Protection and provisioning: the role of parental behaviour in terms of chick growth and survival in a pelagic seabird

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 530:153-162 (2015) - DOI: https://doi.org/10.3354/meps11317 Protection and provisioning: the role of parental behaviour in terms of chick growth and survival in a pelagic seabird Gavin M. Rishworth*, Pierre A. Pistorius DST/NRF Centre of Excellence at the Percy FitzPatrick Institute, Department of Zoology, Nelson Mandela Metropolitan University, Summerstrand 6031, South Africa *Corresponding author: gavin.rishworth@gmail.com ABSTRACT: Long-lived organisms maximise lifetime reproductive output by shifting the negative effects of temporal environmental variability onto their offspring while maintaining adult survival. Amongst seabirds, chick growth and survival could be influenced by a range of factors, including prey delivery and parent behaviour as well as predation and exposure to adverse weather conditions. In this study, an automated method of recording adult Cape gannet Morus capensis time-activity budgets by means of new generation VHF technology was used to relate their behaviour to chick growth and survival at Bird Island, Algoa Bay, South Africa, across 2 breeding seasons (2011-2012 and 2012-2013). Using one of the most comprehensive datasets of breeding seabird foraging effort, we showed that, although chick growth was predominantly associated with age, parents which made shorter foraging trips clearly raised chicks which grew faster. Chick survival varied greatly between the 2 seasons (40 versus 97%), which was explained by different levels of nest non-attendance by parents. Chicks in the 2011-2012 season which were exposed to longer periods of non-attendance were particularly vulnerable to unseasonal storms and they were also more vulnerable to kelp gull Larus dominicanus predation while young. In contrast to Cape gannets in the declining west coast populations, chick survival at Bird Island was primarily related to parental protection rather than food provisioning rate, which probably reflects favourable foraging conditions along the southern coast of South Africa. This study highlights the importance of understanding the interplay between factors affecting chick growth and survival for the effective conservation of threatened seabird populations. KEY WORDS: Automated monitoring · Cape gannet · Chick provisioning · Foraging effort · Parental roles · Survival · Time-activity budget · VHF Full text in pdf format PreviousNextCite this article as: Rishworth GM, Pistorius PA (2015) Protection and provisioning: the role of parental behaviour in terms of chick growth and survival in a pelagic seabird. Mar Ecol Prog Ser 530:153-162. https://doi.org/10.3354/meps11317 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 530. Online publication date: June 18, 2015 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2015 Inter-Research.