Raptor Migration Report Autumn 2012
After 5 years monitoring of raptors at the Batumi bottleneck, we have surpassed all expectations this autumn. We tallied ONE Million migrating birds of prey passing our two count stations along the eastern Black Sea route. Here is the report on this great bar hitting event!
The beginning of the autumn season started promising with a good amount of Honey Buzzard. The first peak day was the 30th of August, when we counted over 100,000 raptors of which 99,038 Honey Buzzards. This overwhelming day was already above our previous day record and we celebrated well with local dishes, drinks and a beach party. Only 4 days later, a seemingly never ending stream of Honey Buzzard took our full concentration from dawn till dusk. It was more than overwhelming and completely out of our imagination. The previous record was entirely shredded with a new day-record of 179,342 Honey buzzards!
From this day on our expectations have grown and we counted eagerly from sunrise till 1 hour before sunset. At the 2nd of September we have counted 1,653 Montagu's harrier, after an amazing flight of 4,364 harriers on one day! The bulk was passing just in the first hour after sunrise. It was incredible and from this on day everybody tried to be the first on the station to catch up with the early Harriers.
From the middle of September, the numbers of Honey Buzzard decrease, and the migration builds up towards the peak of Steppe Buzzards and Eagles. Peak day for the Steppe buzzards happened on the 24th of September (56,527), together with a good flow of Aquilas (496). At the end of September, the total count tailed 956,267 raptors, and to reach the one-mil-milestone seemed only one good day away. From then on we carried two bottles of Champagne to the stations – every day in full expectation to count the 1 Million bird. But – visible migration became low. High pressure systems were opening the mountainous passage for the raptors and many of them passed the Caucasus apart from our count stations. At the same time our powerline survey team was counting raptors along another transect line up to 50 km inland. They sent us messages with nice migration of Steppe Buzzards and Eagles. But in Batumi, the sunny sky was empty of birds and clouds. Only a couple of thousands passed our stations and the counters were waiting and waiting for 9 more days. A strong rain front had struck the region and lasted for 3 days. We all knew that, as soon as this front would calm down, a migration wave would push through. And so it happened.
The next morning the sky was clear with still some clouds hanging over the higher mountains. On station two the number of migrants became higher and higher as the day went by. Folkert de Boer was counting a large stream of Steppe Buzzard in the East while we continuously checked the totals of the day and then it was clear. We have just reached the 1 Million counted raptors at Batumi for the first time of the monitoring program on the 10th of October 2012! (see video)
With this bar, the Batumi Raptor Count can be added to the list of the raptor watchpoints in the world that has counted more than 1 Million raptors in one season.
Veracruz River-of-Raptors, Mexico in Autumn: 5,200,000 (Bildstein 2006)
Panamana, > 3 Million (historical day record)
Kéköldi Indigenous Reserve, Costa Rica Autumn: av. 1,950,000 (Bildstein 2006)
Eilat, Israel in Spring: av. 827,000 (max >1.200.000 Shirihai & Christie 1992)
We'd like to thank all participants of the BRC since 2008 including all counters, sponsors, eco-tourists, partner-organisations and the local families for their support. You made it happen that this important bottleneck for raptors has been well monitored since 5 years!
Bildstein K. 2006 – Migrating Raptors of the world. Their ecology and conservation, Cornell University Press
Shirihai, H. & Christie, D.A. 1992. Raptor migration at Eilat. Brit. Birds 85:141-186.