
present time we do not know how closely these birds are associated 
with the residential areas; some of them, at least, are birds from 
other areas that are present only occasionally within the limits of 
the residential area. (See Figure 7.) 
6. Nest destruction shifts breeding birds into unemployed 
status, with a highly significant increase in occurrence over the 
runways. 
7+ Only one marked bird (unemployed) from Eastern Island 
has been recorded in the observations over the Sand Island runways, 
indicating that Eastern Island birds contribute only an insignificant 
amount t the hazard. 
8. It must be pointed out that the above statements apply 
only to the specified period of observations. Different conditions 
may prevail at other periods of the nesting cycle. 
studies of Control Methods 
Small Scale Elimination Experiments 
A series of plots was established on which the effects of 
elimination of certain segments of the population, at certain stages 
in the breeding cycle, could be measured on a quantitative basis under 
controlled conditions (Figure 16). The objectives were twofold: (1) 
To determine the results of such control methods during the present 
season, and (2) to determine how such control methods affect the 
breeding population in the following year. The results of the first 
phase are sunrmerized here. 
On all plots (except No. 1), all nests were marked with 
numbered stakes, and both birds of each pair were banded with numbered 
bands and*given a distinctive dye mark, making them easily recogniz~- 
able. (On plots No. 2 and No. 7, only the surviving member of each 
pair was marked.) Plots were checked every two or three days. 
Effects of total destruction early in the nesti eycle 
(Plot No. 1).--On an area of approximately one-half acre (187 x 110 
feet), all of the 67 albatrosses and all of their eggs were destroyed 
on December 2 (Figure 17). Following this removal there was a rapid 
repopulation of birds on the area. In two weeks the number of nests 
with eggs was 50 percent that of the pre-kill population, and the 
total number of birds present over 75 percent that of the pre-ldll 
number. 
On January 4, 211 birds and eggs in this plot were again 
destroyed (Figure 17). Again, there was a rapid repopulation. By 
the end of the month there were almost as many as had been present 
prior to the December kill. However, no eggs were laid on the area 
after the January kill. 
31 
