DIVING AND FORAGING IN THE COMMON EIDER

We recorded the duration of successive dives and pauses during sequences of foraging by wintering Common Eiders Somateria mollissima in the Gulf of St. Lawrence. The length of each pause on the surface between dives increases at an increasing rate with the length of the preceding dive. Based on this relationship, the deviation from the estimated surface time (DEVEST, for short) was computed for each dive. DEVEST is positively correlated over short series of dive-cycles. The significance of these results is discussed and compared with an earlier study on Western Grebes Aechmophorus occidentalis.