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鈥淲e really don't have the ability to monitor wild bears year-round in their natural habitat,鈥� Curry said. 鈥淲hereas with our zoo population of polar bears, we can monitor them 24 hours a day, 365 days a year.鈥�

Zoo bears provide easy access to biological material like fecal samples, which can be collected and studied on a daily basis over a bear鈥檚 lifetime. Although samples can be taken from wild bears, they are only a piece of a much larger puzzle.

鈥淲ith wild bears, we don鈥檛 know what has happened between those samples,鈥� Curry elaborated. 鈥淲e don鈥檛 know if they鈥檝e had cubs, how many seals they鈥檝e eaten, whether they're fighting an infection or have an underlying health condition. Their history is a big mystery, which can make it difficult to interpret their blood values.鈥�

Zoo bears, whose health and history are well documented, allow researchers to put the samples into context.

鈥淲e can learn a ton from our zoo polar bears, and then we can apply that knowledge to conserving wild polar bear populations,鈥� said Curry.聽

One goal is to identify blood biochemistry reference intervals for healthy polar bears. Reference intervals allow scientists to define the normal range for all values measured via blood tests. Similar to the blood work panel that a veterinarian may order for your dog.聽

鈥淭he results show where an animal's liver enzymes fall within the normal range, for example,鈥� Curry said.聽

While scientists can collect blood samples from wild polar bears, they don鈥檛 yet know what a normal liver enzyme level is for a healthy polar bear.聽

鈥淲e鈥檙e probably missing some early indicators of disease by not knowing what a normal reference interval is,鈥� Curry explained.

The health of zoo bears, on the other hand, is monitored meticulously. Even their cause of death is investigated and recorded.聽

鈥淏y pulling reference values from zoo bears of known health status, we can establish what a normal polar bear blood glucose level is or what a normal insulin level is, for all the different biochemistry values that we can use to better assess the health of wild bears,鈥� Curry said.聽

Polar pregnancies

Curry specializes in reproductive biology. When she started working with polar bears, their reproductive physiology was poorly understood, and wild birth rates were in decline. In 2012, Curry and a team of CREW scientists completed the world鈥檚 first artificial insemination on a polar bear. They have since repeated the procedure 17 times.聽聽

鈥淯sually, when we鈥檙e asked to do an artificial insemination, it鈥檚 because the female isn鈥檛 getting pregnant naturally, even though she鈥檚 been breeding for years,鈥� said Curry, who notes that no cubs have yet resulted from the procedure. 鈥淲e know that the success rate will probably be very, very low.鈥澛�

Curry and her colleagues have published more than 30 scientific papers contributing to the advancement of our understanding of reproductive physiology in animals.

There is currently no way to test for pregnancy in polar bears. Curry is searching for pregnancy biomarkers in blood samples.

鈥淢ost zoos are training their bears for voluntary blood collection,鈥� Curry explained. 鈥淭hese bears will put their paw into a blood port, and they鈥檙e trained to have their fur shaved, and to be poked with a needle to give a blood sample.鈥澛�

So, how do you get an animal that can weigh up to 1,400 pounds to cooperate? Luckily, polar bears will work for food. Peanut butter, apple juice and marshmallows are among their favorite bribes.

January through April is the pre-breeding season and Curry鈥檚 busiest time of the year. She visits zoos throughout the U.S. while the bears are anesthetized during their annual physical exams.