The biochemical and biological activity of the soils of the Adelie penguin colonies at Cape Bird was studied over two seasons. Biochemical markers of decomposition of penguin guano were studied by in situ incubation studies and analysis of samples in the laboratory. Five sites with guano of different ages were selected for this study including a) a presently occupied penguin colony, b) a recently ... abandoned penguin colony, c) re-deposited guano in a low swale between colonies, d) a long abandoned colony and e) a never colonised area. Samples of surface guano from sites a-d and the 2-8 cm soil horizon from site e were incubated for 10-12 days buried at the sites to test a range of parameters of decomposition and biological activity including the enzymes urease, phosphatase and protease, respiratory activity and evolution of ammonia. In addition to the samples buried in the field, a similar set of respiration samples were incubated in the Cape Bird Hut giving an estimated mean incubation temperature of 10C as opposed to the estimated 4C in the field. Eleven guano and soil samples were sealed in plastic bags and returned to New Zealand for biochemical, biological and chemical analysis. These samples were tested specifically for enzymology (five enzymes assayed = urease, phophatase, protease, dehydrogenase and sulphatase), respiration, bacterial numbers and chemistry. Each soil types was characterised and described and the water content, soil temperature and the depth to frozen ground was measured. In the second field season of this study, the range of sites and samples was extended using improved techniques and more controlled incubation conditions.