R.S. Crassin 1968 McKean Island 24 Oct. Plot 3 146 adults 68 ½ grain chicks. 32 rotten eggs. 25 Oct. Plot 4 227 chicks 83 ½ aged chicks. 61 rotten eggs As can be seen in Plots 2 & 3, ½ more chicks and or rotten eggs are present than adults to supply this crèche. Never more more birds are flying before I get to that plot to count or adults which have had unsuccessful nesting; i.e., rotten eggs have left the area and no longer count on their territories. The latter seems more likely since I take great care not to catch the birds when coming in to count, but perhaps it is impossible. 25 Oct. An estimated 20,000 nesting on the main plots along 5-6 mi. long shore. 26 Oct. In figuring the number of Sooty Terns in the breeding colony, the logical figures to use are the average of the combined eggs and chicks and the surviving plots since the parents of the chicks cannot be part of the population of the rotten eggs - the chicks are not large enough for parents. I unsuccessful eggs to have hatched and, brood off any of the relics present. Since some egg, and chicks are bound to have disappeared from the plots, the numbers 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 passing a sort of that have lost egg, or chicks Breeding birds which have field nests...P.S. R.S. Crassin 1968 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 bring up; presumably because they have already given up to a chick. wt (gms.) Contents (estimated) Adults: 1. 5.1 100% Small fish 2. 6.4 100% " 3. 23.6 100% " 4. 17.4 100% " ¾ chicks 1. 26.9 80% fish, 20% squid. 2. 18.8 100% fish, 70% flying fish 3. 32.5 40% fish, 60% squid. 4. 13.0 100% Small fish. 5. 16.8 100% Small fish. 6. 15.3 30% fish, 70% squid. ½ chicks 1. 26.4 10% fish, 90% squid. 2. 25.4 100% squid. 3. 27.2 100% fish 4. 17.9 50% fish, 50% squid. 5. 36.6 100% fish 6. 32.2 100% fish 7. 16.3 100% fish 8. 7.7 100% fish. 9. 10.8 40% fish, 60% squid 10. 31.0 5% fish, 95% squid. The fish were apparently juvenile Scombridae, except where noted otherwise.