Area ; JansFeb. June-July 


1 1300 296 
2 1370 424 
3 178 13 
4 56 O (killed during 
experimental 
. killing program) 
5 285 140 
6 23 13 
7 270 81 
8 157 83 
Total 3,639 1,050 
These figures indicate a mortality of over 70 percent on Sand 
Island. However, some of the young black-foots had already departed 
when the counts were made in late June and early July. Using as a 
correction factor the proportion of banded birds whichleft Eastern 
Island between early June and early July (see below), the total number 
of young black-foots successfully fledged should be increased by 69 
percent, or an additional 725 birds. This gives a total of 1,775 
surviving young black-footed albatrosses on Sand Island. The mortality 
rate between January-February and June-July was approximately 50 percent. 
Black-footed albatross juvenile mortality on Eastern Island.-- 
A total count of surviving young black-footed albatrosses was also made 
on Eastern Island, on 3 July. On 3 and 4 May, 1,000 young black-foots 
were banded on Eastern Island. When the counts were made on 3 July, 
banded and unbanded birds were counted separately, in order to determine 
what proportion had already departed. The total number which survived, 
and the mortality rate, were calculated as follows: 
a) Total count of nests, 27 February 1,669 
b) Total banded, 3-4 June 1,000 
c) Total banded birds counted, 3 July 507 
d) Total unbanded birds counted, 3 July 239 
e) Total birds counted, 3 July 746 
f) Total estimated, 3 July 1,471 
f= be 
c 
g) Estimated mortality, Feb.-July 12% 
: g-100-(£.200) 
a 
Laysan albatross juvenile mortality on Sand Island.-- 
Mortality figures of juvenile Laysan albatrosses on Sand Island are 
available only from the study area on the post office lawn, which was 
followed quite closely throughout the season. It may be regarded as 
representative of the entire residential area of the island, as regards 
15 
