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Owning a nest is a prerequisite for breeding in Procellariiform seabirds, which can leave their single egg and/or chick unattended for long periods and show high nest fidelity. However, the determinants of nest fidelity vary among species. Amongst them, Bulwer’s Petrel Bulweria bulwerii lays the biggest egg relative to body size within the Family Procellariidae. Therefore, individuals should choose their nests carefully and change essentially if they can improve their reproductive performances. This study conducted on Vila islet, Azores, aimed to determine why Bulwer’s Petrels actually change nest. Nest fidelity exceeded 85%. Nest changes were most likely to occur after a breeding failure or a non-breeding year, but they did not allow improving breeding success and they often resulted in missed breeding years. On average, the new nests were not of higher quality than the old ones, except for the individuals whose first breeding attempt in the new nest was successful. In addition, the quality of the new nest was unrelated to the number of skipped years and to the distance moved. Almost half of changes occurred towards neighbouring nests. They were associated with a lower probability to skip years. Therefore, Bulwer’s Petrels might prioritize proximity over nest quality to reduce the costs of nest changes. communities. This study was part of the project PTDC/BIA-BDE/67286/2006 funded by FCT and by FEDER through the Programme COMPETE (Ref: FCOMP-01-0124-FEDER-007061). The Programmes ‘MARE’ (Integrated Management of Coastal and Marine Sites of the Azores, Life contract B4-3200/98-509), ‘OGAMP’ (Planning and Management of Marine Protected Areas, Interreg IIIB-MAC/4.2/A2), ‘MARMAC’ (Knowledge, Promotion and Valorization for a Sustainable Utilization of Marine Protected Areas in Macaronesia, Interreg IIIB/FEDER/MARMAC/003-4/2005-6 and Interreg IIIB-05/MAC/4.2/A4), and MoniAves, all coordinated by R.S. Santos, also provided support for fieldwork. IMAR-DOP/UAc is funded by FCT and DRCT-Azores as Research Unit 531 and Associate Laboratory 9 (ISR-Lisbon). info:eu-repo/semantics/publishedVersion

International audience; Climate change has repeatedly been shown to impact the demography and survival ofmarine top predators. However, most evidence comes from single populations of widely distributed species, limited mainly to polar and subpolar environments. Here, we aimed to evaluate the influence of environmental conditions on the survival of a tropical and migratory seabird over the course of its annual cycle.We used capture-mark-recapture data fromthree populations of Bulwer's petrel (Bulweria bulwerii) spread across the NE Atlantic Ocean, from the Azores, Canary, and Cabo Verde Islands (including temperate to tropical zones). We also inferred how the survival of this seabird might be affected under different climatic scenarios, defined by the Intergovernmental Panel on Climate Change. Among the environmental variables whose effect we evaluated (North Atlantic Oscillation index, Southern Oscillation Index, Sea Surface Temperature [SST] and wind speed), SST estimated for the breeding area and season was the variable with the greatest influence on adult survival. Negative effects of SST increase emerged across the three populations,most likely through indirect trophicweb interactions. Unfortunately, our study also shows that the survival of Bulwer's petrel will be profoundly affected by the different scenarios of climate change, even with the most optimistic trajectory involving the lowest greenhouse gas emission. Furthermore, for the first time, our study predicts stronger impacts of climate change on tropical populations than on subtropical and temperate ones. This result highlights the devastating effect that climate changemay also have on tropical areas, and the importance of considering multi-population approaches when evaluating its impacts which may differ across species distributions.

Trophic networks in small isolated islands are in a fragile balance, and their disturbance can easily contribute toward the extinction vortex of species. Here, we show, in a small Atlantic island (Raso) in the Cabo Verde Archipelago, using DNA metabarcoding, the extent of trophic dependence of the Endangered giant wall gecko Tarentola gigas on endemic populations of vertebrates, including one of the rarest bird species of the world, the Critically Endangered Raso lark Alauda razae. We found that the Raso lark (27%), Iago sparrow Passer iagoensis (12%), Bulwer's petrel Bulweria bulwerii (15%), and the Cabo Verde shearwater Calonectris edwardsii (10%) are the most frequent vertebrate signatures found in the feces of the giant wall gecko. This work provides the first integrative assessment of their trophic links, an important issue to be considered for the long‐term conservation of these small and isolated island ecosystems.

Moku‘ae‘ae Rock Islet is located off the north shore of Kaua‘i and is protected as a Hawai‘i State Seabird Sanctuary. In the late 1970s it was also the site of a cross-fostering project for the endangered Newell’s Shearwater, Puffinus newelli . Few avifauna surveys have been undertaken on the islet, and none since 2007. In 2013 and 2015, we conducted burrow searches across the entire islet to obtain breeding population estimates for each species and to evaluate whether the Newell’s Shearwater had become established as a breeding species after the cross-fostering project. Auditory surveys were also conducted for 2 hr after sunset and 1.5 hr before sunrise, which are the peak calling periods for the Newell’s Shearwater on Kaua‘i. A total of seven seabird species was recorded on the islet, of which three, Bulwer’s Petrel, Bulweria bulwerii ; Wedge-tailed Shearwater, Ardenna pacifica ; and Red-tailed Tropicbird, Phaethon rubricauda , were confirmed breeding. This is the first time Bulwer’s Petrel has been confirmed breeding on Moku‘ae‘ae. Searches for Newell’s Shearwater did not produce evidence that this species breeds on the islet, suggesting that the cross-fostering project was not successful. Although the islet is small, it represents an important refuge for seabird species. However, high levels of depredation were recorded on Bulwer’s Petrel; we conclude that these were all killed by the introduced Barn Owl, Tyto alba , based on disposition of the bodies and the injuries they had sustained. Management recommendations for the islet include creation of a management plan, annual breeding bird surveys, annual rat monitoring, and Barn Owl control.

Bird feathers are one of the most widely used animal tissue in mercury biomonitoring, owing to the ease of collection and storage. They are also the principal excretory pathway of mercury in birds. However, limitations in our understanding of the physiology of mercury deposition in feathers has placed doubt on the interpretation of feather mercury concentratoins. Throughout the literature, moult sequence and the depletion of the body mercury pool have been taken to explain patterns such as the decrease in feather mercury from the innermost (P1) to the outermost primary feather (P10) of the wing. However, it has been suggested that this pattern is rather a measurement artefact as a result of the increased feather mass to length ratio along the primaries, resulting in a dilution effect in heavier feathers. Here, we attempt to untangle the causes of variation in feather mercury concentrations by quantifying the mercury concentration as μg of mercury (i) per gram of feather, (ii) per millimetre of feather, and (iii) per day of feather growth in the primary feathers of Bulwer's Petrel Bulweria bulwerii chicks, effectively controlling for some of the axes of variation that may be acting in adults, and monitoring the growth rate of primary feathers in chicks. The mercury concentration in Bulwer's Petrel chicks' primaries increased from the innermost to the outermost primary for all three concentration measures, following the order of feather emergence. These observations confirm that the pattern of mercury concentration across primary feathers is not an artefact of the measure of concentration, but is likely an effect of the order of feather growth, whereby the earlier grown feathers are exposed to higher blood mercury concentrations than are later moulted feathers as a result of blood mercury depletion. Fundação para a Ciência e Tecnologia - FCT info:eu-repo/semantics/publishedVersion

Small-sized nocturnal Procellariiformes are abundant predators in oceanic areas worldwide and are thought to play an important role in many marine food webs as consumers of superabundant mesopelagic prey. However, the spatial ecology and foraging behaviour of the great majority of these species remain largely unknown. We studied the non-breeding distribution and at-sea activity of a migratory small-sized Procellariiform, the Bulwer’s petrels Bulweria bulwerii, from the Selvagem Island colony (subtropical Northeast Atlantic). We found that soon after breeding Bulwer’s petrels migrate towards deep (mean depth of 4416 m), open oceanic waters of the tropical Atlantic, spending the winter far from shelf and shelf-break areas, on regions avoided by most other avian migrants in the Atlantic. When at sea, Bulwer’s petrels spent more time flying during the night ([90 %, all year round) than any other seabird studied so far. This nighttime activity was not influenced by the lunar cycle, suggesting that this highly specialised nocturnal seabird is probably very well adapted to locating and capturing prey even in very dark conditions. The results from the present study may have important implications for the identification of important bird areas in the marine realm, whose boundaries have been delineated so far mostly on the basis of the distribution and behaviour of better studied medium- to large-sized seabirds. Fundação para a Ciência e a Tecnologia (FCT)

Invasive ants have the potential to cause severe impacts on the structure and composition of native invertebrate communities and interfere with the natural processes of pollination and seed dispersal. Less frequently reported, direct and indirect impacts on vertebrates, namely birds, are also known to occur. The Argentine ant Linepithema humile is one of the worst invasive species worldwide, and is responsible for economic and ecological impacts in Madeira since its introduction. Previous reports indicated that Argentine ants may be a frequent predator of nestlings on the Desertas Islands which harbour internationally important seabird colonies. Here, we provide a survey of the records of bird predation by Argentine ants in the Desertas. Furthermore, we also assessed if these invasive ants affected the most abundant crevice-nesting seabird on Deserta Grande, the Bulwer’s petrel Bulweria bulwerii, by nest monitoring in the years of 2014–2016. We found that breeding success varied annually between 0.56 and 0.63 chicks produced per nesting attempt. Ant predation of chicks was observed in only two out of 294 study nests. Furthermore, no relationship was found between local abundance of Argentine ants and breeding success of Bulwer’s petrels. We conclude that Argentine ants do not seem to pose a major threat to nesting petrels on the Desertas, although we acknowledge the possibility that environmental changes and episodic population explosions of this invasive species may lead to a greater impact on seabirds’ reproductive success. European Regional Development Fund through Program LIFE Recover Natura; Fundação para a Ciência e a Tecnologia (FCT) info:eu-repo/semantics/publishedVersion

Existe informação suplementar disponível na versão online. The lunar cycle is believed to strongly influence the vertical distribution of many oceanic taxa, with implications for the foraging behaviour of nocturnal marine predators. Most studies to date testing lunar effects on foraging have focused on predator activity at-sea, with some birds and marine mammals demonstrating contrasting behavioural patterns, depending on the lunar-phase. However, to date no study has focused on how the lunar cycle might actually affect predator-prey interactions in the upper layers of the ocean. Here, we tested whether the diet of the predominantly nocturnal pelagic predator, the Bulwer's petrel (Bulweria bulwerii) would change throughout the lunar cycle, using molecular analysis to augment detection and taxonomic resolution of prey collected from stomach-contents. We found no evidence of dietary shifts in species composition or diversity, with Bulwer's petrel always consuming a wide range of mesopelagic species. Other co-variables potentially affecting light availability at-sea, such as percentage of cloud cover, did not confound our results. Moreover, many of the species found are thought not to reach the sea-surface. Our findings reveal that nocturnal predators are probably more specialized than previously assumed, irrespective of ambient-light, but also reveal deficiencies in our current understanding of species vertical distribution and predation-dynamics at-sea. Fundação para a Ciência e a Tecnologia (FCT); FEDER info:eu-repo/semantics/publishedVersion

Thebreeding foraging andpost-breedingdispersal movementsof five satellite-tagged Bulwer’s Petrels fromthe Canary Islands were recorded. Foraging trips lasted 5.6 days in average (n=3), while the meandistance covered was1261km,andforaging areas were located over the continental slope andthe adjacent pelagic waters, around 1200–2000 mdepth and up to 350 kmfromthe colony. After the chick-rearing period, birds dispersed southwestwards to the tropical waters of the central Atlantic

The secretive breeding behaviour of petrels makes monitoring their breeding populations challenging. To assess population trends of Cory’s Shearwater Calonectris diomedea, Bulwer’s Petrel Bulweria bulwerii and Macaronesian Shearwater Puffinus baroli in Tenerife from 1990 to 2010, we used data from rescue campaigns that aim to reduce the mortality of fledgling petrels attracted to artificial lights as proxies for trends in breeding population size. Despite increases in human population size and light pollution, the number of rescued fledglings of Cory’s Shearwater and Bulwer’s Petrel increased and remained stable, respectively, whereas numbers of rescued Macaronesian Shearwaters sharply declined. In the absence of more accurate population estimates, these results suggest a worrying decline in the Macaronesian Shearwater’s breeding population.

Studying the diet of top marine predators, such as seabirds, is important in understanding their place in the trophic network and effects of global climate change, but knowledge of the diet of several procellariiformes remains anecdotal. The diet of Bulwer's Petrel (Bulweria bulwerii) in the Azores was studied over two consecutive years using stomach flushings from 85 birds. The frequency of occurrence of prey taxa (%0) was similar in both years (χ2 = 5.396, d.f. = 5, p = 0.370), with squid being the most common. Fish and squid were of similar occurrence by number (%N) in the diet (49% and 51%, respectively) in 1998 but in 1999 fish were more numerous (62% against 38% for squid). Squid lower beaks from five families and fish otoliths from six families were identified, representing 20 taxa. The most abundant prey in both years were squid Pyroteuthis margaritifera and the mesopelagic fish Electrona risso. The maximum standard length offish and squid consumed was 7 cm and 11 cm, respectively. Given...

Stable-isotope analysis of whole blood was used to examine the feeding of adults and chicks of five seabirds (Wedge-tailed Puffinus pacificus and Christmas Shearwaters P. nativitatus, Bonin Pterodroma hypoleuca and Bulwer's Petrels Bulweria bulwerii and Tristram's Storm-petrel Oceanodroma tristrami) in the northwestern Hawaiian Islands. The goal was to compare community foraging patterns as determined by stable-isotope analysis with traditional studies conducted in the early 1980s. Furthermore, chick-rearing Procellariiformes have been hypothesized to practice a bimodal food-provisioning strategy, a behavior yet to be documented in any of the northwestern Hawaiian Islands species outside the albatrosses. Except for Christmas Shearwaters, adults and chicks had significantly different isotope ratios, suggesting differential self- and chick-provisioning by adults. Wedge-tailed Shearwaters foraged opportunistically for themselves, while providing prey of higher trophic position to their chicks. Bulwer's Petrel and Tristram's Storm-petrel adults likely brought prey of more uniform trophic position to their chicks, while relying on more permanent prey patches differing in composition for themselves during the breeding season. Results suggested little overlap in stable-isotope ratios among species and were likely a result of behavioral and morphological differences in feeding.

Reptiles are uncommon as seabird predators on islands. While conducting a study on Cory's Shearwaters (Calonectris diomedea) on Selvagem Grande, North Atlantic, incidental observations during 2006 early hatching period indicated that some chicks were being killed by Madeiran Wall Lizards (Teira dugesii). In the same year and in 2007, the phenomenon was further examined and samples of 78 and 153 nests, respectively, were followed. Also, non-systematic visits were made to other nests. A total of 40 episodes of lizards depredating Cory's Shearwaters hatchlings was recorded. This hitherto unknown source of predation for this shearwater accounted for the failure of four (5.1%) study nests in 2006 and eight (5.2%) study nests in 2007. All recorded predation cases took place either during or shortly after hatching. Also, non-systematic observations indicated that three other species of burrowing petrels (Bulwer's Petrel, Bulweria bulwerii; Madeiran Storm-petrel, Oceanodroma castro, White-faced Storm-pe...

SUMMARY In the course of the International Indian Ocean Expedition two storm-petrels, thought to be Oceanodroma matsudairae and O. monorhis, were encountered in the western Indian Ocean in some numbers. Two specimens of each species were collected, monorhis in the Arabian Sea, matsudairae off N.W. Australia. O. matsudairae, which had not been recorded before from these waters, appeafed to be concentrated within 5° of the equator and the birds probably belonged to the spring-breeding population of Volcano Island. O. monorhis was found mostly in the Arabian Sea. Bulweria bulwerii, for which there was but one certain Indian Ocean record, was also encountered several times.

Summary. The birds seen on the Berlengas, the Desertas, Baixo Island, and the Salvages in June and July 1939 are listed and field notes are given on certain species. In Puffinis kuhlii borealis incubation was by both sexes. Where it is unmolested by man, as at Grande Salvage, this bird is partly diurnal in visiting the land; where molested, as on the Berlingas' and Desertas, it is nocturnal. In Bulweria bulwerii incubation is by both sexes, probably in shifts of two or more days. At Grande Salvage there appears to be a division of the year into specific breeding seasons by which the maximum use is made of the ground–burrows by two if not three species of petrels. This probable breeding competition is discussed, and other examples suggested from the literature of petrels breeding on small tropical and sub–tropical islands.

Bulwer's petrels are nocturnal seabirds that mostly prey on mesopelagic fauna. As aerial foragers and shallow divers, their feeding opportunities are limited by near-surface availability of their prey, which is highly variable both temporally (reflecting diurnal and lunar cycles) and spatially. Here we studied how Bulwer's petrels cope with these constraints by analysing their at-sea distribution and activity during the incubation period. We tracked the movements of 20 birds from Selvagem Grande (NE Atlantic) during a complete lunar cycle, and recorded 30 foraging trips that lasted 11 days on average. Birds were both distributed around the colony and in waters close to the Azorean archipelago (mid-Atlantic) located 1700 km away, and were significantly more active at night (especially just after sunset and before sunrise), when mesopelagic fauna is also closer to the sea surface due to their diel vertical migrations. Bulwer's petrels spent significantly more time flying during moonlight, although the effect of the moon was relatively weak (ca. 10–15% difference between moonlit and dark periods of the night), and not obvious when birds were foraging in mid-Atlantic waters, which were also targeted more often during full-moon. These results reveal key adaptations of the Bulwer's petrel to the highly dynamic ecology of its mesopelagic prey.

AIM: Our current understanding of migratory strategies and the reasons for their high variability along the phylogenetic tree remains relatively poor. Most of the hypotheses relating to migration have been formulated for terrestrial taxa; classically, oceanic migrations were considered as merely dispersive because of the scarcity of observations in the open ocean. We describe for the first time, the migration strategy of a small seabird, the Bulwer's petrel (Bulweria bulwerii), and provide new insights into the ecology and evolution of long-distance marine migrations. LOCATION: Subtropical and tropical Atlantic Ocean. METHODS: Using cutting-edge geolocators, we examined the year-round distribution and at-sea activity patterns of adult Bulwer's petrels sampled at five localities throughout the species' breeding range in the Atlantic, within the Azores, Salvages, Canary and Cape Verde archipelagos. We assessed the migratory connectivity of the species and its habitat use at population and metapopulation scales. RESULTS: Our results provide the first evidence of an oriented leapfrog migration in oceanic seabirds. Ecological niche models based on breeding-season data effectively predicted that subtropical waters of the South Atlantic would be the preferred habitat for the northern populations of Bulwer's petrels during the non-breeding season. Habitat modelling also highlighted similarities in distributions between the breeding and non-breeding periods for the southern populations. Data on at-sea activity patterns suggested that birds from the northern and southern populations behave differently during the breeding season, as well as in the northern and southern non-breeding ranges during the non-breeding period. MAIN CONCLUSIONS: These results indicate that specific habitat preferences, presumably related to differences in prey availability, explain the observed distributions and hence the pattern of leapfrog migration described for Bulwer's petrel. Our study demonstrates the utility of integrating diverse tracking data from multiple populations across international boundaries, and habitat modelling, for identifying important areas common to many marine species in the vast oceanic environments. FEDER (CGL2009-11278/BOS); SEO/BirdLife (project LIFE+INDEMARES: LIFE07NAT/E/000732) info:eu-repo/semantics/publishedVersion

Three new species of the feather mite subfamily Ingrassiinae (Acariformes: Astigmata: Xolalgidae) are described from shearwaters and petrels (Procellariiformes: Procellariidae) in the North-East of Atlantic Ocean: Ingrassia calonectris sp. n. from Calonectris borealis (Cory) (type host) and Calonectris edwardsii (Oustalet), Ingrassia micronota sp. n. and Opetiopoda bulweriae sp. n. from Bulweria bulwerii (Jardine and Selby). Copyright © 2013 Magnolia Press.

Two new species of the feather mite genus Promegninia Gaud & Atyeo, 1967 (Avenzoariidae: Bonnetellinae) are described from procellariids in the northeasterm Atlantic Ocean: Promegninia bulweriae n. sp. from the Bulwer's petrel Bulweria bulwerii (Jardine & Selby) and P. calonectris n. sp. from the Cory's shearwater Calonectris borealis (Cory) (Procellariiformes: Procellariidae). Males of P bulweriae n. sp. are most clearly distinguished from the other known species in the genus by having short legs III extending only to the level of lobar apices and short conical tarsi III with lanceolate ventral seta w; females of this species are characterised by the absence of additional sclerites at postero-lateral angles of the prodorsal shield. Males of P. calonectris differ from the other known species in having bidentate terminal lamellae on the lobar apices and the entire adanal shield; females of this species are distinguished by having well-developed pygidial shields and a hysteronotal shield encompassing the bases of setae c2. Sequence data of the mitochondrial cytochrome c oxidase subunit I gene fragment (COI) are also obtained for the new species. An updated diagnosis of Promegninia and a key to the known species are provided.

New island records are presented for Melanesia. Most are from 11 months’ fieldwork in 1997–98, with other records from fieldwork in 1990 and a few other recent unpublished records. Whilst most records are of migrants or species previously overlooked, a number of waterbirds and grassland species appear to be expanding their ranges. The most notable records are of possible new subspecies of Lonchura tristissima on Umboi and Todiramphus chloris on Anuta; the proved breeding of Gallinula tenebrosa on New Britain; the presumed breeding of Gallicolumba jobiensis and Monarcha infelix on Tong and Ducula finschii on Lavongai; migrant Bulweria bulwerii at several sites in north Melanesia and Fregata andrewsi in the Solomon Islands; and vagrant Aythya fuligula and Oriolus sagitattus on New Britain.

O Ilhéu Raso é um autêntico santuário para aves marinhas, algumas delas endémicas de Cabo Verde. Realizámos um estudo de estimativas populacionais com marcação de plots circulares ao longo do ilhéu, entre Agosto a Novembro de 2013. Foram amostrados 28 plots, obtendo uma previsão da densidade de ninhos para combinações de variáveis ambientais descritas através de uma regressão múltipla, e recorreu-se a uma extrapolação da área das colónias pela densidade de ninhos para obter uma estimativa populacional. Para Bulweria bulwerii obtivemos uma estimativa de 8 600 pares reprodutores, demonstrando claramente o aumento da população relativamente ao número referido em outros trabalhos; para Calonectris edwardsii os 27 869 pares reprodutores obtidos, é efetivamente um valor elevado relativamente aos primeiros censos, mas claramente enviesado devido aos constrangimentos ambientais enfrentados. Identificámos a percentagem de vegetação e o número de rochas soltas grandes como as variáveis mais importantes na seleção do habitat nidificante das espécies; Analysis of Monitoring Methods of Seabird Communities of Raso Islet, Cape Verde. Abstract: The Raso Islet is an authentic sanctuary for seabirds, some of them endemic to Cape Verde. We conducted a study of population estimates through circular plots marking between August and November of 2013. Twenty eight plots were sampled, predicting nest densities for a combination of environmental variables described, through multiple regression, and resorted to an extrapolation of the colony area by the nest densities to obtain a population estimate. For Bulweria bulwerii we obtained an estimate of 8 600 reproductive pairs, which clearly demonstrates the increasing population, comparatively to the number referred in other studies; for Calonectris edwardsii the obtained estimate of 27 869 reproductive pairs, is effectively a high value comparative to the first census, but clearly skewed because of environmental constraints faced. We identified the percentage of vegetation and the number of large loose rocks as the most important variables in the nesting habitat selection for these species.

We describe 10 new variable dinucleotide microsatellites in the wandering albatross Diomedea exulans , as well as conditions for multiplexing and simultaneous genotyping sets of loci. Their variability was assessed in two and one populations from the Crozet and Kerguelen archipelagos (southern Indian Ocean), respectively. Two to 13 alleles were detected per population, and the mean gene diversity was around 0.4. The low genetic differentiation suggests that these populations constitute a single panmictic unit. Cross-species amplification provided some variability at three and five loci in two other marine birds ( Bulweria bulwerii and Pagodroma nivea ), but none in Calonectris diomedea .

For the first time, we describe 11 variable dinucleotide microsatellites and the conditions for multiplexing and simultaneous genotyping sets of loci in Cory's shearwater, Calonectris diomedea. Microsatellite variability was assessed in a colony from the Azores archipelago (Atlantic Ocean). Two to eight alleles were detected per locus, the mean gene diversity being 4.5. Cross-species amplification in three other seabirds (Diomedea exulans, Procellaria aequinoctialis and Bulweria bulwerii) revealed some variability at one, two and eight loci, respectively.

The black rat Rattus rattus is one of the most invasive alien species in the Bonin Islands and has been recorded on at least 16 of the islands. Higashijima, an uninhabited satellite island of Chichijima, provides breeding sites for thousands of Bulwer's petrels ( Bulweria bulwerii), and a massive die-off of this small petrel caused by rat predation was detected there in 2006. In total, 237 adult carcasses and 61 broken eggs were found in small plots totaling 0.035 ha in area during the year; this predation was estimated to have had devastating impacts on the population. Rat eradication was conducted in 2008, and although the petrel population was small, chicks were observed in 2009. The prompt eradication efforts during the early stages of rat predation prevented local extinction of the Bulwer's petrel. Broken eggs, a sign of rat predation, have also been found on other islands, and rats have been detected on most islands >2 ha in size. Eradication programs should be promoted on islands that currently support both small petrel populations and introduced rat populations before a crisis occurs.

All 20 of the Bulwer's petrels Bulweria bulwerii of Selvagem Grande (30°09′N, 15°52′W) equipped with maximum depth gauges had dived during the feeding trips performed during the incubation period, the mean maximum depth being 2.4 ± 1.0 m (range: 1.0–5.3 m). The depth reached showed no correlation with the breeding experience of the birds, with the length of their trip or with their body size and there were no differences between males and females. Thus, the Bulwer's petrel are among the numerous Procellariiformes which perform regular but comparatively shallow dives, unlike shearwaters (Puffinus) and diving petrels (Pelecanoides) which can reach depths of several tens of metres.

Correlations between lunar phase and behaviour have been studied in five different species of petrels (Cory's Shearwater, Calonectris diomedea; Little Shearwater, Puffinus assimilis; Bulwer's Petrel, Bulweria bulwerii; White-faced Storm Petrel, Pelagodroma marina; and Madeiran Storm Petrel, Oceanodroma castro) during 20 nights. Quantitative data on the activity of birds (number of calls per time unit, proportion of nests visited, and number of birds in flight by night), relatively to their breeding status and the phase of the moon, suggest that moonlight may affect primarily the activity of the nonbreeders, especially in the smaller species. The results are compared with those for other species of petrels and possible causes of moon avoidance, such as increased predation risk, are discussed.

A nest and an egg of the Bulwer's Petrel was identified in Birou Island (32°28′N, 131°44′E), located at the northern coast of Miyazaki Prefecture, on 5 September 1998. This is the first evidence of breeding of this species in Miyazaki Prefecture. The nest and the egg was found in a crevice of a rock.

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La croissance pondérale et staturale des poussins de Pétrels de Bulwer, Bulweria bulwerii, de Selvagem Grande (30º09’N, 15°52’W) ne diffère en rien de ce qui est habituel chez les Procellariidés. A partir d’un poids à la naissance un peu inférieur au poids de l’oeuf. Une croissance rapide puis ralentie amène les poussins à un poids maximum supérieur au poids de l’adulte. Par la suite, le poids corporel s’abaisse et, à l’envol, ii est un peu inférieur à celui des adultes. La croissance de l’aile, lente avant la pousse des rémiges, puis rapide. Ne s’achève qu’au moment de l’envol. La croissance du culmen et celle du tarse, d’abord rapides puis ralenties s’achèvent respectivement aux environs des deux-tiers et de la moitié du séjour au nid des poussins. La fréquence des repas est à peu près constante pendant toute la période d’accroissement pondéral. Il est probable qu’elle diminue par la suite. Le poids du repas augmente rapidement pendant la première décade de la vie, puis diminue très lentement. Dans ces conditions, la quantité de nourriture consommée quotidiennement augmente pendant la première décade, reste à peu près constante pendant les trois suivantes, puis décroit. Au total, un poussin aura consommé au cours de sa croissance un peu plus de 0,5 kg de nourriture, dont une partie sous forme d’huile stomacale, ce qui semble correspondre à un prélèvement en mer de 1,5 kg, soit environ 17% de la consommation familiale pendant la même période. ABSTRACT: The growth of the chicks of the Bulwer’s Petrel, Bulweria bulwerii, on Selvagem Grande (30º09’N, 15°52’W) shows no differences with what is usual among Procellariidae. The weight at birth is slightly lower than that of the egg. The subsequent increase, rapid at the beginning, slows down, and a maximum weight higher than the adult weight is reached. Later on the body weight lowers and, at fledging, is slightly lower than that of the adult. The wing grows slowly before the appearance of the remiges, then rapidly, and stops at fledging. The growth of the culmen and tarsus, rapid at first, slows down and stops respectively at the two thirds and at half of the chick sojourn on the nest. The feeding frequency, is almost constant during the period of weight gain, and probably lessens afterwards. In these conditions the amount of food eaten daily increases during the first decade of life, remains constant during the following three, and lessens afterwords. On the whole, a chick eats during its growth a little more than 0.5 kg of food, part of which as stomach oil, which seems to correspond to a catch of 1.5 kg, or about 17% of the family intake during the same period.

Regurgitated food samples were collected from 18 species of seabirds on 8 of the Northwestern Hawaiian Islands between February 1978 and February 1981. Sea-skaters (Halobates sericeus) was found in the diets of 9 species, but can be considered to be an important food item for only 4 species: the blue-gray noddy Procelsterna cerulea; the Bonin petrel Pterodroma hypoleuca; the gray-backed tern Sterna lunata; and Bulwer's petrel, Bulweria bulwerii. The blue-gray noddy, by far the most important avian predator of Halobates spp., may at times feed exclusively on this food item and may appreciably reduce the populations of sea-skaters within their foraging territories.

Studying the movements of oceanic migrants has been elusive until the advent of several tracking devices, such as the light-level geolocators. Stable isotope analysis (SIA) offers a complementary approach to infer areas used year-round, but its suitability in oceanic environments remains almost unexplored. To evaluate SIA as a tool for inferring movements of oceanic migrants, we sampled an oceanic seabird, the Bulwer’s petrel, Bulweria bulwerii, in four breeding colonies spread along its Atlantic distribution. We first studied the species moulting pattern from 29 corpses collected in the colonies. Secondly, based on this moult knowledge, we selected three feathers from tracked birds to infer their breeding and non-breeding grounds using SIA: the 1st primary (P1), the 8th secondary (S8) and the 6th rectrix (R6) feathers. Birds migrated to two main non-breeding areas, the Central or the South Atlantic Ocean. P1 showed similar isotopic values among petrels from different breeding colonies, suggesting this feather is replaced early in the non-breeding period in a common area used by most birds, the Central Atlantic. S8 and R6 feathers correctly assigned 92% and 81%, respectively, of the birds to their non-breeding areas, suggesting they were replaced late in season, when birds were settled in their main non-breeding grounds. Our results showed that the isotopic baseline levels of the Central and South Atlantic are propagated through the food web until reaching top predators, suggesting these ratios can be used to infer the movement of long-distance migrants among oceanic water masses.

This paper reports the first comprehensive surveys of Fea's Petrel (Pterodromafeae), Bulwer's Petrel (Bulweria bulwerii), Manx Shearwater (Puffinus puffinus), Little Shearwater (Puffinus assimilis baroli) and two temporally-segregated forms of Band-rumped Storm-petrel (Oceanodroma castro) in the whole Azores archipelago, conducted from 1996 to 1998. Listening to nocturnal vocalizations was the main survey method. Breeding of Fea's Petrel was not confirmed and new sites of Bulwer's Petrel were not found (previous status: one site, 50 pairs), but previously undocumented colonies were identified for the remaining species. Manx Shearwater occurred in four colonies with 115-235 pairs (previous status: probable breeder), Little Shearwater occurred in 28 colonies with 840-1,530 pairs (previously: four locations, >150 pairs), hot-season Band-rumped Storm-petrels occurred in 5 colonies with 250-300 pairs (previously: two locations, 200 pairs) and cool-season Band-rumped Storm-petrels were found in eight locations with 665-740 pairs (previously: three locations, 600 pairs). Most colonies were confined to precipitous cliffs and islets, which may be a result of predation threats by introduced mammals. Although these surveys provided a valuable revision of the status and distribution for these species of conservation concern, further survey work is warranted and target areas are indicated. We discuss the potential and limitations of listening for nocturnal vocalizations as a method to survey and monitor shearwater and petrel populations in inaccessible habitats. Received 24 May 1999, accepted 8 July 1999.