nesting areas of the two species overlapped. 
Table 5 below compares population data from this July with that 
obtained on previous July visits. 
Table 5• Comparison of July populations of Great 
Frigatebirds 
on Howland 
Island in 1963 , 
1964 , 1966 , 
and 1968 . 
1963 
1964 
1966 
1968 
July 6-8 
July 22-25 
July 12-22 
July 16-18 
Estimated population 
150 
250 
480 
Breeding population 
96 
204 
268 
430 
of nests counted 
48 
102 
134 
214 
5 of nests/eggs 
65$ 
63 $ 
43 $ 
12 $ 
10 of nests/naked or small 
downy young 
13 $ 
* 
37 $ 
12 $ 
$ of nests/larger young 
22 $ 
20 $ 
76$ 
* Most young stated lo have been recently hatched. 
The data in this Table suggest that 1968 is an optimum, or near opti¬ 
mum., year for Howland Great Frigatebirds and further indicates that the 
laying-period was decidedly earlier than in the other three years tabulated. 
Only in 1965 did the population apparently begin to lay as early in the 
year. Judging from the 1968 nest count data the laying peak this year was 
about five to six months earlier, or from about February through March. 
(The egg peaks for 1963 and 1964- probably occurred in May, that for 1965 
was probably February and March, and that for 1966 was probably April and 
May). 
me three returns, all breeding birds, had been previously banded on 
Howland. 
Lesser Frigatebird * Estimated population --- 35,000 
Estimated $ of active nests - Ig,k50 
Estimated # of nests/eggs *—----- 8,420 (4-8$) 
Estimated # of nests/naked young- 250 ( 1 $) 
Estimated $ of nests/small downy yg 1,530 ( 9 $) 
Est. § nests/medium downy young - 7,200 {kl$) 
Est. # nests/large downy young — 50 ( . 356 ) 
# of nests/larger young--- Hone 
No. returned -— 1 (S-U) 
No. Blood Samples - 70 (12 A-M, 58 
A-F) 
The 1968 Lesser Frigatebird colony was situated on the west side of 
the Corciia grove. Its northernmost extension was about 100 feet south of 
the depression containing the one live Cordia tree. From there the four 
^-ive subcolonies extended east nearly to the beach and a considerable 
distance to the south. 
* Most data on this”species was taken~by~Cr'ossin 
