An assessment of temporal variability and interrelationships between CEMP parameters collected on Adélie penguins at Béchervaise Island

We examined temporal variability in a series of CEMP parameters collected over the period 1991/92 to 2001/02 on Adélie penguins at Béchervaise Island. Parameters relating to chick survival (brooding counts, 2/3 crèche counts and fully crèched chick counts) show large temporal variability while the other parameters were more stable. We also explored the correlation between CEMP parameters, and the correlation of each parameter with breeding success. Breeding success was measured in terms of 1) the absolute number of chicks on the island which fully crèche and 2) the number of chicks crèched per nest with eggs. We found a low degree of correlation between incubating and brooding nest counts which supports the notion that events occurring during the hatching period are crucial for chick survival. The sex of the foraging birds and the timing of foraging trips were important in determining whether foraging trip duration was correlated negatively to breeding success. Additionally, we examined within season penguin weights, the simplest output from the Automated Penguin Monitoring System (APMS), in terms of their correlation with breeding success. This analysis showed that lower weights of females at the time they depart after egg laying would appear to be the first indication that a season may have low breeding success. The results obtained throughout these analyses indicate that knowledge of the sex of birds is important for understanding interrelationships between CEMP parameters and breeding success.