May 17, 2011
Six Flags Discovery Kingdom Walrus Loses Calf
Pacific Walrus Calf is Stillborn; Staff Saddened by the Loss
Six Flags Discovery Kingdom staff are mourning the loss of what would have been the first ever Pacific walrus calf born at the park and only the 12th to be born in a U.S. zoological facility.
There have been no more than 11 recorded walrus calves born over the past 80 years and only 17 individuals in U.S. facilities today. Park animal staff members, though hopeful, remained guarded as the 16-year-old female walrus, Uquq, went through obvious labor signs starting late Saturday and culminating in 40 more hours before active labor occurred. Uquq gave birth to the stillborn calf early Monday evening. Results from a necropsy to be performed will determine why the calf did not survive.
“Over the past 30 days, we stepped up our observation and monitoring via ultrasound, and all signs showed a live birth was imminent,” said Michael Muraco, Six Flags Discovery Kingdom Animal Care Director. “The staff is extremely upset but attending to the welfare of Uquq at this time. We have always known that the survival rate of walruses in zoos and aquariums was only 50 percent and actually less in the wild - but despite the odds, we felt that all of the dynamics were in place – a healthy female that was conditioned and trained to allow us to keep track of her progress on a daily basis from the very start of her pregnancy - and an experienced animal and veterinary staff that knew their animals well. The odds this time were just not in our favor.”
When the rare pregnancy was first announced in April, park officials said the pregnancy itself represented significant advancements in captive reproductive efforts for the species. The work of outside marine mammal reproductive physiologist Holley Muraco – from the identification of sunlight as the regulator to determine the male’s reproductive season to documentation and understanding biomarkers using salivary testing to monitor progesterone and estradiol in females and testosterone in males - and working in tandem with a dedicated marine mammal team, has been one breakthrough and discovery after another in this quest to understand why walruses have traditionally not bred well nor have been born in a captive environment.
“We’ve learned so much from this pregnancy,” said Michael Muraco. “While there is obvious disappointment and sorrow, we accomplished a great deal in understanding walrus reproduction and even more importantly, we can apply what we’ve learned to future walrus breeding opportunities and share that knowledge with other facilities.”
