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This note summarises key identification criteria for Fuegian Storm Petrel Oceanites oceanicus chilensis that permit field separation from Wilson's Storm Petrel O. o. oceanicus/exasperatus. Multiple sightings of presumed Fuegian Storm Petrel off São Tomé are considered in the light of these identification criteria. Here, we establish a provisional range for presumed Fuegian Storm Petrels in the Atlantic based on relevant literature, photographs in the Macaulay Library, and responses to social media requests. [ABSTRACT FROM AUTHOR]

We report the development of a colony of threatened Newell's Shearwater Puffinus newelli (NESH) at Makamaka'ole, West Maui, USA, a successful first undertaking in the Hawaiian Islands. Efforts involved the construction of two predator-proof fenced areas, removal/control of predators, placement of nest boxes, and social attraction using recorded calls and decoys. Initially, one of the management areas was intended for Hawaiian Petrel Pterodroma sandwichensis (HAPE) and the other for NESH. Exclosures were completed and mammalian predators were removed in 2013, and social attraction began in 2014. Both species almost immediately began flyovers to inspect speakers and by 2015, they had landed to inspect nest sites. Cameras recorded activity at nests during which individuals showed interest and, in at least one case, competed for the same nest. The first NESH eggs were laid in 2017, by which time HAPE had lost interest. NESH numbers continued to grow, especially after more speakers were added in 2019, when at least one but as many as five NESH chicks fledged. Two main questions arose: 1) What was the source population from which NESH had come, given their near extirpation on Maui? and 2) Why did HAPE, which are abundant in East Maui and on the nearby island of Lāna'i, eventually lose interest? Better understanding the population and behavioral ecology of these species might well inform planning for similar projects elsewhere in Hawai'i. [ABSTRACT FROM AUTHOR]

We report predation by an Arctic Fox Alopex lagopus on two seabird species, Atlantic Puffins Fratercula arctica and Leach's Storm Petrels Hydrobates leucorhous, nesting on Bakeapple Island, Little Fogo Islands, Newfoundland, Canada. This event took place in 2022, when a whole-island inspection revealed that fox, facilitated by over-ice invasion, killed at least 139 adult storm petrels and 8 puffin chicks. The fox also dug out 83 storm petrel and 4 puffin burrows. Breeding by seabirds on the island, which harbours some of the northernmost colonies in Newfoundland, was also largely disrupted; we documented extremely low egg and chick production values associated with the fox's presence and activity. We discuss the implications of such events for local seabird populations and the need for long-term monitoring to fully understand the impact of these predation events. [ABSTRACT FROM AUTHOR]

On 16 May 2021, a storm petrel was photographed on a pelagic trip in the Benguela Current off Cape Town, South Africa, exhibiting the diagnostic features of Pincoya Storm Petrel Oceanites pincoyae. This sighting occurred far from other records, the closest being approximately 7500 km away. The record, therefore, requires us to reassess our understanding of the movements and ecology of Pincoya Storm Petrel, which was previously known only from shallow waters in fjords and adjacent seas in south-central Chile. Pincoya Storm Petrel is considered Data Deficient by the International Union for Conservation of Nature (IUCN), the breeding range remains unknown, and the population was estimated to number only around 3000 individuals. While Pincoya Storm Petrel is recognised as a valid species by the International Ornithological Congress (IOC), eBird/Clements checklists, and the South American Classification Committee, its taxonomic status has been questioned. This sighting of a bird with all the features of Pincoya Storm Petrel distant from previous sightings, and in a markedly different ecological setting, may lead us to re-evaluate our understanding of species limits and phenotypic variation in Oceanites storm petrels. Further research to collect phenotypic, phylogenetic, and phenological data will allow us to re-examine species boundaries in Oceanites and enhance our understanding of this fascinating genus. [ABSTRACT FROM AUTHOR]

Shifts in zooplankton communities due to changing ocean climate can affect foraging patterns among planktivorous seabirds. To better understand seabird response to environmental change in Bass Strait, southeast Australia, we investigated the prey species and 16 elements in prey and feathers of the planktivorous White-faced Storm Petrel Pelagodroma marina. The krill Nyctiphanes australis was the most abundant prey species, followed by several species of post-larval fish; otherwise, the species appeared to be a generalist feeder. Element concentrations of feathers were not significantly influenced by dietary composition. Likewise, element concentrations did not significantly differ between major prey species, confirming that the nutritional profile of these species is likely linked to their seawater environment. Given that Whitefaced Storm Petrels in Bass Strait substantially rely on a narrow range of prey species, this may increase their vulnerability to events that change their availability. As coastal krill is highly sensitive to sea surface temperatures (SST), the increases in SST predicted under climate change scenarios may alter the timing and abundance of krill swarms, which in turn may affect planktivores, including White-faced Storm Petrels. [ABSTRACT FROM AUTHOR]

Man-made debris is a global problem for seabirds because it is ingested by many species. Markham's Storm Petrel Hydrobates markhami, which breeds in the Atacama Desert and is endemic to the Humboldt Current in the eastern South Pacific, has been poorly studied in this regard. Earlier studies found low levels of man-made debris in the species' diet. We quantified the present-day frequency-occurrence of man-made debris in fledglings and adults of Markham's Storm Petrel in Chile. We found that 16 of 25 fledglings and all adults contained man-made debris in their digestive tract, indicating the prevalence of man-made debris in this species' diet is higher than previously reported. Additional work is needed to assess the importance of this finding to conservation efforts. [ABSTRACT FROM AUTHOR]

Artificial nest chambers have become a common management tool for monitoring nocturnal burrow-nesting seabirds, although their utility varies among species and locations. The widespread Band-rumped Storm Petrel Hydrobates castro species complex potentially harbours a cryptic species endemic to the South Atlantic. Here we evaluate the installation of artificial nest chambers as a tool for long-term conservation and monitoring of this species, which breeds in two distinct seasons on St Helena. Based on six years of observational data, we analysed factors affecting occupancy, mate and chamber fidelity, and reproductive success to optimise nest chamber installation and to enhance future management. Occupancy rates were high, increasing from 5% after the first season following installation to 85% after five years. Occupancy was positively associated with (1) the number of seasons since chamber installation, (2) whether the chamber was occupied in the previous season, and (3) whether the chamber was occupied in the same season in the previous year. Occupancy also varied with chamber location and lid construction material: chambers with wooden lids had 7% lower occupancy and 18% lower breeding success than chambers with other lid types. Lid replacement also negatively affected occupancy. Chamber monitoring revealed that individuals exhibited 93% mate fidelity and 86% chamber fidelity with little effect of previous breeding outcome. From 312 monitored nests, hatching success was 15% higher during the hot season, while fledging success was 28% higher during the cool season, leading to only 3.2% difference in overall productivity between seasons. Fledging success of each seasonal population varied by year. Chick mortality was considerably higher during the hot season (41% compared to 13% during the cool season), possibly reflecting different responses to temperature regime. We conclude that installation of artificial nest chambers represents an effective monitoring tool, and recommendations for the design and management of chambers are discussed. [ABSTRACT FROM AUTHOR]

This note reports observations of a presumed Beck's Petrel Pseudobulweria becki and a Vanuatu Petrel Pterodroma [cervicalis] occulta in April 2022, in the low latitudes of the North Pacific, north of Kiritimati, Republic of Kiribati. The sightings are significant because the ranges of both taxa are barely known and their conservation classifications are concerning. We explain the circumstances of each sighting and the process of identification, reflecting upon current identification criteria and our studies of Beck's Petrel and Vanuatu Petrel at their breeding grounds. Discussion is illustrated with photographs of each bird and its cryptic confusion counterpart--the larger Tahiti Petrel Pseudobulweria rostrata for Beck's Petrel, and the larger White-necked Petrel Pterodroma cervicalis for Vanuatu Petrel. These two confusion pairs are generally considered inseparable at sea, but we demonstrate otherwise, given favourable circumstances. [ABSTRACT FROM AUTHOR]

Population trends of seabirds nesting on Kaua'i in the Hawaiian Islands, USA, were assessed across four decades using data from the Save Our Shearwaters (SOS) program. Started in 1979, the SOS database was intended to track the incidence of attraction of Kaua'i's seabirds to artificial lights, but recovery rate data also became useful to index population trends. These data documented precipitous declines of Newell's Shearwater Puffinus newelli through 2017. Here we expand on those efforts by including four additional species and consider data to 2018. All five species exhibited increasing trends during SOS's first decade, coincidental with increasing human population, suburban infrastructure, and public awareness. Counts of the once-numerous Newell's Shearwater decreased sharply beginning in the late 1980s, but stabilized around 2012. Since that approximate time, counts of Wedge-tailed Shearwater Ardenna pacifica and White-tailed Tropicbird Phaethon lepturus have increased. Conversely, counts of Hawaiian Petrel Pterodroma sandwichensis and Band-rumped Storm Petrel Hydrobates castro have remained stable since 1990. The implications of sizable decreases in a population are rarely considered from a community ecology perspective, but in this case, such an examination is possible: the decline of Newell's Shearwater may have led to a competitive release of trophic resources and nesting habitat, benefitting Wedge-tailed Shearwaters and White-tailed Tropicbirds, respectively. We also explore other issues potentially explaining observed trends. Clearly the SOS program is an important contributor to the success of both seabird conservation, by rehabilitating seabirds grounded by artificial lights, and management, by documenting long-term population changes that would have otherwise been unknown. [ABSTRACT FROM AUTHOR]

Population declines of Leach's Storm Petrels Hydrobates leucorhous in the western Atlantic have both led to the species' recent assessment as Threatened in Canada and contributed to a Vulnerable designation by the IUCN. Limited information suggests low adult survival rates are an important contributing factor. Off eastern Nova Scotia, Canada, Country Island is managed for avian predators and mustelids to protect nesting endangered Roseate Terns Sterna dougallii. The island also hosts a colony of Leach's Storm Petrels. In 2016, a capture-markrecapture program was initiated for storm petrels, from which we estimated apparent survival and recapture probabilities for 571 breeding birds using data collected from 2016 to 2021. Models with a time-since-marking effect were consistently ranked higher than those without; annual apparent survival estimates in the first year after capture were lower than in subsequent years, presumably due to some captured birds not returning to the study area. Apparent survival in the years subsequent to first capture was lowest in forested areas with no understorey vegetation, slightly higher in forested areas with fern understorey, and highest in open areas with dense fern cover. While the mechanism driving habitat differences in adult survival is unknown, predation pressure may be strongest in forested areas with open understorey where it is easier for predators to find burrow entrances. Although apparent adult survival rates were higher than reported previously for nearby Bon Portage Island where predation is significant, Country Island may represent a best-case scenario for Leach's Storm Petrel in Atlantic Canada, since predators are managed and adult mortality from avian predators is relatively low at this site. Even so, survival rates at Country Island are lower than those reported previously at two Pacific colonies and provide evidence that adult survival rates of Leach's Storm Petrels in eastern Canada are depressed. [ABSTRACT FROM AUTHOR]

Tracking studies show that diving petrels regularly disperse thousands of kilometres from their colonies during the non-breeding season, yet there are relatively few vagrant records of diving petrels. We report the first record of a diving petrel from continental Africa. A Common Diving Petrel Pelecanoides urinatrix was found dead near Cape Town, South Africa, on 03 March 2021. It appeared to be from the subAntarctic subspecies P. u. exsul, which is supported by sightings at sea; P. u. dacunhae is not recorded away from Tristan da Cunha and Gough Islands. However, diving petrels are common ~1500–2000 km southwest of Cape Town in March, in an area where diving petrels from South Georgia winter. In April, diving petrels—presumably from colonies at islands in the southwest Indian Ocean—are common in Antarctic waters 2 100–2600 km south of Africa and have been seen within 1200 km of Africa. The Cape Town bird may have come from either of these populations. At-sea and tracking data show that diving petrels are widespread from ca. 45–60°S throughout the Southern Ocean, possibly excluding the southeast Pacific sector. [ABSTRACT FROM AUTHOR]

Marine predators are an important component of marine trophic webs, and their decline has important consequences on whole ecosystem dynamics. Understanding their movements and habits is vital for conservation, yet extremely challenging. Tracking technologies, coupled with a robust, reproducible, and quantitative analytical framework, are being used to successfully identify Important Conservation Areas (ICAs) for seabirds, which are wide-ranging and declining marine predators. However, the identification of such areas is skewed towards large-bodied seabird species, and there are few marine ICAs for small-bodied birds like storm petrels. We GPS-tracked Mediterranean Storm Petrels Hydrobates pelagicus melitensis breeding in northwestern Sardinia over three consecutive breeding seasons (2019–2021), and we applied a recently proposed analytical framework for the assessment of ICAs using GPS data. We identified an area of 40638 km2 in the central Mediterranean Sea that spans three different national marine jurisdictions and partially falls within the Pelagos Sanctuary for Mediterranean Marine Mammals. In these ICAs, a range of human activities take place (e.g., fishing activities, maritime traffic, tanker maritime routes), particularly in the neritic zones. Despite the relatively low human presence in the area, the human impact on the Mediterranean Sea is predicted to increase in future years, with important consequences for conservation. International cooperation to identify ICAs at the basin scale is needed, given the trans-national nature of storm petrel movements. Here, we describe the polygon of the identified ICAs for the Italian population of Mediterranean Storm Petrel we studied (available for download) to help inform marine spatial planning and target the conservation and protection of the species. [ABSTRACT FROM AUTHOR]

We report the depredation by a single Eastern Barn Owl Tyto javanica delicatula on prospecting White-faced Storm Petrels Pelagodroma marina during the re-establishment phase of a colony on Big Island, off Port Kembla, New South Wales, Australia in 2018. Storm petrels were likely extirpated from this colony 56 years previously when invasive weeds rendered their habitat inaccessible. Restoration of vegetation together with storm petrel call broadcasting, commencing in 2014, resulted in significant increases in prospecting numbers, culminating in breeding (three pairs) in the 2017/18 austral summer season. A significant depredation event (> 59 adults) occurred between August and September 2018, providing a set-back to colony establishment. Previously, barn owl depredation on Big Island had been limited to Silver Gulls Chroicocephalus novaehollandiae as prey. However, in the 2018/19 season, the gulls commenced nesting later than usual. The delay appeared to cause the owl to switch target prey. Despite the intense depredation pressure, at least two pairs of storm petrels attempted to breed in the 2018/19 season and 10 birds were trapped and banded at the commencement of the 2019/20 season. Discovery of the mainland roost of the owl was attempted between the two seasons, and its potential death by car strike was investigated. Our findings show that even a single individual predator can have significant impacts on seabird colonies establishing or re-establishing in island environments, especially those under restoration. [ABSTRACT FROM AUTHOR]

Western Iberian waters are important migratory flyways, stopover sites, and wintering areas for several of the world's seabird species. To describe seabird species composition, distribution, and abundance in these waters, we performed six aerial surveys in September and/ or October of each year, 2010--2015, covering 74 840 km2. Using line-transect methodology, 27 396 seabird sightings from 17 taxonomic groups were recorded along 10 496.3 nautical miles (19 433 km). Using the program "Distance," annual and overall abundance estimates were obtained for nine taxonomic groups: Balearic Shearwater Puffinus mauretanicus, Great Shearwater Ardenna gravis, Cory's Shearwater Calonectris borealis, shearwaters, Northern Gannet Morus bassanus, Sabine's Gull Xema sabini, Great Skua Stercorarius skua, storm petrels, and Red Phalarope Phalaropus fulicarius. For the six-year period, Northern Gannet was the most abundant species (89 630 individuals, coefficient of variation [CV] = 6.28%), followed by Cory's Shearwater (25 044 individuals, CV = 7.56%) and Balearic Shearwater (13 632 individuals, CV = 20.81%). The remaining taxonomic groups exhibited variable abundances. Results confirm that the study area is important to several seabird species, providing baseline estimates to inform conservation policies and instruments, such as the Birds Directive and the Marine Strategy Framework Directive. [ABSTRACT FROM AUTHOR]

We report on the occurrence of albatrosses (Diomedeidae) and petrels (Procellariidae) associated with an artisanal small-scale fishery (SSF) for Humboldt Squid Dosidicus gigas in waters of southern Peru during El Niño 2015-2016 and coastal El Niño 2017. We deployed as observers on a number of fishing trips to assess seabird interactions. White-chinned Petrels Procellaria aequinoctialis and Waved Albatross Phoebastria irroata were the most abundant species observed, followed by Salvin's Thalassarche salvini and Chatham T. eremita albatross, and Cape Petrels Daption capense. The majority of procellariid species (> 60% of total birds) visited while vessels were positioned over the continental slope. Salvin's and Chatham albatross, and White-chinned Petrels, were mostly absent during summer (only 5% and 15% of birds present, respectively), but Waved Albatross and Cape Petrels were present year-round. Thus, the prevalence of each of these species was disproportionate relative to expectation based on non-fishery surveys. All assessed species foraged on offal discards associated with the fishery (~17%), with a higher frequency of consumption among Salvin's (27%) and Chatham (21%) albatross; in contrast, Waved Albatross largely fed on pelagic fish at the surface. Bycatch rate was found to be low; one Chatham Albatross was hooked and released in a hand-held squid jig (0.042 By Catch Per Unit Effort [BPUE] per fishing trip, n = 16). Probably due to El Niño conditions, Waved Albatross were more abundant than expected (43.9% of albatross, and 2.8% of total seabirds observed) and were 1 300-1 400 km farther south than their usual southern limits. We report the first sighting of Southern Royal Albatross Diomedea epomophora in Peru. Bycatch in longline fisheries are a conservation concern, but the magnitude and constant growth of SSFs, especially for Humboldt Squid, needs to be further investigated. [ABSTRACT FROM AUTHOR]

We found nesting Red-billed and Red-tailed tropicbirds Phaethon aethereus and P. rubricauda in the Islas Desventuradas archipelago, Chile. We visited Islote González on 14-15 December 2020 and on 23 August 2021. During the December visit, we encountered a colony of Red-billed Tropicbirds totaling a minimum of 62 breeding pairs. The nests were in cavities on steep cliffs and slopes located mainly on the northern part of the island, and we were able to access 34, of which 11 had eggs, 11 had nestlings of different ages, and 12 were active but empty. During the August visit, we found four nests with adults attending but no eggs or nestlings, one nest with a chick close to fledging, and one adult attempting to take a nest site from a De Filippi's Petrel Pterodroma defilippiana. We visited San Ambrosio Island on 10-12 December 2019, and we found only the Red-tailed Tropicbird breeding, as evidenced by four active nests: two with eggs, one with a well-grown nestling, and one with a pair of adults but no nest contents. However, we observed several pairs in aerial display and estimated the Red-tailed Tropicbird population to be at least 10-12 breeding pairs, in addition to the five to six pairs at Islote González and about eight pairs at San Félix Island. Our findings represent a new Red-billed Tropicbird population and the largest breeding colony of the species for Chile. Furthermore, Islote González is one of the very few known places where sympatric breeding of Red-billed and Red-tailed tropicbirds occur. The White-tailed Tropicbird Phaethon lepturus is also known to nest at San Félix Island in the Desventuradas archipelago, but we did not visit that island. It appears that all three species of tropicbird nest in this archipelago. [ABSTRACT FROM AUTHOR]

Southern Giant Petrels Macronectes giganteus are partial migrants, but the proportion of adult males and females that visit the colony on Gough Island during winter is poorly defined. A better understanding of winter colony attendance is important to predict the possible impact of non-target mortality during restoration efforts involving poison baiting to eradicate introduced mammals. We repeatedly checked the individual identity of all giant petrels attending the largest breeding colony on Gough Island for rings during April-May 2021. Although the maximum number of individually identifiable ringed adults in a single check was 202, overall, 353 ringed adults were recorded, including almost 90% of the individuals that bred in 2020. Males were more likely to be present than females, but the ratio of males to females decreased from the end of April (3.24:1) to the latter half of May (1.25:1). Many birds were paired with their previous breeding partners by the end of May, despite egg laying not starting until late August. Our observations indicate that most adult Southern Giant Petrels are present at their breeding colonies on Gough Island three to four months before breeding, and are thus potentially susceptible to non-target poisoning during mammal eradication operations. [ABSTRACT FROM AUTHOR]

The ‘Ua‘u (Hawaiian Petrel Pterodroma sandwichensis) is an endangered petrel endemic to the Hawaiian Islands. In this short paper, we describe two cases of Hawaiian Petrels with leucistic plumage recorded on the island of La¯na‘i. In both cases, the birds were chicks that fledged successfully in different years from the same burrow. There is only one other documented case of leucism recorded for this species in the Hawaiian Islands despite intensive monitoring of petrel burrows on Kaua‘i, La¯na‘i, and Maui over the last few decades, highlighting the rarity of this plumage aberration. [ABSTRACT FROM AUTHOR]

Acquiring basic knowledge such as at-sea distribution is often difficult for cryptic seabird species. Northern storm petrels (Hydrobatidae) are one family of seabirds that includes several cryptic species, including Ainley’s Storm Petrel Hydrobates cheimomnestes, which appears quite similar to southern Leach’s H. leucorhous and Townsend’s H. socorroensis Storm Petrels when at sea. For the first time, we describe the at-sea distribution of breeding Ainley’s Storm Petrels obtained using GPS tracking. We found that these birds visit waters of the eastern North Pacific between central Baja California, Mexico and southern Alta California, USA. These findings expand existing knowledge of the range of this species, which had previously been based on a few at-sea sightings and specimens. [ABSTRACT FROM AUTHOR]

We describe the first known documentation of on-land foraging by Leach's Storm Petrels Oceanodroma leucorhoa, a behaviour that has been documented only once before among members of the family Hydrobatidae. During a rain/windstorm from 15 to 17 July 2020 in eastern Newfoundland, individuals fed on coastally spawning and beach-cast capelin Mallotus villosus. This behaviour occurred in conjunction with a marine heatwave in the species' foraging range. Examination showed that wrecked birds were emaciated with negligible stomach contents. This finding, combined with the abnormal weather and foraging behaviour, suggests that these birds were in a weakened state preceding stranding in coastal waters. With the only other recorded instance of on-land foraging by hydrobatids occurring in highly emaciated birds concurrent with a marine heatwave, we suggest that this atypical behaviour is associated with birds experiencing extreme food stress linked to oceanic climate change. [ABSTRACT FROM AUTHOR]

Bycatch is a significant threat for albatrosses and petrels in general but especially within Brazilian waters. As part of a monitoring program, Projeto de Monitoramento de Praias da Bacia de Santos (PMP-BS), an unusually high number of White-chinned Petrels Procellaria aequinoctialis was recorded at Santa Catarina Island: 72 birds from August 2015 to July 2016 (60 dead and 12 alive) and 31 birds from 29 December 2015 to 05 January 2016 (28 dead and 3 alive). Evaluation of the carcasses showed that 12 birds had external evidence of anthropogenic interaction, and necropsy demonstrated that at least two had perforation of internal organs due to hook attachment. Hooks were identified as the type used by the Itaipava fleet. This fleet targets dolphinfish Coryphaena hippurus; tunas Thunnus obesus, T. alalonga, and T. albacares; and swordfish Xiphias gladius, and it typically operates in waters off southeastern Brazil. Although Brazil has strict laws to prevent albatross and petrel bycatch, enforcing bycatch mitigation measures has been a challenge. It is crucial to understand the dynamics of threats and their effects on populations, especially in terms of mass mortalities. For now, beach surveys can at least document the incidence of this problem. [ABSTRACT FROM AUTHOR]

The Ashy Storm Petrel (ASSP) Oceanodroma homochroa population has been surveyed intensively, both at sea within the California Current and on the adjacent breeding grounds. Nevertheless, colony-based estimates of breeding populations have significantly underestimated the species' abundance, especially in the northern portion of its range compared to the southern portion. The species has been described as abundant in central-northern waters, whereas it is considered rare or uncommon in the southern portion. We analyzed aerial and ship tracks from 1980 to 2017 (~497 000 km covering 91 267 km2), to estimate total ASSP population size and at-sea distribution. Modeling the results of these formal surveys (7211 ASSPs seen) led to an estimated total population of about 13 445 ASSPs (95% confidence interval = 10 128-27 820), with 62% of the population frequenting the northern portion of the range, i.e., north of Point Conception (especially Monterey Bay north through the Gulf of the Farallones to Cordell Bank), compared with 38% in the south (especially waters around the northern Channel Islands). Based on over a thousand well-organized bird-watching surveys, almost the entire population can occur in a single flock in the northern portion during the California Current's autumn Oceanic Period. These flocks occur in trophic hotspots: areas where submarine canyons cut into the shelf. Such large "molting flocks" have been shifting north from Monterey Bay to Cordell Bank since about 2007, but reasons for the northward shift remain a mystery. The apparent mismatch in at-sea vs. colony-based population sizes likely involves the non-breeding portion, which is especially difficult to estimate because it includes immature individuals as well as "floating" individuals: adults capable of breeding but denied access to breeding sites, which are limited by intraspecific competition. [ABSTRACT FROM AUTHOR]

Seabirds exploit marine habitats for resources, responding to many complex environmental signals that ultimately drive their distributions. Occasionally, influxes of seabird species to regions outside their normal range occur and determining the drivers of these patterns can aid in understanding their ecology and their conservation. I documented five birdwatching observations of Bulwer's Petrel Bulweria bulwerii in the Tasman Sea between 24 January and 08 March 2020, roughly 2 000 km south of their core range. Based on demographic, environmental, and anecdotal observations of seabirds, cetaceans, and bait fish, I suggest that the influx was most likely resource-driven, rather than accidental, age-related, or directly linked to adverse weather. Increasingly frequent observations of Bulwer's Petrel off eastern Australia may also indicate a southward distributional shift in this pantropical seabird, and monitoring of this potential shift will depend on the documentation of further observations. [ABSTRACT FROM AUTHOR]

Seabirds are declining worldwide, and predation by introduced and endemic species is one threat that affects many of them. Leach's Storm Petrel Hydrobates leucorhous (hereafter LHSP) populations are declining in a number of locations for reasons that are likely multicausal, and perhaps local or regional, but relative contributions of individual causes are poorly understood. To help understand causes, we quantified predation at two Nova Scotian LHSP breeding colonies that differ in predator management: no management occurs on Bon Portage (BP) Island, whereas management is used on Country Island (CI). Transects were monitored for evidence of predation approximately biweekly on BP and CI in 2018 and 2019, during May-October on BP and May-July on CI. We did not have data on predator densities, but in both colonies, predatory density would have been very location-specific. Evidence such as LHSP carcasses, feather piles, dug up nest burrows, and gull and owl pellets was removed or destroyed during each visit. Predation of eggs and nestlings was scarcely detected. Similarly, adult predation on CI was seldom detected. We estimated that 4 000 individuals were depredated on BP in each year of this study. Approximately 42% of predation events were ascribed to gulls and 10% to owls; 48% of remains could not confidently be ascribed to a particular predator. We do not know how general these rates will be because of differences among colonies in predator communities. In any case, LHSP are listed as "Vulnerable" globally, and although up to a 5% annual loss of adults may be sustainable for a healthy population, such losses may exacerbate population declines if other factors are additive. [ABSTRACT FROM AUTHOR]

The density and distribution of Westland Petrel burrows was assessed over a 12-year period (2007-2019). During that time, burrow density increased while occupancy remained stable, commensurate with an annual population growth rate of 1.022 (95% confidence interval: 0.971-1.076), as estimated using mark recapture data. From our surveys, we estimated a 2019 baseline population of ~6 200 breeding pairs and a world population of 13 800-17 600 individuals, covering around 95% of the population. Transects were conducted to establish the location and density of 17 petrel sub-colonies in rugged, untracked terrain in Paparoa National Park, West Coast, New Zealand. Major storms in 2014-2018 caused widespread treefall and landslides, destroying breeding habitat throughout the species' breeding range. Demographic effects of the major and ongoing habitat loss may continue in the medium to long term, as birds re-establish burrows and partnerships following loss of their habitat. Our study illustrates the complex effects of climate-related disruption on the biology of a long-lived species. With a single nesting area in the West Coast region, climate change will likely have an ongoing influence on the species' global population, since an increase in the frequency of severe weather events, including ex-tropical cyclones, is expected. However, current indications suggest that the species has some flexibility to adapt and to occupy new areas following habitat disturbance. [ABSTRACT FROM AUTHOR]

We visited San Ambrosio Island off northern Chile (26°21'S, 079°47'W) on 10-12 December 2019. We found a large population of Kermadec Petrel Pterodroma neglecta juana that appeared to be healthy. In the area that we could survey, we estimated at least 22 686 breeding pairs, which is an underestimate of the entire population as we could not access some steep areas. Introduced mammals, which have since been eradicated, caused a loss of island vegetation that might be a drawback for this population, as shading from the sun appears to be important for nest-site selection. Egg-laying started by early December. We assessed 223 birds with respect to coloration: most birds were intermediate phase (65%) and the rest were either very dark (23%) or very pale (12%). We found skeletal remains of goats and rabbits on the island but no living mammals, although a single goat may still be alive. In the context of an estimated world population of ~100 000 pairs of Kermadec Petrel, the San Ambrosio Island population contributes significantly. [ABSTRACT FROM AUTHOR]

Leach's Storm Petrels Oceanodroma leucorhoa were listed as Vulnerable by the IUCN in 2018. Population declines in the western North Atlantic are associated with low annual adult survival rates, but trends and vital rates of populations in the eastern North Pacific are poorly known. To address this knowledge gap, we estimated the annual apparent survival of breeding adults at two colonies off the coast of British Columbia (Rock Islets: 52°20'40"N, 131°14'10"W and Cleland Island: 49°10'17"N, 126°05'28"W), using capture-mark-recapture data collected between 2006 and 2010. Transient models received substantially more support than standard Cormack-Jolly-Seber models, suggesting that the initial capture and banding reduced burrow fidelity. The model-averaged annual apparent survival rates for both colonies were high (estimate for each colony = 0.975 ± 0.011), compared to rates reported for colonies in the western North Atlantic (< 0.80). Capture effects reduced annual apparent survival estimates for the first year after capture by ca. 6%. Higher apparent adult survival at colonies in the eastern North Pacific may be due to lower exposure to direct and indirect anthropogenic stressors while foraging (specifically, marine oil and gas infrastructure) and reduced avian predation by gulls at breeding colonies. The high survival rates we found suggests that eastern North Pacific populations of Leach's Storm Petrels are under less stress than those in the western North Atlantic. [ABSTRACT FROM AUTHOR]

An organism's reproductive phenology is closely connected with environmental variables and resource availability, and an earlier reproduction is generally predicted as temperatures warm. Sibling giant petrels Macronectes spp. have a circumpolar Southern Hemisphere breeding distribution, which provides an opportunity to test predictions of phenological change in breeding stages over large environmental gradients. Mean comparisons confirmed a ~50 day separation in egg-laying phenologies for the two species, and linear regression showed that variation in phenology was not linked to latitude when the data were separated by species. There was a significant predictive interaction model for temperature and day length at onset of copulation in Southern Giant Petrels M. giganteus, but plots of the raw data suggested that temperature has little, if any, effect on gonad maturation. While day length was the most important factor related to onset of copulation, temperatures at hatching likely constrained the overall phenology of breeding, especially for populations reproducing at extreme high latitudes. [ABSTRACT FROM AUTHOR]

Inaccessible Island, in the Tristan da Cunha archipelago, is the sole breeding site of the Spectacled Petrel Procellaria conspicillata. The island also supports globally important populations of four threatened seabirds, as well as populations of other seabird species. A seabird monitoring protocol was established in 2004, following baseline surveys of most surface-breeding species in 1999. For the species monitored, we report population trends that are based on visits in 2009 and 2018. Populations of most monitored species appear to be stable or increasing, including three albatross species currently listed as Endangered or Critically Endangered. However, numbers of Northern Rockhopper Penguin Eudyptes moseleyi may have decreased slightly since 1999, and numbers of Antarctic Tern Sterna vittata have decreased since 1982. The population of Spectacled Petrels is estimated to be at least 30 000 pairs and continues to increase since feral pigs Sus scrofa died out on the island in the early 20th century. We describe a new monitoring protocol for Spectacled Petrels that will be easier to repeat and implement and that should provide a more sensitive measure of future population changes. [ABSTRACT FROM AUTHOR]

Nightingale is a group of three small, uninhabited islands in the central South Atlantic Ocean. The islands are free of introduced mammals and are largely pristine, supporting two endemic land birds as well as globally important populations of several species of seabirds. Seven species of burrow-nesting petrels are known to breed on the islands, including roughly 40 % of the world's population of Great Shearwaters Ardenna gravis. We estimated burrow densities by systematically searching for their burrows in 5×5-m quadrats across the main island in the austral summer of 2015. A total of 1 789 petrel burrows fell within the 75 sample quadrats with an average density of 0.95 burrows·m-2, suggesting that upwards of four million petrels breed on the main island. Burrow densities and occupancy rates were extrapolated by species for each habitat type to generate population estimates: Great Shearwaters 2.34 million burrows (1.82 million pairs, 95 % CI 1.67-1.97 million); Broad-billed Prions Pachyptila vittata a minimum of 83 000 burrows (with many more pairs breeding in rock crevices, total estimate 100 000-500 000 pairs), White-faced Storm Petrels Pelagodroma marina 17 800 burrows (11 700 pairs, 95 % CI 4 700-16 600), Softplumaged Petrels Pterodroma mollis 12 100 burrows (estimated 8 000-10 000 pairs), Fregetta Storm Petrels F. grallaria/tropica 6 600 burrows (estimated 5 000 pairs), Common Diving Petrels Pelecanoides urinatrix 3 900 burrows (estimated 5 000 pairs), and Subantarctic Shearwaters Puffinus elegans an estimated 1 000 pairs. Although Great Shearwater burrow densities and occupancies were lowest in the areas historically used for exploitation of chicks and eggs (ongoing, but now monitored), these results suggest the great shearwater population on Nightingale Island has remained relatively stable since the first estimates in the 1950s. [ABSTRACT FROM AUTHOR]

We describe a deformed tibiotarsus in a museum skeleton of a White-faced Storm Petrel Pelagodroma marina (Oceanitidae), probably resulting from a healed but malaligned fracture. Digital 3D modeling of intertarsal joint kinematics suggested that the affected leg could support neither terrestrial walking locomotion nor the usual foraging activities on open water. Nonetheless, the bird survived, presumably because it employed alternative feeding strategies. Considering this case in the context of previous studies on hindlimb injuries in other storm petrels, we conclude that these birds experience high frequencies of leg injuries but low frequencies of leg fractures. [ABSTRACT FROM AUTHOR]

The Black-capped Petrel Pterodroma hasitata is a pelagic seabird with a dangerously small population size. Remaining breeding sites are threatened by habitat loss, introduced predators, and direct harvesting. The species likely also faces several threats at sea, but because knowledge of its distribution range and ecology is meagre at best, it is challenging to take concerted action to improve its conservation status. The species is currently known to breed only on Hispaniola (in the northern Caribbean Sea), but most at-sea observations are from the Florida Current and the Gulf Stream off the southeastern coast of the USA. Within the Caribbean Sea, observations are scarce. We compiled a database of at-sea sightings of Black-capped Petrels in the Caribbean Sea from 1953 to 2018 by thoroughly reviewing published and unpublished records (Appendix 1); here, we add to the literature 12 new records from a research cruise conducted in February 2018 across the Caribbean Sea. Our database was augmented with recently published information from three birds that were fitted with tracking devices. Based on the collected information, we argue that the existing distribution maps of Black-capped Petrels need adjustments. We show that Black-capped Petrels have been recorded throughout the central parts of the Caribbean, from the known breeding sites in the north down to coastal waters off Panama, Colombia, and Venezuela. However, the birds probably forage only in small parts of the Caribbean Sea (i.e., the coastal upwelling zones off Hispaniola and Cuba in the north and off the South American mainland in the south). The waters in between (i.e., in the central Caribbean Sea) appear to be mainly used as a corridor, while the eastern and western parts are unimportant. This indicates that certain hotspots within the Caribbean Sea may be more important to this endangered species than previously thought. [ABSTRACT FROM AUTHOR]

Studying the migration routes and wintering areas of seabirds is crucial to understanding their ecology and to inform conservation efforts. Here we present results of a tracking study carried out on the little-known Mediterranean Storm Petrel Hydrobates pelagicus melitensis. During the 2016 breeding season, Global Location Sensor (GLS) tags were deployed on birds at the largest Mediterranean colony: the islet of Filfla in the Maltese Archipelago. The devices were retrieved the following season, revealing hitherto unknown movements and wintering areas of this species. Most individuals remained in the Mediterranean throughout the year, with birds shifting westwards or remaining in the central Mediterranean during winter. However, one bird left the Mediterranean through the Strait of Gibraltar and wintered in the North Atlantic. Our results from GLS tracking, which are supported by data from ringed and recovered birds, point toward a system of partial migration with high inter-individual variation. This highlights the importance of trans-boundary marine protection for the conservation of vulnerable seabirds. [ABSTRACT FROM AUTHOR]

There is growing interest in the consistency of individual differences in animal behavior as it relates to life history traits and fitness. Despite the relatively large number of studies investigating repeatable behaviors, studies have only recently investigated repeatability in foraging or migratory behaviors, and this has seldom been explored between years. We examined the individual consistency in foraging behavior of the Grey Petrel Procellaria cinerea, a pelagic long-distance migrant seabird. We analyzed how foraging, activity, and migratory patterns were repeatable across different seasons. We used tracking data to monitor the migratory movements and behavior of individuals during the nonbreeding period over five years. Despite the small sample size, we found that there was a relatively high individual consistency in wintering strategies across years, with birds displaying high fidelity to their non-breeding destinations during consecutive years. Activity parameters, date of departure of inward migration, duration of migration, and duration spent in non-breeding areas were repeatable as well. The duration of the non-breeding period was the most repeatable, reflecting consistent departure times and, to a lesser extent, consistent arrival times. A high overall repeatability was seen in the timing of return migration. With respect to sex, males tended to be more consistent in their migration strategy (i.e., timing of migration, time spent in non-breeding areas) than females. Although conditions during the Holocene have generally been stable in the Southern Ocean, species lacking variability in migratory traits are probably at a considerable disadvantage in terms of their capacity to respond to the rapid environmental changes currently underway. [ABSTRACT FROM AUTHOR]

Little is known about the movements of small seabirds during migration, but such information is important for their conservation. Leach's Storm Petrel Oceanodroma leucorhoa is the most abundant seabird in Atlantic Canada, but its population has declined in recent years. Here, we describe trans-equatorial and trans-Atlantic migration movements of 13 Leach's Storm Petrels, which were tracked with geolocators from two breeding colonies in Nova Scotia, Canada: Bon Portage Island and Country Island. Our results indicate that Leach's Storm Petrels have low migratory connectivity and that they use multiple stopover areas and overwintering destinations. Birds with stopover areas at higher latitudes overwintered in the North Atlantic Ocean, either in areas associated with the North Equatorial Current or in waters off Newfoundland and Labrador. Birds with lower-latitude stopover areas overwintered in the South Atlantic Ocean, in areas associated with the Benguela Current off southwestern Africa. We observed greater δ15N values (indicating a higher trophic level) in feathers from birds that migrated south compared to birds that stayed in the Northern Hemisphere, but we observed no difference in δ13C (which may be interpreted in multiple ways). Species distribution modelling using remotely sensed oceanographic data indicated that high sea surface temperatures and high chlorophyll a concentrations were important predictors of habitat use in winter. [ABSTRACT FROM AUTHOR]

The Band-rumped Storm Petrel Oceanodroma castro is an endangered subtropical pelagic seabird found along the Atlantic and Pacific oceans. We used a combination of acoustic monitoring, night vision surveys, dog searches, and remote camera surveillance to search for occupied nests in support of the US Army's natural resource management requirements in Hawai'i. We discovered a breeding colony at 2 113 m elevation on the northern slope of Mauna Loa within the US Army's Pohakuloa Training Area (PTA) on Hawai'i Island. Camera surveillance confirmed active breeding nests. Because this is the first confirmed location of a colony in Hawai'i, it deserves further investigation. [ABSTRACT FROM AUTHOR]

The Atlantic Petrel Pterodroma incerta breeds during the austral winter and mainly on Gough Island, remaining near the colonies during the breeding season and wintering on the South Atlantic Subtropical Convergence waters. Until now, all information about the diet of this species has been obtained during the breeding season, but these birds may take different prey items on the breeding grounds vs. the wintering grounds. We examined the stomach contents of 61 Atlantic Petrels stranded during the wintering season. A total of 1 183 food items were recorded, mainly cephalopods (93.9%) and fish (6.1%). Anthropogenic objects (i.e., debris) were found in 23 birds (37.7%). Cephalopods are the main prey during both the breeding and the non-breeding seasons. The ingestion of debris by more than one-third of individuals is noteworthy and reveals an additional threat to this endangered species. [ABSTRACT FROM AUTHOR]

We report the first results from a three-year study of the annual cycle of Southern Giant Petrels Macronectes giganteus in two colonies in East Antarctica. Wc tested the utility of a system of automated cameras that monitored and recorded events in the colonies year-round. Based on the collected images, we determined a detailed phenology of breeding events and activities throughout winter. The timing of some portions of the annual cycle (e.g., laying dates) were similar, whereas other aspects of the annual cycle differed between locations (e.g., pair formation and length of the non-brooding guard phase). Comparisons with other breeding locations throughout the species' range showed that lay dates vary with latitude but are synchronous at each site. [ABSTRACT FROM AUTHOR]

Threat status assessments provide a benchmark for identifying priorities for conservation and related research for special-status species. We review data about an endemic New Zealand seabird, the Westland Petrel Procellaria westlandica. and provide information to assist future threat assessment reviews. A range of threats have potential or have already contributed to reductions in population growth at a level that may exceed 10% over 10 years (ranked "High" or "High potential" threats). The realised (observed) threats include landslips and extreme climate events that degrade nesting habitat; bycatch mortality in commercial, recreational, and high-seas fisheries; attraction of fledglings to lights; and the potential encroachment of pigs Sits scrofa and dogs Canis familiaris into breeding areas. Low-ranked threats (which may contribute <10% to population reduction over 10 years) include habitat degradation by browsing introduced mammals and land development; death of individuals by striking wires or buildings; disturbance at colonies; the petrels' consumption of fisheries waste and plastics; human harvest; and naturally occurring mortality such as predation by native species or entrapment in tree branches and vines. Population size estimation, demographic modelling, and trend information indicate that the population is small (~2800 breeding pairs), with very low productivity and therefore potential vulnerability to stochastic events. Recent surveys show that the area of breeding habitat occupied by the birds is only about 0.16 km². Storm events in 2014 severely reduced habitat quality, destroyed large parts of some colonies, and increased the likelihood of further erosion and landslip for at least 75% of the global breeding population. Storm impacts at other colonies have not yet been assessed. In light of this information, we recommend immediate review of the threat status of the species and initiation of mitigation to reduce the severity of threats. The information available indicates that a relisting to IUCN Endangered status may be warranted, and that the Agreement on the Conservation of Albatrosses and Petrels threat assessments should be revised to include two high-level potential threats: pig predation and dog predation. [ABSTRACT FROM AUTHOR]

Collared Petrel Pterodroma brevipes and Gould's Petrel P. leucoptera are two closely related gadfly petrels that breed on islands in the Pacific Ocean. Pale individuals of the polymorphic Collared Petrel are remarkably similar to Gould's Petrel, so it is unsurprising that published descriptions of differences between the two species are incomplete or misleading. Museum specimens of both species and live Gould's Petrels were examined to identify diagnostic plumage characteristics. Pale Collared Petrels were most reliably distinguished from Gould's Petrels by their proportionally longer and tapered tail and by a clear contrast between the grey primaries and white primary coverts on the underwing. Pale Collared Petrels also exhibited a different pigment pattern on the side of the head; a subtle contrast between the breast sides and crown, which is absent in Gould's Petrel; a thicker dark trailing edge on the underwing; and a usually diffuse, rather than abrupt (as in Gould's Petrel), posterior edge of the breast patch. The presence of a collar across the upper breast was not diagnostic of intermediate Collared Petrels. Additional characteristics that may facilitate identification of some Gould's Petrels include a thinner dark ulnar-carpal bar on the underwing, prominent white blotches within the dark ulnar-carpal bar, and conspicuous white sides to the spread tail. [ABSTRACT FROM AUTHOR]

A Tahiti Petrel Pseudobulweria rostrata was observed and photographed 33 km offshore of Durban, South Africa (at 30.040°S, 31.346°E), on 11 November 2018. The only other reports of this species in Africa or the western Indian Ocean are unconfirmed and are from off southern Mozambique, dated November 1987 and December 1990. We believe that the size of the Durban bird distinguishes it from the very similar but smaller Beck's Petrel P. becki. [ABSTRACT FROM AUTHOR]

Catching oceanic birds is challenging for researchers interested in studying migration and feeding dynamics. To address that challenge, we evaluated a new method for catching Wilson's Storm Petrels Oceanites oceanicus at sea. Using an extended butterfly net and a sweeping technique, we successfully captured 50 sub-adult and adult storm petrels offshore in the Northwest Atlantic with a 94% success rate. All were processed without sign of physical trauma or injury; 100%; flew off in apparently good condition. This method provides a cost-effective and safe approach for the capture and study of small oceanic birds attracted to fish slicks. [ABSTRACT FROM AUTHOR]

The current estimate of the number of breeding pairs of Great-winged Petrels Pterodroma macroptera on Tristan Island is 1 000 or less. In the last few hours of daylight on 11 April 2018 we observed large numbers of Great-winged Petrels off the southeast coast of Tristan Island and estimated from this a breeding population of 3000-1000 pairs. This article details the initial observation and the method used to derive the estimate of the number of breeding pairs. [ABSTRACT FROM AUTHOR]

The article discusses findings of a study to determine the impact of cavity size and snow accumulation on the nest selection and breeding of the Snow Petrel or Pagodroma nivea snowbird in Béchervaise Island, East Antarctica. It notes that Snow Petrels were observed in accessed cavities during the 2009-2010 breeding season, with most of these laying eggs in cracks or under boulders. It confirms that cavities with narrower entrances showed a higher rate of occupancy and egg-laying.

The article discusses findings of a study to analyze the vocalizations of the Tahiti Petrel seabird or Pseudobulweria rostrata in American Samoa. It notes that the Tahiti Petrel was able to produce a ground call used for finding mates in burrows, and an aerial call to signal arrival to the colony. Researchers also distinguished the vocal repertoire based on the length and variety of calls recorded through a sonogram.

The article discusses findings of a study to evaluate the accuracy of methods used to monitor burrowing activity and population of the Atlantic Petrel or Pterodroma Incerta seabird in Gough Island in the South Atlantic Ocean. It notes the use of a burrowscope to validate activity signs and playback response to recorded calls in order to estimate Atlantic Petrel population. It confirms that the burrowscope provided a more accurate representation of occupancy for 94 percent of burrows.

The article investigates the diet composition of two procellariids, Cape and Snow Petrels, at Signy Island during the breeding season 2005-2006. Results reveal significantly different diet compositions between chick-feeding and self-provisioning Cape Petrels. However, there was no significant disparities found between chick-feeding Snow Petrels and self-provisioning birds. Antarctic Krill Euphausia superba and the myctophid fish Electrona antarctica were the dominant prey items. Cape Petrels at Signy Island had higher dietary fractions of crustaceans versus findings undertaken at other locations.

The article focuses on reducing the incidence of seabird burrow collapse through the use of petrel boards. An overview of the various methods used by researchers when traversing densely-populated seabird breeding colonies is presented such as narrow plywood planks and purpose-built research trails. The snowshoe-like attachment to footwear is described, outlining the design principles, dimensions and bindings, as well as the potentials for further development and improvement. Limitations include entanglement, mud accumulation, and being inappropriate for steep or broken ground.

The article presents a study on the use of permanent plots to monitor the population trends of burrow-nesting seabirds in British Columbia. The researchers used information from the intensive surveys conducted by the Canadian Wildlife Service to collect baseline population data for most colonies of burrow-nesting seabirds in the 1980s. They also assessed trends in burrow numbers for every colony using repeated-measures analyses in a general linear model. They found that permanent monitoring plots offer an effective method for identifying trends in seabird populations at colony and regional scales.