Sovon Dutch Center for Field Ornithology

Nijmegen, Netherlands

Sovon Dutch Center for Field Ornithology

Nijmegen, Netherlands
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Ave M.H.,Sovon Dutch Center for Field Ornithology | Voslamber B.,Sovon Dutch Center for Field Ornithology | Hallmann C.A.,Radboud University Nijmegen | Stahl J.,Sovon Dutch Center for Field Ornithology
Wildlife Biology | Year: 2017

Anthropogenic changes to the landscape such as fertilization and mowing schemes have been correlated with goslings obtaining a higher weight gain during the first weeks of their life, which in turn increases breeding success and survival at the adult stage. As goose numbers rise, conflicts with farmers become stronger as the birds use agricultural sites for foraging. In this study, habitat choice for individually marked greylag geese from four different rearing conditions, categorized by their temporal application of fertilizer, was documented over a seventeen-year period. Weekly observations took place on a resident population of wild greylag geese within the Ooijpolder, the Netherlands. The region comprises of areas dedicated to nature restoration as well as agricultural use. In essence, we infer the habitat choice of greylag geese from the frequency of sightings of individually marked geese in different habitat patches, and model habitat choice as a function of rearing conditions, age, and seasonality. Despite a general preference for agricultural grassland, about 40% of the habitat choice was determined by the rearing condition of geese. Interestingly, geese reared in restored meadows, a less favorable rearing habitat, exhibited strong habitat fidelity and preferred to forage in meadows in the spring. Habitat choice was furthermore influenced by age of adult geese and seasonal changes in plant availability. We discuss management implications of our results on habitat choice in an agricultural landscape for increasing resident goose populations. An efficient management measure would be the limitation of goose access to improved grassland during rearing period in the spring. © 2016 Sovon.

Johnston A.,British Trust for Ornithology | Ausden M.,Royal Society for the Protection of Birds | Dodd A.M.,Royal Society for the Protection of Birds | Bradbury R.B.,Royal Society for the Protection of Birds | And 21 more authors.
Nature Climate Change | Year: 2013

The dynamic nature and diversity of species' responses to climate change poses significant difficulties for developing robust, long-term conservation strategies. One key question is whether existing protected area networks will remain effective in a changing climate. To test this, we developed statistical models that link climate to the abundance of internationally important bird populations in northwestern Europe. Spatial climate-abundance models were able to predict 56% of the variation in recent 30-year population trends. Using these models, future climate change resulting in 4.0C global warming was projected to cause declines of at least 25% for more than half of the internationally important populations considered. Nonetheless, most EU Special Protection Areas in the UK were projected to retain species in sufficient abundances to maintain their legal status, and generally sites that are important now were projected to be important in the future. The biological and legal resilience of this network of protected areas is derived from the capacity for turnover in the important species at each site as species' distributions and abundances alter in response to climate. Current protected areas are therefore predicted to remain important for future conservation in a changing climate. © 2013 Macmillan Publishers Limited. All rights reserved.

PubMed | University of Veterinary Medicine Budapest, Kansas State University, University of Aveiro, Max Planck Institute for Ornithology (Seewiesen) and 47 more.
Type: Journal Article | Journal: Nature | Year: 2016

The behavioural rhythms of organisms are thought to be under strong selection, influenced by the rhythmicity of the environment. Such behavioural rhythms are well studied in isolated individuals under laboratory conditions, but free-living individuals have to temporally synchronize their activities with those of others, including potential mates, competitors, prey and predators. Individuals can temporally segregate their daily activities (for example, prey avoiding predators, subordinates avoiding dominants) or synchronize their activities (for example, group foraging, communal defence, pairs reproducing or caring for offspring). The behavioural rhythms that emerge from such social synchronization and the underlying evolutionary and ecological drivers that shape them remain poorly understood. Here we investigate these rhythms in the context of biparental care, a particularly sensitive phase of social synchronization where pair members potentially compromise their individual rhythms. Using data from 729 nests of 91 populations of 32 biparentally incubating shorebird species, where parents synchronize to achieve continuous coverage of developing eggs, we report remarkable within- and between-species diversity in incubation rhythms. Between species, the median length of one parents incubation bout varied from 1-19h, whereas period length-the time in which a parents probability to incubate cycles once between its highest and lowest value-varied from 6-43h. The length of incubation bouts was unrelated to variables reflecting energetic demands, but species relying on crypsis (the ability to avoid detection by other animals) had longer incubation bouts than those that are readily visible or who actively protect their nest against predators. Rhythms entrainable to the 24-h light-dark cycle were less prevalent at high latitudes and absent in 18 species. Our results indicate that even under similar environmental conditions and despite 24-h environmental cues, social synchronization can generate far more diverse behavioural rhythms than expected from studies of individuals in captivity. The risk of predation, not the risk of starvation, may be a key factor underlying the diversity in these rhythms.

Verhagen J.H.,Erasmus Medical Center | Munster V.J.,National Institute of Allergy and Infectious Diseases | Majoor F.,Sovon Dutch Center for Field Ornithology | Lexmond P.,Erasmus Medical Center | And 8 more authors.
PLoS ONE | Year: 2012

Avian influenza virus (AIV) surveillance studies in wild birds are usually conducted in rural areas and nature reserves. Less is known of avian influenza virus prevalence in wild birds located in densely populated urban areas, while these birds are more likely to be in close contact with humans. Influenza virus prevalence was investigated in 6059 wild birds sampled in cities in the Netherlands between 2006 and 2009, and compared with parallel AIV surveillance data from low urbanized areas in the Netherlands. Viral prevalence varied with the level of urbanization, with highest prevalence in low urbanized areas. Within cities virus was detected in 0.5% of birds, while seroprevalence exceeded 50%. Ring recoveries of urban wild birds sampled for virus detection demonstrated that most birds were sighted within the same city, while few were sighted in other cities or migrated up to 2659 km away from the sample location in the Netherlands. Here we show that urban birds were infected with AIVs and that urban birds were not separated completely from populations of long-distance migrants. The latter suggests that wild birds in cities may play a role in the introduction of AIVs into cities. Thus, urban bird populations should not be excluded as a human-animal interface for influenza viruses. © 2012 Verhagen et al.

Lehikoinen A.,University of Helsinki | Jaatinen K.,Australian National University | Vahatalo A.V.,Novia University of Applied Sciences | Vahatalo A.V.,University of Jyväskylä | And 11 more authors.
Global Change Biology | Year: 2013

Climate change is predicted to cause changes in species distributions and several studies report margin range shifts in some species. However, the reported changes rarely concern a species' entire distribution and are not always linked to climate change. Here, we demonstrate strong north-eastwards shifts in the centres of gravity of the entire wintering range of three common waterbird species along the North-West Europe flyway during the past three decades. These shifts correlate with an increase of 3.8 °C in early winter temperature in the north-eastern part of the wintering areas, where bird abundance increased exponentially, corresponding with decreases in abundance at the south-western margin of the wintering ranges. This confirms the need to re-evaluate conservation site safeguard networks and associated biodiversity monitoring along the flyway, as new important wintering areas are established further north and east, and highlights the general urgency of conservation planning in a changing world. Range shifts in wintering waterbirds may also affect hunting pressure, which may alter bag sizes and lead to population-level consequences. © 2013 Blackwell Publishing Ltd.

Koffijberg K.,Sovon Dutch Center for Field Ornithology | Van Winden E.,Sovon Dutch Center for Field Ornithology | Clausen P.,University of Aarhus
Wildfowl | Year: 2013

From 1978/79 onwards, eleven influxes of East Atlantic Light-bellied Brent Geese Branta bernicla hrota were recorded in the Netherlands, to the south of their regular wintering areas in northern Denmark and northeast England. During most influxes, c. 3-6% of the total population occurred in the Netherlands, but large influxes in 1995/96 and 2010/11 involved as many as 800-907 individuals, i.e. 18% and 11% of the flyway population respectively. Core wintering sites within the Netherlands were in the southwest Wadden Sea, in the northern part of Noord-Holland and in the Delta area in the southwest of the country. The first two of these areas are thought to have been more regular wintering areas for Light-bellied Brent Geese in the first part of the 20th century, although good documentation on numbers is lacking. The highest number recorded at a single site was 245 birds in Polder Kimswerd/ Eendracht, Friesland, in December 2010. The distribution pattern was similar during all influxes, indicating traditional site use by the wintering flocks. Winters with peak numbers in the Netherlands show a significant, negative correlation with average daily temperatures at the Danish wintering sites. During prolonged and/or heavy cold spells, feeding conditions in Denmark deteriorate due to ice- or snow cover, making both aquatic and agricultural food resources unavailable and forcing birds to depart; this was confirmed by count data from Denmark. In 1995/96, phenological patterns and sightings of marked birds also indicated an influx from birds from the wintering site at Lindisfarne in the UK, but this could not be confirmed for more recent winters. Sightings of marked birds showed that at least some birds (eight out of 34 observed individuals) were involved in successive influxes; in non-influx years they were seen regularly at wintering sites further up the flyway as well as on breeding sites at Svalbard. The regular patterns of influxes, the traditional use of particular sites during influx years and repeated observations of the same individuals at these sites (which may transfer knowledge of alternative wintering sites in the Netherlands to their offspring, indicated by ringed birds being seen with their goslings) illustrates that the Netherlands should be considered as a regular hard weather winter refuge for the sub-species. Appropriate measures therefore should be taken to include these sites within the national Natura 2000 network. © Wildfowl and Wetlands Trust.

Kampichler C.,Netherlands Institute of Ecology | Kampichler C.,Juarez Autonomous University of Tabasco | Kampichler C.,Sovon Dutch Center for Field Ornithology | van der Jeugd H.P.,Netherlands Institute of Ecology
Environmental and Ecological Statistics | Year: 2013

All ecological communities experience change over time. One method to quantify temporal variation in the patterns of relative abundance of communities is time lag analysis (TLA). It uses a distance-based approach to study temporal community dynamics by regressing community dissimilarity over increasing time lags (one-unit lags, two-unit lags, three-unit lags). Here, we suggest some modifications to the method and revaluate its potential for detecting patterns of community change. We apply Hellinger distance based TLA to artificial data simulating communities with different levels of directional and stochastic dynamics and analyse their effects on the slope and its statistical significance. We conclude that statistical significance of the TLA slope (obtained by a Monte Carlo permutation procedure) is a valid criterion to discriminate between (i) communities with directional change in species composition, regardless whether it is caused by directional abundance change of the species or by stochastic change according to a Markov process, and (ii) communities that are composed of species with population sizes oscillating around a constant mean or communities whose species abundances are governed by a white noise process. TLA slopes range between 0.02 and 0.25, depending on the proportions of species with different dynamics; higher proportions of species with constant means imply shallower slopes; and higher proportions of species with stochastic dynamics or directional change imply steeper slopes. These values are broadly in line with TLA slopes from real world data. Caution must be exercised when TLA is used for the comparison of community time series with different lengths since the slope depends on time series length and tends to decrease non-linearly with it. © 2012 Springer Science+Business Media, LLC.

PubMed | Sovon Dutch Center for Field Ornithology, Polish Academy of Sciences, Copenhagen University, Statistics Netherlands and 9 more.
Type: Journal Article | Journal: Global change biology | Year: 2016

Species attributes are commonly used to infer impacts of environmental change on multiyear species trends, e.g. decadal changes in population size. However, by themselves attributes are of limited value in global change attribution since they do not measure the changing environment. A broader foundation for attributing species responses to global change may be achieved by complementing an attributes-based approach by one estimating the relationship between repeated measures of organismal and environmental changes over short time scales. To assess the benefit of this multiscale perspective, we investigate the recent impact of multiple environmental changes on European farmland birds, here focusing on climate change and land use change. We analyze more than 800 time series from 18 countries spanning the past two decades. Analysis of long-term population growth rates documents simultaneous responses that can be attributed to both climate change and land-use change, including long-term increases in populations of hot-dwelling species and declines in long-distance migrants and farmland specialists. In contrast, analysis of annual growth rates yield novel insights into the potential mechanisms driving long-term climate induced change. In particular, we find that birds are affected by winter, spring, and summer conditions depending on the distinct breeding phenology that corresponds to their migratory strategy. Birds in general benefit from higher temperatures or higher primary productivity early on or in the peak of the breeding season with the largest effect sizes observed in cooler parts of species climatic ranges. Our results document the potential of combining time scales and integrating both species attributes and environmental variables for global change attribution. We suggest such an approach will be of general use when high-resolution time series are available in large-scale biodiversity surveys.

Tulp I.,Institute for Marine Resources and Ecosystem Studies | Schekkerman H.,Sovon Dutch Center for Field Ornithology | de Leeuw J.,Swedish University of Agricultural Sciences
PLoS ONE | Year: 2012

Birds construct nests for several reasons. For species that breed in the Arctic, the insulative properties of nests are very important. Incubation is costly there and due to an increasing surface to volume ratio, more so in smaller species. Small species are therefore more likely to place their nests in thermally favourable microhabitats and/or to invest more in nest insulation than large species. To test this hypothesis, we examined characteristics of nests of six Arctic breeding shorebird species. All species chose thermally favourable nesting sites in a higher proportion than expected on the basis of habitat availability. Site choice did not differ between species. Depth to frozen ground, measured near the nests, decreased in the course of the season at similar non-species-specific speeds, but this depth increased with species size. Nest cup depth and nest scrape depth (nest cup without the lining) were unrelated to body mass (we applied an exponent of 0.73, to account for metabolic activity of the differently sized species). Cup depth divided by diameter 2 was used as a measure of nest cup shape. Small species had narrow and deep nests, while large species had wide shallow nests. The thickness of nest lining varied between 0.1 cm and 7.6 cm, and decreased significantly with body mass. We reconstruct the combined effect of different nest properties on the egg cooling coefficient using previously published quantitative relationships. The predicted effect of nest cup depth and lining depth on heat loss to the frozen ground did not correlate with body mass, but the sheltering effect of nest cup diameter against wind and the effects of lining material on the cooling coefficient increased with body mass. Our results suggest that small arctic shorebirds invest more in the insulation of their nests than large species. © 2012 Tulp et al.

Verhagen J.H.,Erasmus Medical Center | Majoor F.,Sovon Dutch Center for Field Ornithology | Lexmond P.,Erasmus Medical Center | Vuong O.,Erasmus Medical Center | And 5 more authors.
Emerging Infectious Diseases | Year: 2014

We sampled 7,511 black-headed gulls for influenza virus in the Netherlands during 2006-2010 and found that subtypes H13 and H16 caused annual epidemics in fledglings on colony sites. Our findings validate targeted surveillance of wild waterbirds and clarify underlying factors for influenza virus emergence in other species.

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