Surface temperatures of albatross eggs and nests

Abstract

Knowledge of thermal traits is essential for understanding and modelling physiological responses to environmental change. Egg temperatures are poorly studied in most tubenose species. We employed a contactless infrared thermometer to measure egg and nest surface temperatures throughout the incubation period for four albatross species at Bird Island, South Georgia. The observed mean warm-side temperature of 33.4°C for Wandering Albatross (Diomedea exulans) was similar to measurements obtained from this species using dummy eggs elsewhere. Observed mean warm-side temperatures for Black-browed Albatross (Thalassarche melanophris), Greyheaded Albatross (Thalassarche chrysostoma), and Light-mantled Albatross (Phoebetria palpebrata), reported here for the first time, were 30.7-31.5°C, which is lower than the egg temperatures reported for most Procellariiformes. Temperature gradients across viable eggs declined by up to 9°C during incubation, reflecting increased embryonic circulation and metabolic heat production. This suggests that bioenergetic models should not assume constant egg temperatures during embryo development. Non-viable (addled) eggs could be identified by large temperature gradients in late incubation, indicating that infrared thermometry can be used to determine whether the embryo has died or the egg is infertile in monitoring and managed breeding (e.g. translocation) programmes. Egg temperatures were correlated with ground temperatures, indicating that incubated eggs are vulnerable to environmental variability.

Comparative egg attendance patterns of incubating polar petrels

“…When comparing only polar procellariiforms (N = 4 species), mean egg temperatures vary by 1.6 °C. Including additional measurements for other procellariiforms, regardless of environment, mean egg temperatures range between 29.6 °C for Cory's shearwater (Calonectris diomedea; [54]) and 37.5 °C for Laysan albatross (Phoebastria immutabilis; [26]) and the overall mean egg temperature is 33.4 °C (N = 19 species; calculated from published data [14,20,26,[55][56][57][58][59][60][61]).…”

“…When feasible, future studies should measure egg attendance patterns over multiple days to capture variation between day/night egg temperatures. Secondly, egg temperatures measured in the field have been obtained using probes inserted into real eggs [20,[55][56][57], biologging devices [24,26,42,43,60,62], and more recently using thermal imaging [61]. Methodological differences are important to consider because thermal gradients are known to occur across the egg surface [2,61,63], a main reason eggs are turned.…”