Diet and Foraging Area of Antarctic Fur Seals at Heard Island

Brief description

Antarctic Fur Seals from Heard Island fed mainly on fish, but the prey species changed both seasonally and inter-annually. The majority of prey were pelagic myctophids characteristic of deep oceanic water, and were generally taken in autumn and winter. The only other fish taken in significant numbers was Champsocephalus gunnari which was mostly taken from late winter through early autumn when it was co-dominant in the diet with the Krefftichthys anderssoni. Males and females foraged in different localities and in different parts of the water column. Males foraged mainly to the south of Heard Island in winter usually diving deep by day, feeding on scattering layers. In summer males also fed on the shelf, presumably to the north and east of Heard Island on K. anderssoni at shallow depths primarily at night. Although diet studies provided little evidence of feeding on crustaceans, diving data indicate that some males may travel to Antarctic waters in winter to feed on krill.

The fields in this dataset are:

Months
Species
Scats
Time foraging
Number of Dives
Time Submerged (minutes)
Mean Dive Duration (minutes)
Maximum Depth (metres)

Lineage

Progress Code: completed

Statement: Collections were made on a monthly basis from February 1992 through to March 1993. In winter, scats were only collected on new snow because it was difficult to determine the age of scats exposed by frequent snow thaws.