ENLERBURY 
DRAFT 
bi rd 3 *$mm mmm 
Red-footed Booby ( Sula sula ) 
Current S+atus: Common resident and nesting species* 
Prior Records :Cassin (1858) records that the Wilkes Expedition found them ne. ting 
in January on bushes as on Honden Island* The nests ere built of sticks and 
obtained some contained fresh eggs while others were occupied by young birds 
in all stages of growth* He states that two young or two egg’s were rarely found 
in the same nest* Since 10BSP personnel have never found a nest with two eggs 
or young in the southern islands one orders if such nests were found more than once 
by the Hikes Expedition. 
Population: On five of the seven visits to the island that population has been 
estimated at between 1100 and 1500* On the other two visits in February, 1961 and 
November, 1964 the population as respectively 500 and 800* The population 
curve closely follows the curve for the number of nests and usually over 50 % of 
the population is breeding birds. 
1606 adults have been banded and in Hay, 1965 approximately 50/2 of the birds 
3 ooo 
handled ..ere banded. This would indicate a population of approximately 3^-50^ birds 
using the island and that only 50/2 of these are on the island during any given da 
Annual Cycle : Prom July, 1963 to November, 1964 the nests c unts indicate a 
y. 
regular annual cycle with a summer peak and a winter low. In February, M. 
Hay 1965 the cycle did not follow the expected pattern* 
there were still a large number of nests in F bruary and very little increase In 
Cs 
the number of nests by Hay June 1* February, 1964 was evidently a 
very poor time for nesting and perhaps the large number of nests found in 
February, 1965 is the normal situation* The slight increase through May 
be within the range of normal variation. In any case these two visits which 
do not exactly match the cycle from the previous year do not disprove the 
existence of a regular annual cycle. Table 
presents the nest counts for 
each visit* 
