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Dynamics of Humboldt Penguin Colonization on Port Terminal Infrastructure in Southern Peru
No full textThe use of artificial structures by seabirds is a globally recognized phenomenon driven by escalating human coastal development. Designed as maritime infrastructure, breakwaters, jetties, and bridges inadvertently offer nesting habitat and refuge for a diverse assemblage of seabird species. The construction of a detached breakwater at the port terminal of the PERU LNG natural gas liquefaction plant in Melchorita, Peru, provided a unique opportunity to observe seabird colonization of new habitat, in this case colonization by Humboldt Penguins Spheniscus humboldti from 2008 to 2024. The penguins founded a permanent breeding site within 3.5 years after cessation of human activity at the site, which had provided protection from terrestrial predators and human interference. Between 2012 and 2021, penguin numbers increased to 2091 birds, peaking during the January molt, although numbers fluctuated. By 2021, the breakwater harbored a substantial proportion of the penguin population in Peru. The breakwater exemplifies the potential of artificial structures in mitigating habitat loss and supporting seabird conservation, underscoring the need for proactive management strategies amidst escalating coastal development and environmental challenges
Have Rodents Impacted the Breeding and Distribution of Black Noddy \u3ci\u3eAnous minutus\u3c/i\u3e on Lord Howe Island?
No full textRodents are well known to impact nesting seabirds. However, not all seabird species are equally susceptible to rodents due to variations in size, nest-site selection, or nesting behaviour. The Black Noddy Anous minutus, a common tropical, tree-nesting species, began colonisation of North Bay on Australia’s Lord Howe Island in 1989, 70 years after the establishment of Black Rats Rattus rattus. In 2014, when the breeding colony consisted of 560 pairs, we commenced a pilot study to assess impacts of rodents. Ten motion-triggered cameras monitoring 12 nests showed no rodent presence on any branches within view; 11 of those nesting attempts (92%) resulted in fledglings. A further 38 nests were monitored for breeding success, of which 28 (74%) produced a fledgling. In 2019, coincident with the eradication of rodents from Lord Howe Island, noddies started breeding in small numbers in the Settlement Area. In 2020, visitor disturbance was low at this colony due to COVID-19 lockdowns, and by the 2022 season, the entire original North Bay colony had relocated here. From initial colonisation until 2014, the population grew at 10% per annum, but it increased only marginally (0.7% per annum) during 2014–2024. It appears that neither colony establishment nor breeding by the Black Noddy is affected by the presence of Black Rats. Contributing factors may include the selection of tree nest sites, which reduces rodent access and provides only one point of contact to a nest, and the presence of adults at nests during all nocturnal periods, which enables nest defence
‘Floating Populations’ of Seabirds: The Bane of Demographic Modelers and Managers
No full text’Floating’ portions of seabird populations (mature but non-breeding individuals) are generally ignored in seabird research and management despite frequent evidence of their existence, especially in cavity-nesting species for whom nest habitat is often limiting. Here we demonstrate, using a few among an appreciable number of cases, that often more adults contribute to regional populations than colony-based censuses reveal, and that these birds are able to breed but do not. Once given the chance through the creation of nesting habitat, either by natural or human-caused processes, these populations reveal themselves by occupying the newly created habitats to become breeders. We include a brief discussion of the degree to which natal philopatry contributes to relatively sudden colony establishment. Not recognizing the existence of floating populations due to exclusively colony-based management, which is often politically necessary (e.g., Wildlife Refuge management), hinders conservation because it ignores the source and role of potential immigrants. Instead, management tends to emphasize supposed natal philopatry. Floaters will exploit mortality-caused vacancies in a breeding population, masking temporal variation in adult mortality, falsely indicating colony-size stability as a measure of the ‘health’ or resilience of a colony/habitat. In addition, the most successful efforts at establishing new colonies or restoring others by ‘social attraction’ are those in which a floating population is present, although unrecognized until it is revealed by the social attraction ‘experiment.’ Success comes when the artificially established breeding aggregation becomes an attractant to ‘floaters.’ Thus, recruitment of these floaters (especially on a predator-free colony or island) accelerates the limited growth provided by the return of hand-raised translocated nestlings. A lack of appreciation for the presence of floaters also limits the validity of assessments of the impact of bird wrecks and the ability of populations to recover from them
Seasonal Changes in Diving and Flying Activities of Rhinoceros Auklets \u3ci\u3eCerorhinca monocerata\u3c/i\u3e throughout the Non-breeding Period
No full textTo understand how migratory seabirds meet the energetic challenges associated with wing molt and wintering, a full annual cycle behavioral study is needed. We studied the diving and flying activities of three Rhinoceros Auklets Cerorhinca monocerata migrating in the northwestern Pacific. The auklets decreased daily flight time and dive depth for seven weeks from the end of summer, presumably associated with primary feather molt. In winter, they increased dive depth (~81 m) and daily dive time. We suggest that Rhinoceros Auklets adjust their diving and flying behaviors in response to wing molt and energy demands in winte
Salvin\u27s Albatross \u3ci\u3eThalassarche salvini\u3c/i\u3e Interacting with Freezer Trawlers in Waters of the Patagonian Shelf
No full textWe present a new record of Salvin’s Albatross Thalassarche salvini in waters of the Patagonian continental shelf. During a seabird census on 06 December 2019, a sub-adult individual within a mixed-species flock was observed eating fishery discards. In addition, we review sightings of this species outside its known core range using published records and other information. The species’ presence in Argentine waters has possibly been underestimated and further work to elaborate its interaction with fishery fleets is required
Successful Breeding by Black-legged Kittiwakes \u3ci\u3eRissa tridactyla\u3c/i\u3e at the Only Colony along Canada\u27s Pacific Coast
No full textThe Black-legged Kittiwake Rissa tridactyla is a widely distributed and well-studied northern hemisphere seabird. Authoritative publications document the existence of breeding colonies in Canada’s Arctic and Atlantic regions but not in the Pacific region. We visited the small (ca. 50 pairs in recent years) kittiwake breeding colony at Holland Rock, British Columbia, in July and August 2021, and documented what we believe to be the first record of successful breeding at this site. Previous records have documented successful breeding no further south than 58° latitude in Alaska, ~600 km to the north, making Holland Rock the southernmost colony in the eastern Pacific