Autumn Report 2018
The 11th Batumi Raptor Count launched on the 17th of August 2018. We started the count with 12 volunteer counters/coordinators and ultimately 46 volunteers (43% women) from 18 nationalities joined our monitoring efforts over the course of 2 months. The number of Georgian participants was higher than during any previous season and especially the group of young falconers (sent by Flora and Fauna International) that stayed with us for 2 weeks was one of the highlights of this year. We were really moved by the enthusiasm of the group and found them a nice addition to the team – they were often the first ones to pick up approaching raptors in the sky, their ID skills were impressive and their eagerness to learn was very strong.
In the days leading up to the start of the count, during the final preparations, we could already observe several raptors moving southwards over the guesthouses. The species composition, surprisingly, was already quite diverse with nice numbers of MonPals (Montagu's/Pallid harriers) and some Booted Eagles passing. Although the first days of the count season are usually a little slow and — admittedly — can be a little boring for experienced counters, they are a good gradual start for most others. We start the count early to be able to detect changes in phenology. Well, this year's count showed the importance of that very clearly, with many days in the first week being rather enjoyable and everything but slow. Already in the first week we witnessed impressive Black Kite migration, relatively high numbers of Montagu's and Pallid Harriers and a very early Imperial Eagle. Other highlights during these first two weeks were an adult Pallas' Gull overhead and an incredible flock of 423 White Storks. This was the biggest flock seen by us in all 11 years and resulted in a day record for this species.
Ringtail harriers’ migration peaked early this year with the highest number of birds recorded in a single day already on the 8th day of the count. On the 24th of August we could enjoy more than 1300 MonPals migrating south. Amongst the Montagu’s, there were also good numbers of Pallid Harriers, many of which were still actively moulting their secondaries. This is strange as usually Pallids have undergone a full moult cycle before they start their migration. At one point we stopped recording this phenomenon, but during the first weeks of the count, this applied to the majority of immature males (in which it is easiest to detect).
Anyone who has been to Batumi knows that weather forecasts — independent of the source/model you choose to use — are mostly useless. The vicinity of the bottleneck to the mountains of the Lesser Caucasus and the Black Sea makes for weather that is incredibly hard to predict. Nevertheless, over the seasons, we had noticed that even if the morning starts with a clear sky, the intense sunlight evaporates so much water in the mountains that cloud cover from the east starts emerging latest around noon. As we burned in the sun for weeks, we learned that this was not the case this year. With no clouds, raptors can migrate over a much wider area and from our stations we often saw streams of unidentified raptors (or more specifically: ‘dots’) flying far inland and disappearing in the haze behind ‘Little Ginger’ (an important landmark). To keep our data comparable over the years, our protocol states we can only count birds that are visible through binoculars, so these birds unfortunately cannot be counted. A positive side effect of the birds flying this far and high is that they stay out of reach of many hunters' rifles.
In the evenings after the count in late August we would contemplate when the Honey Buzzard migration was finally going to show signs of peaking, but at one point we gave up. The cloudless mountains and the steady pace of migration on many days with more than 15 000 birds made us think the Honeys would not peak this season. But then, suddenly, on the 7th of September, while two of our coordinators were sleeping in Chorokhi, they still — sort of — came: 63 000 Honey Buzzards passed the transect line that day in just over 2 hours. This last boost was needed to get a decent season total of 498.405 HBs. During the season and despite many birds passing too far away to do so, we managed to age a good 25 000 Honeys. This is generally more than sufficient to entertain even the veterans and information like this is which makes the BRC data extra valuable.
One of the most enjoyable days of the season was the 10th of September, when cloudy weather and occasional light rain forced a staggering 1233 Marsh Harriers through the bottleneck, the highest number recorded in a single day by BRC so far. The challenge of ageing and sexing these birds, and the fascinating dark morph individuals, make it one of the most interesting species that passes the bottleneck. Interesting as well that day was the first burst of Steppe Buzzard migration, which – like several other species – seemed quite early compared to previous seasons. The following days could best be characterised as rather slow for this period of the season. On some days we struggled to count more than 3 000 raptors even. Some eagles, a few Crested Honey Buzzards, a massive flock of 600+ Pratincoles and very impressive migration of hundreds of thousands of Hirundines and thousands of Sand Martins somewhat made up for it.
Slow days are not what one comes to Batumi for, but they're still good for practicing and sharpening identification skills, as you can spend a little bit more time on birds than usually. These days were a good preparation for what hit us on the 18th and 19th of September, when we counted more than 130 000 raptors passing the transect line in incredibly mixed streams. Unfortunately, these mixed streams also meant that we simply didn't have the capacity to count them on species level, so we ended up counting loads of medium-sized raptors these days. Furthermore, there was an impressive wall of Black Kites moving west of station 1, which resulted in an excellent number of more than 20 000 birds counted on the 19th. In total we registered just short of 160 000 Black Kites this season. Another nice observation with regard to this species was done by our own Wim Bovens (a.k.a. Ecotourist No. 2) when he photographed a Black Kite with Israeli wing tag on the 22nd of September.
Interspersed with the mid-September streams were — finally — good days of Booted Eagles. On the 18th we counted 818 of them and another 466 on the 19th. All in all, however, this season has seen very low numbers of Booted Eagles pass through the bottleneck (only 5355 individuals – the lowest number in 7 years). We're unsure about the cause of this and are looking forward to what the next seasons will bring.
We encountered a few shockingly slow days during the end of September, with a total of 943 birds counted on the 25th and only 117 birds on the 26th. After truly hitting rock bottom, we were quickly up for an incredible spectacle on the 28th when more than 105 000 raptors passed through the bottleneck. Additionally, we observed a total of 450 Black Storks between the two stations, making it the record day for this species. Contrary to what we were expecting, most birds passed close to the coast and the Sakhalvasho station was overwhelmed not only with 50 000 Steppe Buzzards, but also with incredible numbers of large eagles. A total of over 2000 large eagles were counted on a single day, 1700 of which passed the Sakhalvasho station. Thanks to this incredible day, a.k.a. ‘the beautiful mess’, the total of raptors counted this season came very close to the million, a milestone we'd surely break in the upcoming days.
In fact, directly on the next day, after six weeks of counting, the 8000 raptors needed to pass the million were quickly counted in an early push of Steppe Buzzards. In line with this year’s ‘odd’ phenology, the million was hit relatively early this year as it usually happens in October. Passing the million couldn't happen on a better day: the scenery was great, the diversity of species was very high, we had great views of the birds and the migration was at the right pace to give plenty of time to enjoy individual birds. This marked the 7th year in a row during which we've counted more than a million raptors in a season, placing Batumi firmly amongst the best raptor migration bottlenecks worldwide.
After a fantastic finish to September, the first week of October was rather slow but FINALLY brought some rain. The rain came at exactly the right moment, a day before the EuroBirdwatch started, promising some build-up of birds to our north. After counting only raptors for such a long period of time, it is nice when you can also spend some time counting passerines and waterbirds moving through the bottleneck. Nevertheless, the raptors were a clear highlight. Especially on the 6th, we could enjoy a fantastic passage of eagles, including 11 Imperials, 59 Steppe, 68 Greater Spotted, 467 Lesser Spotted and 177 Short-toed Eagles. Unusual high-altitude migration of another 40.000 Steppe Buzzards made the day complete. Finally, we would count a total of 329.237 Steppe Buzzards this season, quite a lot more than the ~250 000 of the last two years.
The last week of the count was calm, sunny and relatively uneventful, but we had great views of the birds. Not only the continuous push of large eagles from all age classes, but also the incredible diversity of Steppe Buzzard plumages could be greatly enjoyed. Other than that, these calmer days also gave us the opportunity to finally answer the question that had been bugging counters throughout the entire season: “How long is the seemingly never-ending roll of ‘Soviet’ toilet paper”. A proper experimental set-up on Station 1, critically followed by the counters on Station 2, proved it to reach all the way from the centre of the shelter until the bend in the stairs leading up to Station 1. Quite a distance really.
Some other highlights were the 9 Imperials seen from station 1 on a single day, a very late Crested Honey Buzzard (on the 11th of October), the only Saker Falcon of the season and the early onset of migration of Common Cranes. 13th of October was particularly fruitful in this regard as our total of 143 Cranes culminated in yet another day record (within the official count period that is). Sadly, sometimes these beautiful moments are abruptly ended, as happened when two birds from a family flock, trumpeting their way south in the early morning light, were shot and dwindled down into the valley.
Usually there is plenty of rain in October, which results in a build-up of birds to our North, but with the good weather this year that was not the case. Instead, we got to see a decent more-or-less continuous passage of birds throughout the month, slowing down towards the end. On the final day of the count we still counted almost 1500 birds, but at least we did not have to fear a sudden big day right after the count had officially stopped (as happened previously with more rain in October). The continuous good weather was also not optimal for visiting the Chorokhi Delta this year as fewer birds than usual used the area as a stop-over site. Nonetheless, two counters (Filiep T'Jollyn and Jos Koopman) found a Sardinian Warbler there, which is only the second record for this species in Georgia.
Ultimately, we look back on a somewhat unusual, but very interesting and successful season. During the 11th edition of the Batumi Raptor Count we have counted 1.145.774 raptors in 1337 hours of counting (both stations combined). None of this would have been possible without the work of all volunteers involved in the project to whom we owe a big thanks! We are also very grateful for all the other people that continue to support us and make this project possible: our host families with their hospitality and delicious meals; the tourism department of Batumi; our members, donors and sponsors for their financial support; Gerard Troost and www.trektellen.nl.
GAUMARJOS to all of you!
To continue monitoring migration in the Batumi bottleneck, we rely on the support of many volunteers, our members and donators. Want to support our work?