Final Update - Raptor Migration Study in Thoolakharka (Nepal)- autumn 2013

Steppe Eagle (Aquila nipalensis) - first plumage or juvenile bird

The autumn migration study of the raptors in Thoolakharka Nepal has been completed from 8 Dec 2013 that was started from 15 September (total of 85 days). In total we have counted 35 species of migrating raptors ( 13,485 individuals) with highest number of 8684 Steppe Eagles. Other migrant raptor species were 11 species of Eagles, Five species of Vultures, Six species of Falcons, Three species of Buteos, Two species of Accipiters, Four species of Harriers, Osprey (Pandion haliaetus), Oriental Honey-buzzard (Pernis ptilorhyncus), Black kite (Milvus migrans) and Black-eared Kite (Milvus lineatus). Steppe Eagle migration was started from 7th October and continued till last of the season with highest number of 308 Steppe eagles per hour in 21 Nov and highest daily count of 1102  eagles on 20 Nov. In Thoolakharka watch site approximately 57% (4967) Steppe Eagles passing overhead were aged; among them we identified and counted 19.4% (964) Juveniles, 36.6% (1816) Sub-adults and 44% (2187) adults. This age ratio indicates the healthy population of steppe eagles. Overall number of migrating raptors increased this year by around 3,500 and we conclude this is due to good weather condition and rain around the breeding area that makes favorable conditions for prey species.  Overall, the best time to see the most species in one day was early November – but different species peak at different times during the autumn migration.  For example, Amur Falcon (Falco amurensis) and Lesser Kestrel (Falco naumanni) migration peaked from approx. 20 October through 5 November, Oriental Honey-buzzard peaked from 25 to 31 October, Himalayan Vulture (Gyps himalayensis) peaked from 15 to 30 November.  On the other hand, the largest movement of Steppe Eagles occurred in mid-November to third week.  Among the 35 species of migrating raptors one species (white-rumped vulture) is critically endangered, two species (Egyptian vulture and Saker falcon) are endangered, Three species (Pallas’s fish eagle, Imperial eagle, Greater spotted eagle) are vulnerable and two species (Cinereous vulture and Pallid harrier) are near threatened in the IUCN list. Beside the 35 migrating species 7 additional non migratory species (including 2 critically endangered species) were regularly seen in the area.

Detail  about migrating species and number with highest daily count and comparison with last year count is given below.  

Species	2012 Total	Highest Daily Count	Total Count till date
Oriental Honey-buzzard	381	60	642
Common Buzzard	180	12	102
Long-legged Buzzard	4	3	11
Upland Buzzard	4	2	8
Unidentified Buteo	3	1	3
Northern Sparrowhawk	107	7	110
Northern Goshawk	3	4	10
Unidentified Sparrowhawk	9	1	1
Steppe Eagle	6597	1102	8684
Booted Eagle	155	7	109
Short-toed Eagle	2	1	2
Crested Serpent-eagle	26	1	5
Pallas's Fish Eagle	2	1	1
White-tailed Eagle	0	1	2
Imperial Eagle	0	1	1
Indian Spotted Eagle	3	0	0
Greater Spotted Eagle	3	1	2
Bonelli's Eagle	13	4	30
Mountain Hawk-eagle	1	2	6
Golden Eagle	7	1	4
Unidentified Eagle	8	1	2
Black Kite	324	40	356
Black-Eared Kite		22	153
Osprey	3	2	5
Hen Harrier	19	2	9
Eastern Marsh Harrier	0	1	1
Pallid Harrier	1	1	2
Pied Harrier	0	1	1
Unidentified Harrier	3		0
Peregrine Falcon ssp. calidis	29	2	18
Saker Falcon	5	1	1
Northern  Hobby	80	33	211
Amur Falcon	78	24	90
Lesser Kestrel	66	14	69
Common Kestrel	83	29	318
Unidentified Falcon	21	2	14
Egyptian Vulture	24	6	40
White-rumped Vulture		16	127
Himalayan Vulture	1270	221	2215
Cinereous Vulture	73	11	57
Griffon Vulture	85	12	44
Unidentified Vulture	3	1	1
Unidentified Raptor	79	3	18
Total	9,754	1,238	13,485