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Wednesday, February 20, 2008

Baby Blues

Working with clouded leopards is incredibly rewarding - they are wonderfully charismatic cats, they develop strong bonds with their caretakers, and they have a compelling conservation story to share with zoo visitors. However, they also provide us with frustrations, most notably their obsessive lack of ability to procreate in zoos. The challenge of breeding cloudies is legend among zoo keepers. Primary among the problems is the extreme aggression that sometimes occurs during introductions or breeding that can culminate with a male killing a female.

We have not been immune to this issue with our cats at Point Defiance Zoo & Aquarium. Our pair was introduced when they were both very young - usually the key component of developing a successful pairing. However, Raja and Josie never formed the close relationship that can sometimes develop between pairs. Instead, their relationship was rocky from the start and they spent most of their time sparring with an element of seriousness so uncharacteristic of typical cub playtime. When not annoying each other, they would be found resting at opposite ends of their play area. This uneasy relationship may have been largely due to early issues with Raja's vision, a story I'll be sharing at the end of the month.

Despite their clear dislike of one another, they did show interest in breeding when Josie matured. Eventually breeding succeeding and resulted in the birth of cubs in 2003. At the time, we were optimistic that this would be the first of many litters. We welcomed this possibility, especially in light of the fact that Josie was considered the top female from a genetic standpoint in all North American clouded leopards. However, we were disappointed to see the relationship between Raja and Josie continue to deteriorate. Raja began to show extreme aggression toward Josie and ultimately we decided to permanently separate them for her protection.

This move did not kill all hopes of further cubs from Raja and Josie, however. We were excited by the potential to breed them through the use of artificial insemination. Because both cats still live at the zoo, it is straightforward (in theory, at least) to collect semen from Raja and inseminate Josie. We've tried this through several of Josie's estrus periods over that last two years. Because Josie is handleable, we are actually able to insert the semen vaginally through a catheter. To achieve this, three of us play the behavioral role of the male: one grabs Josie's scruff in a simulated nape bite-hold, one inserts the catheter, and the other "tickles" her for stimulation. Josie has been extremely cooperative during this process, thanks to the raging hormones of estrus that make her super affectionate with us at this time.

Unfortunately, all these efforts have proven unsuccessful so far. The key factor for achieving pregnancy is timing the insemination just right so that ovulation occurs as the sperm is racing its way up the reproductive tract. This is fairly tricky with cats as they are generally induced ovulators, meaning they need the stimulation of breeding to release an egg. (Although in true clouded leopard fashion, this isn't always the case so their situation can be more complicated!) So since we weren't really giving Josie the mechanical stimulation of breeding our timing wasn't working out. (We are able to track her cycle through the evaluation of hormones extracted from fecal samples.) So for the last attempt we injected Josie with a hormone to trigger ovulation to coordinate with our insemination. The evaluation of her hormones showed that our timing was good, but still did not result in pregnancy. This may have been due to simply not having enough volume of semen so we plan to add extra fluid (called an extender) for the next attempt.

That brings us to the present. The reason I'm sharing all of this is because Josie appears to be entering estrus again. We plan on an even more aggressive approach to breeding her this time including both vaginal and surgical insemination. I'll update you on the process day-by-day to share our progress. Josie doesn't have that many good reproductive years left (she's ten) so we may be running out of chances. Although it's frustrating and often disappointing, one look at the cub pictured should tell you it is definitely worth the effort! Keep your fingers crossed and make your offerings to the fertility gods...

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