MEPS 346:299-312 (2007)  -  DOI:

Feeding, fasting and foraging success during chick rearing in macaroni penguins

J. A. Green1,3,*, I. L. Boyd2, A. J. Woakes3, C. J. Green4, P. J. Butler3

1Department of Zoology, La Trobe University, Bundoora, Melbourne, Victoria 3070, Australia
2Sea Mammal Research Unit, Gatty Marine Laboratory, University of St Andrews, St Andrews, Fife KY16 8LB, UK
3Centre for Ornithology, School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
4British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK

ABSTRACT: Foraging behaviour and energy expenditure were measured continuously throughout the chick-rearing period of free-ranging macaroni penguins Eudyptes chrysolophus. These data were integrated with values obtained from the literature on body mass, assimilation efficiency, body reserve consumption and deposition rates, chick growth and energy expenditure and energy content of food in a new type of algorithm to predict (with 95% confidence limits [CL]) foraging success and daily changes in body mass. A successfully breeding pair of macaroni penguins will capture 111.7 kg (95% CL: 79.4 to 158.0 kg) of prey during the chick-rearing period. The crucial phase of the chick rearing period was around the time that chicks crèche, when prey consumption rates more than doubled as the male assisted in foraging and recovered from a long fast. Female macaroni penguins extracted 2.28 (1.60 to 3.26) and males extracted 2.84 (2.02 to 3.99) g of prey from their environment for every minute spent submerged during foraging. Only 15.3 (14.7 to 15.6)% of all prey consumed was fed to chicks. While food capture rates increase in the middle of the breeding season, this may be more a function of greater food availability than a response to demands from their chick. Male and female macaroni penguins have differing breeding strategies with the male showing the characteristics of a capital then income breeder while the female has a strategy that shows characteristics of both capital and income strategies simultaneously. The high synchronicity and precise timing of the macaroni penguin breeding season and timing of the increase in prey capture rates suggest an influx of prey to their foraging area during the middle of the breeding season. A depletion of prey resources in the foraging area used during the breeding season could affect foraging success and have profound effects on the body condition and composition of this species and its ability to raise chicks successfully.

KEY WORDS: Penguin · Antarctic krill · Foraging · CPUE · Energetics · Diving · Breeding

Full text in pdf format 
Cite this article as: Green JA, Boyd IL, Woakes AJ, Green CJ, Butler PJ (2007) Feeding, fasting and foraging success during chick rearing in macaroni penguins. Mar Ecol Prog Ser 346:299-312.

Export citation
Mail this link - Contents Mailing Lists - RSS
- -