France as a staging and wintering area for Greylag Geese Anser anser.

France is traditionally a staging area for Greylag Geese Anser anser migrating fromnorthwest Europe to wintering sites in Spain, though increasing numbers havewintered in France over the last three decades. This paper considers sightings withinFrance of neck-banded individuals marked elsewhere in Europe since the 1980s, todetermine the origin of Greylag Geese staging and now wintering in the country. The geese included in this study were all caught in summer during the annual moult, either as family groups or in non-breeding flocks. Most sightings of neck-banded geese were from western France, and most birds identified were from breeding areas in the Nordic countries or to a lesser extent in the Netherlands. The Lac du Der area in northeast France was found to be a wintering area for an introduced population of Greylags established southwest of Stockholm in Sweden, and the geese wintering on the Camargue in southern France were recruited mainly from central Europe. Numbers wintering in France have increased in line with the general increase in the European Greylag Goose population, whereas numbers on passage in France have not increased in the same way, possibly due to a northward shift in the winter distribution of Greylags across Europe. The numbers wintering in France are, however, still small compared to other areas along the flyway

Latitudinal-Related Variation in Wintering Population Trends of Greylag Geese (Anser Anser) along the Atlantic Flyway: A Response to Climate Change?

The unusually high quality of census data for large waterbirds in Europe facilitates the study of how population change varies across a broad geographical range and relates to global change. The wintering population of the greylag goose Anser anser in the Atlantic flyway spanning between Sweden and Spain has increased from 120 000 to 610 000 individuals over the past three decades, and expanded its wintering range northwards. Although population sizes recorded in January have increased in all seven countries in the wintering range, we found a pronounced northwards latitudinal effect in which the rate of increase is higher at greater latitudes, causing a constant shift in the centre of gravity for the spatial distribution of wintering geese. Local winter temperatures have a strong influence on goose numbers but in a manner that is also dependent on latitude, with the partial effect of temperature (while controlling for the increasing population trend between years) being negative at the south end and positive at the north end of the flyway. Contrary to assumptions in the literature, the expansion of crops exploited by greylag geese has made little contribution to the increases in population size. Only in one case (expansion of winter cereals in Denmark) did we find evidence of an effect of changing land use. The expanding and shifting greylag population is likely to have increasing impacts on habitats in northern Europe during the course of this century.Peer reviewe

Latitudinal-related variation in wintering population trends of greylag geese (Anser anser) along the Atlantic flyway: a response to climate change?

La alta calidad de los datos del censo para las grandes aves acuáticas en Europa es poco frecuente y facilita el estudio sobre cómo la población varía a través de una amplia gama geográfica, que se relaciona con el cambio global. La población de la invernada graylag goose Anser anser en la ruta atlántica abarca de Suecia a España y ha aumentado de 120 000 a 610 000 casos durante las últimas tres décadas. Se ha ampliado su zona de invernada hacia el norte. Si bien el tamaño de la población que se registró en enero ha aumentado en los siete países de la zona de invernada, encontramos un pronunciado efecto latitudinal de norte en el que la tasa aumenta más cuanto mayor es la latitud; esto provoca un cambio constante en el centro de gravedad de la distribución espacial en la invernada de los gansos. En invierno las temperaturas locales tienen una fuerte influencia en el número de gansos, pero de una forma que depende también de la latitud, por el efecto parcial de temperatura (controlada por la creciente tendencia de la población en esos años), que alcanza el extremo sur negativo y positivo en el extremo norte de la ruta migratoria. Contrariamente a los supuestos vistos en la literatura, la expansión de los cultivos explotados por graylag ocas ha contribuido en poco a los aumentos en el tamaño de la población. Sólo en un caso (expansión de los cereales de invierno en Dinamarca) no encontramos evidencia de un efecto de cambio de uso de la tierra. La expansión y el desplazamiento de poblaciones graylag es probable que tenga repercusiones cada vez mayores sobre los hábitats en el norte de Europa durante el curso de este siglo.The unusually high quality of census data for large waterbirds in Europe facilitates the study of how population change varies across a broad geographical range and relates to global change. The wintering population of the greylag goose Anser anser in the Atlantic flyway spanning between Sweden and Spain has increased from 120 000 to 610 000 individuals over the past three decades, and expanded its wintering range northwards. Although population sizes recorded in January have increased in all seven countries in the wintering range, we found a pronounced northwards latitudinal effect in which the rate of increase is higher at greater latitudes, causing a constant shift in the centre of gravity for the spatial distribution of wintering geese. Local winter temperatures have a strong influence on goose numbers but in a manner that is also dependent on latitude, with the partial effect of temperature (while controlling for the increasing population trend between years) being negative at the south end and positive at the north end of the flyway. Contrary to assumptions in the literature, the expansion of crops exploited by greylag geese has made little contribution to the increases in population size. Only in one case (expansion of winter cereals in Denmark) did we find evidence of an effect of changing land use. The expanding and shifting graylag population is likely to have increasing impacts on habitats in northern Europe during the course of this century.peerReviewe

The analysis of surface texture goniospectrophotometry

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Regression coefficients, adjusted standard error, values of t or z (for full averaged model) and p values from linear regression models between wintering greylag geese (log-transformed) as dependent variable and year, surface of crops and January temperatures as predictors.

<p>¹z value;</p><p>² t value</p><p>Only best sub-models are represented. When there is more than one sub-model with ΔAIC < 2 (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0140181#pone.0140181.s003" target="_blank">S2 Table</a>) full model averaged coefficients are shown (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0140181#sec002" target="_blank">methods</a>). Sample sizes vary greatly because of missing data for predictor variables, especially for land use.</p

January mean temperatures in the wintering countries of greylag geese from 1980 to 2009, together with fitted linear regression lines.

<p>January mean temperatures in the wintering countries of greylag geese from 1980 to 2009, together with fitted linear regression lines.</p

Trend in the first arrival of greylag geese to the Guadalquivir marshes (Doñana) in autumn between 1961 and 2012.

<p>The fitted regression line is: Day = − 539.954 + 0.4087 × Year (r = 0.516, P < 0.001).</p

Winter greylag geese population estimates (mid January counts) in different countries of the Atlantic flyway between 1980 and 2009.

<p>Winter greylag geese population estimates (mid January counts) in different countries of the Atlantic flyway between 1980 and 2009.</p