Category — Polar Bears
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
Welcoming Two New Post-Doctoral Fellows
Two new post-doctoral fellows, Dr. Lindsey Vansandt and Dr. Anne-Catherine Vanhove, were welcomed to CREW in the fall of 2014.
With funding support from the Joanie Bernard Foundation, Dr. Vansandt will be working with Dr. Bill Swanson, CREW’s Director of Animal Research. Dr. Vansandt obtained her Doctor of Veterinary Medicine degree from the University of Missouri and her Doctor of Philosophy degree from the University of Maryland (in collaboration with the Smithsonian Conservation Biology Institute). Her Ph.D. studies focused on characterization and propagation of spermatogonial stem cells in domestic cats as a model for conserving endangered cat species. Dr. Vansandt also has experience working in veterinary emergency services. At CREW, she will be conducting studies to improve the health and welfare of feral and shelter cats as well as helping to apply oviductal AI for propagation of endangered felids.
With funding from the Institute of Museum and Library Services (IMLS), Dr. Vanhove will be evaluating survival of plant samples in CREW’s Frozen Garden under the supervision of Dr. Valerie Pence, Director of Plant Research. Dr. Vanhove will complete the second phase of the IMLS project, focusing primarily on the survival of shoot tips and gametophytes after long-term storage in liquid nitrogen. She recently received her Ph.D. from the Division of Crop Biotechnics, Katholieke Universiteit Leuven, in Leuven, Belgium. Her thesis work with meristem culture, stress physiology, and cryopreservation makes her well suited for the IMLS project.
The University of Cincinnati/Cincinnati Zoo Connection
CREW has had a long-standing collaborative relationship with the University of Cincinnati’s (UC) Department of Biological Sciences, but today it is strengthened by two promising young scientists who split their time between CREW and UC. Corrina DeLorenzo and Megan Philpott are both enrolled in UC’s Ph.D. program under Drs. Ken Petren and Theresa Culley, respectively, but they are conducting much of their dissertation research at CREW.
Corrina earned her bachelor’s degree at Miami University, with a double major in Zoology and Environmental Science. As an undergraduate, she became involved in research evaluating the population genetics of the Italian wall lizard or “Lazarus lizard” in the Cincinnati area. After graduating, Corrina was accepted to CREW’s summer internship program, working with Dr. Erin Curry on the Polar Bear Signature Project. She was recruited into UC’s graduate program in January 2014. Since starting her Ph.D. research, Corrina has identified multiple antibodies that detect specific proteins in polar bear feces in an effort to develop a polar bear pregnancy test.
Megan received her bachelor’s degree from UC in Biology and was also an intern at the Cincinnati Museum Center, managing the Museum’s Philippine Bird Genetics project. Her Ph.D. research is part of the Plant Lab’s IMLS funded project to evaluate samples that have been stored for years in CREW’s CryoBioBank for genetic changes that might have occurred over time. In April, Megan was awarded the Botanical Society of America’s Public Policy award to attend Congressional Visits Day on Capitol Hill. There, she learned about communicating science to policy makers and met with the offices of Ohio Senators and Representatives to request their support for increased federal funding of scientific research, using CREW’s research as an example of the importance of federal funding and support. (Students supported by the UC Department of Biological Sciences, Institute of Museum and Library Services and CREW Eisenberg Fellowship.)
P&G Wildlife Conservation Scholars
In 2011, CREW established a partnership with the Ohio State University’s College of Veterinary Medicine to train veterinary students in conservation sciences with funding support from Procter & Gamble Pet Care. This past summer, two OSU veterinary students, Kelly Vollman and JaCi Johnson, were selected as P&G Wildlife Conservation Scholars.
Kelly worked with Dr. Monica Stoops analyzing urinary testosterone and glucocorticoid concentrations to determine if the pattern of excretion could be used to predict gender, parturition date and assess fetal viability during Indian rhino gestation. Kelly analyzed urine samples collected throughout seven Indian rhino pregnancies that resulted in three male and four female calves. Six of the pregnancies ended with the birth of live calves, whereas one pregnancy ended in a stillbirth, a relatively common occurrence in this rhino species. By learning more about the endocrinology of pregnancy, results from Kelly’s study will help establish physiological markers to improve pregnancy outcome in this species.
JaCi worked with Dr. Bill Swanson to investigate cat sperm vitrification as an alternative to standard slow freezing methods. Vitrification involves ultra-rapid cooling to avoid ice crystal formation and form a “glass” instead. For this study, JaCi collected semen from domestic cats (and one ocelot) and compared vitrification in a sucrose solution, with direct pelleting in liquid nitrogen, to slow freezing with glycerol in straws over liquid nitrogen vapor. Post-thaw sperm motility and acrosome status were similar between methods and 25% of domestic cat oocytes were fertilized following insemination with vitrified
sperm. This simplified approach to cat semen preservation may be particularly useful for field biologists working with felids in the wild.
November 21, 2014 No Comments
Written by Crissi Lanier & Shasta Bray
It’s not as easy as one would think. Dr. Erin Curry with our Center for Conservation and Research of Endangered Wildlife (CREW) is committed to finding a way.
The Cincinnati Zoo is currently home to two polar bears, Little One and Berit. Little One is a 24-year-old male and, despite his name, is the taller of the two bears. Berit is a 16-year-old female. She has a longer and leader body and face and sharper features than Little One. Plus her ears tend to stick out a little more. Polar bears can reproduce until about 26 years old and Berit is at a prime age for reproduction. She and Little One have been together since 2007 and are observed breeding every year, yet Berit has never had cubs. We aren’t giving up yet.
In the meantime, Dr. Erin Curry has been working very hard in the CREW lab to develop a non-invasive pregnancy test for polar bears. It’s important for zoos to know when their polar bears are pregnant to be able to properly care for and monitor them. It is very difficult to determine if a female polar bear is pregnant because there is a period of time between mating and implantation of about 4 to 7 months, making it extremely difficult to know if breeding successfully resulted in a pregnant female. Polar bears also go through a period called pseudo-pregnancy, in which females show an increase in progesterone level similar to that of a pregnant female, but in the end there is no cub born. Pseudo-pregnancy also occurs in otters, wolverines, red pandas and some cat species. These factors make it extremely difficult to determine if a bear is pregnant. While there is not a definitive test yet, she has multiple projects underway that look promising.
Maybe the answer can be found in feces. Feces samples are very easy to collect without requiring invasive procedures. Samples from about 55 bears from 24 different institutions across North America and Canada are sent to Dr. Curry three times a year, packed in dry ice, to research any possible chemicals that may be present in pregnant bears but absent in others. She is also examining various protein levels in the feces and has identified five proteins that are higher in pregnant bears than in non-pregnant or male bears. More research is needed and it is a very expensive test. The goal would be to develop a cost-effective and user-friendly test.
You may have heard about Elvis, the polar bear poo-sniffing dog. Elvis has been pretty successful so far in distinguishing between feces from pregnant and non-pregnant bears. Dr. Curry continues to try to determine what exactly Elvis smells that alerts him to the pregnancy. Read more about Elvis’ story here.
Another way to determine if a bear is pregnant could be through an ultrasound, but conducting one on a polar bear has its challenges. Dr. Curry along with Megan-Kate Ferguson (Curator of Animal Development and Training) and the bear keepers have been working with Berit to desensitize her to being touched so she can undergo medical procedures, such as ultrasounds, without sedation. Desensitization is a process by which the animal is touched through a training wall with an instrument, such as an ultrasound probe, over a period of time as the animal becomes less reactive to it and it becomes like a routine practice. The animal is rewarded throughout the process, called operant conditioning, to associate positive rewards with being touched. As the animal becomes more used to being touched, more actions and commands are added to eventually complete the behavior necessary for the procedure. It is a multi-step process that takes time and patience to develop an animal’s level of trust and comfort. Megan-Kate explains this process further in previous blog posts here.
Now that Berit is conditioned to being touched through the training wall while standing with her abdomen pressed up against it, the next step is to perform exploratory ultrasounds to find her uterus. Even though we know Berit is not currently pregnant, the ability to even find the uterus at all is important if performing ultrasounds is to become a reliable way of detecting pregnancy. Despite a polar bear’s large size, the uterus is small and very difficult to find. Polar bears have two uterine horns, each of which (in a non-pregnant state) is roughly the size of a pencil.
First, Berit is called in to the training area and asked to stand up at the training wall. When she completes this, she is immediately rewarded with ground meat treats. Megan-Kate then hoses her lower abdomen down through the wall; performing an ultrasound is more successful on a wet bear because a more solid connection is made between the bear’s skin and the probe. There can’t be any air or space between the probe and the skin, which is difficult due to her thick, fur coat. Once Berit is sufficiently wet, Dr. Curry uses the probe to search for the uterus. A transducer on the probe emits sound waves into the body and picks up the echoes as they bounce back from organs. The ultrasound machine then translates the information into a two-dimensional image of the bear’s insides that Dr. Curry interprets. During this time, Berit receives treats and constant positive reinforcement as she stands very still and calm.
On this day, Berit cooperated like a champ and Dr. Curry was able to find the bowels, but not the uterus. Maybe next time! Even so, it was a successful day of continued training with Berit.
Solving the problems facing polar bear reproduction in zoos isn’t going to happen overnight, but it’s an ongoing challenge that Dr. Curry and the rest of the Zoo are committed to seeing through. Learn more here.
September 1, 2014 2 Comments