A Milestone for Sun Bear Bulan
Posted at 12:20 pm February 27, 2008 by Suzanne HallOur sun bear cub, Bulan, is nearing 18 months of age, and soon she will be weaned from her mother (see Suzanne’s blog, Baby in a Bag). Already short periods of separation have been built into her day. She and Marcella are apart for about two hours early in the morning and reunited when they go on exhibit in Sun Bear Forest at the San Diego Zoo for the day.
These separations are beneficial for several reasons. First, a gradual separation from the dam allows the cub to adjust to time alone, preparing her for future housing as an independent animal. Some sun bears prefer to be housed this way as adults; Ting Ting, now residing at the Oakland Zoo, seemed happy to be housed jointly with Marcella (a female) but less thrilled about the presence of Dibu (a male).
Additionally, a separation time each day enables the keepers to feed both Bulan and Marcella some food without worrying about who eats what. This has become an important issue for Marcella, who finds that as her cub ages she competes heavily for the food provided to the pair. Marcella, while still lactating, can find herself with less and less food to eat as her cub consumes more and more. Thus, separating them allows Marcella to get a guaranteed quantity of food without interference from Bulan.
One final reason to wean Bulan from her mother: she has a new home waiting for her as soon as she is ready. The Minnesota Zoo is home to a male sun bear that is in need of a healthy mate. Since the Bornean subspecies is in dire straits, suffering from only two births in U.S. zoos since the 1990s, Bulan’s role as a prospective breeder is a very important one. Hopefully she can successfully breed and rear young in Minnesota in the near future.
By the same token, once weaning is complete we will again pair Marcella with Bulan’s father, Dibu. After the weaning of Danum, our first Bornean cub, Marcella experienced an estrus rather quickly. However, it may have been an infertile estrus, as no cub was born from couplings of our breeding pair. However, Marcella’s second estrus was clearly fertile, as Bulan was born about 100 days later. Hopefully the only successfully reproducing pair in the U.S. can replicate its past performance and provide the Bornean population with another cub in 2008!
Bulan will continue to be on exhibit with her mother for some time each day for the next month or so. If you want to catch them together, come soon! At some point after weaning is complete we will know more about the timeline for Bulan’s move to Minnesota. Before she leaves, come enjoy this beautiful little bear and wish her well as she prepares for the next phase of her life.
Suzanne Hall is a senior research technician with the San Diego Zoo’s Giant Panda Unit.
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February 27th, 2008 at 1:02 pm
Although it is somewhat bittersweet, it is great to know that each bear cub is growing up healthy, happy, and ready to go fulfill their destiny. Bulan is a cute girl, and her parents have been prolific. Hopefully they will continue to be so, as well as their progeny.
Has Danum been designated for breeding too? Since no mention of Danum’s cub, my guess is that he is still too young to be bred.
What is the normal breeding age of Borean Sun Bears?
February 27th, 2008 at 2:04 pm
Margaret #1,
Danum will hopefully breed in captivity soon. We dont know precisely when Borneans become reproductively mature, but they are thought to be ready sometime between 3-6 years of age, probably on the later end of that range for the males. Danum turned 4 this month.
February 27th, 2008 at 3:12 pm
The weaning process is a bittersweet but normal and necessary conclusion to a joyful birthing event. I know that intellectually, but it is still difficult to accept emotionally. In Zoo Atlanta Mei Lan will soon be permanently separated from Lun Lun but fortunately both seem ready for this change in their lives. I recall how Su Lin used to call out to Bai Yun after they were separated and both were somewhat distressed. Of course it turned out well and one day Su Lin will go on to have her own cubs, nurture them, and then leave. Perhaps it is harder for the human observers than for the animals themselves.
Good luck to Bulan and Marcella and their keepers for an easy weaning.
February 27th, 2008 at 3:53 pm
The sun bears at the Fort Worth Zoo are among my favorite animals when I visit. Those claws are formidable! Although I don’t know the sexes of our pair, they seem to like to wrestle a lot. Marcella & Dibu appear to be quite the romantic couple. Best of luck for another cub this year. I would love to see a current picture of Bulan. Would it be possible to add one to this blog?
Moderator’s note: We checked, but our busy Zoo photographer hasn’t taken one of Bulan since May 2007.
February 28th, 2008 at 12:04 am
Bulan got so big and when she’s by herself, I’m not quite sure if I’m seeing her or her mom. When she’s with her mom, I can see the size difference, though. She’s so playful. I will miss Bulan, but I am sure that people in Minnesota will fall in love with her. I hope to catch her once before her departure.
February 28th, 2008 at 11:32 am
How wonderful to know that Bulan is going out into the world to help the species!! Please let us know how she is doing after her arrival in Minnesota. Maybe the photographers will be able to capture a picture of her before she leaves. (Wink, wink)
April 5th, 2009 at 6:36 pm
you can ever tell me what i want to no b/c i am trying to find out when a baby sun bears is ready to start mating.You also make thing so long and it takes me forever to read when I am trying to go fast.
Moderator’s note: Sun bears become mature at 3 to 5 years of age.