The studies reported here represent a collection of experiments and observations on sea bird ticks over a numberof years, undertaken on the rare occasions that material became available. Collection details from ticks in 70%ethanol were the source of basic seasonality data for 4 species. In addition, living Ixodes eudyptidis andOrnithodoros capensis collected from sea bird colonies were able to be fed in the laboratory using, respectively,mice and domestic chickens. Life cycle details were obtained from ticks kept at ambient temperature and in amoist atmosphere. Observations on birds in the field infested with I. eudyptidis showed that paralysis of thehosts was common, and in some instances was reversible once ticks were removed. Examples of paralysiscaused by other ticks and the implications for bird conservation in New Zealand are discussed.