;i\EDERBUKx 
DRAFT 
BIRDS 
r.RGUN BOOB v 
II 
A 
} Wj 
: h During the seven POBSP trips to Enderbury Island three 
peaks In the breeding cycle have been observed* 
These are approximatedy eight months apart but the 
visits have been too infrequent to show the actual existence of such a cycle* 
The peaks are else minor and 4he-4441e^ertee~fee4weeR there Is always a considerable 
amount of nesting at all times so that the peaks may be the result of random 
variation in a species which will nest whenever it Is able* ( Ibis, 1965) 
Table 
1963 
Feb 
Broun Booby nest on Enderbury Island 
July 
10 9-0 
November 
34_^p=§ *1 
1964 
4-i>*=4- ^ 
11 - 5=21 >4 
11-5=# W 
1965 
32-^9> 
Sable-; 
T ble 
8 -fel| 
i | 
1 First figure is the number of nests with 
eggs an h the second is the number of young* 
w \/w ■ 
_ . . 
____ shows the actual nests counts taken on each visit* of 
but these 
the shyness of the species some nests are always overlooked -and 414-6 nest counts 
cover at least 90% of the nests present* It is difficult to calculate exactly when 
a nesting peak occured because of the infrequency of the visits and the high 
mortality. In November, 1963 there were 34 nests with eggs but very few if any of 
these produced young. The interval between the November and February visit 
s 
would not be sufficient for a young bird to hatch and fledge and the number of young 
birds seen in February wo’ld represent the maximum survival of young hatched 
from nests found in November. There must also have been a high mortality among 
nests started after the November visit and it is possible that the actual nesting 
peak occurred after the November visit rather than before # jf we n ]_ 0 g on j v the 
