Late Holocene colonisation of snow petrels (Pagodroma nivea) of the Prince Charles Mountains, Antarctica

Abstract

The effect of long-term environmental changes on sea bird populations with respect to changes in their breeding and foraging habitats is difficult to assess due to the scarcity of records that go beyond direct observational data. Information on the past distribution of snow petrel Pagodroma nivea (Forster) breeding colonies can be obtained from deposits of their proventricular stomach oil, so-called Antarctic mumiyo. In our study, we present 14C ages of mumiyo deposits from northern and southern Prince Charles Mountains, East Antarctica, to reconstruct the timing of snow petrel occupation at these inland breeding localities. 14C ages indicate a minimum age of snow petrel occupation of 3680 cal year bp. The colonisation post-dates the de-glacial local and regional ice sheet retreat by several thousand years. This either suggests limited accessibility of the inland sites or a lack of suitable nesting locations prior to the Mid-Holocene and/or changes in the marine habitat affecting access to the foraging grounds. 14C ages of mumiyo deposits from Vestfold and Larsemann Hills to the east of Prydz Bay point to a regional pattern of snow petrel dispersal starting in the Mid-Holocene. This suggests environmental changes in the foraging habitat to be the most likely drivers for extending breeding site locations of snow petrels to more inland ice-free areas in the Prydz Bay Region.