First BRC publication in Russian Raptors Conservation journal
We are proud to announce the publication of our first Russian language paper in the Russian Raptor Research and Conservation Network’s (RRRCN) journal ‘Raptors Conservation’.
The cover of Raptors Conservation features a stunning juvenile Short-toed Eagle giving onlookers in the Batumi bottleneck a close look.
Spearheaded by Olga Zaytseva, the new publication is a follow-up to our British Birds article, providing both a translation to the Russian-speaking community as well as a review of likely breeding areas of migrants passing Batumi and a comparison between Russian breeding population estimates and numbers of migrants in Batumi.
Despite ongoing conflict in our flyway, we are proud to feature on the cover of Raptors Conservation journal. It truly is an important milestone for us in connecting with the researchers that work in the breeding areas of most of the raptors that we are monitoring every autumn in Georgia.
From counts to knowledge: research in progress at BRC
While Batumi Raptor Count has hosted student internships and dissertations for many years, our popularity among students of bird migration rose substantially in recent years, to the point that our Research Coordinator has been struggling to accommodate all requests. Strap in for a overview of what research is being conducted at BRC right now.
Comparing relative timing of different species of raptors between the Pyrenees (red) and the Caucasus (blue)
First and foremost, after the successful completion of our last spring count earlier this year our new chairman Tohar Tal will soon be submitting a paper on the first full-season description of Batumi spring raptor migration to a peer-reviewed ornithological journal. Now a student at University of Groningen (NL), Tohar will describe spring abundance and timing of raptors in Batumi for the first time, and also contrast seasonal flight paths through the bottleneck.
The spring data are also being included in a study of sex differences in seasonal migration timing of Pernis and Circus species at Batumi, led by Marc Heetkamp. Marc completed a literature study on this topic as part of his education at the University of Utrecht (NL) last spring, and is now proceeding with analyses.
Beyond using just count data, Elien Hoekstra is using digital photography to study the moult of migrant raptors. Elien got a great grade for her dissertation at Van Hall University of Applied Sciences this year (NL). Now a MSc student at Wageningen University (NL), Elien aspires to publish her interesting results in a reputable ornithology journal.
In addition to the more advanced projects above, several students have initiated new projects after participating in this year’s autumn count. Two of them are actually combining BRC data with high-quality count data of other sites to look at larger scale patterns in migration.
For example, some species like Black Kite are known to migrate much earlier in the western than the eastern flyway (Fig1, top panel). Michaëla Berdougo, based at Lund University (SW), obtained data from count sites in the French and Spanish Basque country — situated at the same latitude as Batumi — to investigate how common it is for different (sub) species to show differences between western and eastern flyways, and why this may be.
Isaac West, geography student at the University of Cambridge (UK), is using historic count data from SPNI in Israel from 1990-2013 and BRC data from 2011-2022 to study whether raptor migration timing has shifted in our flyway in response to climate warming. Against our expectations, his results indicate that autumn raptor timing has changed very little over the past 3 decades!
Zooming in on the Batumi bottleneck again, Joachim Pintens completed a full-season internship as assistant coordinator, and is now proceeding with a study of Booted Eagle migration for a BSc. Dissertation at Ghent University of Applied Sciences and Arts (BE). He is comparing the seasonal abundance and timing of dark morph and light morph individuals, which may offer clues about the geographic origin of these birds.
Number of flocks of different sizes recorded at BRC during standardized daily time periods (sunrise + 1h to sunset – 2h) during 11 autumn counts since 2011.
Finally, our long-time president Dries Engelen is preparing a descriptive study of European Roller migration at Batumi. The abundance, and especially the occurrence of loose but large flocks in Batumi (as many as 240 birds together, Fig2) seems to be rather unique in the world. After consulting many specialists and old literature from across the species range we’ll be writing up our findings soon.
From Georgia to Tanzania: the secret ways of the Levant Sparrowhawk
by Dries Engelen & Triin Kaasiku
Levant Sparrowhawk ‘Dudu’ shortly after being released with a GPS/GSM transmitter. Photo by Pelle Mellov.
Young falconers ringing Eurasian Sparrowhawks. Photo by Gizo Seskuria.
After 3 months of flying from woodland to woodland, often following river valleys and making longer stops on the way, ‘our’ Levant Sparrowhawk ‘Dudu’ is now sending data from the savannahs of Tanzania! This is the second time a Levant Sparrowhawk’s migration has been followed to Tanzania, a previously unknown wintering site for the species. All in all, a fantastic result for the work that BRC has carried out with the young falconers and Fauna & Flora International over the last 5 years.
After introducing the young falconers to raptor ringing in 2021, we were thrilled to successfully apply for the William A. Burnham Memorial Fund of the Peregrine Fund at the beginning of this year which allowed us to get some tags and take things to the next level. Our search for lightweight GPS/GSM transmitters brought us to Hunan Global Messenger Ltd, who were excited about our project and decided to sponsor us with some extra tags still! After all these years of talking about it, and laying out the ground work with the help of the WWF INNO-fonds, we were finally going to Georgia to bring together traditional falconry practises with modern tracking technology to further study the migration of the Levant Sparrowhawk. With experienced tagger Pelle Mellov joining the BRC and FFI field team nothing could go wrong anymore, right!? Well…
Upon arriving by the end of August, count coordinators told us that most raptor species seemed to be delayed this year. Even after 14 years of counting, we learned that migration timings are not as fixed as we have believed them to be. On top of being late, weather conditions were such that birds migrated high through the blue skies, far out of reach for our young falconers to lure them down into their nets. We tried everything, while moving between our host families in Poti and Sakhalvasho, to try and find the best trapping locations in these sub-optimal conditions. We even set up a few mist nets in parallel to the trapping efforts of the young falconers, all of it to increase the chances of catching a Levant.
Young falconer waiting for Levant Sparrowhawks to arrive. Photo by Dries Engelen.
Deploying the tag on Levant Sparrowhawk ‘Dudu’. Photo by Gizo Seskuria.
Then finally, in the afternoon of the 1st of September our waiting paid off! We deployed our first tag (4.5 g) on a juvenile bird, and nicknamed it ‘Gizo’. The excitement gave the entire team a boost, providing all of us with energy needed to spend another two weeks hoping for trapping conditions to improve… Another 10 days passed before we finally caught a second bird, on September 11th. Again a juvenile, this time nicknamed ‘Dudu’, after one of our team members who ended up fighting (and overcoming) a sudden serious illness. We kept on trying for some more, but unfortunately the weather was just not on our side this year, and as the days passed, so did the Levants… high up in the skies, or further east over the mountains… until eventually Levant Sparrowhawks got replaced by Eurasian Sparrowhawks and our chances of trapping more individuals were over…
We returned home with mixed feelings, still having 6 tags left, and not getting regular updates from Gizo anymore either. Thankfully Dudu was still sending us data, allowing us to track its journey into Africa, until by mid-October Dudu too, stopped communicating. Two months passed, and we had pretty much lost hope, until suddenly, out of the blue, Dudu sent its greetings from Tanzania! Apparently, it spent a month in South Sudan, out of reach of GSM coverage, after which it continued south passing Lake Victoria and arriving to the plains of Tanzania. The tag is still in great condition and Dudu is communicating with us again on daily basis.
This was such a rewarding result that any doubts we had about continuing this work next year, were instantly replaced with enthusiasm and motivation to return to Georgia once more and deploy the six remaining tags, nicely coinciding with the 15th birthday of BRC.