Tigers Together Again
Posted at 3:25 pm August 3, 2006 by Bridget Mulholland
Keepers in the San Diego Zoo's Tiger River habitat recently reintroduced two of our Malayan tigers that had been separated for over two years. Belang, a 13-year-old male, and Danai, a 12-year-old female, were reunited two weeks ago in their bedrooms and now spend every other afternoon and night together on exhibit.
Belang and Danai both came to us from the Cincinnati Zoo where they were born. They arrived at the San Diego Zoo when they were youngsters and have been here ever since. Over the years, Danai gave birth to six cubs (in two litters, three cubs in each) that Belang sired. Danai was a great mom to her first litter, but for some reason she showed no interest in her second litter. The three cubs (one female and two males) needed to be hand-raised at the Zoo's nursery. Some of you may remember seeing Satu, Dua, and Tiga out on exhibit in Tiger River learning the ropes with their keepers!
Because Belang and Danai have had six cubs who have all grown and been sent to other zoos, they are well represented genetically in the captive population. Since we did not want them to breed again, they were separated from each other. Although tigers are solitary animals in the wild, Belang and Danai really do seem to enjoy each other's company. So, two months ago, our veterinarians performed a tubal ligation through a laparoscope on Danai so she would no longer be able to become pregnant. After she healed from the surgery, we waited for her to come into estrous for the reintroduction.
Although Belang and Danai always got along well in the past, we wanted to be sure that for this reunion the two would be thinking about something other than fighting! Sure enough, the reintroduction went very smoothly. After lots of chuffing, which is a tiger greeting, Belang and Danai bred several times. Tiger breeding involves a lot of loud vocalization and appears to be fairly aggressive as the male bites the back of the female's neck, and then the female turns around and swipes at the male with claws out. But we were not terribly worried as we watched Belang and Danai, as this is just natural tiger behavior and rarely ends with any injuries.
Now that Danai is out of estrous, the breeding has stopped, but the two continue to get along very well. Stop by Tiger River in the afternoon or evening to see our tiger pair together again!
Bridget Mulholland is a senior mammal keeper at the San Diego Zoo.
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August 3rd, 2006 at 10:28 pm
Ah. I don't understand the decision to sterilize Danai–why not artificial insemination with a different male, or just allow her to conceive with Belang? Perhaps six Danai/Belang offspring are " enough," but would 2 or 3 more be " too many" ? I must be missing something here–or is it the financial cost of new cubs that makes it better to prevent further pregnacies in Danai? Thanks for the blog; hoping for a bit more clarification!
August 4th, 2006 at 6:27 am
How great that Belang and Danai can once again be together. I note that they will be out in the afternoons and evenings. Will the cubs and Mek still be out in the morning? Will they alternate with dad Awang? And what plans are being made for Mata and Rimba as they get older? Lots of questions! Thanks so much for the update, Bridget, and for all you and your fellow keepers do to care for these magnificent animals.
August 6th, 2006 at 1:39 pm
Debra - I'm not an expert or anything, but since nobody answered your question I will share what I remember from biology class.
Any animals that are closely related can't mate with each other, to prevent passing on undesireable recessive traits (same reason that humans aren't supposed to marry their siblings).
There are a limited number of these tigers in captivity, so if there are too many cubs from one set of parents, it will be harder to match those tigers up to mate in succeeding generations. That's what the post meant by " well represented genetically in the captive population."
August 6th, 2006 at 10:53 pm
Thanks, Clarissa–Isn't " inbreeding" also used to increase desireable traits (as in purebred dogs)? I'm curious to learn the cost of raising cubs enters into the picture here….with an endangered species, I'd think the more babies, the greater chance of species survival, especially because of accidental deaths. And why, then, sterilize the female rather than the male, as surgery on the latter is less difficult?
August 7th, 2006 at 12:27 pm
Debra - I think that inbreeding is okay with dogs because although you do run the risk of genetic problems, you're working with such a small part of the overall population that if any problems come up, they don't have any affect on the species as a whole. Whereas with tigers, there are so few of them that it's important to maintain genetic diversity as much as possible to ensure the survival of the species.
I don't know anything about how cost affects decisions like this; I hope someone from the zoo will pop by and answer! I would imagine that there is a limited amount of zoo space overall, especially for large animals that need a lot of space, and that they need to plan years ahead to make sure they have enough room for new generations. You can't just build a new tiger habitat overnight if you have more cubs than expected.
And I'm wondering if they sterilize the female instead of the male because it is less likely to fail (as for humans) - but that's just a guess.