Raptor migration past Batumi

In 1999 a study into the importance of a migratory bird flyway along the Georgian Black Sea coast (in the Caucasus) was initiated by Erwin van Maanen et al. (1998; 2001a & 2001b) as part of the development of a biodiversity center in the harbor town of Batumi and the advancement of nature conservation research and management in the Caucasus. This was achieved under the Black Sea Environmental Program and in collaboration with the Georgian Center for the Conservation of Wildlife (GCCW).

The study was based on earlier accounts on the importance of raptor migration and the shooting and trapping of raptors in the foothills along the eastern Black sea coastline of Turkey by Gernant Magnin (1989). The initial study on the Georgian side of the border revealed that the coastal fringe of the Adjaria-Imereti mountain range, in a north-south trajectory, is indeed of great importance as a migratory route and bottleneck for a great diversity and tremendous volume of birds, in particular birds-of-prey. In terms of volumes and diversity of birds, it exceeds other well-known passageways along the Mediterranean, like Gibraltar and the Bosporus (Van Maanen 1998; Van Maanen et al. 2001b).

The Batumi bottleneck is part of a larger flyway across the Trans-Caucasus, with other but smaller concentrations of, or stowed bird migrations across inland regions. These are dictated by mountain ridges and valleys, including for example the Zekari pass in the lesser Caucasus and the Dariali Gorge in the Greater Caucasus (Van Maanen et al. 2001b).

The Black Sea in combination with the lush subtropical foothills, which in the hot and humid fall produces warm updrafts or thermals, present an energetically ideal gateway for passive migrants like soaring birds-of-prey (for example thousands of Honey-buzzards Pernis apivorus), but also to countless more active flyers like Accipiters, harriers and falcons and other birds like rollers, bee-eaters, orioles, nightjars and quails. Over the coastal Black Sea and the lowland plains, including Kolkheti Wetlands, a wide range of other birds may be observed passing low overhead or resting; including rarities.

A bottleneck of great importance previously unknown

Actually, the significance of the migratory flyway was already known and reported during the Soviet era (Abuladze 1994 & 1997) and even before (Villkonskii 1897). For a long time it remained unknown and unappreciated in the West until more European birders started to visit and explore Georgia in the last five years. Before that several conservation initiatives were undertaken by the GCCW in partnership with BirdLife International, facilitated by Erwin van Maanen from EcoNatura.

This included the initiation of systematic bird counting, the production of educational materials – including a beautifully illustrated Georgian raptor identification guide (Gálvez et al. 2005) – and motivation for the protection of raptors to the environmental authorities. The first edition of the raptor identification guide for the Caucasus was produced with illustrations by Dutch bird artists, including Erik van Ommen.

More systematic, organised and well-supported counts by a group of young Belgian ornithologists started in 2008 and revealed to date that an estimated million migratory birds pass the Batumi bottleneck during the fall (Verhelst et al, 2011; → Batumi Raptor Count where the current tally is kept). In spring the number of birds through the Batumi bottleneck is much less, perhaps due to alternative and more diffuse routes across the Caucasus from wintering to breeding grounds.

Very little is known about the origins of many of the bird species, particularly those from the Eastern Palearctic. We do know for instance, from recovery of rings, that Honey-buzzards from Fenno-Scandinavia pass through.

However, there is much more to learn about the biogeography of the birds and the differential migration of cohorts of age and gender. New techniques like the analysis of stable isotopes (isotope ecology) and satellite telemetry may present novel research opportunities. This may reveal new information about migratory biology, as well as the range and population ecology of species, not to forget new insights into the state of the environment with respect to land use changes and the effects of climate change within the Western and Eastern Palearctic.

The views of the raptor migration in the foothills of the Adjarian Mountains, including hilltops like in the village area of Machindjauri and Orta Batumi, just north of the harbor city, are nothing less than spectacular. For example, on 24 September 2012, in Orta Batumi and close to the Mtirala National Park, during a warm clear day just after a few days of rain, hundreds of Honey buzzards, steppe buzzards, Black kites and Marsh harries could be seen rising on the thermals and then gliding south; wave after wave. Among them tens of Pallid harrier, Booted eagle, Short-toed eagle, Lesser-spotted eagle, Levant sparrowhawk, kestrel and an occasional Red-footed falcon. Specialties during that day were several Imperial eagles (a group of three), Long-legged buzzard and a Dalmatian pelican (!).

The trapping and shooting of raptors

Unfortunately the joy of watching the continuous flow of migratory birds in the Batumi foothills and in the Chorokhi can be spoiled by hunters, who shoot a large number of low flying raptors of all sorts, and also other migratory birds. In fact they shoot at everything flying within range, mostly for sport and fun.

Above – Left: Hunter with a Steppe buzzard Buteo buteo vulpinus he just shot (Makhindjauri, fall of 1999). Right: Remains of a shot Honey-buzzard at Makhindjauri in the fall of 2012.

Some hunters eat Honey-buzzards Jajia as a delicacy, but the other raptors Irao are regarded as distasteful.

Beside the hunters in the hills are the falconers, who trap juvenile Eurasian sparrowhawks and goshawks to train for falconry activities in the late fall (Van Maanen et al. 2001). The raptors are caught using a blinded Red-backed shrike as lure behind a sail-shaped net.

Occasional by-catch such as Levant sparrowhawks, kestrels and hobbies, and even a disproportional number of rarities or less-tempted birds like Pallid, Ferruginous harrier and Short-eared owl, are regarded as useless and killed to feed the birds kept for falconry, as their remains around the trappers huts show. Only rarely a highly prized Peregrine or Saker falcon is caught. There is also talk of a very rare and special “white falcon”, which could refer to a pale version of a Tundra peregrine falcon Falco peregrinus calidus.

Falconry activities include mainly the hunting for quails and corncrakes and participation in several falconry competitions.

Falconry is an age-old tradition in Georgia, shared with counterparts on the Turkish coastline from Sarpi to around Trabzon; where, however, the mistreatment of raptors is perhaps curtailed these days instead of unregulated like in Georgia.

It is estimated that between 3000-7000 raptors die (Van Maanen et al. 2001a and pers. comm. J. Janssen) from the shooting, trapping and falconry each year in Georgia, not counting the birds that are taken from nests in inland Georgia, including falcons, eagles and vultures.

Unfortunately and despite the intended accession to the European community, the ban on, or rather the enforcement of environmental law regarding the protection of migratory birds and other biodiversity or natural assets, still needs to be effectuated in Georgia, and on many other fronts as well.

References

Abuladze, A. (1994) Birds of Prey in Georgia in the 20th Century. In: Meyburg, B.-U. and R.D. Chancellor, eds. Raptor conservation today. World Working Group of Birds of Prey. London: Pica Press.

Abuladze, A. (1997). Status and conservation problems of raptors in Caucasia. Newsletter World Working Group of Birds of Prey 26/27: 15–19.

Fenech, N. (1992) Fatal flight: the Maltese obsession with killing birds. London: Quiller Press.

Gálvez, R.A., L. Gavashelishvili & Z. Javakhishvili 2005. Raptors and owls of Georgia. Buneba Print/ Georgian Centre for the Conservation of Wildlife, Tblisi, Georgia.

Maanen, van E. 1998. Roofvogeltrek naar Afrika en de gevaren onderweg (Raptor migration to Africa and the dangers underway). De Takkeling 6(2): 134-140.

Maanen, E. van, I. Goradze, A. Gavashelishvili & R. Goradze 2001a. Trapping and hunting of migratory raptors in western Georgia. Bird Conservation International 11:77-92.

Maanen, E. van, A. Gavashelishvili, I. Goradze & R. Goradze 2001b. Ecologie, aantallen en bescherming van roofvogels in Georgië (Ecology, numbers and protection of raptors in Georgia). De Takkeling 9(2):118-134. (Journal of the Dutch Working Group on Birds of Prey).

Magnin, G. (1989) Falconry and hunting in Turkey during 1987. Cambridge, U.K.: ICBP (Study Report 34).

Verhelst B. Jansen J. & Vansteelant W. 2011. South West Georgia: an important bottleneck for raptor migration during autumn. Ardea 99:137-146.

Villkonskii, F.V. 1897. Ornithological fauna of Adjaria, Guria and northeastern part of of Lazistan. Materials  on the study of Fauna and Flora of the Russian Empire. Journal of the Russian Zoological Society 3:1-121.