15 
\ 
10-8-63 
We bagan early today as at 2:30 there was a tidal wave ^ 
alert for the island which lasted until 445 hours. Then back 
to sleep until 1000.. Skinned out the sparrow whichWs 
really a mess - many many shot in him, and I had to sett the 
skin three times. Spent until 1300 fiddling with the equipment 
and then .out^to^^hunt and look at booby behavior. Saw nothing 
of note knit 19'50 another finch flew over the buildings, so I 
have nota eliminated thctpopulation yet. Helped Bill set his 
traps and then watched the flick. 
Concern Masked and Brown Booby behavior._Both q£2 r these 
boobys are very attentive to eggs and chicks.^rHo^egg 1 ' * 
cubated constantly and the incubating bird cannot be flushed 
off the nest unless one moves it bodily or runs at it. Basked 
3oobys are even more attentive to chicks of the predown stage 
and will hold their ground against all attacks by people. 
If the bird is captured and removed from the nest and chick 
( especially if there is a chick ) the bird on release moves ‘ 
quickly back to the nest and chick inspite of a person being 
within several feet of the nest. I believe now that each 
member of the pair normally incubates fey or broods for 
4 to 6 hours at a stretch, rarely longer than six hours. 
Older Chicks ( in the downy or feathered out stages of develop¬ 
ment ) may be left alone all day by both parents, but the 
family group apparently reunites at dusk each evening until 
the crick is fledged and on his own. Males with their high 
pitched voices are distinguishable in every pair from the 
low-pitched voice of the females. Masked booby nests are always '• 
placed directly in the ground, and the two under observation 
now are unlined scrapes in the soil. 
Many of the observations on Masked Booby behavior are 
applicable to Brown Boobys. Brown booby nests are placed on 
the ground, but are lined with vegitation, and often partially 
or completely surrounded by bushes ( here Scaveola ) which 
Masked Booby nests never are close to. Brown Boobys while 
very attentive to their eggs and chicks can be easily flushed 
from their nests: As an matter of note, it is particularly 
difficult to capture Brown Boobys during the day, while 
Masked can be caught at any time. Brown boobys can talc© off 
either downwind ( Masked cannbb, and require about 50-75 feet 
of level ground, facing available wind to get off. ) or into 
the wind, and get airborne very quickly. In a sense, it may be 
