, rock protected, and vegetation nests. Breeding success ranged from 26% to 37% and the presence of five invasive alien species in the colony: Polynesian Rat (Rattus exulans), stray dogs (Canis familiaris), stray cats (Felis catus), Argentinian Ant (Linepithema humile) and Chimango Caracara (Phalcoboenus caracara), the latter being the most severe predator of unattended eggs and chicks and causing the failure of ca. 25% of the Tropicbirds nests. Argentinian ants, cats and dogs corresponded to anecdotal events in the colony. Polynesian rat, showed the highest probability and frequency of visit a tropicbird nest, however there was no interaction between the species. On the other hand, Chimango Caracara showed the lowest probability and frequency of visits but caused nest loss in all the recorded events. Invasive alien species are widely distributed in Rapa Nui, and although the Redtailed Tropicbird has a high resilience to disturbances, invasive species are a serious threat to birds and therefore urgent measures must be taken to control and/or eradicate the alien species to improve reproductive success and to avoid the extirpation of this and other species of seabirds from this island, which possess a unique bird assemblage in the Pacific Ocean.