231 
1921.] Velocity of Migratory Flight among Birds. 
Note E. Observations taken in southern Palestine by stop-watches at 
440 yards distance and timing birds flying between two 
points aligned by posts. 
Note F. Observations made near Montreuil in north-east France by 
means of theodolites on a 1420-foot base and small 
balloons to ascertain the velocity of the wind at the 
altitude of flight. All birds believed to be on migration. 
Species. 
Place. 
Ground 
speed: 
Remarks. 
Ravens ... 
S. Palestine. 
m.p.h. 
32-39| 
Eleven observations. Birds pass¬ 
Rooks ... 
N.E. France. 
*45 
ing to and from roosting. Wind 
calm. Altitude of flight 310- 
840 feet. See note D. 
Taken with air-speed indicator 
Rooks ... 
do. 
39 
from aeroplane. (R.A.F.) 
Altitude of flight 1740 feet. 
Rooks . 
do. 
38 
Wind 17 m.p.h. side. See 
note F. 
Altitude of flight 2120 feet. 
Rooks and Jack¬ 
do. 
40 
Side wind of 31 m.p.h. See 
note F. 
Altitude of flight 690 feet. 
daws. 
Rooks . 
do. 
39i 
Slight side wind on ground. 
See note F. 
Altitude of flight 2008 feet. 
Hooded Crow. 
Rossitten. 
31-5 
Head wind 12 m.p.h. See 
note F. 
Average of observations on 
Jackdaw. 
do. 
39-6 
20 birds. ( Thienemann .) 
Average on several birds. ( Thie - 
Chough . 
Quetta. 
Hi 
nemann.) 
Very strong head wind. See 
Starling' . 
do. 
43-49 
note A. 
Thirteen observations. Wind 
Starling . 
S. Palestine. 
45-48± 
calm. See note A. 
Twenty-two observations. Alti¬ 
Starling . 
Rossitten. 
46-5 
tude of flight 120-325 feet. 
Wind calm. See note D. 
A single bird. ( Thienemann .) 
Rose-coloured 
Quetta. 
38, 401 
Two observations. Weather 
Starling. 
Finches . 
Rossitten. 
33 
calm. See note A. 
Six observations. . (Thiene - 
mann.) 
* Air-speed. 
