Storm-petrels Oceanodroma Leucorhoa Research Articles

Temporal trends of essential omega-3 fatty acids in Atlantic and Pacific food webs as measured in eggs of Leach’s storm-petrel Oceanodroma leucorhoa

Leach’s storm-petrel Oceanodroma leucorhoa populations in the North Atlantic have declined in recent decades. The cause of those declines is not clear but one potential contributing factor could be reductions in the availability of essential nutrients due to changing marine ecology resulting from global warming. One group of particular concern is the omega-3 highly unsaturated fatty acids (n-3 HUFAs), in particular, eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Dietary sources of EPA and DHA are required for normal growth and development in higher consumers, including birds. However, previous work has predicted increases in sea surface temperatures may cause declines in their availability. Here, we investigate this possibility by examining temporal trends (1992-2015) in EPA and DHA concentrations in Leach’s storm-petrel eggs from 5 Canadian colonies: 2 on the Atlantic coast (Gull, Kent Islands) and 3 on the Pacific coast (Hippa, Storm, Cleland Islands). Neither EPA nor DHA concentrations in eggs decreased with time on either coast; rather, on the Atlantic coast, both EPA and DHA increased over the period of study. Carbon stable isotopes in the same eggs indicated that storm-petrels foraging in offshore, pelagic waters may have had increased access to n-3 HUFA. The data generated here provide a baseline for future comparisons. Ongoing regular monitoring of fatty acids in seabird eggs would be prudent given the likelihood of further increases in ocean temperatures.

Seabird species‐ and assemblage‐level isotopic niche shifts associated with changing prey availability during breeding in coastal Newfoundland

Shifting prey availability can lead to altered species interactions, indicated by variation in the dietary niche breadth and position of species within an assemblage. On the Newfoundland coast, annual inshore spawning migration of the dominant forage fish, CapelinMallotus villosus, provides an excellent opportunity to investigate the influence of varying prey availability on dietary niche breadth and position among species. During June–August 2017, we investigated species‐ and assemblage‐level dietary responses to shifting Capelin availability of three Capelin‐eating, sympatrically breeding auk species, the Atlantic PuffinFratercula arctica, RazorbillAlca tordaand Common MurreUria aalge. The diet of Leach's Storm PetrelsOceanodroma leucorhoa, which breed alongside the three auk species but are not known to rely on Capelin, was also examined to determine dietary shifts throughout breeding that were unrelated to Capelin availability. We quantified stable isotope ratios (δ15N, δ13C) in seabird blood components (plasma, cellular component) collected both before and after spawning Capelin arrived in the study area and compared isotopic niche breadth within a Bayesian framework. At the species level, auk trophic position increased and isotopic niche breadth narrowed after Capelin arrived, suggesting a more Capelin‐based diet. Simultaneously, trophic diversity of the auk assemblage, reflecting the extent of spacing among niches of species, decreased after spawning Capelin arrived inshore. Contrastingly, increased trophic position but broader isotopic niche breadth during higher relative to lower Capelin availability for Leach's Storm Petrel confirm that this species is probably not affected by the inshore arrival of Capelin, but instead that isotopic changes may be more related to a shift in breeding stage to chick‐rearing. Overall, our findings reiterate the importance of Capelin as a prey resource for breeding auks in coastal Newfoundland, but that the degree of reliance on Capelin varies among species, possibly allowing coexistence of these ecologically similar species. The findings highlight potential changing species interactions, such as increased competition, under declines in Capelin biomass.

Divergence between genes but limited allelic polymorphism in two MHC class II A genes in Leach's storm-petrels Oceanodroma leucorhoa.

The major histocompatibility complex (MHC) is critical to host-pathogen interactions. Class II MHC is a heterodimer, with α and β subunits encoded by different genes. The peptide-binding groove is formed by the first domain of both subunits (α1 and β1), but studies of class II variation or natural selection focus primarily on the β subunit and II B genes. We explored MHC II A in Leach's storm-petrel, a seabird with two expressed, polymorphic II B genes. We found two II A genes, Ocle-DAA and Ocle-DBA, in contrast to the single II A gene in chicken and duck. In exon 2 which encodes the α1 domain, the storm-petrel II A genes differed strongly from each other but showed little within-gene polymorphism in 30 individuals: just one Ocle-DAA allele, and three Ocle-DBA alleles differing from each other by single non-synonymous substitutions. In a comparable sample, the two II B genes had nine markedly diverged alleles each. Differences between the α1 domains of Ocle-DAA and Ocle-DBA showed signatures of positive selection, but mainly at non-peptide-binding site (PBS) positions. In contrast, positive selection within and between the II B genes corresponded to putative PBS codons. Phylogenetic analysis of the conserved α2 domain did not reveal deep or well-supported lineages of II A genes in birds, in contrast to the pronounced differentiation of DQA, DPA, and DRA isotypes in mammals. This uncertain homology complicates efforts to compare levels of functional variation and modes of evolution of II A genes across taxa.

Long-term declines in common breeding seabirds in Japan

SummaryGlobal seabird populations are in decline, with nearly half of all seabird species currently in an extinction crisis. Understanding long-term seabird population trends is an essential first step to inform conservation actions. In this study, we assembled historical breeding records of seabirds throughout the Japanese archipelago and quantified the long-term population trends of 10 major breeding seabird species using a hierarchical Bayesian state-space model. The model revealed that six species had increasing or no detectable trends (Short-tailed Albatross Phoebastria albatrus, Leach’s Storm Petrel Oceanodroma leucorhoa, Pelagic Cormorant Phalacrocorax pelagicus, Japanese Cormorant Phalacrocorax capillatus, Spectacled Guillemot Cepphus carbo, and Rhinoceros Auklet Cerorhinca monocerata). However, decreasing trends were found not only in nationally threatened species (Common Murre Uria aalge, and Tufted Puffin Fratercula cirrhata) but also common species that are often described as abundant (Black-tailed Gull Larus crassirostris and Slaty-backed Gull Larus schistisagus). These declining species have declined to 3–35% of baseline levels over the past 30 years. This study provides the first evidence of long-term declines in common and widespread seabirds in Japan.

Assessment of Great Skua Stercorarius skua pellet composition to inform estimates of storm petrel consumption from bioenergetics models

Generalist predators may exert levels of predation on particular prey that result in, or contribute to, decline of that prey species. Bioenergetics models have been used to estimate the rates of consumption of Leach’s Storm Petrels Oceanodroma leucorhoa (45 g) and European Storm Petrels Hydrobates pelagicus (25 g) by Great Skuas Stercorarius skua on St Kilda (Western Isles, UK) and Hermaness (Shetland, UK). The models require estimates of the number of indigestible pellets produced from each individual storm petrel consumed, which have previously been determined by captive feeding trials or examination of pellets cast by free-living birds, but which have not discriminated between the two storm petrel species. Here we use information from dissection of 427 Great Skua pellets collected on Hirta (St Kilda, UK) and Mousa (Shetland, UK) to provide empirical estimates of the pellet:prey ratios for Leach’s and European Storm Petrels separately. We found that pellet:prey ratios were similar for collections of the ‘standing crop’ of pellets accumulated over the entire breeding season and samples of pellets cast within the preceding five days. However, pellet:prey ratios of both Leach’s and European Storm Petrel were considerably lower than reported previously. Furthermore, we found the pellet:prey ratio for European Storm Petrels consumed on St Kilda was 80% higher than the value for the same species on Mousa. Our study suggests that the use of a single generic value for the pellet:prey ratio for both species and all locations may lead to inaccuracies in estimation of consumption rates, and we recommend further work to understand the causes of such variation.

Leach’s Storm PetrelOceanodroma leucorhoapopulation trends on Bon Portage Island, Canada

Regular estimates of breeding populations are important for detecting declines and for implementing appropriate conservation measures in a timely manner. In Atlantic colonies, Leach’s Storm Petrels Oceanodroma leucorhoa are in decline at most colonies that have been surveyed. Consequently, the species has recently been uplisted from ‘Least Concern’ to ‘Vulnerable’ by the International Union for the Conservation of Nature. On Bon Portage Island, the largest Leach’s Storm Petrel colony in Nova Scotia, the last survey was completed in 2001. The aim of this study was to update the population estimate for this colony. Our results suggested that the current population is 38,916 ± 8,749 pairs, a 20% decline in 16 years. Several factors are most likely responsible for this decline, but loss of breeding habitat may be the principle cause on this island.

Foraging areas, offshore habitat use, and colony overlap by incubating Leach's storm-petrels Oceanodroma leucorhoa in the Northwest Atlantic.

Despite their importance in marine food webs, much has yet to be learned about the spatial ecology of small seabirds. This includes the Leach’s storm-petrel Oceanodroma leucorhoa, a species that is declining throughout its Northwest Atlantic breeding range. In 2013 and 2014, we used global location sensors to track foraging movements of incubating storm-petrels from 7 eastern Canadian breeding colonies. We determined and compared the foraging trip and at-sea habitat characteristics, analysed spatial overlap among colonies, and determined whether colony foraging ranges intersected with offshore oil and gas operations. Individuals tracked during the incubation period made 4.0 ± 1.4 day foraging trips, travelling to highly pelagic waters over and beyond continental slopes which ranged, on average, 400 to 830 km from colonies. Cumulative travel distances ranged from ~900 to 2,100 km among colonies. While colony size did not influence foraging trip characteristics or the size of areas used at sea, foraging distances tended to be shorter for individuals breeding at the southern end of the range. Core areas did not overlap considerably among colonies, and individuals from all sites except Kent Island in the Bay of Fundy foraged over waters with median depths > 1,950 m and average chlorophyll a concentrations ≤ 0.6 mg/m3. Sea surface temperatures within colony core areas varied considerably (11–23°C), coincident with the birds’ use of cold waters of the Labrador Current or warmer waters of the Gulf Stream Current. Offshore oil and gas operations intersected with the foraging ranges of 5 of 7 colonies. Three of these, including Baccalieu Island, Newfoundland, which supports the species’ largest population, have experienced substantial declines in the last few decades. Future work should prioritize modelling efforts to incorporate information on relative predation risk at colonies, spatially explicit risks at-sea on the breeding and wintering grounds, effects of climate and marine ecosystem change, as well as lethal and sub-lethal effects of environmental contaminants, to better understand drivers of Leach’s storm-petrel populations trends in Atlantic Canada.

A survey of Leach’s Petrel Oceanodroma leucorhoa on North Rona, Western Isles, Scotland in 2015

Comparable surveys have been made of the Leach’s Storm-petrel Oceanodroma leucorhoa colony on North Rona, Western Isles, Scotland in 2001, 2009 and 2015 using responses to tape recordings played at burrow entrances. Response rates estimated from a calibration plot were used to correct the total number of responses to tape playback from an island-wide survey. A ‘simple arithmetic’ method of calculating the population estimate suggested 606 apparently occupied burrows (AOB) for 2015, which is the lowest number to date and represents a c.15% decline since the last survey in 2009, when 713 AOB were found. In 2001 there were 1,084 AOB, giving an overall decline of 44% since this first survey. The ‘first response’ method, which only makes use of the first response from each burrow in the calibration plot, is designed to avoid potential bias, caused either by habituation or by very vocal individuals. As this suggests a population of 805 AOB there is a need to be cautious about inferring a further island wide decline since 2009.

Finding the best predictor of reproductive performance of Leach's Storm-Petrels

ABSTRACT Physiological and environmental factors shape foraging strategies and energy balance. For species that breed seasonally, physiological changes in an individual can have short-term effects, but also can persist as carry-over effects from one season to the next, such as from the overwintering season to the breeding season. We tested the hypothesis that reproductive performance could be predicted by diet and energy balance during the breeding and nonbreeding seasons in a long-lived seabird, the Leach's Storm-Petrel (Oceanodroma leucorhoa). Specifically, we predicted that better reproductive performance would be correlated with four factors: (1) a high-lipid diet, as indexed by a high C:N ratio in stable isotope analyses; (2) a diet rich in antioxidants, as indexed by high plasma antioxidant capacity; (3) foraging at a high trophic level, as indexed by high values of δ15N in stable isotope analyses, which is positively related to lipids; and (4) a positive long-term energy balance, revealed by low le...

Foraging movements of Leach's storm‐petrels Oceanodroma leucorhoa during incubation

Knowledge of foraging movements during the breeding season is key to understanding energetic stresses faced by seabirds. Using archival light loggers (geolocators), a Bayesian state–space model, and stable isotope analysis, we compared foraging movements of Leach's storm‐petrels Oceanodroma leucorhoa during their incubation periods in 2012 and 2013. Data were collected from two colonies, Bon Portage Island and Country Island, which are 380 km apart along the coast of Nova Scotia, Canada. Based on allometry for procellariiform mass, predicted foraging ranges for Leach's storm‐petrels are 200 km; however, observed maximum distances from the colony were 3 to 5 times that. Storm‐petrels from Country Island travelled 1015 ± 238 km southeast to the Laurentian fan and south of the Grand Banks whereas storm‐petrels from Bon Portage Island travelled 613 ± 167 km southeast, beyond the continental slope, east of Georges Bank. The average distance travelled in a return trip was 2287 ± 603 km and 1303 ± 351 km for Country Island and Bon Portage Island, respectively. There were no differences between years in cumulative distances travelled within islands, but foraging trips did not last as long in 2013 (4.7 ± 1.5 d) as they did in 2012 (6.2 ± 2.1 d). Stable isotope analyses indicated that, during the incubation period, prey items from Country Island were from higher trophic levels and possibly had higher energy content than those from Bon Portage Island, perhaps explaining the more distant and longer foraging trips for Country Island birds.

Population genetic structure and long‐distance dispersal among seabird populations: Implications for colony persistence

Dramatic local population decline brought about by anthropogenic-driven change is an increasingly common threat to biodiversity. Seabird life history traits make them particularly vulnerable to such change; therefore, understanding population connectivity and dispersal dynamics is vital for successful management. Our study used a 357-base pair mitochondrial control region locus sequenced for 103 individuals and 18 nuclear microsatellite loci genotyped for 245 individuals to investigate population structure in the Atlantic and Pacific populations of the pelagic seabird, Leach's storm-petrel Oceanodroma leucorhoa leucorhoa. This species is under intense predation pressure at one regionally important colony on St Kilda, Scotland, where a disparity between population decline and predation rates hints at immigration from other large colonies. AMOVA, F(ST), Φ(ST) and Bayesian cluster analyses revealed no genetic structure among Atlantic colonies (Global Φ(ST) = -0.02 P > 0.05, Global F(ST) = 0.003, P > 0.05, STRUCTURE K = 1), consistent with either contemporary gene flow or strong historical association within the ocean basin. The Pacific and Atlantic populations are genetically distinct (Global Φ(ST) = 0.32 P < 0.0001, Global F(ST) = 0.04, P < 0.0001, STRUCTURE K = 2), but evidence for interocean exchange was found with individual exclusion/assignment and population coalescent analyses. These findings highlight the importance of conserving multiple colonies at a number of different sites and suggest that management of this seabird may be best viewed at an oceanic scale. Moreover, our study provides an illustration of how long-distance movement may ameliorate the potentially deleterious impacts of localized environmental change, although direct measures of dispersal are still required to better understand this process.

Relationship between Body Water and Lipid in Three Seabird Species: Leach's Storm-Petrel, Rhinoceros Auklet and Black-Tailed Gull

Abstract Measuring the individual body conditions of living birds is essential for understanding tradeoffs in life-history studies, especially in long-lived species. The aim of this study was to further develop a method for measuring body condition (lipid content), without killing birds. In theory, the lipid content mass in the body should have a close inverse relationship with water mass. Using this relationship, body condition can be evaluated without killing because the amount of water in the body can be estimated in live birds. However, the inverse relationship has only been shown to exist in a few studies of bird species. In this study, significant inverse relationships between water and lipid contents of three seabird species, Leach's Storm-Petrel Oceanodroma leucorhoa, Rhinoceros Auklet Cerorhinca monocerata and Black-tailed Gull Lams crassirostris, were shown. These facts highlight that body condition (lipid content) , can be estimated from the water content of the body.

Characterisation and predicted genome locations of Leach’s storm-petrel (Oceanodroma leucorhoa) microsatellite loci (Procellariidae, Aves)

Forty-one microsatellite loci were found to be polymorphic in the Leach’s storm-petrel Oceanodroma leucorhoa when characterised in 24 unrelated individuals sampled from a population located at Gull Island, Newfoundland, Canada. Sequence homology was used to assign a predicted chromosome location for 39 of the polymorphic loci. Four polymorphic microsatellite loci were Z-linked based on the typing of known sex individuals and/or sequence homology. The set of 37 autosomal markers will be suitable for population and parentage studies of the Leach’s storm-petrel (combined first parent non-exclusion probability <0.0001).

Maximum Load-Carrying During Takeoff of Leach's Storm-PetrelOceanodroma leucorhoaand Cassin's AukletPtychoramphus aleuticus

Abstract. Birds at-sea increase body mass as a consequence of food consumption and plumage wettability. However, little is known about the effect of maximum extra load on takeoff of aquatic birds. Experimental evaluation of maximum load-lift during takeoff was performed on a wing-propelled diver with high wing loading, Cassin's Auklet Ptychoramphus aleuticus, and on a surface feeder with low wing loading, Leach's Storm-Petrel Oceanodroma leucorhoa. Leach's Storm-Petrel supported a maximum extra load of 45% of its body mass, and that of Cassin's Auklet was 25%. The relation of maximal load to food transport and plumage wettability indicates that the storm-petrel and the alcid maintain safety load margins of 31% and 8% of the maximum supported extra load during takeoff, respectively. Load margin showed by storm-petrels suggests an enhanced flight performance, increasing specific lift during foraging; meanwhile that of auklets allows for reduction of specific buoyancy during diving.

Leach’s Storm-petrels Oceanodroma leucorhoa nesting at a new site in Shetland

In August 2010, six small islands in northern Shetland were prospectively surveyed for breeding colonies of Leach’s Storm-petrels Oceanodroma leucorhoa using vocalisation playback methods. Four adult birds, two with a nest, were located on 10 August in burrows at a new site for the species in the UK: Gloup Holm, off north Yell. Under license, three birds were temporarily extracted and examined; all had brood patches entirely bare of feathering and highly vascularised. Eggs and chicks were not located but burrows were all too deep to check conclusively. Future surveys of Gloup Holm and other small islands in the north of Shetland, carried out in June, may locate further adults, eggs and chicks.

Takeoff flight performance and plumage wettability in Cassin’s Auklet Ptychoramphus aleuticus, Xantus’s Murrelet Synthliboramphus hypoleucus and Leach’s Storm-petrel Oceanodroma leucorhoa

Due to their marine habitats and distinctive foraging modes, seabirds face unique challenges with respect to flying that are negotiated differently by various species. One such challenge is taking off from the water with wet plumage. This study evaluated plumage wettability and takeoff performance in three seabird species: two wing-propelled divers with high wing loading, Cassin’s Auklet Ptychoramphus aleuticus and Xantus’s Murrelet Synthliboramphus hypoleucus; and Leach’s Storm-petrel Oceanodroma leucorhoa, a surface feeder with low wing loading. The plumages of the diving birds held less water than that of O. leucorhoa (~6.7% of body mass vs 9.5%). This difference is explained by O. leucorhoa’s surface to volume ratio being larger than that of the alcids. Furthermore, the alcids have afterfeathers larger than those of O. leucorhoa, which promotes a better insulation during diving. Examination of takeoff performance both before and after experimentally submerging the birds indicated that wingbeat frequency, speed and mass-specific power (peak and mean), and energy per wingbeat decreased in all species when plumage was experimentally wetted, whereas mean acceleration increased. O. leucorhoa was more strongly affected by wet plumage than the alcids, with a 32% of reduction in mass-specific energy per wingbeat compared to ≤25% in the alcids. Takeoff angle was reduced in alcids, but not significantly so in O. leucorhoa. Our results offer insights into the takeoff mechanics problems of wet seabirds given their differences in life history and morphology.

Population decline of Leach’s Storm-petrel Oceanodroma leucorhoa within the largest colony in Britain and Ireland

This study used diurnal playback of vocalisations to examine the abundance of breeding Leach’s Storm-petrel Oceanodroma leucorhoa on Dun, St Kilda in 2003 and 2006 in relation to the only previous survey conducted using similar methodology in 1999. The number of Apparently Occupied Sites in 2006 was 12,770, not significantly different to the 14,490 found in 2003, but significantly lower than the 27,811 found in 1999, by 54%. The magnitude and rate of the decline are of major conservation concern. Great Skua Stercorarius skua predation is thought the most likely cause but other factors such as poor food supply cannot be ruled out. The importance of continued monitoring of Leach’s Storm-petrel and Great Skua is discussed.

Population decline of Leach’s Storm-petrel Oceanodroma leucorhoa within the largest colony in Britain and Ireland

This study used diurnal playback of vocalisations to examine the abundance of breeding Leach’s Storm-petrel Oceanodroma leucorhoa on Dun, St Kilda in 2003 and 2006 in relation to the only previous survey conducted using similar methodology in 1999. The number of Apparently Occupied Sites in 2006 was 12,770, not significantly different to the 14,490 found in 2003, but significantly lower than the 27,811 found in 1999, by 54%. The magnitude and rate of the decline are of major conservation concern. Great Skua Stercorarius skua predation is thought the most likely cause but other factors such as poor food supply cannot be ruled out. The importance of continued monitoring of Leach’s Storm-petrel and Great Skua is discussed.

Fugler i Norge 2004 – Rapport fra Norsk faunakomite for fugl (NFKF)

THE NORWEGIAN BIRD REPORT 2004 - a report on locally uncommon and scarce birds in Norway in 2004, by the Norwegian Birds Records Committee (NFKF)The basis of this report is the annual reports produced by the county rarities committees. For 2004 all the counties contributed to the report, although Finnmark, Troms, Sogn &amp; Fjordane, Rogaland and Vest-Agder counties did not publish own county reports. We believe this report reflects fairly well observations from Norway in 2004. Readers should take care to note the geographical or time delimitation of the records stated for the different species, as stated in codes immediately after the scientific name of the species. The Norwegian Birds Records Committee (NFKF) has been publishing annual reports since 1991. The occurrence of Bewick&rsquo;s Swan Cygnus columbianus was one of the poorest in NFKFs history, and the occurence of Lesser White-fronted Geese Anser erythropus at the traditional feeding and roosting site Valdakmyra, Porsanger (FI) continued to be very low. White-fronted Geese Anser albifrons was seen in good numbers. Mandarin Ducks Aix galericulata occurredin record high numbers. Gadwalls Anas strepera have occurred in steadily increasing numbers in Norway in recent years, and 2004 was the second best year to date for this species. Quails Coturnix coturnix occurred in good numbers for the third year in succession. Yellowbilled Divers Gavia adamsii experienced the second best year since 1991. Leach&rsquo;s Storm Petrel Oceanodroma leucorhoa was seen in record high numbers in Rogaland in September. Many Common Kestrels Falco tinnunculus were seen during the winter months. The Eurasian Hobby Falco subbuteo is a raptor that has occurred in high numbers in recent years, and 2004 was the second best year ever. The occurrence of Avocets Recurvirostra avosetta was the best ever in NFKFs history. Several shorebirds, such as European Golden Plovers Pluvialis apricaria, Northern Lapwings Vanellus vanellus, Great Knots Calidris canutus, SanderlingsCalidris alba and Woodcocks Scolopax rusticola wintered in low numbers. The number of migrating Broad-billed Sandpipers Limicola falcinellus was the second best in NFKFs history. Migrating Pomarine Skuas Stercorarius pomarinus and Long-tailed Skuas Stercorarius longicaudus were seen in good numbers, and the occurrence of Little Gulls Larus minutus was the second best in NFKFs history. Compared to the last three years, Glaucous Gulls Larus hyperboreus occurred in considerable lower numbers in 2004. Also the occurrence of Snowy Owls Bubo scandiaca and Great Grey Owls Strix nebulosa were very poor. The negative trend related to migrating Horned Larks Eremophila alpestris continued in 2004, and the last five years represent the five poorest years for this species. The occurrence of Red-throated Pipits Anthus cervinus was one of the poorest in NFKFs history, while Yellow Wagtails Motacilla flava flavissima and Pied Wagtails Motacilla alba yarrellii occurredin near record numbers. Many breeding attempts of Waxwings Bombycilla garrulus were recorded, especially in Nordland county. Stonechats Saxicola torquata occurred in record high numbers, and nine confirmed breeding pairs were recorded. The number of singing Common Grasshopper Warblers Locustella naevia was the highest ever recorded, and the number of Marsh Warblers Acrocephalus palustris and Redbreasted Flycatchers Ficedula parva continued to be high. Many breeding attempts of Red-backed Shrikes Lanius collurio were recorded in Rogaland county, and Great Grey Shrikes Lanius excubitor had another good year throughout the country. The Eurasian Tree Sparrow Passer montanus still show a marked increase in the north of its distribution range, especially in Nord- Tr&oslash;ndelag county. In November, the southernmost parts of Norway experienced a major influx of Pine Grosbeaks Pinicola enucleator producing record numbers in the history of NFKF. In October, Norway also had a major influx of Bullfinches Pyrrhula pyrrhula. These Bullfinches probably came from other parts of Europe than Fennoscandia. The Ortolan Bunting Emberiza hortulana continued to occur in low numbers and the Rustic Bunting Emberiza rustica experienced the poorest year in NFKFs history. The occurrence of Little Buntings Emberiza pusilla was very good.

A survey of Leach’s Oceanodroma leucorhoa and European Storm-petrel Hydrobates pelagicus populations on North Rona and Sula Sgeir, Western Isles, Scotland

Leach’s Storm-petrel Oceanodroma leucorhoa was first recorded breeding on North Rona in 1883 and on Sula Sgeir in 1939. European Storm-petrel Hydrobates pelagicus was first recorded on North Rona in 1885 and on Sula Sgeir in 1958. Since then, there have been attempts to estimate the population size of both species on North Rona but there is little information about their current status on Sula Sgeir. In 2001, systematic surveys of both species using tape playback were conducted for the first time on both islands. North Rona held 1,133 Apparently Occupied Sites (AOS) of Leach’s Storm- petrel but only 371 AOS of European Storm-petrel; numbers on Sula Sgeir were five and eight AOS respectively. The combined population of both North Rona and Sula Sgeir of Leach’s Storm-petrel and European Storm-petrel, comprise 2.3% and 1.4% respectively, of the total number of each species breeding in Great Britain.