Populations of Birds on Midway and the 
Man-Made Factors Affecting Them 
Harvey I. Fisher 1 
The birds of Midway are of interest and im- 
portance for several reasons. They are of interest 
to professional ornithologists because of their 
great numbers, their ecology, and because some 
of them breed in no other region of the world 
except that of the leeward islands of Hawaii. 
The endemic species are of great interest pet se. 
To the chance visitor to the atoll and to the men 
stationed there in military service the birds con- 
stitute a beneficial recreational and morale fac- 
tor. Certain of the species would be of signifi- 
cance to a fishing industry if it were ever estab- 
lished in this area, since by their concentrations 
over schools of forage organisms they indicate 
to the fisherman the location of schools of mar- 
ketable fish feeding on the same organisms. 
Chapman (1946: 166) has emphasized re- 
cently the importance of birds to any fishing 
done in the area around Midway. He states, 
Fishing was done entirely, after some experience, 
by following the flocks of seabirds which were 
feeding on the same organisms as the fish. The 
birds were actively scouting for food all during 
the sunlit hours. They gathered over the spot 
where the fish would rise, some seconds or min- 
utes before the fish came to the surface, in suf- 
ficient numbers that the flock could be seen 
for three or four miles, and they would follow 
a feeding school as long as it stayed at the sur- 
face. They furthermore seemed able to estimate 
where a school of fish would rise next with far 
better precision than we could, and when there 
were no fish in sight we formed the habit of 
idling the boat near a large flock of resting 
birds with the assurance that if they were not 
in the right place their scouts, which were always 
out, would lead them quickly to the right place 
before the fish rose to the surface. Fairy terns, 
1 Department of Zoology, University of Hawaii. 
Manuscript received February 14, 1948. 
because they were pure white and could be seen 
so far away, were particularly valuable in sight- 
ing distant schools as were the high flying 
frigate birds, but it was the mutton birds and 
boobies that formed the main mass of feeding 
birds. 
With postwar expansion in Hawaiian fish- 
eries already including French Frigate Shoal, it 
seems probable that the colonies of birds on 
islands farther to the west, Laysan, Pearl and 
Hermes Reef, Midway, and Kure, will become 
important to commercial fishermen. 
In view of these facts it seems worthwhile to 
assemble all information relative to the trend 
of populations of the species inhabiting Midway 
Atoll and to investigate the man-made factors, 
past and present, that cause shifts in population 
numbers. This is the primary purpose of this 
paper. As an auxiliary objective, I wish to note 
the recovery of the populations since May, 
1945, when a definite program of conservation 
was first initiated. Most of this latter informa- 
tion is based upon a survey which I made in 
late December of 1946. 
I wish to express my sincere appreciation for 
the aid and hospitality of Captain R. W. D. 
Woods, Commanding Officer of Midway, dur- 
ing my visit in December, 1946. He arranged 
transportation to Midway and gave all possible 
assistance. I also wish to thank Commodore 
Gale Morgan and Commodore Gordon Rowe, 
successively in command at Midway prior to 
Captain Woods, for their genuine interest in 
the avifauna and their initiation of protective 
measures. Dr. Alexander Wetmore of the United 
States National Museum and Mr. Chapman 
Grant, who were members of the "Tanager” 
1103] 
MAYl 0 
