501 
1921 .] Bird’'Migration by the Marking Method. 
same estate) during their first winter, one in the same district 
in the summer of 1912, and the other two as follows :— 
Case 367 at Gottrup, Aalborg, northern Denmark, on 18 
July 1911, and Case 738 at Osterley, Upland, Sweden 
(110 km. north of Upsala), on 10 August 1913; the 
former was described as a mother in charge of a large 
brood of ducklings. 
Of 31 hand-reared ducklings marked at Dunecht House, 
Aberdeenshire, in 1911, 13 were recovered in the same 
district (11 on the same estate) in their first season 
(9 on 31 August, 2 in November, 1 in December, and 
1 in January). Of 67 hand-reared ducklings marked at 
the same place in 1912, 38 were recovered in the same 
district (36 on the same estate), 35 in their first season 
(31 in September and October, 2 in November, and 2 
in December), and 3 in their second season (1 in June 
with a brood of young, 1 in October, and 1 in January). 
Of 11 marked at the same place in 1913 none was 
recovered. Of hand-reared ducklings marked elsewhere 
in Aberdeenshire, 3 were recovered in the same district, 
1 of them in its first season and 2 in their second. 
At Leadenham House, Lincolnshire, 38 hand-reared duck¬ 
lings were marked in 1912, and 19 of these were recovered 
on the same estate, 15 in their first winter and 4 in their 
second. In 1913, 28 were marked there, and 2 of these 
were recovered at the same place on 4 October of that 
year. A hand-reared duckling marked in Hampshire was 
recovered at the place of marking in its first winter. 
Of birds marked as wild ducklings, five marked in 
Aberdeenshire (two), Inverness-shire, Berwickshire, and Co. 
Monaghan respectively were recovered at the places of 
marking in their first seasons ; and one marked in Aber¬ 
deenshire was recovered there on the 1st of August of its 
third year. 
Bearing in mind that most of the birds referred to were 
hand-reared, the following conclusions may be drawn. With 
two exceptions all the birds were recovered at or very near 
