Delayed start of full incubation is related to a delayed brood patch development in Magellanic penguins

MELINA BARRIONUEVO; ESTEBAN FRERE

BIRD STUDY

TAYLOR & FRANCIS LTD

Año: 2016 vol. 63 p. 1 - 6

0006-3657

Capsule: Most bird species start full incubation before the clutch is complete. Others long after laying the last egg, gradually increasing the incubation temperature as incubation progresses, as is the case in Magellanic penguins (Spheniscus magellanicus).Aims: In this study, we analysed the possible mechanisms underlying this delayed start of full incubation in Magellanic penguins. We postulated two possible mechanisms not mutually exclusive: delayed development of the brood patch, and/or variation in the adult´s incubation postures.Methods: We conducted our work at Isla Quiroga, Argentina (47°45´S, 65°53´W) during 2011-2013. We measured the development of the brood patch area, its temperature (using electronic probe thermometer), as well as the egg temperature (with iButtons thermochron temperature data logger), and observed the adult penguin´s postures.Results: We found no association between the adults´ postures and the delay start of full incubation, but a positive association between brood patch area and egg temperature.Conclusion: Our results support the fact that the delayed start of full incubation is a consequence of a delayed development of the brood patch area and not of the brood patch temperature or adults positions during incubation.