Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    A network approach to prioritize conservation efforts for migratory birds
    Xu, Yanjie ; Si, Yali ; Takekawa, John ; Liu, Qiang ; Prins, Herbert H.T. ; Yin, Shenglai ; Prosser, Diann J. ; Gong, Peng ; Boer, Willem F. de - \ 2020
    Conservation Biology 34 (2020)2. - ISSN 0888-8892 - p. 416 - 426.
    bird migration - connectivity - conservation designation - habitat loss - network

    Habitat loss can trigger migration network collapse by isolating migratory bird breeding grounds from nonbreeding grounds. Theoretically, habitat loss can have vastly different impacts depending on the site's importance within the migratory corridor. However, migration-network connectivity and the impacts of site loss are not completely understood. We used GPS tracking data on 4 bird species in the Asian flyways to construct migration networks and proposed a framework for assessing network connectivity for migratory species. We used a node-removal process to identify stopover sites with the highest impact on connectivity. In general, migration networks with fewer stopover sites were more vulnerable to habitat loss. Node removal in order from the highest to lowest degree of habitat loss yielded an increase of network resistance similar to random removal. In contrast, resistance increased more rapidly when removing nodes in order from the highest to lowest betweenness value (quantified by the number of shortest paths passing through the specific node). We quantified the risk of migration network collapse and identified crucial sites by first selecting sites with large contributions to network connectivity and then identifying which of those sites were likely to be removed from the network (i.e., sites with habitat loss). Among these crucial sites, 42% were not designated as protected areas. Setting priorities for site protection should account for a site's position in the migration network, rather than only site-specific characteristics. Our framework for assessing migration-network connectivity enables site prioritization for conservation of migratory species.

    Loss of functional connectivity in migration networks induces population decline in migratory birds
    Xu, Yanjie ; Si, Yali ; Wang, Yingying ; Zhang, Yong ; Prins, Herbert H.T. ; Cao, Lei ; Boer, Willem F. de - \ 2019
    Ecological Applications 29 (2019)7. - ISSN 1051-0761 - p. e01960 - e01960.
    bird migration - habitat loss - life history - network robustness - population dynamics - species traits - wetland

    Migratory birds rely on a habitat network along their migration routes by temporarily occupying stopover sites between breeding and non-breeding grounds. Removal or degradation of stopover sites in a network might impede movement and thereby reduce migration success and survival. The extent to which the breakdown of migration networks, due to changes in land use, impacts the population sizes of migratory birds is poorly understood. We measured the functional connectivity of migration networks of waterfowl species that migrate over the East Asian-Australasian Flyway from 1992 to 2015. We analysed the relationship between changes in non-breeding population sizes and changes in functional connectivity, while taking into account other commonly considered species traits, using a phylogenetic linear mixed model. We found that population sizes significantly declined with a reduction in the functional connectivity of migration networks; no other variables were important. We conclude that the current decrease in functional connectivity, due to habitat loss and degradation in migration networks, can negatively and crucially impact population sizes of migratory birds. Our findings provide new insights into the underlying mechanisms that affect population trends of migratory birds under environmental changes. Establishment of international agreements leading to the creation of systematic conservation networks associated with migratory species' distributions and stopover sites may safeguard migratory bird populations.

    Data from: Predicting effects of water regime changes on waterbirds: insights from staging swans
    Nolet, Bart A. ; Gyimesi, A. ; Krimpen, A. van; Boer, W.F. de; Stillman, R.A. - \ 2016
    Wageningen University & Research
    bird migration - Individual-based Modelling - MORPH - predictive modelling - staging site - water level
    (1) Count data of Bewick's swans at Lauwersmeer in autumns of 2005 - 2008; (2) Tuber sampling data in Lauwersmeer in autumns of 2005 - 2008; (3) Metadata water levels in Lauwersmeer and adjacent Wadden Sea in autumns of 2005 - 2008
    Do Arctic breeding geese track or overtake a green wave during spring migration?
    Si, Y. ; Xin, Q. ; Boer, W.F. de; Gong, P. ; Ydenberg, R.C. ; Prins, H.H.T. - \ 2015
    Scientific Reports 5 (2015). - ISSN 2045-2322
    goose branta-leucopsis - russian barnacle geese - anser-brachyrhynchus - time-series - brent geese - large herbivores - forage quality - bird migration - decision - bernicla
    Geese breeding in the Arctic have to do so in a short time-window while having sufficient body reserves. Hence, arrival time and body condition upon arrival largely influence breeding success. The green wave hypothesis posits that geese track a successively delayed spring flush of plant development on the way to their breeding sites. The green wave has been interpreted as representing either the onset of spring or the peak in nutrient biomass. However, geese tend to adopt a partial capital breeding strategy and might overtake the green wave to accomplish a timely arrival on the breeding site. To test the green wave hypothesis, we link the satellite-derived onset of spring and peak in nutrient biomass with the stopover schedule of individual Barnacle Geese. We find that geese track neither the onset of spring nor the peak in nutrient biomass. Rather, they arrive at the southernmost stopover site around the peak in nutrient biomass, and gradually overtake the green wave to match their arrival at the breeding site with the local onset of spring, thereby ensuring gosling benefit from the peak in nutrient biomass. Our approach for estimating plant development stages is critical in testing the migration strategies of migratory herbivores.
    The Development of a Genome Wide SNP Set for the Barnacle Goose Branta leucopsis
    Jonker, R.M. ; Zhang, Q. ; Hooft, W.F. van; Loonen, M.J.J.E. ; Jeugd, H.P. van der; Crooijmans, R.P.M.A. ; Groenen, M.A.M. ; Prins, H.H.T. ; Kraus, Robert - \ 2012
    PLoS ONE 7 (2012)7. - ISSN 1932-6203
    breeding range expansion - migratory connectivity - bird migration - geese - markers - conservation - relatedness - populations - divergence - evolution
    Migratory birds are of particular interest for population genetics because of the high connectivity between habitats and populations. A high degree of connectivity requires using many genetic markers to achieve the required statistical power, and a genome wide SNP set can fit this purpose. Here we present the development of a genome wide SNP set for the Barnacle Goose Branta leucopsis, a model species for the study of bird migration. We used the genome of a different waterfowl species, Mallard Anas platyrhynchos, as a reference to align Barnacle Goose second generation sequence reads from an RRL library and detected 2188 SNPs genome wide. Furthermore, we used chimeric flanking sequences, merged from both Mallard and Barnacle Goose DNA sequence information, to create primers for validation by genotyping. Validation with a 384 SNP genotyping set resulted in 374 (97%) successfully typed SNPs in the assay, of which 358 (96%) were polymorphic. Additionally, we validated our SNPs on relatively old (30 years) museum samples, which resulted in a success rate of at least 80%. This shows that museum samples could be used in standard SNP genotyping assays. Our study also shows that the genome of a related species can be used as reference to detect genome wide SNPs in birds, because genomes of birds are highly conserved. This is illustrated by the use of chimeric flanking sequences, which showed that the incorporation of flanking nucleotides from Mallard into Barnacle Goose sequences lead to equal genotyping performance when compared to flanking sequences solely composed of Barnacle Goose sequence
    The role of Mallard (Anas platyrhynchos) in the spread of avian influenza: genomics, population genetics, and flyways
    Kraus, R.H.S. - \ 2011
    Wageningen University. Promotor(en): Herbert Prins; Ron Ydenberg, co-promotor(en): Pim van Hooft. - [S.l.] : S.n. - ISBN 9789461730282 - 143
    aviaire influenzavirussen - aviaire influenza - anas platyrhynchos - ziekteoverdracht - vogeltrek - genomica - populatiegenetica - evolutionaire genetica - zoögeografie - bioveiligheid - ziekteoverzichten - epidemiologie - avian influenza viruses - avian influenza - anas platyrhynchos - disease transmission - bird migration - genomics - population genetics - evolutionary genetics - zoogeography - biosafety - disease surveys - epidemiology

    Birds, in particular poultry and ducks, are a source of many infectious diseases, such as those caused by influenza viruses. These viruses are a threat not only to the birds themselves but also to poultry farming and human health, as forms that can infect humans are known to have evolved. It is believed that migratory birds in general play an important role in the global spread of avian influenza (AI). However, it is still debated how large this role precisely is and whether other modes of spread may be more important. The mallard (Anas platyrhynchos) is the world’s most abundant and well-studied waterfowl species. Besides being an important game and agricultural species, it is also a flagship species in wetland conservation and restoration. Waterfowl (Anseriformes: Anatidae) and especially ducks currently are the focal bird group in long distance dispersal of Avian Influenza in the wild, and the mallard has been identified as the most likely species to transport this virus.

    In my thesis I report aspects of the biology of this important host species of AI by molecular ecological means. As molecular marker system I established a genome-wide set of more than 100,000 SNPs of which I developed a subset of 384 SNPs into an assay to genotype about 1,000 ducks. This subset was employed to study the evolutionary history and speciation processes in the Anas genus. Further investigations into the world-wide mallard population structure on a species level were based not only on this set of 384 SNPs but also on mitochondrial DNA sequences. Last but not last, I investigated an option of AI sampling and detection from duck faeces by technology that is safe from a biohazard perspective, and solves transportation issues related to cold chains.

    The main results of my thesis include the development of a generally applicable improved analysis pipeline to develop genome-wide SNP sets for non-model organisms. Further, my results show that, from a migration system perspective, mallard flyways/populations can hardly be delineated from a biological point of view. Detailed phylogenetic, population genetic and coalescent analyses of a data set of samples spanning the whole northern hemisphere leads me to conclude that the only firm population boundaries that I can draw are between Eurasia and North America, within which panmixia is almost achieved. Mallards’ and other Anas-ducks’ whole continental to global distribution brings them together in sympatry. I can show that a combination of sympatric distribution, conflicting genetically determined and learned mate recognition mechanisms, and genomic compatibility between species helps to explain the long-standing puzzle of waterfowl hybridisation and introgression of genes from one duck species into another. Besides obvious management implications I propose that this fact can be part of the explanation why ducks are so well adaptable and successful, as well as why they show extraordinary abilities to withstand AI infections, or its consequences for health status.

    Evolution and connectivity in the world-wide migration system of the mallard: Inferences from mitochondrial DNA
    Kraus, R.H.S. ; Zeddeman, A. ; Hooft, W.F. van; Sartakov, D. ; Soloviev, S.A. ; Ydenberg, R.C. ; Prins, H.H.T. - \ 2011
    BMC Genetics 12 (2011). - ISSN 1471-2156
    duck anas-platyrhynchos - influenza-a viruses - avian influenza - bird migration - population-structure - north-america - black ducks - gene flow - hybridization - philopatry
    Main waterfowl migration systems are well understood through ringing activities. However, in mallards (Anas platyrhynchos) ringing studies suggest deviations from general migratory trends and traditions in waterfowl. Furthermore, surprisingly little is known about the population genetic structure of mallards, and studying it may yield insight into the spread of diseases such as Avian Influenza, and in management and conservation of wetlands. The study of evolution of genetic diversity and subsequent partitioning thereof during the last glaciation adds to ongoing discussions on the general evolution of waterfowl populations and flyway evolution. Hypothesised mallard flyways are tested explicitly by analysing mitochondrial mallard DNA from the whole northern hemisphere.
    Avian influenza and migratory birds : a spatial - ecological perspective
    Si, Y. - \ 2011
    University of Twente. Promotor(en): Andrew Skidmore; Herbert Prins; T. Wang. - Enschede : University of Twente Faculty of Geo-Information and Earth Observation ITC - ISBN 9789061643081 - 129
    aviaire influenzavirussen - watervogels - vogeltrek - ruimtelijke ecologie - virologie - epidemiologie - milieufactoren - avian influenza viruses - waterfowl - bird migration - spatial ecology - virology - epidemiology - environmental factors
    Factoren die van invloed zijn op de ontwikkeling van weidevogelpopulaties : belangrijke factoren tijdens de trek, de invloed van waterpeil op voedselbeschikbaarheid en graslandcultuur op kuikenoverleving
    Teunissen, W. ; Wymenga, E. ; Hooijmeijer, J. ; Bruinzeel, L. ; Kamp, J. van der; Piersma, Th. - \ 2011
    Wageningen : Alterra (Alterra rapport 2187) - 101 p.
    weidevogels - limosa limosa - onvolwassenheid - voedingsgedrag - bodemecologie - bodemwater - graslanden - vogeltrek - agrarisch natuurbeheer - grassland birds - limosa limosa - juvenility - feeding behaviour - soil ecology - soil water - grasslands - bird migration - agri-environment schemes
    De Kenniskring Weidevogellandschap heeft SOVON, Bureau Altenburg & Wymenga en Alterra gevraagd onderzoek te doen naar sturende factoren die de populatie van weidevogels kan beïnvloeden. Toegespitst op de aspecten: Trek van de Grutto naar Afrika (via satellietzenders, i.s.m. RU Groningen); Waterpeil (in relatie tot foerageren van Grutto's); en de vegetatiestructuur. Conclusies zijn o.a. dat de trekroutes veilig gesteld dienen te worden; in Nederland zal het waterbeheer dusdanig moeten zijn, dat het vochtgehalte van de bodem niet onder de 30% zal dalen, zodat de voedselbeschikbaarheid optimaal is.
    African winter population trends of European waterbirds : the identification of critical sites and the effectiveness of Ramsar and IBA site designation for the conservation of migratory waterbirds
    Kleijn, D. ; Nagy, S. ; Delany, S. ; Nasirwa, O. ; Dodman, T. ; Goedhart, P.W. - \ 2011
    Wageningen : Alterra (Alterra-report 2148) - 30
    watervogels - winter - vogeltrek - wildbescherming - populatiedynamica - afrika - europa - vogels - monitoring - waterfowl - winter - bird migration - wildlife conservation - population dynamics - africa - europe - birds - monitoring
    IBA = important bird area
    Black-tailed Godwits in West African winter staging areas : habitat use and hunting-related mortality
    Kleijn, D. ; Kamp, J. van der; Monteiro, H. ; Ndiaye, I. ; Wymenga, E. ; Zwarts, L. - \ 2010
    Wageningen : Alterra (Alterra-report 2058) - 32
    vogels - limosa limosa - overwintering - natte rijst - wildbescherming - habitats - bevolkingsafname - jagen - west-afrika - guinee-bissau - gambia - senegal - nederland - weidevogels - vogeltrek - birds - limosa limosa - overwintering - flooded rice - wildlife conservation - habitats - population decrease - hunting - west africa - guinea-bissau - gambia - senegal - netherlands - grassland birds - bird migration
    The persistence of the Dutch Black-tailed Godwit population depends largely on high adult survival. Adult survival may be influenced by hunting pressure and land use change in the wintering area, the West African coastal zone. Here we examine hunting pressure on and habitat use of Black-tailed Godwits in West African rice-growing areas. The Black-tailed Godwit is exposed to hunting throughout the core wintering area in West Africa but hunting related mortality does not seem to be the main driver of the ongoing population decline. Habitat use of godwits seems to be governed by the availability of their preferred habitat: (man-made) bare wet soil which is consecutively available in different parts of West Africa throughout the entire wintering period.
    Predation danger can explain changes in timing of migration: the case of the Barnacle goose
    Jonker, R.M. ; Eichhorn, G. ; Langevelde, F. van; Bauer, S. - \ 2010
    PLoS ONE 5 (2010)6. - ISSN 1932-6203 - 8 p.
    optimal avian migration - branta-leucopsis - heart-rate - oxygen-consumption - spring migration - range expansion - bird migration - climate-change - stopover site - trade-off
    Understanding stopover decisions of long-distance migratory birds is crucial for conservation and management of these species along their migratory flyway. Recently, an increasing number of Barnacle geese breeding in the Russian Arctic have delayed their departure from their wintering site in the Netherlands by approximately one month and have reduced their staging duration at stopover sites in the Baltic accordingly. Consequently, this extended stay increases agricultural damage in the Netherlands. Using a dynamic state variable approach we explored three hypotheses about the underlying causes of these changes in migratory behavior, possibly related to changes in (i) onset of spring, (ii) potential intake rates and (iii) predation danger at wintering and stopover sites. Our simulations showed that the observed advance in onset of spring contradicts the observed delay of departure, whereas both increased predation danger and decreased intake rates in the Baltic can explain the delay. Decreased intake rates are expected as a result of increased competition for food in the growing Barnacle goose population. However, the effect of predation danger in the model was particularly strong, and we hypothesize that Barnacle geese avoid Baltic stopover sites as a response to the rapidly increasing number of avian predators in the area. Therefore, danger should be considered as an important factor influencing Barnacle goose migratory behavior, and receive more attention in empirical studies
    An Atlas of Wader Populations in Africa and Western Eurasia
    Delany, S. ; Scott, D. ; Helmink, A.T.F. ; Dodman, T. ; Flink, S. ; Stroud, D. ; Haanstra, L. - \ 2009
    London : Wetlands International - ISBN 9789058820471 - 524
    populatie-ecologie - conservering - zoögeografie - afrika - europa - waadvogels - vogeltrek - population ecology - conservation - zoogeography - africa - europe - waders - bird migration
    This publication is a compilation of current knowledge of the numbers, distribution and movements of one of the most remarkable groups of birds in the region covered by the African-Eurasian Migratory Waterbird Agreement (AEWA). Long-term waterbird count data have been combined with an extensive literature review, especially published results of bird ringing and national bird atlases, to produce maps showing the population boundaries that are used as a basis of the conservation of these species. The maps are supported by informative species accounts that highlight the movements, population status and conservation of waders in the AEWA region.
    De betekenis van lichtverontreiniging voor vogels in kustgebieden en de Noordzee
    Smit, C.J. ; Baptist, M.J. ; Mesel, I.G. de; Ysebaert, T. - \ 2009
    Texel : IMARES (Rapport / IMARES Wageningen UR C122/09) - 30
    vogels - mariene gebieden - kunstlicht - nadelige gevolgen - verontreiniging - offshore - waddenzee - vogeltrek - birds - marine areas - artificial light - adverse effects - pollution - offshore - wadden sea - bird migration
    Elk jaar maken 10-12 miljoen vogels gebruik van de internationale Waddenzee, als pleisterplaats op hun jaarlijkse heen- en terugreis tussen de broedgebieden en de overwinteringsgebied. Deze vogels gebruiken de Waddenzee voor een korte stop, als opvetgebied om langduriger bij te tanken voor een langere etappe, als ruigebied en als overwinteringsgebied. De Waddenzee vormt daarmee een essentiële halte voor het voortbestaan voor deze vogels. Een deel van de in de Waddenzee pleisterende vogels bereikt dit gebied via een route over de Noordzee. Lichtverontreiniging alhier, als gevolg van verlichting door boorplatforms, zou een negatief effect kunnen hebben op de oriëntatiemogelijkheden van vogels die ’s nachts over de Noordzee trekken. Ook zou verlichting in het Waddengebied zelf van invloed kunnen zijn op de leefwijze van wadvogels en op de mogelijkheden om voedsel te zoeken. Kennis over de mogelijke effecten van lichtverontreiniging is daarom van belang voor de beheer van de trekkende vogelpopulaties in dit gebied.
    Foraging site selection of two subspecies of Bar-tailed Godwit Limosa lapponica: time minimizers accept greater predation danger than energy minimizers
    Duijns, S. ; Dijk, J.G.B. van; Spaans, B. ; Jukema, J. ; Boer, W.F. de; Piersma, Th. - \ 2009
    Ardea 97 (2009)1. - ISSN 0373-2266 - p. 51 - 59.
    long-distance migrant - stopover site - migration strategies - relative importance - western sandpipers - raptor predation - calidris-mauri - bird migration - large falcons - banc-darguin
    Different spatial distributions of food abundance and predators may urge birds to make a trade-off between food intake and danger. Such a trade-off might be solved in different ways in migrant birds that either follow a time-minimizing or energy-minimizing strategy; these strategies have been assigned to two subspecies of Bar-tailed Godwits Limosa lapponica that use the European Wadden Sea during northward migration. At the study area on Terschelling, we recorded feeding site selection, time budgets and intake rates (prey/min) in the period that both lapponica (energy minimizer) and taymyrensis (time minimizer) subspecies were present (late April till the end of May 2007). Prey availability (number of prey/m2) was negatively correlated to the distance from cover. Based on sightings of colour-ringed Bar-tailed Godwits, taymyrensis was foraging closer to cover, and for a higher proportion of time than lapponica (67% vs. 33%). During the high tide period taymyrensis was also foraging on inland coastal meadows. Moreover, taymyrensis was more vigilant than lapponica, whereas lapponica showed more resting and preening behaviour. Lapponica had a higher instantaneous intake rate, but taymyrensis had a higher overall intake rate and the birds were more successful in taking larger prey items than lapponica. Supposedly, due to the increased foraging time and additional foraging on the inland meadows, the time-minimizing taymyrensis achieved a higher fuel deposition rate than lapponica. Taymyrensis shifted towards food-rich areas, apparently accepting higher predation risks, whereas energy-minimizing lapponica avoided predation danger by foraging further from cover
    Samen op reis op de rug van... : Educatiemodule Ganzentrek voor VMBO Groen
    Mulder, S. ; Vliet, A.J.H. van; Bron, W.A. - \ 2008
    Wageningen : Wageningen Universiteit, Leerstoelgroep Milieusysteemanalyse - 27
    lesmaterialen - agrarisch onderwijs - voortgezet onderwijs - ganzen - vogeltrek - teaching materials - agricultural education - secondary education - geese - bird migration
    In de educatiemodule “Samen op reis door de natuur op de rug van….” staat de kolganzentrek van Nederland naar Siberië centraal. Aan de hand hiervan moeten leerlingen vragen beantwoorden en opdrachten maken over onder andere de ecologie van de ganzen en de topografie van hun trekroute. Het doel van deze module is om leerlingen aan de hand van ganzentrek kennis te laten maken met het gebruik van geo-informatie, de jaarlijkse trek van beesten door de natuur, het effect van klimaatverandering op de natuur en de betekenis van natuur in hun eigen omgeving
    Effects of predator landscapes on the evolutionary ecology of routing, timing and molt by long-distance migrants
    Ydenberg, R.C. ; Butler, R.W. ; Lank, D.B. - \ 2007
    Journal of Avian Biology 38 (2007)5. - ISSN 0908-8857 - p. 523 - 529.
    falcons falco-peregrinus - bird migration - stopover site - risk - danger - strategies - behavior - songbird - routes - rates
    The arctic pulse : timing of breeding in long-distance migrant shorebrids [i.e.] shorebirds
    Tulp, I.Y.M. - \ 2007
    University of Groningen. Promotor(en): T. Piersma, co-promotor(en): G.H. Visser. - [S.l.] : S.n. - ISBN 9789090222288 - 259
    vogels - diergedrag - migratie - veredelen - broedplaatsen - nesten - dierecologie - oevers - vogeltrek - birds - animal behaviour - migration - breeding - breeding places - nests - animal ecology - shores - bird migration
    Veel steltlopers zijn lange-afstandtrekkers: ze brengen de winter door in gematigde of tropische streken en trekken in het voorjaar noordwaarts om te broeden in de Arctis. Hier is de zomer kort en wordt gekenmerkt door een koud en grillig klimaat. Bovendien vertoont het voedselaanbod, dat voor zowel ouders als kuikens uit insecten bestaat, een gepiekt verloop en een sterke weersvariatie. De timing van broeden kan daarom van grote invloed zijn op het broedsucces. Om te onderzoeken welke factoren deze timing beïnvloeden hebben we het seizoenspatroon in het aanbod van insecten gemeten en dit vergeleken met de energetische behoeften en prestaties van ouders en kuikens door het seizoen. We zagen dat de groeisnelheid van kuikens afhankelijk is van het weer, maar ook van het voedselaanbod, en dat vroeg geboren kuikens beter groeien dan latere kuikens. In de drie jaren van het onderzoek werden de kuikens relatief laat geboren ten opzichte van de voedselpiek en vanuit de kuikens bekeken begonnen de ouders dus te laat met broeden. Die moeten echter niet alleen rekening houden met het belang van de kuikens. Ze arriveren op de toendra na een lange trekvlucht met een beperkte hoeveelheid lichaamsreserves, hooguit voldoende om een paar dagen te overleven mocht de toendra nog met sneeuw bedekt zijn. Te vroeg aankomen brengt daarom risico¿s mee, en de vogels hebben ook tijd nodig om nieuwe reserves op te doen voor de aanmaak van eieren. Daarnaast moeten ze tijdens het broeden, dat energie maar vooral veel tijd vergt, ook zelf genoeg voedsel kunnen vinden. Dat geldt het sterkst voor soorten die de eieren zonder hulp van een partner uitbroeden, die een afweging moeten maken tussen foerageren en het bebroeden van de eieren. De incubatieperiode is voor hen daardoor energetisch gezien stressvoller dan de kuikenperiode, terwijl dat voor samen broedende soorten niet zo is. In overeenstemming hiermee komen alleen broedende soorten later aan op de toendra en beginnen ze later met leggen. Onder invloed van recente klimaatveranderingen lijkt de voedselpiek naar voren te verschuiven, en daarmee ook het beste moment om eieren te leggen.
    Ecological factors associated with the breeding and migratory phenology of high-latitude breeding western sandpipers
    Niehaus, A.C. ; Ydenberg, R.C. - \ 2006
    Polar Biology 30 (2006)1. - ISSN 0722-4060 - p. 11 - 17.
    yukon-kuskokwim delta - climate-change - calidris-mauri - british-columbia - bird migration - north-america - sex-ratio - alaska - shorebirds - chronology
    Environmental conditions influence the breeding and migratory patterns of many avian species and may have particularly dramatic effects on longdistance migrants that breed at northern latitudes. Environment, however, is only one of the ecological variables affecting avian phenology, and recent work shows that migration tactics may be strongly affected by changes in predator populations. We used long-term data from 1978 to 2000 to examine the interactions between snowmelt in western Alaska in relation to the breeding or migration phenologies of small shorebirds and their raptor predators. Although the sandpipers¿ time of arrival at Alaskan breeding sites corresponded with mean snowmelt, late snowmelts did delay breeding. These delays, however, did not persist to southward migration through British Columbia, likely due to the birds¿ ability to compensate for variance in the length of the breeding season. Raptor phenology at an early stopover site in British Columbia was strongly related to snowmelt, so that in years of early snowmelt falcons appeared earlier during the sandpipers¿ southbound migration. These differential effects indicate that earlier snowmelt due to climate change may alter the ecological dynamics of the predator¿prey system.
    Pristine wilderness of the Taimyr peninsula; 2005 report
    Ebbinge, B.S. ; Mazurov, Y.L. - \ 2006
    Moscow (Russia) : Heritage Institute - ISBN 9785864431382 - 180
    wildernis - vogels - ganzen - laridae - zoogdieren - landschap - vegetatie - fauna - watervogels - ecotoerisme - lemmingen - siberië - vogeltrek - expedities - wilderness - birds - geese - laridae - mammals - landscape - vegetation - fauna - waterfowl - ecotourism - lemmings - siberia - bird migration - expeditions
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