Examinando por Autor "Ippi, S."

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    Evidence of low within-pair genetic relatedness in a relict population of Thorn-tailed Rayadito despite long-term isolation
    (John Wiley and Sons Ltd, 2022-03) Botero-Delgadillo, E.; Quirici, V.; Ippi, S.; Vásquez, R.; Kempenaers, B.
    Investigating whether mating patterns are biased in relation to kinship in isolated populations can provide a better understanding of the occurrence of inbreeding avoidance mechanisms in wild populations. Here, we report on the genetic relatedness (r) among breeding pairs in a relict population of Thorn-tailed Rayadito (Aphrastura spinicauda) in north-central Chile that has experienced a long-term history of isolation. We used simulations based on 8 years of data to assess whether mating is random with respect to relatedness. We found that mean and median population values of pair relatedness tended to be lower than randomly generated values, suggesting that mating is not random with respect to kinship. We hypothesize that female-biased dispersal is the main mechanism reducing the likelihood of mating among kin, and that the proportion of related pairs (i.e., r > 0.125) in the study population (25%) would presumably be higher in the absence of sex-biased dispersal. The occurrence of other mechanisms such as extra-pair copulations, delayed breeding, and active inbreeding avoidance through kin discrimination cannot be dismissed and require further study.
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    The Subantarctic Rayadito (Aphrastura subantarctica), a new bird species on the southernmost islands of the Americas
    (Nature Research, 2022-08) Rozzi, R.; Quilodrán, C.; Botero-Delgadillo, E.; Napolitano, C.; Torres-Mura, J.; Barroso, O.; Crego, R.; Bravo, C.; Ippi, S.; Quirici, V.; Mackenzie, R.; Suazo, C.; l Rivero-de-Aguilar, J.; Goffinet, B.; Kempenaers, B.; Poulin, E.; Vásquez, R.
    We describe a new taxon of terrestrial bird of the genus Aphrastura (rayaditos) inhabiting the Diego Ramírez Archipelago, the southernmost point of the American continent. This archipelago is geographically isolated and lacks terrestrial mammalian predators as well as woody plants, providing a contrasted habitat to the forests inhabited by the other two Aphrastura spp. Individuals of Diego Ramírez differ morphologically from Aphrastura spinicauda, the taxonomic group they were originally attributed to, by their larger beaks, longer tarsi, shorter tails, and larger body mass. These birds move at shorter distances from ground level, and instead of nesting in cavities in trees, they breed in cavities in the ground, reflecting different life-histories. Both taxa are genetically differentiated based on mitochondrial and autosomal markers, with no evidence of current gene flow. Although further research is required to define how far divergence has proceeded along the speciation continuum, we propose A. subantarctica as a new taxonomic unit, given its unique morphological, genetic, and behavioral attributes in a non-forested habitat. The discovery of this endemic passerine highlights the need to monitor and conserve this still-pristine archipelago devoid of exotic species, which is now protected by the recently created Diego Ramírez Islands-Drake Passage Marine Park.