SCS: Subantarctic Fur Seal (Arctocephalus tropicalis)
species under CITES. There appear to be no major threats
currently facing the species.
Subantarctic fur seals on World Heritage listed Macquarie Island were
afforded additional protection in 2000 by the creation of a new federal 16 million hectare
Marine Park on the eastern side of the island. The Tasmanian government also announced in
2000 an extension to the Macquarie Island Nature Reserve to cover all Tasmanian waters out
to three nautical miles surrounding the island.
A recent genetic study was carried out to investigate the potential
impacts of commercial sealing and range contractions on the genetic variation and
population structure of Subantarctic fur seals. The study revealed that despite commercial
sealing, high levels of genetic diversity and population structure are still present in
the species. Three genetic lineages or clades are apparent, none of which represents fixed
geographic distributions. However the seals from Gough, Prince Edward and Amsterdam
Islands all differ significantly in the percentages of each clade represented in their
populations. The recently established populations at άes Crozet and Macquarie Island are
more similar genetically to each other than they are to any of the potential
"source" populations. Results suggest that these populations were recolonised
primarily by animals from the Prince Edward Islands and, to a lesser extent, Amsterdam
Island.
Photo: Simon Goldsworthy,
Latrobe
University
Lifestyle
The Subantarctic fur seal usually hauls out on rocky shores from
November to January in order to breed. The adult males arrive at the breeding grounds just
prior to the females and form territories, usually containing between 4-12 females. They
defend these territories by means of fighting, vocalisation and bluff. The females usually
arrive in November-December and their pup is born a few days later with a black coat.
Mating takes place about a week after the birth and the female then begins a cycle of
feeding at sea for approximately 5 days (although foraging trips lasting a month have been
reported) and returning to nurse her pup on land for 2-3 days. The milk that the mothers
feed their pups is high-energy, containing approximately 39% fat.
|
