Swennen C. & Duiven P. (1983) Characteristics of Oystercatchers by cold-stress in the Dutch Wadden Sea area. ARDEA 71 (1): 155-159

In the mild winter of 1976 a spell of frost of only 11 days caused high (3-4%) mortality among the Oystercatchers wintering in the western part of the Wadden Sea. It appeared that the mortality mainly concerned abnormal individuals. The mean weight of the 380 victims studied was about 38% less than the mean normal winter-weights of the age classes distinguished .. Anatomical deviations were found in 61.3% of the frost victims, especially on bill and legs. More than 19% of the dead Oystercatchers older than yearling had not yet finished primary moult, which in normal birds is completed already two months earlier. Indications were found that juveniles and males could resist the cold stress somewhat less than adults and females. Such a high mortality during a short spell of frost is unusual. However, the mortality can be related to the unusually frequent raising of the sea level by high winds in the two months before the frost, by which feeding had already been prevented frequently. At that time obviously handicapped birds were unable to built up a sufficient energy reserve to survive the cold stress.