106 
PACIFIC SCIENCE, Vol. Ill, April, 1949 
a dozen of them, sometimes bending a prop or 
cracking a windshield. Worst of all, the goonies 
loved to fly in groups, sitting almost motionless 
high in the air in a perfect battle formation that 
fooled many a lookout and sent the island to 
battle quarters more than once.” At night the 
shearwaters and petrels were killed in the air. 
However, it was not only in the air that planes 
killed birds; in landings, in take-offs, and in 
moving from place to place on the ground the 
planes were forced to pass through flocks of 
birds on the runways and parkways. Sooty and 
Noddy Terns, Wedge-tailed Shearwaters, both 
albatrosses, and Bonin Island Petrels were prone 
to alight on the runways which no doubt cov- 
ered parts of their former nesting grounds. 
Trucks, jeeps, and other passenger vehicles 
which were constantly moving about on the nar- 
row, Scaevola-bot&eted roads ran down countless 
thousands of individuals of these species. Fur- 
ther, vehicles sometimes* left the roads and 
traveled "cross country” through colonies of 
ground-nesting terns, killing young and adults 
and smashing eggs; or they went across areas 
honeycombed by the burrows of shearwaters 
and petrels with the same result. 
The presence of so many human beings 
(about 15,000 at one time) on so small an area 
(less than 2 square miles) was also an im- 
portant factor in reducing the populations. In 
December, 1946, less than 1,000 people were 
stationed at Midway, but in the future the per- 
manent complement of military personnel may 
be about 3,000. Psychological disturbances to 
all species no doubt reduced the success of their 
nesting; most adversely affected were the col- 
onies of Sooty Terns, Gray-backed Terns, and 
Fairy Terns. Albatrosses, Red-tailed Tropic 
Birds, and Red-footed Boobies seem less dis- 
turbed by the mere presence of man near the 
nest, but the actual effect on them is unknown. 
The nocturnal, burrow-nesting species were 
least affected, as far as psychological disturbances 
were concerned, but these species were the most 
hated by the men and consequently suffered 
more physical violence. The adults were killed, 
their young and eggs destroyed, and their bur- 
rows tramped shut. It should be noted that this 
persecution of shearwaters and petrels was 
limited for the most part to the Wedge-tailed 
Shearwater and the Bonin Island Petrel; Bul- 
wer’s Petrel and the Christmas Island Shearwater 
suffered less because of their relative scarcity 
and because they are limited to Eastern Island 
which always had fewer men stationed on it 
than did Sand Island. The Wedge-tailed Shear- 
water was also subjected to another form of 
human depredation — the daily gathering of eggs 
for food. The extent of this form of adverse pres- 
sure is unknown for Midway, but it did occur. 
Wanton killing of birds (other than the 
"moaning birds”) by military personnel during 
the war was probably a relatively unimportant 
factor in decreasing the populations, and naval 
authorities set up stringent, but sometimes by- 
passed, regulations about it. 
No doubt the most serious factor brought by 
man was the rat, which was inadvertently 
introduced early in 1943. By the time con- 
trol measures were initiated in 1945, it was 
computed on the basis of bait eaten from 
feeding station pans that the rat popula- 
tion was greater than 100 per acre. Trapping 
and poison baits aided in controlling the rats 
during 1945 and the first half of 1946 at which 
time the scope of the control program had to 
be reduced because of lack of personnel. How- 
ever, the control never was complete, and since 
1944 rats have exerted a depressing effect on 
various species. The Bonin Island Petrel, Bul- 
wer’s Petrel, and the Fairy Tern have suffered 
from rats. Extinction of the Laysan Finch and 
Laysan Rail may be attributed principally to rat 
depredations. The Hawaiian Tern, although it 
is a shrub- and tree-nesting species, has been 
affected. Alsatt (1945: 49-51) noted that 
adults of the Fairy Tern were not obviously 
fewer in numbers, but fewer young were seen 
in early 1945. Further, he found that immature 
birds under observation disappeared overnight. 
The decline in numbers of the Domestic Canary 
also started with the introduction of the rat. 
