Blue-faced Booby 
Lisianski 
Bon-breeding Distribution Data: 
mid-March 1963 
late Aug, 196k -• 
mid-Mar. 1965 
mid-June 1966 
mid-Oct. 1966 
early June 196$ 
early Sept. 1967 - 
solitary and perhaps non-breeding birds roosting along the 
beaches. (WOW) 
most of the birds concentrated in two large flocks composed 
mainly of adults at opposite ends of the island.(Kept) . 
...a large concentration of Masked Boobies on the south beach 
-- at least 100. 
..many non-nesting blue-faced around also (WOW) we saw a club 
with 100 birds in it sitting on the beach. 
roosting birds occurred on two or three wide sandy points on 
the southwest side where about 300 were counted at dusk 19 
June and an estimated 200 to 300 more roosted on the north¬ 
west beach. (PCS) birds roosting in small clubs on W and 
£>W beaches. 
numbers were very much greater at night when many clubs of 
50 to 70 birds were encountered. (KB) 
Over 300 roosting birds were found at the south end of the 
island and a club of 100 was found at the northwest end of 
the island. Scatterred roosters were found around the 
island except along the east beach. (DLS) On the night of 
June 2 ...a club of 100+ birds was found on the north shore. 
Four clubs were present on the island. The largest, co ntaining 
about 200 birds was located on the south tip of the island. 
Most of the birds in this club (and in the other clubs) 
appeared to have fully adult plumage but a small proportion 
were subadults. Two independent immatures were also seen in 
this club. Another small club of about 15-20 birds was 
present on the sandy southeast beach and a club of about A0 
birds was seen several times on the southwest beach. A club 
of about 100 birds was present on the north beach. We frequent1; 
observed small roasting agg^eagations of about 8-10 birds on 
the beaches particularly those of the north, northwest, and 
west sides of the island. Many of these aggregations had 
roughly the number of immatures (dependent?) present that 
would account for the number of adults present. We suspect 
that such aggregations represent a stage of the breeding cycle 
intermediate between territory ;holding and use of club areas 
as roosting grounds. (RBC) 
