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Interannual variation in pup production and the timing of breeding in benthic foraging Australian fur seals

journal contribution
posted on 2009-07-01, 00:00 authored by J Gibbens, John ArnouldJohn Arnould
¯Large interannual variations in reproductive success caused by fluctuations in oceanography and prey availability are common to many species of air breathing epipelagic predators. In contrast, little is known about variation in benthic foragers such as Australian fur seals (Arctocephalus pusillus doriferus). Between 1997 and 2007, pup production was assessed in 9 yr, while the timing of breeding and adult female condition was assessed in 5 yr at Kanowna Island in Bass Strait, southeastern Australia. Pup production was variable ( ¯x = 1,726 ± 42, range = 1,386–2,301), but without temporal trend, as was median birth date ( ¯x = 23 November±1, range = 21–25 November) and pupping synchrony (period of 90% births: ¯x = 28 ± 2 d, range = 23–31 d). Pup production was negatively correlated with median birth date and positively correlatedwith female condition,winter sea-surface temperature (SST) and zonal wind strength within Bass Strait. Pup production was also negatively correlated with SST in the previous summer within Bass Strait and in the eastern Great Australian Bight upwelling region. The results suggest that the reproductive success of Australian fur seals is influenced by oceanography but less so than in otariids foraging epipelagically in major upwellings. Despite spanning several El Niño events, no correlation between pup production and the Southern Oscillation Index was observed.

History

Journal

Marine mammal science

Volume

25

Issue

3

Pagination

573 - 587

Publisher

Wiley-Blackwell

Location

Malden, MA

ISSN

0824-0469

eISSN

1748-7692

Language

eng

Publication classification

C1 Refereed article in a scholarly journal

Copyright notice

2008, Wiley-Blackwell