Autumn migration of soaring birds at Bosporus: validating a new survey station design

Figures & data

Table 1. A review of the studies published about autumn migration of soaring birds over the Bosporus.

Year	Period	Locations	Number of days	Raptors	Black Storks	References
1931	13 September–4 November	Büyük Çamlıca	53	13199	516	Steinfatt (1932) (cited from Nisbet & Smout 1957)
1956	14–22 September and 27 September–1 October	Büyük Çamlıca, Küçük Çamlıca	16	8448	1376	Nisbet & Smout (1957)
	15–16 and 20–22 September	Kadiköy
	15 and 21 September	Çekmece
	18 and 27–30 September	Büyükdere, Rumehilisari
	11–13 September	various parts of Istambul
	20 September	Princess Islands
1959	20 August–7 September	Büyük Çamlıca, Küçük Çamlıca	17	5396	110	Ballance & Lee (1961)
1966	14 July–8 November	Küçük Çamlıca	114	37139	6194	Porter & Willis (1968)
1969	25 August–13 October	Büyük Çamlıca	51	61640	5700	OST (cited from Arslangündoğdu (2011))
1971	13 August–4 October	Büyük Çamlıca	53	75176	7208	OST (cited from Arslangündoğdu (2011))
1972	5 August–6 October	Büyük Çamlıca, Küçük Çamlıca	63	-	4300	Bijlsma (1987) (cited from van den Bossche & Lens (1994))
1973	8 September–3 October	Büyük Çamlıca	26	-	7400	OST (Cramp & Simmons 1980)
1975	9 August–2 October	Büyük Çamlıca	50	26376	5246	OST (cited from Arslangündoğdu (2011))
1980	31 August–4 October	Büyük Çamlıca, Küçük Çamlıca	35	-	5898	Bijlsma (1987) (cited from van den Bossche & Lens (1994))
1986	21–28 September	Büyük Çamlıca, Küçük Çamlıca	8	-	5049	Franckx and Verschueren (1989) (cited from van den Bossche & Lens (1994))
1988	8 September–1 October	Büyük Çamlıca, Küçük Çamlıca Sariyer	24	58154	8781	van den Bossche & Lens (1994)
2007	1–30 September	Büyük Çamlıca	30	24622	1679	Arslangündoğdu (2011)
2008	22 September–10 October	Anadolu Kavağı, Koç Park, Büyük Çamlıca, Kadiköy	19	141844	16088	Present study

Figure 1. Map showing the exact locations of the survey stations on the Asian bank of the Bosporus.

Table 2. The complete list of species migrating at Bosporus recorded during the full study period. Individual abundances at the different survey stations present the total number of migrants observed including double counts. The overall abundances, which are corrected for double counts, are presented in the last column of the table.

	Survey station name
Species name	Anadolu Kavağı	Koç Park	Büyük Çamlıca	Kadıköy	Total (corrected)
Raptors
European Honey-buzzard Pernis apivorus	122	14	27	11	174
Griffon Vulture Gyps fulvus	30	28	2	1	55
Egyptian Vulture Neophron percnopterus	4	0	0	0	4
Common Buzzard Buteo buteo	6795	31765	12639	23133	74055
Long-legged Buzzard Buteo rufinus	2	1	19	2	24
Booted Eagle Aquila pennata	86	61	31	14	192
Eastern Imperial Eagle Aquila heliaca	0	2	1	1	4
Steppe Eagle Aquila nipalensis	0	2	0	1	3
Greater Spotted Eagle Aquila clanga	2	0	2	2	6
Lesser Spotted Eagle Aquila pomarina	17757	23 803	11829	7454	58327
Western Marsh Harrier Circus aeruginosus	6	6	32	5	49
Hen Harrier Circus cyaneus	1	1	0	0	2
Montagu's Harrier Circus pygargus	0	0	1	0	1
Pallid Harrier Circus macrourus	2	1	1	0	4
Black Kite Milvus migrans	1	8	24	9	42
Northern Goshawk Accipiter gentilis	0	0	0	2	2
Eurasian Sparrowhawk Accipiter nisus	274	438	371	374	1450
Levant Sparrowhawk Accipiter brevipes	35	112	509	1799	2455
Short-toed Eagle Circaetus gallicus	1928	1462	646	466	4242
White-tailed Eagle Haliaeetus albicilla	1	0	0	0	1
Peregrine Falcon Falco peregrinus	3	2	5	2	12
Common Kestrel Falco tinnunculus	3	0	3	1	7
Red-footed Falcon Falco vespertinus	27	18	42	18	105
Eurasian Hobby Falco subbuteo	22	10	13	12	57
Osprey Pandion haliaetus	1	0	0	0	1
Unidentified raptor Rapaces sp.	104	420	37	14	570
Total	27206	58154	26234	33321	141844
Non-raptors
Black Stork Ciconia nigra	1717	6423	3479	5197	16088

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