Disturbance of incubating African Black Oystercatchers: is heating of exposed eggs a problem?

We measured temperatures of incubated and exposed eggs of African Black Oys tercatchers Haematopus moquini nesting in coastal dunes, Algoa Bay, South A frica through three of the 10 hottest days of summer during the 1994/95 bre eding season. Mean incubation temperature was 34.4 +/- 0.7 degrees C (range : 32.2-37.0; n=3). The average maximum temperature attained by exposed dumm y eggs, averaged higher at 37.4 +/- 2.7 degrees C (n=5). The absolute maxim um recorded for exposed eggs was 40.1 degrees C. These temperatures are wit hin lethal limits measured for other birds and suggests that heating of exp osed eggs after disturbance of incubating was not a direct factor in explai ning variation in breeding success of oystercatchers in the Alexandria Dune field, Algoa Bay.