Spring migration of Black-tailed Godwits in Iberia 2015:Mission Report Sado, Tejo and Extremadura

• Main Authors: Hooijmeijer, Jos, Galama, Ysbrand, Hoekstra, Gjerryt, van der Velde, Egbert, Valkema, Haije, Terpstra, Sytse, Loonstra, Jelle, Senner, Nathan, Verhoeven, Mo, McBride, Alice, Piersma, Theunis
• Format: Book
• Language: English
• Published: University of Groningen 2015
• Subjects: black-tailed godwit; Limosa limosa
• Online Access: https://hdl.handle.net/11370/910f2b54-1a6d-4add-9c31-1d5b167faa36; https://research.rug.nl/en/publications/910f2b54-1a6d-4add-9c31-1d5b167faa36; https://pure.rug.nl/ws/files/250901975/BTG_Iberia_2015_Mission_Report.pdf

In 2004 the University of Groningen has started a long-term demographic project on a partly colourringed breeding population of Black-tailed Godwits Limosa limosa in SW Friesland, The Netherlands (read more on http://www.rug.nl/research/gelifes/ceg/_piersma/meadow-birds). Mainly from December onwards, Black-tailed Godwits leave their wintering areas in West-Africa to stopover areas in southern Iberia. Here they are confined to three main areas: Doñana NP and Extremadura in Spain and the rice fields surrounding the Tejo and Sado estuaries near Lisbon in Portugal. Resighting color marked birds during the stopover period is necessary for several reasons. Firstly, if a godwit disperses outside our study area, the chance that it will be resighted elsewhere in The Netherlands is small. Without the resightings in the stopover area, we would assume that this individual is dead and therefore underestimate annual survival. Secondly, with enough resightings in the Iberian Peninsula we can calculate seasonal survival. In other words, we can calculate in which period mortalities occur more often. Thirdly, by measuring the density of individuals with colour marks, we can monitor the population size of the western European part of the Black-tailed Godwit population. Below you will find a summary and detailed day-to-day trip report of our work in Portugal and Extremadura in 2015.