Category — CREW
According to Elvis, it’s going to be another disappointing year for polar bear births. There is no pregnancy test for polar bears, but Elvis, a 3-year old beagle who lives at IronHeart High Performance Working Dogs, is being evaluated on his ability to diagnose pregnancy by smelling fecal samples (to read more about Elvis and his training, click here). Polar bears experience low reproductive rates world-wide but are exceptionally challenging to study because traditional methods of pregnancy detection, such as progesterone analysis, don’t distinguish pregnancy from pseudo-pregnancy this species. The 17 potential polar bear moms involved in this year’s Elvis study reside in zoos as close as Columbus and as far as Copenhagen. Last year, Elvis was 93% accurate in his pregnancy predictions. If his diagnostic accuracy is similar to last year, we’ll be lucky if just one or two bears have cubs.
But while Elvis sniffs poop, scientists at the Center for Conservation and Research of Endangered Wildlife (CREW) are using cutting-edge research to figure out which components of a fecal sample Elvis might be recognizing in an effort to develop a laboratory-based pregnancy test. A pregnancy test would allow them to determine where the reproductive process is failing so that potential causes can be addressed. A polar bear pregnancy test wouldn’t just be useful for bears in zoos- it could also help their wild cousins. Since the test would rely on a fecal sample, it could be used to non-invasively monitor wild populations of polar bears, whose numbers are predicted to decline.
Unfortunately, the Elvis test showed that “Berit”, the Cincinnati Zoo’s female is not pregnant again this year and so far, there’s been no other word of cub arrivals. Polar bears can give birth anytime from October to January, so Elvis will need to wait a few more weeks to find out how he performed.
To make a donation to CREW’s polar bear research, please visit the Polar Bear Challenge webpage. Donations made by Dec 31st will be matched dollar for dollar by the Young Family Foundation.
December 10, 2014 2 Comments
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.
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.
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.
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.
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.
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.
November 17, 2014 No Comments
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?
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.
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).
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.
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