3 
* 
■co Johnston Island to roost (see recent bi-weeklies from Johnston 
Atoll). They probably "find it easier to remain" on the wing when 
it is windy, and are able to stay aloft at night with less 
expenditure of energy than during calm weather. During the grid 
survey there were markedly lower roosting populations on JI. Data 
on the effects of wind on the JI bird populations are being analyzed 
elsewhere. 
One Red-foot was collected. 
Phaethon rubricauda Red-tailed Tropicbird 3 
All three birds were seen on 21 February in the West Quadrant. 
Phaethon lepturus White-tailed Tropicbird 9 
Birds were seen in each quadrant but two-thirds were sighted 
on the eastern side of the grid on l8 and 19 February. 
One bird was collected. 
Fregata minor Great Frigatebird 15 
The fifteen frigates were seen throughout the grid, but were 
concentrated in the Worth and East quadrants. Wind probably has 
a similar influence on the frigates as it has on the Red-footed 
Booby. 
Sterna Puscata Sooty Tern 291 
During diurnal observations all 291 Sooties were seen in tne 
North and East quadrants. Ninety-nine percent of the Sooty 
observations were birds in flocks. All observations were close 
to Johnston Island where the birds were beginning to nest. They 
apparently were not going far from the island to feed. 
Nocturnal observations accounted for 28l Sooties. All buu 
four of these birds were recorded in the North quadrant on the night 
of 20-21 February when we re-entered the grid after leaving JI. 
