Iwan

male Pacific walrus (O. r. divergens)

wild caught in 1974

deceased in May of 1989

Ancestors and Descendants

None.

Transfer History

  1. capture 1974 in Wrangel Island, Russia

  2. transfer 1974 to Moscow Zoo

  3. transfer 1974 to Dolfinarium Harderwijk

  4. death 1989-May at Dolfinarium Harderwijk

Physical Data

The dates listed here generally represent the time at which the measurements were published, not necessarily the date on which they were taken.

Weight

  • 1988: 1,383 kg · 3,048 lb

  • 1988: 1,385 kg · 3,053 lb

  • 1988: 1,363 kg · 3,004 lb

  • 1988: 1,320 kg · 2,910 lb

  • 1988: 1,289 kg · 2,841 lb

  • 1989: 1,300 kg · 2,866 lb

Length

  • 1989: 350 cm · 11 ft 5 in

Diet

"The animals were fed 3 to 6 times per day on an average diet of 35% herring (Clupea harengus; approx. 8880 kJ/kg), 26% mackerel (Scomber scombrus; approx. 9550 kJ/kg), 9% sprat (Sprattus sprattus; approx. 10.400 kJ/kg), 2% whiting (Merlangius merlangus; approx. 4750 kJ/kg), and 28% squid (Illex spp.; approx. 1000 kJ/kg) by weight. Vitamins (Seavit>, 1 tablet per 2.5 kg of food) were added to this thawed diet." (R. A. Kastelein et al, 2000)

  • 1976: 5,500 kg · 12,125 lb annually

  • 1978: 10,000 kg · 22,046 lb annually

  • 1988: 8,500 kg · 18,739 lb annually

Image Gallery

No images available at this time.

Identifiers

Notes and Information

The images found here have all been gathered either from this facility's official resources or news articles.

This walrus was estimated to have been born in May of 1974, arriving at Harderwijk at five months of age -- this places his date of transfer around October.

Iwan died of a tusk infection.

While most sources agree that Iwan was captured in Russia, at least one states that he was collected in Alaska.

References

  • 1976-Jul-13. Leidsch Dagblad. Privé "Nova Zembla" voor die walrussen. Retrieved from Erfgoed Leiden [archive].

  • 1989. Kathy Irene Fisher. Food habits and digestive efficiency in walrus, Odobenus rosmarus. Retrieved from University of Manitoba [archive].

  • 1990-Jan. R. A. Kastelein and N. M. Gerrits. The anatomy of the Walrus head (Odobenus rosmarus). Part 1: The skull. Retrieved from researchgate.net [archive].

  • 2000-Jan. R. A. Kastelein et al. Food consumption and body weight of captive Pacific walruses (Odobenus rosmarus divergens). Retrieved from researchgate.net [archive]

  • 2000-Dec. R. A. Kastelein et al. Food dispensers as occupational therapy for the Walrus: Odobenus rosmarus divergens at the Harderwijk Marine Mammal Park. Retrieved from researchgate.net.