plotted against distance collected from ground zero (Fig. 12), the effect of the site of collection upon the amount of activity within the organs or tissues is apparent. Meter readings were taken at each collecting site with a Juno ionization type instrument at the time the collections were made. These values for Runit, Aaraanbiru and Rigili are given in Table 5 in the Appendix. On the basis of the meter readings the activity levels in the terns from Runit and Rigili should be similar, but those of the terns from Asraanbiru higher. true, however (Fig. 12). This was not found to be At Rigili, downwind from ground zero, there were higher average levels of activity in the terns than at either Runit or Asraanbiru in which the levels were almost equal (Table 17b). The terns taken at Runit may have flown from neighboring northerly islands since, able to fly. although singed, they were The birds taken at Rigili, however, probably did not fly from islands closer to the target area, because all of the birds observed during the post shot collections at Rigill were singed or 11] and not inclined to fly. They would walk away or flutter with effort from the beach to the water when anyone came near. The shore birds and rats have Analysis by Feeding Habit. | similar feeding habits; both subsist mainly on insects, seeds, and grasses so that 4 comparison of average levels of activity The in diverse forms with similar feeding habits can be made. results are as follows: -_ 70 ~- OR ARE 1- 4-4 ‘ of a