Spring migration of Black-tailed Godwits in Iberia 2014:Mission Report Sado, Tejo and Extremadura

In 2004 the University of Groningen has started a long-term demographic project on a partly colour-ringed breeding population of Black-tailed Godwits Limosa limosa in SW Friesland, The Netherlands(read more on http://www.rug.nl/research/animal-ecology/research/piersma-lab/meadow-birds).From half December onwards, Black-tailed Godwits leave their wintering areas in West-Africa to theirstopover areas in southern Iberia. Here they are confined to three main areas: Doñana NP andExtremadura in Spain and the rice fields surrounding the Tejo and Sado estuaries near Lisbon inPortugal. 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 inThe Netherlands is small. Without the resightings in the stopover area, we would assume that thisindividual is dead and therefore underestimate annual survival. Secondly, with enough resightings inthe Iberian Peninsula we can calculate seasonal survival. In other words, we can calculate in whichperiod mortalities occur more often. Thirdly, by measuring the density of individuals with colourmarks, we can monitor the population size of the western European part of the Black-tailed Godwitpopulation. Below you will find a summary and detailed day-to-day trip report of our work inPortugal and Extremadura in 2014