Factors influencing the development and survival of Adelie penguins were investigated from the Cape Bird colony. The fieldwork focused on aspects of vocal recognition but parental care and chick development were also considered. A total of five sub-colonies (three experimental and two control) were selected. Eight focal nests, four center nests (at least three nests from the edge) and four edge ... nests were selected in each sub-colony for analysis. Focal birds (adults and chicks) were marked for identification. Microphones were laid within the colony and recorded adult Loud Mutual Display (LMD) calls, Male Ecstatic Displays and chick calls. Each colony was sampled over its entirety to collect sufficient calls to reveal any within and between colony call variation. Chicks were weighed at the time of their marking and four times subsequently at one week intervals. The behaviour of the focal birds was observed and recorded including levels of aggression, feeding frequency, time at nest, call rates and timing of feeding during feeding chases were observed from a stationary position at a constant location outside the sub-colony. To determine if a human presence affected behaviour in the sub-colonies, two control colonies were remotely sampled. Nest failure, number of active nests and chick number were recorded for comparison with the three experimental sub-colonies over the season. Calls that were digitally recorded had their call parameters (peak intensity, fundamental frequency, phrase length and syllable length) analysed in order to elucidate a potential colony dialect and to account for the individuality of each birds Ecstatic and Loud Mutual Display. Chick calls were analysed in the same way for individual recognition by parents. The data collected was used to (a) identify variations associated with nest locations, (b) examine effects of nest location on aggression, parent chick interactions, feeding frequency and breeding success, (c) identify parameters of chick calls associated with parental recognition, (d) investigate whether natal nest location influences creche dynamics and feeding chases, (e) investigate the effect of clutch size on feeding frequency and chick growth and (f) examine evidence for within and between colony dialects. Additional recordings of LMDs and Ecstatics were gathered in the 02-03 season from Cape Bird (North, Middle and South colonies), Cape Royds and Cape Crozier.