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Multiple Sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system. The risk of developing MS is strongly influenced by genetic predisposition, and over 100 loci have been established as associated with susceptibility. However, the biologically relevant variants underlying disease risk have not been defined for the vast majority of these loci, limiting the power of these genetic studies to define new avenues of research for the development of MS therapeutics. It is therefore crucial that candidate MS susceptibility loci are carefully investigated to identify the biological mechanism linking genetic polymorphism at a given gene to the increased chance of developing MS. MERTK has been established as an MS susceptibility gene and is part of a family of receptor tyrosine kinases known to be involved in the pathogenesis of demyelinating disease. In this study we have refined the association of MERTK with MS risk to independent signals from both common and low frequency variants. One of the associated variants was also found to be linked with increased expression of MERTK in monocytes and higher expression of MERTK was associated with either increased or decreased risk of developing MS, dependent upon HLA-DRB1*15:01 status. This discordant association potentially extended beyond MS susceptibility to alterations in disease course in established MS. This study provides clear evidence that distinct polymorphisms within MERTK are associated with MS susceptibility, one of which has the potential to alter MERTK transcription, which in turn can alter both susceptibility and disease course in MS patients.

From August to December, thousands of Black-necked Grebes Podiceps nigricollis concentrate during the flightless moult period in salt ponds in the Odiel Marshes, southern Spain, where they feed on the brine shrimp Artemia parthenogenetica. We predicted that because Black-necked Grebes moulted in a food-rich, predator-free environment, there would be no net loss of body mass caused by the use of fat stored to meet energy needs during remigial feather replacement (as is the case for some other diving waterbirds). However, because the food resource disappears in winter, we predicted that grebes moulting later in the season would put on more body mass prior to moult because of the increasing risk of an Artemia population crash before the moult period is completed. Body mass determinations of thousands of birds captured during 2000–2010 showed that grebes in active wing-moult showed greater mass with date of capture. Early-moulting grebes were significantly lighter at all stages than late-moulting birds. Grebes captured with new feathers post-moult were significantly lighter than those in moult. This is the first study to support the hypothesis that individual waterbirds adopt different strategies in body mass accumulation according to timing of moult: early-season grebes were able to acquire an excess of energy over expenditure and accumulate fat stores while moulting. Delayed moulters acquired greater fat stores in advance of moult to contribute to energy expenditure for feather replacement and retained extra stores later, most likely as a bet hedge against the increasing probability of failing food supply and higher thermoregulatory demands late in the season. An alternative hypothesis, that mass change is affected by a trophically transmitted cestode using brine shrimps as an intermediate host and Black-necked Grebes as final host, was not supported by the data.

Virtually the entire population of the globally ‘Vulnerable’ Swan Goose Anser cygnoides winters in the Yangtze floodplain. Historically, the species was widely distributed throughout the floodplain but now approximately 95% of the population is confined to three closely-situated wetlands in Anhui and Jiangxi Provinces. Recent counts indicate that at one of these sites, Shengjin Lake (in Anhui), a decline of about 10,000–20,000 birds, to about 1,000 currently, has taken place during the last five years. The likely cause of the decline in Swan Goose abundance at Shengjin Lake is the recent decrease in submerged vegetation, particularly tuber-producing Vallisneria which is the species’s main food; this decrease has been linked with the introduction of intensive aquaculture in the main areas used by Swan Geese within the lake. Earlier range contractions in the Yangtze floodplain may also be linked to reductions in submerged vegetation cover at other sites, where intensive aquaculture has also been implicated. Changes in lake hydrology following construction of the Three Gorges Dam may also have adversely affected submerged vegetation productivity. Key information needs for the effective implementation of conservation measures for Swan Goose include an understanding of (1) the fitness consequences of Swan Geese being forced to switch to different foods; (2) how aquaculture can be managed to minimise impacts on submerged vegetation; (3) the impact of changing lake hydrology on key Swan Goose food plants; and (4) the optimal management of wetlands to ensure that adequate food is both produced during the summer period and is available throughout the winter.

We estimated the size of 30 defined populations of geesewintering in the Western Palearctic (including five releasedor reintroduced populations of three species).Fourteen populations were accurately estimated from almostfull count coverage or robust sampling and ten werewell estimated based on more than 50% of their total beingcounted. An estimated 5.03 million geese winteredin January 2009, up on 3.10 million in January 1993.Only two populations numbered less than 10,000 birds(Scandinavian Lesser White-fronted Goose and Svalbard/Greenland Light-bellied Brent Goose, the formerbeing critically small within restricted range). Eighteenpopulations numbered 10,000–100,000, eight 100,000–1,000,000 and the largest 1.2 million individuals. Of 21populations with known longer term trends, 16 are showingsignificant exponential increases, 4 are stable and onedeclining. Amongst these same populations, five are decliningsince the 1990s. Long term declines in productivitywere found in 7 out of 15 populations. Amongst mostof the 11 populations for which data exist, there were nosignificant long-term trends in annual adult survival. Improvedmonitoring, including demographic, is requiredto retain populations in favorable conservation status.

Tundra ecosystems are widely recognized as precious areas and globally important carbon (C) sinks, yet our understanding of potential threats to these habitats and their large soil C store is limited. Land-use changes and conservation measures in temperate regions have led to a dramatic expansion of arctic-breeding geese, making them important herbivores of high-latitude systems. In field experiments conducted in high-Arctic Spitsbergen, Svalbard, we demonstrate that a brief period of early season belowground foraging by pink-footed geese is sufficient to strongly reduce C sink strength and soil C stocks of arctic tundra. Mechanisms are suggested whereby vegetation disruption due to repeated use of grubbed areas opens the soil organic layer to erosion and will thus lead to progressive C loss. Our study shows, for the first time, that increases in goose abundance through land-use change and conservation measures in temperate climes can dramatically affect the C balance of arctic tundra, Tundra ecosystems are widely recognized as precious areas and globally important carbon (C) sinks, yet our understanding of potential threats to these habitats and their large soil C store is limited. Land-use changes and conservation measures in temperate regions have led to a dramatic expansion of arctic-breeding geese, making them important herbivores of high-latitude systems. In field experiments conducted in high-Arctic Spitsbergen, Svalbard, we demonstrate that a brief period of early season belowground foraging by pink-footed geese is sufficient to strongly reduce C sink strength and soil C stocks of arctic tundra. Mechanisms are suggested whereby vegetation disruption due to repeated use of grubbed areas opens the soil organic layer to erosion and will thus lead to progressive C loss. Our study shows, for the first time, that increases in goose abundance through land-use change and conservation measures in temperate climes can dramatically affect the C balance of arctic tundra

We review whether migratory Anatidae, i.e., swans, geese and ducks, could be acting as vectors for dispersal of Zostera, Ruppia and Potamogeton propagules by endozoochory (carrying seeds in their guts). We list six prerequisites that must all be fulfilled, if successful dispersal should occur. Several Anatidae species feed on these macrophytes, and undertake rapid long-distance movements, making dispersal possible. We identify four problems, which in combination leads us to conclude that long-distance dispersal events are likely to be rare. (i) Most long-distance movements are out of phase with the reproductive efforts of the plants, and if birds arrive at sites when plants still bear seeds, they are likely to depart well after seed stocks have been depleted. (ii) Seed transport by birds will usually be uni-directional, from north to south on autumn migrations. (iii) Most of the gut contents of migratory birds are likely to have been discarded within 300 km of departure. (iv) In many cases, birds will arrive in habitats seriously different from those they departed, i.e., any seeds carried along will have low chances of surviving in their new site. We suggest that northbound dispersal by endozoochory can only occur during spring if waterbirds feed on seeds that have not been depleted and remained frozen down or buried in sediments, or during moult- or post-moult migrations. Moult migration takes place in summer in phase with the reproductive efforts of the plants. Also epizoochorous dispersal (external attachment) is subject to restrictions i, ii and iv. [KEYWORDS: Anas; Branta; Cygnus; Potamogeton; Ruppia; Zostera marina], We review whether migratory Anatidae, i.e., swans, geese and ducks, could be acting as vectors for dispersal of Zostera, Ruppia and Potamogeton propagules by endozoochory (carrying seeds in their guts). We list six prerequisites that must all be fulfilled, if successful dispersal should occur. Several Anatidae species feed on these macrophytes, and undertake rapid long-distance movements, making dispersal possible. We identify four problems, which in combination leads us to conclude that long-distance dispersal events are likely to be rare. (i) Most long-distance movements are out of phase with the reproductive efforts of the plants, and if birds arrive at sites when plants still bear seeds, they are likely to depart well after seed stocks have been depleted. (ii) Seed transport by birds will usually be uni-directional, from north to south on autumn migrations. (iii) Most of the gut contents of migratory birds are likely to have been discarded within 300 km of departure. (iv) In many cases, birds will arrive in habitats seriously different from those they departed, i.e., any seeds carried along will have low chances of surviving in their new site. We suggest that northbound dispersal by endozoochory can only occur during spring if waterbirds feed on seeds that have not been depleted and remained frozen down or buried in sediments, or during moult- or post-moult migrations. Moult migration takes place in summer in phase with the reproductive efforts of the plants. Also epizoochorous dispersal (external attachment) is subject to restrictions i, ii and iv. [KEYWORDS: Anas; Branta; Cygnus; Potamogeton; Ruppia; Zostera marina]

Greenland White-fronted Geese, Plumage variation (belly barring)

Diurnal and nocturnal time—activity budgets were compiled for White-headed Ducks at their most important wintering area, Burdur Lake in Turkey, during February and March 1993. During the day, ducks spent 28% of the time feeding, 57% resting, 11% in locomotion, 4% preening and 1% in alert behaviour. No courtship behaviour was observed. Resting peaked in the middle of the day. As wave-height increased, feeding and swimming increased and resting decreased. At night, 92% of time was spent feeding. Sites used by White-headed Ducks held a higher biomass of food items (benthic chironomid larvae) than other parts of the lake. Movement of individuals and marked differences in diurnal time budgets occurred between sites, as birds concentrated in flocks for resting and dispersed to feed. The proportion of birds resting increased with the number of birds present, both within and between sites. Feeding was concentrated at those sites supporting a higher biomass of chironomids for a given depth.

Canada geese, Branta canadensis, Greenland

Phleum pratense, Anser albifrons flavirostris, Grazing, Overcompensation, Protein content

Goose populations, Moult, Body Mass, Anser albifrons, Anser Anser, Branta canadensis