Kentie, Rosemarie

English

University of Groningen

   University of GroningenOn grassland monocultures Black-tailed Godwits are doomedKentie, RosemarieIMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite fromit. Please check the document version below.Publication date:2013Link to publication in University of Groningen/UMCG research databaseCitation for published version (APA):Kentie, R. (2013). On grassland monocultures Black-tailed Godwits are doomed: Influence of agriculturalmanagement on demographic parameters of Black-tailed Godwit chicks and adults in the Netherlands.CopyrightOther than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of theauthor(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).Take-down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediatelyand investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons thenumber of authors shown on this cover page is limited to 10 maximum.Download date: 12-11-2019On grassland monocultures Black-tailed Godwits are doomedRosemarie Kentie1, Jos C.E.W. Hooijmeijer1 & Theunis Piersma1,21. Animal Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, P.O. Box 11103, 9700 CC Groningen, The Netherlands2. Department of Marine Ecology, NIOZ Royal Netherlands Institute for Sea Research, P.O. Box 59, 1790 AB Den Burg, Texel, The NetherlandsIntroduction:The number of breeding Black-tailed Godwits (Limosa limosa limosa) in The Netherlands is rapidly declining. Most of their breeding habitat - wet herb-rich meadows - has been transformed into intensively used grassland monocultures and arable fields. Will godwits persist in this modern agricultural landscape, what are sources and where are sinks? We studied the demography of colour ringed godwits in a large study area in The Netherlands between 2007 and 2012. This included the quantification of nest survival, apparent survival of chicks and adults, as well the growth rates of chicks hatched in grassland monocultures compared with herb-rich meadows. Inuence of agricultural management on demographic parameters of Black-tailed Godwit chicks and adults in The Netherlandsherb-rich meadows grassland monoculturesMethods:Our study area comprised 6000 ha grasslands monocultures, 780 ha arable fields, and 1700 ha herb-rich wet meadows. Between 2007 and 2012, we monitored nests, captured and colour marked adult godwits as well as their 1-day old chicks. Nest survival and apparent survival of adults and juveniles was calculated in MARK. Chick growth was calculated for recaptured chicks of known age and compared with a previously derived Gompertz curve calculated for chicks caught mainly on herb-rich meadows between 1976 and 1985 (Beintema & Visser 1989). 0010020050150Chick body mass (g)1510 20 255Real age (days)MeadowMonocultureGompertz curveNests on meadows had a higher hatching success than nests on grassland monocultures. The incuba-tion period was assumed 25 days.2008 2009 2010 2011 20120.000.050.100.150.200.250.300.350.40Apparent survival 1st year (95% CI)MeadowMonoculturecorrectedcorrected30354045505560Percentage nests hatched (95% CI)MonoculturesMeadowsApparent survival of the first year of godwits is higher for chicks hatched on herb-rich meadows. We corrected for methodological differences because we marked re-captured older chicks with a colour ring combination instead of a numbered flag, which resulted in a higher resighting probability.Discussion:Less eggs hatch on modern grassland monocultures than on traditional herb-rich mead-ows, and the chicks that do hatch there have a lower condition and survival rate, than chicks hatched on meadows. With an average yearly adult survival rate of 0.86 (which did not differ between meadows and monocultures), grassland monocultures hold a sink population while herb-rich meadows hold a source population. Conservation effort should focus on creating herb-rich meadows, instead of the popular method of sparing clutches from mowing on grassland monocultures.Recaptured chicks that hatched on monocultures were lighter than recaptured chicks hatched on meadows, although at hatching there was no difference. Body mass of male fledglings that hatched on monocultures was 16% lighter than that of males hatched on meadows, this differ-ence was 14% for females (Kentie et al. 2013).Results:- Nest survival is lower on monocultures than on meadows- Chick survival is lower on monocultures than on meadows- Chicks grow slower on monocultures than on meadows- Chick growth on herb-rich meadows is similar to chick growth of chicks measured between 1976 and 1985acknowledgements:We thank our fellow members of the successive godwit teams. Nature conservancy organisations (It Fryske Gea and Staatsbosbeheer) and private landowners generously issued permission to access their properties. Volunteers of local bird conservation communities provided locations of many nests. This study was mainly funded by the ‘Kenniskring weidevogels’ of the former Ministry of Agriculture, nature Management and Food Safety. References:Beintema, A.J. & Visser, G.H. (1989) Growth parameters in chicks of Charadriiform birds. Ardea, 77, 169-180.Kentie, R., Hooijmeijer, J.C.E.W., Trimbos, K.B., Groen, N.M. & Piersma, T. (2013) Intensified agricultural use of grasslands reduces growth and survival of precocial shorebird chicks. Journal of Applied Ecology, 50, 243-251.

On grassland monocultures Black-tailed Godwits are doomed:Influence of agricultural management on demographic parameters of Black-tailed Godwit chicks and adults in the Netherlands

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