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
You probably already know that the Cincinnati Zoo is committed to the conservation of lions, tigers and cheetahs, but did you know that we are also leading the way in small cat conservation? And our Small Cat Signature Project just got bigger! Our Center for Conservation and Research of Endangered Wildlife (CREW) recently received a Museums for America Grant from the Institute of Museum and Library Services to improve our ability to maintain healthy captive populations of five small cat species across the country—the Brazilian ocelot, the Pallas’ cat, the black-footed cat, the Arabian sand cat and the fishing cat.
Unfortunately, none of these small cat populations are considered sustainable through natural breeding alone. That’s where Dr. Bill Swanson, CREW’s Director of Animal Research and the world’s leading expert on small cat reproduction, comes in. Working in partnership with Dr. Jason Herrick of the National Foundation for Fertility Research and the Species Survival Plan coordinators for each species, Dr. Swanson will direct the project with a focus on three goals: 1) Collect and freeze semen from the most valuable cats for each species, 2) Produce viable offspring using artificial insemination in recommended breeding pairs that fail to reproduce naturally, 3) Produce offspring with frozen-thawed semen from genetically valuable or under-represented males.
Building on CREW’s decades of ground-breaking research on small cat reproduction, successful completion of this project will greatly enhance the sustainability and stewardship of small cat collections in AZA zoos. Now that’s big news!
October 9, 2014 1 Comment
Over the past year, Zoo staff and volunteers have been getting ready to celebrate World Rhino Day. This year’s festivities will be held from 10 am to 4 pm on Sunday, September 21. The goal for this event is to raise funds for rhino conservation and increase the public awareness of the major challenges faced in protecting wild rhino populations. The Zoo is proud to exhibit three species of rhino; the African black rhino, the Indian rhino and the Sumatran rhino. Zoo visitors can take part in family activities, animal demonstrations, keeper encounters and a rhino-riffic raffle. The day will start with the official announcement of the winners for our Save the Rhinos poster contest. The day will no doubt be a Rhinotastic success!
The raffle items this year include rhino-themed gift baskets, a one-year membership to the Cincinnati Zoo & Botanical Garden, Rhino Rembrandt paintings artistically designed by the Zoo’s African black rhino ‘Seyia’ and Sumatran rhino ‘Harapan’, a one-of-a-kind Sumatran rhino footprint casting created by keeper and artist Lindsay Garrett, and an amazing print of Sumatran rhino ‘Harapan’ as designed and painted by artist Ali Armstrong as part of her ‘Scarce Project’.
Be sure to also come out to the Zoo on Monday, September 22, from 7-9 pm to hear the State of the Rhino Lecture by CREW Rhino Scientists Dr. Terri Roth. Tickets to Dr. Roth’s lecture can be purchased online. A rhino marketplace will take place in the lecture hall before and after the talk and another rhino raffle occur. In addition, renowned children’s book author Mary Kay Carson and photographer Tom Uhlman will be available before and after the lecture to sign copies of their critically acclaimed book, Emi and the Rhino Scientist.
Come one, come all to help us celebrate rhinos!
September 19, 2014 1 Comment