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Category — Cats

Supporting Black-footed Cat Research in South Africa

One of the world’s smallest cats, the black-footed cat is found only in the southern African countries of Botswana, Namibia and South Africa. It lives in dry, open habitats such as desert, savanna and scrubland. Due to its extremely shy and evasive nature, little is known regarding the black-footed cat’s status in the wild, though it is considered to be the rarest cat in Africa.

Black-footed cat (Photo: Alex Sliwa)

Black-footed cat (Photo: Alex Sliwa)

The black-footed cat is one of the five small cat species with which the Zoo’s Center for Conservation and Research of Endangered Wildlife (CREW) works on its Small Cat Signature Project. In addition to conducting zoo-based research on the reproductive biology of the black-footed cat, the Zoo also supports field research in South Africa.

A black-footed cat emerges from its den.

A black-footed cat emerges from its den.

Since 2004, a group of scientists and veterinarians working together as the Black-Footed Cat Working Group (BFCWG) (http://black-footed-cat.wild-cat.org/) have been studying black-footed cats in South Africa. The BFCWG aims to conserve this rare cat species by furthering awareness and conducting multidisciplinary research on the species’ biology, distribution, ecology, health, and reproduction over an extended period.

Scientists with the Black-footed Cat Working Group search for uncollared cats in South Africa.

Scientists with the Black-footed Cat Working Group search for cats in South Africa.

Once a cat is captured, researchers take a variety of measurements and samples are taken and fit a radio collar. Over time, this generates valuable data regarding the behavior, ecology, genetics, and health of the wild black-footed cat population.

A camera trap image of a collared black-footed cat.

A camera trap image of a collared black-footed cat.

Additionally, sperm collected from wild males can be imported into the United States (once frozen) and used to artificially inseminate captive females to infuse genetic diversity into the captive population.

Scientists with the Black-footed Cat Working Group collect samples from a cat.

Scientists with the Black-footed Cat Working Group collect samples from a cat.

This November, the Cincinnati Zoo & Botanical Garden helped to send Dr. Jason Herrick, a former post-doctoral fellow with the Zoo now working with the National Foundation for Fertility Research and as a Research Associate with the Denver Zoo, to South Africa to capture and replace radio collars on five male black-footed cats. At the same time, he is taking measurements and collecting samples.

Scientists with the Black-footed Cat Working Group (Dr. Herrick on the right) prepare to release a newly collared cat.

Scientists with the Black-footed Cat Working Group (Dr. Herrick on the right) prepare to release a newly collared cat.

 

November 17, 2014   No Comments

How do you diagnose pregnancy in a lion?

Many visitors to the Zoo have met our two African lions, John and Imani, in the new Africa exhibit. These two young cats were paired up earlier this year with the hope that they would breed and produce their first litter of cubs in the near future. The good news is that breeding activity has been observed on several occasions this past year, and, after at least one pseudopregnancy, it appears that Imani is now pregnant and due to give birth within the next month. Which raises the question – how do you diagnose pregnancy in a lion anyway?

Imani (Photo: Cassandre Crawford)

Imani (Photo: Cassandre Crawford)

Scientists at the Zoo’s Center for Conservation and Research of Endangered Wildlife (CREW) commonly use three methods for pregnancy diagnosis in wildlife species:  ultrasonography, fecal progesterone analysis, and urine relaxin analysis. Ultrasonography remains the gold standard since visualization of a fetus with a strong heartbeat is the definitive proof of pregnancy. CREW frequently uses abdominal ultrasonography to diagnose and monitor pregnancies in our domestic cats (see below). However, this method can be challenging to apply with a potentially dangerous carnivore, like Imani. Through the Zoo’s operant conditioning program, Imani eventually may be trained to allow voluntary abdominal ultrasound exams, but this method is currently not an option with her.

CREW scientists conduct an ultrasound on a domestic cat.

CREW scientists conduct an ultrasound on a domestic cat.

The second approach for pregnancy diagnosis is the use of fecal progesterone analysis. Lions, like other felids, show an increase in fecal progesterone levels shortly after ovulation that is detectable using CREW’s hormone assays. If lions ovulate but don’t conceive, they will have a pseudopregnancy that lasts 50 to 60 days and then progesterone will decline back to baseline levels. If progesterone concentrations stay elevated beyond 60 days post-breeding, then the female is most likely pregnant. Imani’s fecal hormone profile (below) shows progesterone levels increasing coincident with her last breeding activity and staying elevated through at least 66 days post-breeding (the last fecal sample tested).

Imani's fecal hormone profile

Imani’s fecal hormone profile

The third option for pregnancy diagnosis involves measurement of another hormone, relaxin, that is produced by the placenta and excreted in the urine. CREW has helped to pioneer the use of a bench-top relaxin test for pregnancy diagnosis with urine from cats. Our previous research has found that pregnant domestic cats and Pallas’ cats produce high levels of urinary relaxin that are detectable with the bench-top test, but pregnant cheetahs and clouded leopards apparently do not. Imani is the first lion that we have evaluated late in a suspected pregnancy. Urine samples collected from Imani at day 73 and 74 post-breeding were both positive for relaxin (below, circled line in window #2), providing further presumptive evidence of an ongoing pregnancy. In the absence of a sonogram showing a viable fetus, the positive results from the progesterone and relaxin assays provide our best evidence that Imani is pregnant.

Imani's pregnancy test

Imani’s pregnancy test

Hopefully, Imani will confirm our diagnosis in the next few weeks with the anticipated birth of her first litter of cubs. Since Imani will be a first-time mom, she will be provided with a quiet, off-exhibit den area to give birth and bond with her cubs, and likely will remain off-exhibit until early spring when the cubs are a bit older.

October 28, 2014   No Comments

Keeper’s Blog: The Pride of Cincinnati!

If you’ve seen our 3 year-old female lioness Imani on exhibit lately, you may have noticed that she’s getting a little round around the middle. But Imani isn’t just packing on the pounds for winter, there is a chance that she might be pregnant!

Imani's bump

Imani’s bump

John and Imani came to the Cincinnati Zoo back in 2012 with a breeding recommendation from the African lion SSP (species survival plan). The SSP helps zoos to work cooperatively to manage captive animal populations so that we can avoid in-breeding and maintain healthy genetics within our captive populations. Fortunately for Cincinnati, John and Imani were matched up and brought to the Queen City to start a pride together.

You can read more about John and Imani’s first meeting here:

http://blog.cincinnatizoo.org/2014/05/02/john-the-lion-meets-his-match/

Almost immediately after being introduced to each other, keepers began to see breeding behaviors! Since John and Imani are both young, inexperienced lions, the initial breedings didn’t seem to amount to much. More often than not, Imani would only sit still for John for about 20 seconds, then she would swing around and smack him in the face while snarling. Poor John was receiving some very mixed and confusing signals, and breeding Imani seemed like a very daunting and scary proposition. He stuck with it though, and soon the breeding behaviors began to look more (re)productive! ;)

John and Imani

John and Imani

A little bit of background info on lion breeding. Typically, female lions cycle every 17 days, and they are induced ovulators (meaning they only ovulate, or release eggs, when mating has occurred). Induced ovulation helps ensure that breeding is successful because eggs are not being released and wasted unless breeding (and the possibility of fertilization) has occurred.

Keepers were seeing pretty regular estrus cycles from Imani every 17 days or so for the first few months that the lions were together. At each cycle, we observed breeding from the lions. Then, at the beginning of August, we anticipated an estrus cycle that never came. Since that time, keepers have been collecting and submitting fecal samples from Imani to our research department over at CREW (the zoo’s center for Conservation and Research of Endangered Wildlife). CREW analyzed the progesterone levels in Imani’s feces to help us determine that ovulation HAD occurred during the last observed breeding cycles. Even more exciting, Imani’s elevated progesterone levels were a good indication that she might be pregnant!

Now before we start planning a baby shower or registering for baby gifts, we should note another important and fascinating aspect of lion reproduction: pseudopregnancy. Pseudopregnancy (or “false” pregnancy) can cause the female’s body to exhibit signs and symptoms of pregnancy even if she’s not actually pregnant. For this reason, we are not saying “Imani’s pregnant!”. Instead, we are saying “Imani might be pregnant!” We will only know if there has been a true pregnancy if and when Imani delivers her cub(s) sometime this November.

In preparation for possible cubs, keepers have been working around the clock to ensure that Imani has a safe, secure and comfortable place to give birth. We are setting up a special “denning area” complete with full privacy, a cozy nest area, and even video surveillance cameras so that keepers can monitor Imani from a distance.  Since Imani will be a first time mom, much of the decision-making that happens from this point on will be based on Imani’s comfort level. Maintaining a sense of security and comfort for her during this pivotal and exciting time is our top priority! We ask for your patience and understanding as one (or both) lions may be spending less time on exhibit during the next month or so leading up to the possible arrival of cubs. As always, thank you for the amazing love and support you’ve shown our lions so far and stay tuned to learn if and when we add new lion cubs to our Cincinnati pride!

Wendy Rice
Africa Keeper
Cincinnati Zoo & Botanical Garden

October 28, 2014   3 Comments