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09 December, 2013

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

05 December, 2013

Migration Update Thoolakharka (Nepal)- 4 Dec, 2013

Bearded Vulture ( Sub-adult)
Last Year we stopped to counting by this date however this year it seems the migration will goes more days. In the last days we had continue migration of Steppe Eagles, Himalayan Vulture and Cinereous Vulture. It was expected to go down the number of migrating eagles with the changing of weather into more sunny however we are having around 200 eagles per day. The number of Himalayan Vulture migration is also still high today around 220 vultures. Due to the high intensity of sun the air is more dry and no cloud forming near to the Himalayas so the raptors are very close to the Himalayas and creating difficulties in observation. Due to the high intensity of sun the rocky slope of the Himalayas can create lot of thermal so the raptors prefer this route. most of the eagles are Adults and sub-adults in this time. Local Peregrine, Besra, Sparrowhawk, Bonelli's, Mountain Hawk-eagle and Black eagles area almost every day around us and make the day more exciting and perfect. The summery of the season 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 8274
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 3
Unidentified Eagle 8 1 2
Black Kite 324 40 345
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 2014
Cinereous Vulture 73 11 48
Griffon Vulture 85 12 42
Unidentified Vulture 3 1 1
Unidentified Raptor 79 3 18
Total         9,754             1,238         12,851

29 November, 2013

Migration Update Thoolakharka (Nepal)- 29 Nov, 2013

Peregrine Falcon (Spp. peregrinator)



In Nepal 20 and 21 Nov were two big days for Steppe Eagle migration and approximately 2150 eagles were passed on those two days. The weather is back to normal like last year i.e.  sunny in the morning and more cloudy in the afternoon. Previous observation says that if it is cloudy over the Himalayas the eagles pass more south however we didn’t find so because lot of eagles were passing inside the clouds during the peak days. We found little change in wind direction (let’s say by 100) could enough to shift the migration train i.e. if the wind is more north east the migration of eagles can observe overhead in Thoolakharka and little bit southeast wind can push the birds close to Himalayas. Now I am also observing less and less eagles near to the Himalayas this might be due to more saturated air close to the Himalayas by this time or might be any other weather cause like enough cold. Therefore most of the eagles come overhead to the watch site. Now most of the hawk watchers back to their home and Robert is photographing raptors in the eastern Nepal in Koshi Tappu Wildlife Reserve, therefore the watch site is very silent. There was no movement after 1 pm although having good weather for the migration (only 57 birds today). This observation indicates we are towards the end of migration season, in the morning also birds do not wake up before 9 am. Other raptor in the last week included Vulture (Himalayan, Griffon, Cinereous), White-tailed Eagle (very rare and for the first time here) and Greater Spotted eagle (rare). In the coming week I expect few steppe eagles (<50 or even less birds per day), Himalayan vulture, Griffon vulture, Cinereous vulture etc. Migration summary of the season is given in the table.

Species
2012 Total
Highest Daily Count
Total Count till date


Oriental Honey-buzzard
381
60
640

Common Buzzard
180
12
100

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
7442

Booted Eagle
155
7
107

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
29

Mountain Hawk-eagle
1
2
6

Golden Eagle
7
1
3

Unidentified Eagle
8
1
2

Black Kite
324
40
324

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
317

Unidentified Falcon
21
2
14

Egyptian Vulture
24
6
40

White-rumped Vulture

16
127

Himalayan Vulture
1270
140
1450

Cinereous Vulture
73
5
31

Griffon Vulture
85
14
47

Unidentified Vulture
3
1
1

Unidentified Raptor
79
3
16

Total
        9,754
            1,238
        11,412