The invertebrate fauna of High Arctic seabird nests: the microarthropod community inhabiting nests on Spitsbergen,Svalbard

The invertebrate fauna of the nests of three seabird species, black-legged kittiwakes (Rissa tridactyla), common eider (Somateria mollissima) and glaucous gull (Larus hyperboreus), were sampled in Kongsfjorden, Spitsbergen, Svalbard. The invertebrate community was species poor, consisting predominantly of the flea, Mioctenopsylla arctica arctica (Insecta: Siphonaptera), but with six species of oribatid mite (Acari: Oribatida), Diapterobates notatus, Oribatula tibialis, Ameronothrus lineatus, Hermannia reticulata, Trichoribates trimaculatus and Ceratoppia bipilis, plus an occasional mesostigmatid mite. No Collembola or ticks (Acari: Ixodidae) were observed. With the exception of M. arctica arctica, the fauna of seabird nests consisted of opportunistic microarthropod species rather than specialised nest-dwelling or bird parasitic species. Species diversity of soil oribatid mites was greater in nests of the common eider than compared to nests of the black-legged kittiwake, which may be related to the ground nesting behaviour of the common eiders. No rare or unusual microarthropod species for Svalbard were found in the seabird nests. The contentions that nests may facilitate microarthropod colonisation of High Arctic regions via bird phoresy by providing a high-quality habitat at the point of arrival, or that there might be a specialised microarthropod fauna exploiting this habitat, were not supported in this study. These are amongst the first data on the microarthropod community of seabird nests in the High Arctic.     

Bird feather fungi from Svalbard Arctic

Despite feather fungi being an important component of the Arctic fungal flora, their ecological role and diversity are not fully known. In the current study, fungal cultures were isolated from feathers (barnacle goose, common eider, and glaucous gull) collected in the Ny-Ålesund region, Svalbard. Isolates were identified by ITS region sequences, which include the ITS1, ITS2, and 5.8S rRNA. The result showed culturable yeast and filamentous fungi belonging to three classes: Ascomycota (Pyrenochaetopsis pratorum, Cladosporium herbarum, Thelebolus microsporus, Aspergillus versicolor, Penicillium commune, and Venturia sp.), Basidiomycota (Mrakia blollopis and Rhodotorula mucilaginosa), and Zygomycota (Mucor flavus). Most of the fungal isolates appeared to be cold-tolerant, and about 60 % of the isolates showed keratinase activity. The reasonably low fungal diversity colonizing feathers indicates that the birds of Svalbard are casual carriers of fungi which may result in a negligible impact on their health. To the best of our knowledge, this is the first record of fungal communities present on the feathers of birds in the high Arctic.     

Stealing bivalves from common eiders: kleptoparasitism by glaucous gulls in spring

Here I report on glaucous gulls (Larus hyperboreus), an opportunistic, generalist predator, stealing bivalves from a diving duck, the common eider (Somateria mollissima). The study took place in spring, the pre-breeding period of the common eider, in an Arctic fjord (Adventfjorden) at western Spitsbergen, Svalbard. Eiders were abundant, their presence predictable, and they fed on large prey requiring surface handling—all factors facilitating food theft. Only adult glaucous gulls attended the eider flocks. The glaucous gulls brought stolen prey ashore. Amongst these the bivalve Mya neoovata (Myidae) was common. The probability that an eider flock was attended by glaucous gulls declined as the season progressed and increased with the foraging activity of the eiders. Eider flock size and the degree of aggregation within flocks were poor predictors of gull presence. However, eider flocks attended by a single gull were smaller than flocks attended by more than one gull. Common eiders are capital breeders which build up large energy reserves prior to breeding. Kleptoparasitism, therefore, may have a negative impact on eider energy acquisition in early spring. For the glaucous gull, kleptoparasitism may be important as few other food sources are available this time of the season.     

Winter diets of four seabird species in the Barents Sea after a crash in the capelin stock

Summary I describe the winter diets (early March) of four seabird species, black-legged kittiwake (Rissa tridactyla), northern fulmar (Fulmarus glacialis), glaucous gull (Larus hyperboreus) and Brüinnich's guillemot (Uria lomvia) collected in the south eastern Barents Sea, in open water approximately 70 km from the ice edge. All species preyed heavily on commercial fish species such as cod (Gadus morrhua), polar cod (Boreogadus saida) and redfish (Sebastes marinus/S. mentella). The median total length of fish eaten ranged from 51 mm in fulmars to 88 mm in Brünnich's guillemots and differed significantly among all species pairs except kittiwake and glaucous gull. Although the size of fish eaten differed among the four bird species they all fed upon much the same age categories of fish. Cod and redfish eaten were almost exclusively one year old, whereas polar cod was 1–4 years old. Other important food items were crustaceans (B unnich's guillemots), and squid Gonatus sp. (fulmars); the glaucous gull also preyed on other birds. Body weights and amounts of stored fat suggest that individuals of all species except Brüinnich's guillemots were in good physical condition. The diets described here differed substantially from those of birds caught mainly during the prelaying season near the colonies in this area. Some of these differences may be attributed to the very low density of capelin (Mallotus villosus) when this study was conducted.     

Foraging success, kleptoparasitism and feeding techniques in scavenging seabirds: does crime pay?

Scavenging seabirds in the North Sea exploit discards with different success and by different feeding techniques. Northern gannet (Sula bassana) had the highest foraging success index, followed by lesser black-backed gull (Larus fuscus) and black-legged kittiwake (Rissa tridactyla). Northern fulmar (Fulmarus glacialis), mew gull (Larus canus) and black-headed gull (Larus ridibundus) were the least successful species. Ranking species according to the ratio of fish stolen from vs. lost to other species (=robbery index), northern gannet, great black-backed gull (Larus marinus) and great skua (Catharacta skua) were at the top, northern fulmar and black-legged kittiwake at the bottom. Varying compositions of the feeding flocks influenced the foraging success of the species significantly. Both body length and body mass of the birds can well explain species order in the robbery index but not in the foraging success index. Our hypothesis that the most successful species employ particular feeding techniques and/or exhibit the strongest kleptoparasitic abilities could be confirmed to a large extent but not totally. During reduced overall feeding rates, some less successful species and/or species with weaker kleptoparasitic capabilities fared better than during intense feeding rates as predicted, some others did not.     

Sharing habitat: Effects of migratory barnacle geese density on meadow breeding waders

• 1.Following targeted conservation actions most goose populations have increased. The growing goose populations caused an increase in human-wildlife conflicts and have the potential to affect nature values. As meadow birds, including meadow-breeding waders, were declining throughout Western Europe, the possible negative effect of rising numbers of foraging barnacle geese on their breeding success has been questioned.
• 2.We used GPS-transmitter data to measure the density of foraging barnacle geese during daylight hours. Using dynamic Brownian Bridge Movement Models (dBBMM), we investigated the effect of barnacle goose density on the territory distribution of five wader species, and on nest success of the locally common Northern lapwing. We used model selection methods to identify the importance of barnacle goose density related to other environmental factors.
• 3.Our results showed an insignificant positive association between barnacle goose density and nest territory density of the Northern lapwing and common redshank. Barnacle goose density had no influence on territory selection of godwit, oystercatcher and ringed plover. We did, however, find a negative correlation between barnacle geese density and the nest success of the Northern Lapwing.
• 4.We infer that either barnacle goose foraging leads to improved territory conditions for some wader species, or that both barnacle geese and waders prefer the same type of habitat for foraging and nesting. Higher barnacle goose density was correlated with fewer Northern lapwing nests being successful.
• 5.Synthesis and application: Experimental research is needed to disentangle the causal chain, but based on our observational findings, we suggest to increase water logging that may attract both barnacle geese and wader species. Further investigation on the effects of barnacle geese on wader species is necessary to identify the cause of the negative correlation between barnacle geese density and nest success of lapwings; nest protection experiments could give further insight.

     

Cape Delil-de-la-Kroiera (Sakhalin Island)—A new nesting point of marine birds

Two kekurs on Cape Delil-de-la-Kroiera (east coast of Sakhalin Island, to the north of Cape Ratmanova) were surveyed on July 16, 2003. Nesting of six species of sea birds was observed: slaty-backed gull (Larus schistisagus), black-legged kittiwake (Rissa tridactyla), common murre (Uria aalge), spectacled guillemot (Cepphus carbo), horned puffin (Fratercula corniculata), and tufted puffin (Lunda cirrhata).Original Russian Text Copyright © 2005 by Biologiya Morya, Blokhin, Tiunov.     

A comparative analysis of the helminth fauna of kittiwake Rissa tridactyla (Linnaeus, 1758) and glaucous gull Larus hyperboreus Gunnerus, 1767 from different parts of the Barents Sea

The article is based on the results of helminthological observations made on kittiwake Rissa tridactyla and glaucous gull Larus hyperboreus in 1991-2001 in different areas of the Barents Sea (Eastern Murman coast, Franz Josef Land, Novaya Zemlya, Spitzbergen). 18 helminth species (2 trematodes, 11 cestodes, 4 nematodes, and 2 acanthocephalans) were recorded in the kittiwakes and 19 (3 trematodes, 9 cestodes, 5 nematodes and 2 acanthocephalans) species were recorded in the glaucous gulls. Trematodes were absent in the birds collected at the Franz Josef Land and the northern island of Novaya Zemlya. 3 trematode species, namely Gymnophallus sp. (somateria?), Microphallus sp. 1 (M. pseudopygmaeus), and Cryptocotyle lingua were found in the glaucous gulls of western Spitzbergen. It was supposed that the life cycles of these parasites can be completed there. On the other hand, coastal ecosystems of Arctic archipelagoes turn out to be favourable for the transmission of some cestodes. This is closely connected with the regional traits in the marine bird diet, namely the increase of the amphipod (intermediate hosts of hymenolepidids and some dilepidids) and polar cod (supposed second intermediate host for some tetrabothriids) portion in Arctic. As a result, cestodes are the base of the helminth fauna of kittiwakes and glaucous gulls of the Barents Sea, by their species richness, prevalence and abundance. Nematodes and acanthocephalans were represented by a few species with low infection intensity. The main ecological factors affected the regional difference in the species richness and abundance of the helminths parasitising kittiwakes and glaucous gulls in the Barents Sea are proposed. Those are regional climatic features and regional traits in the behaviour and food priorities of birds, and also the distribution of the helminths intermediate hosts, invertebrates and fishes. The phenomenon of host specificity lowering with respect to the definitive host was recorded in some cestode species (Microsomacanthus diorchis, M. microsoma, and Arctotaenia tetrabothrioides) on the border of their distribution ranges, the coastal ecosystems of Arctic.     

Arctic seabird food chains explored by fatty acid composition and stable isotopes in Kongsfjorden, Svalbard

Marine birds are important predators in the marine ecosystem, and dietary studies can give useful information about their feeding ecology, food webs and oceanographic variability. The aim of this study was to increase our understanding of the diet and trophic level of the seabirds breeding in Kongsfjorden, Svalbard. We have used fatty acids and stable isotopes, both of which integrate diet information over space and time, to determine trophic relationships in marine food webs. Fatty acid compositions of muscle from Little auk (Alle alle), Brünnich’s guillemot (Uria lomvia), Black-legged kittiwake (Rissa tridactyla), Northern fulmar (Fulmarus glacialis) and Glaucous gull (Larus hyperboreus) were determined and compared with their prey species. Canonical analysis (CA) showed that fatty acid composition differed among the five seabird species. Little auk, Black-legged kittiwake and Northern fulmar had high levels of the Calanus markers 20:1n9 and 22:1, indicating that these seabirds are a part of the Calanus food chain. Brünnich’s guillemot differed from the other species with much lower levels of 20:1n9 and 22:1. Brünnich’s guillemot is a pursuit diver feeding on fish and amphipods deeper in the water column, below 30 m. Glaucous gull also differed from the other seabird species, with a larger variation in the fatty acid composition indicating a more diverse diet. Trophic level analysis placed Little auk at the lowest trophic level, Brünnich’s guillemot and Black-legged kittiwake at intermediate levels and Glaucous gull and Northern fulmar at the highest trophic level.     

Contributions of feather microstructure to eider down insulation properties

Insulation is an essential component of nest structure that helps provide incubation requirements for birds. Many species of waterfowl breed in high latitudes where rapid heat loss can necessitate a high energetic input from parents and use down feathers to line their nests. Common eider Somateria mollissima nest down has exceptional insulating properties but the microstructural mechanisms behind the feather properties have not been thoroughly examined. Here, we hypothesized that insulating properties of nest down are correlated to down feather (plumule) microstructure. We tested the thermal efficiency (fill power) and cohesion of plumules from nests of two Icelandic colonies of wild common eiders and compared them to properties of plumules of wild greylag goose Anser anser. We then used electron microscopy to examine the morphological basis of feather insulating properties. We found that greylag goose down has higher fill power (i.e. traps more air) but much lower cohesion (i.e. less prone to stick together) compared to common eider down. These differences were related to interspecific variation in feather microstructure. Down cohesion increased with the number of barbule microstructures (prongs) that create strong points of contact among feathers. Eider down feathers also had longer barbules than greylag goose down feathers, likely increasing their air‐trapping capacity. Feather properties of these two species might reflect the demands of their contrasting evolutionary history. In greylag goose, a temperate, terrestrial species, plumule microstructure may optimize heat trapping. In common eiders, a diving duck that nests in arctic and subarctic waters, plumule structure may have evolved to maximize cohesion over thermal insulation, which would both reduce buoyancy during their foraging dives and enable nest down to withstand strong arctic winds.     

Changes in the species composition and number of gulls in tundra colonies in the western Chukotka over the last 40 years

Long-term data reflecting the abundance and species composition of large colonies of gulls (more than five nests, distance between the nests less than 50 m) on Aiopechan Island, West Chukotka, were compared. A comparative analysis of the data published in 1970–1984 and our data for 1989, 2000–2013 revealed significant changes in the composition and abundance of colonies over the 40-year period with simultaneous shift in the spring phonological characteristics to earlier dates. Growth in the number of the Vega gull (Larus vegae) and decrease in the number of Sabine’s gull (Xema sabini) were revealed. The number of glaucous gulls (Larus hyperboreus) was stable. A change of the dominant species in the colonies and disappearance of some colonies of the Sabine’s gull under the influence of the expansion of the Vega gull were registered. It was found that the increase in the abundance of the Vega gull occurs not owing to the increase of long-term colonies but due to the appearance of new ones.     

Arthropods (Acarina, Coleoptera, Siphonaptera) in nests of hoopoe (Upupa epops) in Central Europe

In 1993–1995 and 2009–2011, during investigation of reproduction biology of hoopoe, 63 nests of this species were collected after fledging of the chicks in Slovakia and Austria and their arthropod fauna was analyzed. Altogether 5,481 individuals and 34 species of mesostigmatic mites were found in 82.5% of the nests examined. The nidicolous mite Androlaelaps casalis was most abundant and frequent, representing 91.7% of all individuals. The richest in species were saprophilous mites (64.7% of all recorded species), while ectoparasites of the genera Dermanyssus and Ornithonyssus represented only 0.4% of all mites. Only 8 beetle species represented by 65 individuals were found in 18 nests. The dominant trophical group were carnivores (mainly nidicolous Gnathoncus buyssoni) with almost identical representation in (86.2%), followed by a similar representation of necrophags (10.8%). Unlike nests of other birds, the typical nidicolous species Haploglossa puncticollis and the fungivors were absent due to the dry character of studied countryside and placement of the nests in boxes situated in vineyard cottages. Only one species of fleas, Ceratophyllus gallinae — parasitizing first of all in the passeriform birds and being particularly abundant in the cavity nesting birds was recorded in hoopoe nests.     

Tardigrada of the Revdalen (Spitsbergen) with the descriptions of two new species: Bryodelphax parvuspolaris (Heterotardigrada) and Isohypsibius coulsoni (Eutardigrada)

Despite a century long history of research, tardigrade fauna of the Svalbard Archipelago remains poorly known. In order to deepen our knowledge of tardigrade biodiversity in the Arctic, we collected forty-one moss and lichen samples from the Revdalen and on the south-east slopes of the Rotjesfjellet (Spitsbergen, Svalbard Archipelago) in June 2010. In these samples, twenty-five tardigrade species were found, including two new for science: Bryodelphax parvuspolaris sp. nov. and Isohypsibius coulsoni sp. nov. B. parvuspolaris sp. nov. belongs to the weglarskae group but differs from all other species of the group by a unique configuration of ventral plates. I. coulsoni sp. nov. differs from the most similar species I. ceciliae Pilato and Binda, 1987 mainly by the absence of ventral sculpture. Two additional species, Milnesium asiaticum Tumanov, 2006 and Diphascon (Adropion) prorsirostre Thulin, 1928, are recorded from the Svalbard Archipelago for the first time.     

Strategies for Nest-Site Selection by King Eiders

ABSTRACT Nest site selection is a critical component of reproduction and has presumably evolved in relation to predation, local resources, and microclimate. We investigated nest-site choice by king eiders (Somateria spectabilis) on the coastal plain of northern Alaska, USA, 2003–2005. We hypothesized that nest-site selection is driven by predator avoidance and that a variety of strategies including concealment, seclusion, and conspecific or inter-specific nest defense might lead to improved nesting success. We systematically searched wetland basins for king eider nests and measured habitat and social variables at nests (n = 212) and random locations (n = 493). King eiders made use of both secluded and concealed breeding strategies; logistic regression models revealed that females selected nests close to water, on islands, and in areas with high willow (Salix spp.) cover but did not select sites near conspecific or glaucous gull (Larus hyperboreus) nests. The most effective nest-placement strategy may vary depending on density and types of nest predators; seclusion is likely a mammalian-predator avoidance tactic whereas concealment may provide protection from avian predators. We recommend that managers in northern Alaska attempt to maintain wetland basins with islands and complex shorelines to provide potential nest sites in the vicinity of water.     

Changes in trophic state and aquatic communities in high Arctic ponds in response to increasing goose populations

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Minimal intra-seasonal dietary overlap of barnacle and pink-footed geese on their breeding grounds in Svalbard

We analysed barnacle Branta leucopsis and pink-footed goose Anser brachyrhynchus summer diets (May–July 2003) based on the proportions of different plant constituents in the faecal material of adult breeding birds in Sassendalen, Svalbard to assess potential inter-specific competition. Diets were highly restricted and overlapped little during pre-nesting and post hatch. During incubation both species showed greatest variety in their diet, reflecting site-specific differences in local food abundance. However, locally the diets of pink-footed and barnacle geese resembled each other most at this time (although still differing significantly). The conflicting needs of nest defence and maintenance of body condition constrains the extent of the feeding resource utilised by nesting pairs and explains slightly greater dietary overlap at this time. Hence, there is little evidence of inter-specific competition (interference or depletion) at present, but this is most likely to be manifest during the incubation period in the future if goose numbers continue to increase. More detailed investigations of the degree of spatial overlap of the two species and their effects on plant structure, quality and community composition are necessary to predict likely outcomes of expected increases in numbers of both goose species.     

Colonial breeding reduces nest predation in the common gull (Larus canus)

It is often suggested that colonial breeding reduces nest predation for birds with a high defence capacity, but experimental comparison of predation at solitary and colonial nests is seldom feasible within a single species. We here report on such a test in the common gull (Larus canus). The rate of predation on experimental eggs was significantly lower near colonies than near solitary gull nests, and the eggs survived longer at the edge of a colony than farther away. Communal mobbing of nest predators is the likely reason. In both of two years, almost all nests of solitary gulls were destroyed by predators, while most clutches survived in colonies. Nest predation hence selects strongly for colonial breeding in the present population of common gulls.     

Predator–prey dynamics of bald eagles and glaucous‐winged gulls at Protection Island,Washington, USA

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