R.B. Bussin 1968 Sooty Tern 24 Oct. PLA 3 McKean Island 146 adults 68 3/4 gram chicks. 32 rotten eggs. Plot 4 227 Adults 83 1/2 gys chicks 61 rotten eggs As can be seen in Plots 2 & 3, if more chicks and or rotten eggs are present than adults to supply this number. Hence many more birds are flying before get to that plot to count or adults which have had unsuccessful nesting; i.e., after eggs have left the area and no longer court on their territories. The latter seems more likely since I take great care not to disturb the birds when coming in to count, but perhaps it is impossible. 25 Oct. An estimated 20,000 roosting on the several plots along 5-6 miles of lagoon shore. 26 Oct. In figuring the number of Sooty Terns in the breeding colony, the logical figures to measure the average of the combined eggs and chicks in the various plots since the parents of the chicks around the part of the parents of the rotten eggs. The adults are not large enough nor do they have wide enough age gaps for currently unsuccessful eggs to have laid and, brought off any of the chicks present. Since some egg and chicks are found to have disappeared from the plots, the number present now are logically the lowest figures of original laying that could have occurred. Perhaps the large numbers of birds that are roosting along the lagoon and on the rock walls are part of a nest that that have lost egg or chicks. Breeding birds which have failed nests...? R.B. Bussin 1968 Sooty Tern McKean Island 24 Oct. Regurgitation samples were collected between 1900-2000, as the adults have very recently come in and fed the chicks. Many adults have nothing to keep egg, presumed because they have already given up to a chick. wt (gms.) Contents (estimated) Adults: 1. 5.1 2. 6.4 3. 23.6 4. 17.4 3/4 Chicks 1. 26.9 2. 18.3 3. 32.5 4. 17.0 5. 16.8 6. 15.8 1/2 Chicks 1. 26.4 2. 25.4 3. 27.2 4. 17.9 5. 36.6 6. 32.2 7. 16.3 8. 7.7 9. 10.8 10. 31.0 100% Small fish 100% " " 100% " " 100% " " 50% fish, 20% Squid ! 100% fish, 70% flying fish 40% fish, 60% squid. 100% Small fish. 100% Small fish. 30% fish, 70% squid. 10% fish, 80% squid 100% Squid. 100% fish 5% fish, 95% squid 100% fish 100% fish 100% fish 10% fish, 40% squid 5% fish, 75% squid. The fish were apparently juvenile Scorbideres, except where noted otherwise.