Northern Elephant Seal - Marine Evening

Prof. Robert (Bob) Siegel bounded in just in time for the marine evening after having been a little lost on the way. In no way did this deter him from giving one of the most entertaining marine evenings (8 March) at the Great White House. Decked in a bow tie, Bob ensured no one would ever forget some very interesting facts about elephant seals  nor the difference between seals and sea lions – his impression of how they walk being most memorable.

Robert is a Professor at Stanford’s School of Medicine University, California. For over two decades he has served as course director of the infectious disease component of the required medical curriculum. Having broad interests, his courses include topics in infectious disease and human virology, Darwin and evolution, global health and development, natural history and ecology, island biogeography, nature photography, and even a course about Stanford.

Robert volunteer guides at the Año Nuevo State Park (ANSP) in Northern California, the first continental breeding colony of the Northern elephant seal to be established since these animals were nearly hunted to extinction in the late 1800s for their blubber.

Elephant seals are the largest members of the mammalian order carnivora - larger than Siberian tigers or polar bears.  The males can grow 4m and can weigh over 3 tons. Females can grow to 3m but weigh less than a third of the males. These animals display many other remarkable features and some of the highlights the guest learnt about include:

· Males can impregnate up to 50 females which gather in his harem (this also affords them protection from other suitors)

· It is possible that a male bull can have up to 500 pups in a lifetime
· They experience an annual moult
· They can stay underwater for an incredible 90 minutes
· They can go to incredible depths – a record of 894m was recorded
· Elephant seals do not drink water instead they metabolise their fat
· They can handle extreme temperatures
· During mating time the males fast for three months and the females for five weeks

The Northern elephant seal population is growing well but their genetic diversity is minimal based on the fact that they originate from less than 100 (possibly 20) individuals left after they were hunted. They are incredibly hardy though and Robert wages this species would probably handle climate change better than most.

Interestingly during the time of Robert’s scheduled talk a Southern elephant seal has been visiting Gansbaai and has been frequently sighted on Geyser Rock.

Brenda du Toit

(Marine  evenings  are  hosted by Marine Dynamics/ Dyer Island Cruises together with the Dyer Island Conservation Trust for the benefit of their tourism partners and other interested persons. Should you wish to be on the invitation list, please email

At the marine evening: ltr: Cari du Preez (Marketing Marine Dynamics), Prof. Robert Siegel, Brenda du Toit (PR Marine Dynamics), Alison Towner (Marine Biologist DICT)
Prof. Robert Siegel