TOT ath eae nameoe auismHiiey Aiettienisiias + -rhnilliinas Ett, senda, -“b. The total absence of natural predation on the’ islets has allowed the| population to soar and-be limited only by population pressures, competition between species and food/harborage availability. With . the exception of the islet of Enewstak the rat population: reachedthe maximum carrying of the islets surveyed. c. _ . Mice, though not taken in traps, are present on the islets. Evidence ©: used to determine their presence was the collection of frass and hmmm signs of damage. ‘The population of mice on the individual islets is. probably low’ due to successful cormmatition from the rat population. d. Ectoparasites found on rats were limited to mites of undetermined species. No ticks or fleas were found. obtain ectoparasites from the rats. . ; 1} Combing. e. Three methods were used to ne re Ty 2) Washing. | Le eo ce 3) Visual examination of the bocy and hair with the aid o¢ f magnifying Be J . optics. Lack of higher ectoparasitic population is attributed to extremely. limited contact with other mammalian species. Various species of Stinging (aculeate) wasps are present on all of the islets. fuscatus “var, aurifer is the most aggressive. Polistes © ium Ropalidia marginata and -an unidentified 5Species in the family Vespidae are also present. Parasitic wasps of the family Sphecidae were also collected. 1) . hod In all cases the wasp populations per islct is low. However, where present the wasps tend to be concentrated in small areas. For example, on the islet of Jedrol (Rex) a P. fuscatus colony . was located in a refrigerator building. Thecolony was old but viable and nests varied in size from the diameter of a quarter to the size of a football. ; 2) About 25 wasps were present in the refrigerator building and a number were observed foragirz in the area. The estimated living beeen re population of the colony is between 100 and 150 wasps. 3) - Limited natural food sources and high winds have severly restricted the numbers of wasps capable of surviving on the islets. Normal - fdods such as lepidopterous larvae, nectar etc, are extremely limited. Colonies are therefore small and focal. They may usualy be located in dense foliage, well shielded from the wind and close to the ground. Some R, marginata were observed nesting up - to’ Six feet above prround onthelee side of the foliage. ES er eme