Mind great reed warblers with data loggers!

Mind great reed warblers with data loggers!,

In collaboration with Vogelbescherming (Birdlife NL), University of Groningen, Sovon, Vogelwacht Utrecht, Martin Poot Ecology and various nature management organizations in the Netherlands such as Natuurmonumenten, Waternet and Plassenschap Loosdrecht, we investigate the causes of the enormous decline of the great reed warbler in the Netherlands. Habitat quality is insufficient in the Netherlands but we cannot exclude bottlenecks during migration or in African staging areas. So we like to identify the stop over and staging areas of the last birds of the Dutch breeding population.

In 2016, we have equipped seven great reed warblers in the Netherlands with geolocators. We recaptured 4 of these in spring 2017. This is a very high percentage, but still a limited sample. That is why we have given 15 extra birds a data logger this spring 2018 in the remaining breeding areas. This means that it is possible GRW might me found or trapped elsewhere in Europe or Africa.

If you catch a bird this summer or fall, you can leave the datalogger on the bird (the probability that there are still birds of 2016 with a logger is close to zero). If you catch a bird with a datalogger next spring 2019 (or afterwards) it would be nice if you could remove it and let me know that you have one in your ring case! You can very simply cut the wire of the leg-loop harness close to the logger. The birds with data loggers also have a black color ring. But there are also birds with color rings flying around without a data logger. So be sure to check the back of every great reed warbler that you catch!

For more information (in Dutch and English) about the background of the project and interim updates about the research see:

https://www.vogelbescherming.nl/bescherming/wat-wij-doen/natuurgebieden/moerassen/grote-karekiet

and

https://www.facebook.com/search/top/?q=large%20karekiet%3A%20bescherming%20en%20onderzoek

Jan van der Winden Ecology
jvdwinden@hetnet.nl

Interessante, porque em Portugal também me parece que houve uma enorme quebra populacional nesta espécie.