snow leopard


Breeding Snow Leopards: Lab View

Does Beau have what it takes?

Last month, Mammal Keeper Todd Speis blogged about the introduction and subsequent breeding of Anna, the Zoo’s snow leopard, and her new mate, Beau (see Snow Leopards: Love at Second Sight?). Our Reproductive Physiology Department staff first met Beau in 2006 at his previous home in the Santa Barbara Zoo. We were there to perform a semen collection procedure to assess his potential fertility, not knowing at the time that one day he would come to the San Diego Zoo. Beau was a gorgeous snow leopard with motile sperm.

Back in San Diego, Anna and her long-time mate, Everett, were a compatible breeding pair, but despite their efforts she never became pregnant. We were asked to examine the pair to try to diagnose the problem and offer a possible solution. The first, and least invasive step, was to analyze Anna’s estrous cycles. Keepers collected fecal samples, froze them, and sent them to our Endocrine Laboratory, where Alan Fetter charted her cycles by measuring her fecal estrogen and progesterone levels.

We could see that she was breeding at the appropriate time in her cycle, and she was ovulating normally. When her progesterone remained elevated after each of two breeding cycles, we were hopeful that she was pregnant. But each time her progesterone plummeted back to baseline within two months, indicating that she had experienced a pseudopregnancy (also known as a false pregnancy). This condition is not uncommon among mammals, especially in carnivores. In most cases, pseudopregnancies last half to two-thirds of the length of a normal pregnancy, which is what we observed with Anna. A pseudopregnancy occurs when a female ovulates but does not conceive. For a few weeks her body produces hormones to support a pregnancy even though there is no embryo present. Eventually, with no communication from an embryo, the female’s body returns to normal, and she cycles again.

After two documented pseudopregnancies, it was time to take the next step by examining Everett’s sperm. Three semen collection procedures from 2008 to 2011 yielded samples completely devoid of sperm! During the last collection, the veterinary staff collected tissue biopsies from each of Everett’s testicles and sent them to our Wildlife Disease Laboratories pathology group. After careful assessment of the tissue, the disappointing report and photos clearly indicated that Everett was not manufacturing sperm. The reason for his inability to produce gametes was unknown, but his infertility was now an indisputable fact.

Curators at both zoos arranged an exchange between San Diego and Santa Barbara, and Beau moved south to our Zoo. As Todd described, Beau and Anna took a little time to get to know each other but then began to breed. We were excited to assay Anna’s samples to see if the new pair would be successful. Following breeding in January of this year, Anna’s progesterone rose significantly, indicating that she had ovulated. Our hopes for a pregnancy, though, were again dashed when two months later her progesterone dropped back down to baseline.

But there was a very encouraging difference in this pseudopregnancy. This time Anna’s estrogen levels were twice as high as in previous pseudopregnancies and remained high for nearly one month in contrast to the rapid decline seen before. We are hopeful that very soon Anna will experience a normal pregnancy and have the opportunity to raise a litter of cubs. We’ll be watching from the lab.

Barbara Durrant is the Henshaw Director of Reproductive Physiology at the San Diego Zoo Institute for Conservation Research. Read her previous post, Meeting Hua Mei’s Son.


Snow Leopards: Love At Second Sight?

Beau needed some romantic persuasion from Anna.

Early this year we received a new snow leopard male, Beauregard, with the hopes of introducing him to our female, Anna (see post A New Snow Leopard Beau). The couple and updates on the pair’s status have been the hot topic on Big Cat Trail at the San Diego Zoo. Initially, we tried an introduction just prior to breeding season. Neither cat took much of a liking to the other, which was not surprising. In the wild, these cats live highly solitary lives and only come together for short periods during breeding season.

Shortly thereafter, Anna started showing signs of entering estrous. This time her mood made an expected 180-degree turn as she immediately approached Beau with friendly chuffing and flirtatious behavior. Strangely, Beau was not receptive, and he either ignored her advances or aggressively repelled them. Anna became increasingly frustrated with Beau’s behavior. Eventually, as Anna’s cycle passed, she became less interested in Beau, and we halted introductions.

Fortunately, snow leopards have more than one chance to breed per season, and three weeks later Anna started showing interest in Beau again. We re-introduced the pair, and Anna tried to solicit attention from Beau again, and again Beau was either indifferent or aggressive toward her. We started to lose hope that this couple just might not be compatible. Yet Anna was not as easily dissuaded. On this go around, she got more and more insistent with her advances toward Beau. Finally something clicked, and we observed several days of successful breeding. Anna’s persistence had paid off! Even after the end of their breeding cycle, we were able to keep the pair together. A bond seemed to have formed, and they would even greet each other with mutual grooming first thing in the morning.

Breeding season is now waning, and the pair is separated again. Now all we can do is keep our fingers crossed and monitor Anna’s behavior for possible indications of pregnancy. Researchers at the San Diego Zoo Institute for Conservation Research are also monitoring her hormones for pregnancy by analyzing her feces (imagine buying that at-home test at your local drug store!). Since neither cat has reproduced before, the possibility of them passing on their genes to ensure a more diverse and healthy future population of these rare, elusive, and endangered animals is very exciting.

Todd Speis is a senior keeper at the San Diego Zoo. Read his previous post, Habitat for Hyenas.


A New Snow Leopard Beau

Welcome to San Diego, Beau!

In search of: White male with black spots. Likes long walks at high altitudes and dining on blue sheep. Must want children. No commitment required.

How do the animals at the San Diego Zoo find their mates? Not through personal ads but a system called Species Survival Plans, or SSPs. They are a lot like online dating for zoo animals, except instead of matching likes, dislikes, or interests, they match animals based on genetics. This matching insures that zoo populations of the most endangered species will keep healthy and viable well into the future. On the Zoo’s Big Cat Trail, one of our active SSP members is the snow leopard.

In 2006, we received a pair of snow leopards, Anna and Everett, who were determined by the SSP to be a desirable pair. Fortunately they also found each other desirable and became the “it” couple of Big Cat Trail. Anna and Everett were unusually compatible, considering that snow leopards, like most cats, are highly solitary. Usually cats only come together during breeding season and separate soon thereafter; the male has no part in raising their kittens. Our pair, in contrast, spent all their time together, grooming each other and even playing together. I could even feed both cats right next to each other with no fighting or spitting! When breeding season came around, usually starting around New Year’s Eve, mating would occur but, unfortunately, never resulted in any births. After several years, the vet staff examined both leopards very closely and came to the conclusion that Everett was infertile.

Giving Anna the chance to contribute to the next generation of snow leopards is still important, so the SSP found a new suitor who resided in nearby Santa Barbara, California: Beauregard. After some training using his favorite treat, beef heart, Everett acclimated to being in a crate and would enter voluntarily. My last vivid Anna/Everett memory will be just after a training session as Everett was rolling in fresh hay in the crate as Anna, just outside the crate, was leaping up and playfully batting him in the face. When the time came, my supervisor and I loaded Everett up, drove him to his new home in Santa Barbara, and brought Beau back with us to San Diego.

Now we face the challenge of introducing two cats to each other. Although it will be hard to match Everett and Anna’s compatibility, we are hoping Anna and Beau get along well, as neither has parented any kittens before. Stay tuned or stop by the snow leopard exhibit to see how Beau and Anna are getting along. Breeding season is just about to start, so keep you fingers crossed!

Todd Speis is a senior keeper at the San Diego Zoo. Read his previous post, Feline Fun.


Feline Fun

A northern Chinese leopard enjoys bone day.

Providing enrichment is one of the most enjoyable, and important, parts of caring for the cats that live on Big Cat Trail at the San Diego Zoo. Enrichment is an item that stimulates the physical and mental health of an animal by encouraging the animal to exhibit natural behaviors just like their wild counterparts do. In a modern zoo, this is considered just as important as providing food, water, and shelter to an animal. As a keeper, it is very rewarding to watch an animal become engrossed with a novel item I’ve given to them.

Scent is an important part of a cat’s life and something I try to offer often as enrichment. All cat species (except lions) are solitary by nature but still communicate with other cats through scents. We use fresh herbs, spices, perfume, and even elephant dung to enrich our cat’s noses! Orson, the melanistic jaguar, favors cinnamon. His entire head turns red after he spends time rubbing it on a sprinkling of cinnamon. Our snow leopards and Siberian lynx are not as picky and enjoy nearly any unique scent that I offer them. My theory is that these two types of cats that naturally live in very sparse habitats, and therefore have large home ranges, find scent even more important, as the chance that they will happen upon another cat is unlikely.

We also like to give items that the cats can bat around and chase, simulating the act of hunting. Lately we’ve received a lot of dried gourds that some of the cats really enjoy play hunting with. The irregular shape of the gourds makes them roll unpredictably, and the dried seeds inside rattle, which also entices the cats. Our two cougars particularly enjoy a new batch of gourds, batting them around and even carrying them in their mouths. Our snow leopards generally are not as enticed by play toys, and although I’ve never observed them play with the gourds, there is evidence that they also enjoy them. When I return to work the next morning, the gourds have always been moved and are sometimes even smashed into bits!

Whole food items are something that every one of our cats enjoys. Most days the cats receive a nutritionally complete mix of beef, vitamins, and supplements. We regularly add items such as bones and rabbit carcasses to give them food items that more closely resemble how they would naturally feed themselves. Whether a cow femur or a rack of ribs, all of our cats will spend hours chewing on bones to remove every bit of meat and maybe even some marrow from inside the bone. This is not only fun for the cat but great for their dental health, as it acts like a good brushing of their teeth, just like when you give your dog a milk bone.

Although it may seem a little gruesome to some, when rabbit carcasses are offered, it is very enriching to the cats as they get to “harvest” a whole animal just as they would if they made a kill in the wild. Jama, our North Chinese leopard, is unique in that he prefers to remove all the hair from his rabbit before he eats it. Skyy, the female Siberian lynx, tosses her rabbit around in the air just like your house cat may do with a favorite toy!

The next time you visit Big Cat Trail, try to find the enrichment items that each cat has that day; it could be a toy, treat, or just a log with really good bark to scratch on.

Todd Speis is a senior keeper at the San Diego Zoo. Read his previous post, Mountain Lion Home Makeover.


Meet the Snow Leopards



I chuckled as I arrived at the snow leopard exhibit along the Big Cat Trail at the San Diego Zoo during my first check of the day. Everett was on his side on a rock at the front of the exhibit, Anna was sitting on him: an example of the bond between these two.

Everett and Anna came to the Zoo in the spring of 2006. Everett is 12 years old, Anna is 6. You can easily tell them apart: Everett is larger and his left eye appears slightly enlarged and seems to view the world from a different angle than the right one. Anna has a kink in her tail about six inches from the end.

In the wild, adults lead solitary lives. However, Everett and Anna live together quite happily. In fact, they are so well bonded, they become nervous if separated for a long time. The other paired cats along the Big Cat Trail must be separated to be fed in order to reduce competition. However, the snows will eat peacefully side by side, each pausing now and then to lick the other’s head. I should add that this goes for their basic carnivore diet: a ground-beef diet with extra nutrients specially formulated for zoo carnivores. When they are given their whole-food items, like a beef shank or rack of ribs, these items are placed at opposite ends of the bedrooms. Upon separation and release from each end of the bedrooms, each cat retires to a distant location with its treat.

As one would expect of an animal native to a harsh climate, they are seasonal breeders. Since their arrival, they have bred many times. Unfortunately, no cubs have resulted. It is possible that Everett is too old. Older snow leopard males in managed care have a poor track record when it comes to siring young. We will report back to the snow leopard Species Survival Plan (SSP), which manages snow leopards across North America using complex computer programs to rank individuals genetically and makes breeding recommendations.

As I care for the different species in my care, I am interested to learn about their different mind-sets and behaviors. For example, the cougars seem very quick in both their movements and thinking; one can almost see the wheels turning. But the snows seem less engaged in their environment, somehow: quieter, gentler, more passive.

I’m told that Anna was very shy and nervous when she first arrived but has calmed greatly. Even so, she can be reluctant to shift off exhibit, often appearing to wait for Everett to shift first. And yet she’ll go through periods when she is first to leap into the bedrooms while Everett hangs back. In general, she is more food motivated than he is.

Everett sometimes makes an earnest-sounding vocalization, but one doesn’t know what it is he wants. He enjoys tactile enrichment, though, and sometimes rubs his head against the enclosure’s wire. He will then remain still while his head is scratched with a back scratcher. When Anna cycled, Everett often had little appetite; this enabled her to monopolize the whole-food items on exhibit. Sometimes, I’d give these items in the bedrooms while they were separated. One day, as I was releasing Everett, I noticed he had the remains of food on his chin. Perhaps there are other reasons why the breeding hasn’t gone so well…?

They are less interactive with toys provided for enrichment. However, scents generally result in a strong reaction, especially from Everett. We grow fresh herbs on Zoo grounds to be used as enrichment, as well as using spices or colognes. Even a handful of fresh hay will produce a strong reaction. One day I placed hay into a large plastic bowl. Everett did a face plant into the bowl, sniffing, rubbing his head, and even nibbling the hay. He lifted his head with a small pile of hay on top with a blissful look on his face.

These cats are one of my favorites. Stop by their exhibit and enjoy these beautiful and enigmatic carnivores.

Karen Barnes is a senior keeper at the San Diego Zoo. Read her previous post, Favorite Jaguar Moments.