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For Rapa Nui (Easter Island) and its largest islet, Motu Nui, the change of the species assemblage over time was analysed, and a trait‐based approach to evaluate the potential losses in seabird function across the past centuries was applied. At a finer scale, the seasonal changes in seabird species composition in the current seabird assemblage was assessed to better understand the dynamics of the long‐term inferred patterns.For Rapa Nui, the composition of the seabird assemblage between the prehistorical, historical, and current time has changed significantly. The most critical change, probably associated with human colonization, was observed between prehistoric and current times. The current diminished number of nesting seabird species was probably the result of local extirpation without evidence of colonization by new species.For Motu Nui, changes in species composition were also followed by changes in trait structure, which were smaller than observed in Rapa Nui. This is probably due to the presence of a relatively high number of related species (i.e. Procellariids) with high similarities in their foraging behaviour.The nesting seabird assemblages in Rapa Nui and Motu Nui differ in exposure to risk; thus, conservation strategies applied to the islands should be planned on a fine spatial scale. For Rapa Nui, which is an urban wildlife area with several invasive species and a low number of remaining native seabird species, management should focus on fencing and pets control. For Motu Nui, management should instead focus on the establishment of quarantine and other biosecurity tools to avoid both the entry and proliferation of new invasive species. [ABSTRACT FROM AUTHOR]

While floating near the sea surface plastic debris interacts with a number of external factors, including many different organisms. Seabirds have the most extensive documented history of interactions with plastics, through ingestion, entanglement, and nest construction.In the present study, eight seabird species from the South Pacific Ocean were used as a proxy to determine potential patterns of removal of marine plastic debris, and three hypotheses were tested in relation to their feeding habits and nesting areas.Plastics from abiotic compartments (Chilean continental coast, South Pacific Gyre, and Rapa Nui beaches) and biotic compartments (surface‐feeding seabirds, diving seabirds, and nesting areas) were compared, according to their type, colour, shape, and density.Continental beaches had a relatively wide range of colours and shapes, with many non‐buoyant plastics. Samples from the South Pacific Gyre (SPG) and Rapa Nui (Easter Island) beaches comprised mainly hard, rounded, buoyant, and white/grey plastics.These results indicate that the composition of floating plastics from terrestrial sources changes during transport with oceanic currents, reducing the proportion of prey‐like plastics present in the subtropical gyres.The stomach contents of surface‐feeding and diving seabirds were dominated by hard, white/grey, and round plastic items, similar to plastics from the SPG, suggesting non‐selective (accidental or secondary) ingestion.Nesting areas had a more variable composition of brightly coloured plastics, suggesting a pattern of selective removal of plastics by seabirds, probably from oceanic sources.The present study reveals extensive interactions of seabirds with plastics on a broader scale, which is highly relevant given that the impacts of plastics on seabirds are increasing worldwide, compromising their efficient conservation. [ABSTRACT FROM AUTHOR]

The largest population of Humboldt Penguins resides in a fertile archipelago of the north-central coast of Chile, formed by eight islands in proximity to upwelling centers of the Humboldt Current System. However, five of these islands lack legal protection. Here, we report the results of breeding Humboldt Penguins tracked while foraging from Tilgo Island. The average and maximum foraging radii around the colony were 22 km and 43 km, respectively. Our data indicate that trip ranges overlap areas proposed for industrial projects. Because Humboldt Penguins are sentinels of local ecosystem health, this underscores the value of expanding conservation zones in this unique marine location. [ABSTRACT FROM AUTHOR]

Summary: As island ecosystems are among the most critical breeding habitats for seabirds, their protection should enhance population viability for many species. The Peruvian Diving-petrel Pelecanoides garnotii breeds only in Chile and Perú, is an endangered seabird with historically large populations of over 100,000 breeding pairs, but fewer than 1,000 remained in the 1980s and it became the first endangered seabird of the Humboldt Current System. In Chile, they breed on five islands, three of which are legally protected, but only two have a management plan. Between 2010 and 2014, we evaluated the density of nests, burrow occupancy, and colony patch sizes on the islands to estimate the breeding population. The population trend was assessed by compiling historical data available in the literature and several unpublished technical reports. The current breeding population size in Chile was ∼12,500 breeding pairs (95% CI: 10,613–14,676 pairs) that is ∼34% of the breeding pairs reported for Peru (∼36,450 pairs). Choros Island, the only island with adequate protection, accounted for ∼95% of the total breeding population of the Peruvian Diving-petrel in Chile. Historical population trends showed a significant increase in breeding pairs during recent years on Choros Island. It seems that the adequate legal protection of Choros Island is leading to the recovery of Peruvian Diving-petrels, demonstrating that protection of breeding colonies remains an essential strategy for the conservation of endemic seabirds. [ABSTRACT FROM AUTHOR]

The evolutionary and adaptive potential of populations or species facing an emerging infectious disease depends on their genetic diversity in genes, such as the major histocompatibility complex ( MHC). In birds, MHC class I deals predominantly with intracellular infections (e.g., viruses) and MHC class II with extracellular infections (e.g., bacteria). Therefore, patterns of MHC I and II diversity may differ between species and across populations of species depending on the relative effect of local and global environmental selective pressures, genetic drift, and gene flow. We hypothesize that high gene flow among populations of Humboldt and Magellanic penguins limits local adaptation in MHC I and MHC II, and signatures of selection differ between markers, locations, and species. We evaluated the MHC I and II diversity using 454 next-generation sequencing of 100 Humboldt and 75 Magellanic penguins from seven different breeding colonies. Higher genetic diversity was observed in MHC I than MHC II for both species, explained by more than one MHC I loci identified. Large population sizes, high gene flow, and/or similar selection pressures maintain diversity but limit local adaptation in MHC I. A pattern of isolation by distance was observed for MHC II for Humboldt penguin suggesting local adaptation, mainly on the northernmost studied locality. Furthermore, trans-species alleles were found due to a recent speciation for the genus or convergent evolution. High MHC I and MHC II gene diversity described is extremely advantageous for the long-term survival of the species. [ABSTRACT FROM AUTHOR]

The article discusses findings of a study to evaluate species abundance distribution of the Humboldt Penguin or Spheniscus humboldti in Peru and Chile. It notes the impact of the El Niño climate phenomenon on the breeding colonies of Humboldt Penguin in La Foca Island, Peru and in Metalui Island, Chile. It confirms that while Humboldt Penguin population in Punta San Juan, Peru decreased by 51 percent from 1980 to 2008, it increased by 89 percent in Chañaral Island, Chile.

The Peruvian Booby ( Sula variegata) is one of the most numerous guano bird species in the Humboldt Current. We used a combination of data logger deployment, at-sea observations and colony-based work to investigate the foraging and diving behaviour, as well as the at-sea distribution and food choice of Peruvian Boobies breeding at Isla Pajaros, northern central Chile. Birds foraged in the vicinity of Isla Pajaros. They performed short foraging trips, varying between a few minutes and several hours. Average foraging range was 17.1 ± 3.5 km and diving took place between 2 and 10 km off the coast. Birds dived to depth of up to 10 m with an average depth of 4.3 ± 1.5 m. By at-sea observations as well as by data logger deployment, we identified important foraging areas close to the coast, especially around protruding points. The birds’ diet was highly variable between years, with Inka scad ( Trachurus murphyi) and anchovy ( Engraulis ringens) being the overall dominant prey species. Despite limited sample sizes, this paper presents first results about the foraging behaviour of Peruvian Boobies at the largest breeding colony in northern Chile. This information is essential for a better understanding of the effects of environmental changes as well as for the implementation of conservation measures. [ABSTRACT FROM AUTHOR]

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We report a specimen record of a Broad-billed Prion found during a beached-bird survey in northern Chile on 28 February 2014. The carcass was in an advanced state of decomposition and the cause of death was unknown. Identification was based on morphological comparison with other prions. This record confirms the species'occurrence offshore of Chile and emphasizes the importance of beached-bird surveys to increase knowledge about the dispersal of vagrant seabirds. [ABSTRACT FROM AUTHOR]