CROW
Every spring and autumn, millions of birds migrate over our country. They mainly do this at high altitudes and at night, making this phenomenon largely invisible to us. But not for weather radars! The CROW project (acronym for Communicating RAVen to the Outside World) is a BELSPO funded initiative to exploit the full potential of the RMIB’s bird detection capacity acquired in a previous BELSPO project (RAVen, BR/154/PI/RAVEN).
In a collaborative effort of the Open science lab for biodiversity at INBO and the Royal Meteorological Institute of Belgium, a web application has been developed allowing anyone to view bird migration in real time across the Benelux. The development of the website was co-supervised by the Royal Belgian Institute of Natural Sciences (RBINS) and financially supported by the Federal Science Policy BELSPO.
At the RMI, we noticed that the occasional news reports about this bird detection often attracted a lot of interest from the general public. Although the bird detections of a large number of European weather radars, including the Belgian ones, have been made available for some time as open data in the data repository of ENRAM/GloBAM, the reading and visualisation of these data remained mostly specialist work. With the launch of the CROW website, RMI and INBO want to make bird detection by weather radar accessible to everyone interested in the fascinating phenomenon of bird migration. The development of the web application has been completely transparent and it is available as open source software, making it portable and reusable for similar initiatives. Moreover, the bird detection data feeding this interactive portal are all pubished in real time in RMI's open data portal.
The CROW web application, showing the Helchteren radar for a three days period around February 21, 2021. Due to the exceptionally warm weather during that period, spring migration started earlier than normal. From the figure it is also clear that the most intense migration always takes place in the first half of the night. The birds reach heights of up to three kilometers (and sometimes even more).