July 3rd, 2024
Making invisible bird migration visible
Mapping bird migration with weather surveillance and dedicated bird radars
For the municipalities of Amsterdam, Diemen and the province of Noord-Holland, we have mapped bird migration using a variety of radar techniques. In particular, we have addressed flight altitudes of birds and have mapped — for the first time — the aggregated spatial distribution of birds while on migration through the province of Noord-Holland. The maps we have developed can aid in the spatial planning of nature-inclusive wind energy in the region. We have made the maps available as open data with an accompanying report full of illustrations.
Self-published — http://doi.org/10.21942/uva.25983196
Dec 7th, 2023
Formidable fireworks
Millions of birds lose precious energy due to fireworks on New Year’s Eve
By combining weather radar data and bird counts, we have quantified how many birds take off immediately following fireworks, at what distance from fireworks this occurs and which species groups mainly react. We have recently published this in Frontiers in Ecology and the Environment.
Fireworks disturbance across bird communities
Bart Hoekstra, Willem Bouten, Adriaan Dokter, Hans van Gasteren, Chris van Turnhout, Bart Kranstauber, Emiel van Loon, Hidde Leijnse, Judy Shamoun-Baranes
Fireworks are important elements of celebrations globally, but little is known about their effects on wildlife. The synchronized and extraordinary use of fireworks on New Year's Eve triggers strong flight responses in birds. We used weather radar and systematic bird counts to quantify how flight responses differed across habitats and corresponding bird communities, and determined the distance-dependence of this relationship. On average, approximately 1000 times as many birds were in flight on New Year's Eve than on other nights. We found that fireworks-related disturbance decreased with distance, most strongly in the first five kilometers, but overall flight activity remained elevated tenfold at distances up to about 10 km. Communities of large-bodied species displayed a stronger response than communities of small-bodied species. Given the pervasive nature of this disturbance, the establishment of large fireworks-free zones or centralizing fireworks within urban centers could help to mitigate their effects on birds. Conservation action should prioritize avian communities with the most disturbance-prone, large-bodied bird species.
in Frontiers in Ecology and the Environment — https://doi.org/10.1002/fee.2694
August 1st, 2020
Batumi Raptor Count
From migration counts to conservation in a raptor flyway under threat
The August 2020 issue of British Birds contains a long paper on the Batumi Raptor Count. It summarises the 12-year history of BRC, provides a detailed description of a typical autumn migration season, and outlines some of our education and conservation plans for the future.
Batumi Raptor Count: From migration counts to conservation in a raptor flyway under threat
Bart Hoekstra, Johannes Jansen, Dries Engelen, Folkert de Boer, Rafa Benjumea, Jasper Wehrmann, Simon Cavaillès, Triin Kaasiku, Diego Jansen, Pia Fetting, Aki Aintila, Wouter Vansteelant
Since 2008, the Batumi Raptor Count project has monitored the autumn migration of raptors at Batumi, on the eastern shore of the Black Sea in southwest Georgia. What started as an expedition by young birders has become an invaluable project for monitoring raptor populations in the little-studied east African–Palearctic flyway. Autumn raptor migration through the Batumi bottleneck is notable for globally important concentrations of Honey-buzzards Pernis apivorus, Montagu’s Circus pygargus, Pallid C. macrourus and Marsh Harriers C. aeruginosus and accounts for at least 1% of the global breeding population of ten raptor species. By stimulating migration-based ecotourism, the project has had a significant economic impact on the communities where the count stations are located, which has increased societal and political support to reduce the widespread illegal raptor shooting in the region; it has also developed an important educational role for schoolchildren and older students. This paper summarises the 12-year history of the Batumi Raptor Count, and provides a detailed description of a typical autumn migration season. The project aims to expand its education and conservation remit while continuing to monitor one of the world’s biggest raptor migration bottlenecks.
in British Birds — https://britishbirds.co.uk/content/batumi-raptor-count