Wednesday 23rd February, 2011One of the highlights of working in the field as employees of the Yellow-eyed Penguin Trust is the unexpected sighting of uncommon 'visitors' to our remote beaches.
This year a male southern elephant seal hauled out on one beach for several days. This one may have originated from one of the New Zealand subantarctic islands. They are known to range throughout the southern ocean around the Antarctic continent. The male is distinctive with its inflatable proboscis (snout) which is thought to increase the effectiveness of the bull elephant seal's roar and appearance as they fight for dominance during the breeding season.
Males are sexually mature at 3-6 years of age, but few breed before they are 10 years old, whilst many will never breed, with 90% dying before reaching sexual maturity. Females are sexually mature at 2-4 years old and generally give birth annually to a single pup for 12 years.
Adult males can reach up to 5 metres in length and weigh 3600 kilograms, whilst females are about half that length and only a quarter of that weight. There has been a long-term annual decline in numbers, possibly due to commercial exploitation of prey stocks and the population returning to pre-sealing numbers after having recovered to abnormally high levels.
As if to confound their status as an uncommon visitor to the Otago coast, just three weeks later a yearling elephant seal was discovered on an adjacent beach.