Interpreting Hormone Roller Coasters

Zoo InternQuest is a seven-week career exploration program for San Diego County high school juniors and seniors. Students have the unique opportunity to meet professionals working for the San Diego Zoo, Safari Park, and Institute for Conservation Research, learn about their job and then blog about their experience online. Follow their adventures here on the Zoo’s website!

Everyone has dealt with hormones. It’s what makes growing up a pain in the butt, right? So what do these acne-inducing chemicals have to do with the conservation of endangered animals? The answer: everything. Dr. Chris Tubbs is a Scientist in the Reproductive Physiology Division at the San Diego Zoo Institute for Conservation Research. He studies animal hormones to monitor the reproductive status for the residents of the San Diego Zoo and Safari Park. For endangered animals with low populations, finding our when a giant panda is in heat or when an elephant is about to give birth can have a huge impact on the species as a whole.

Hormones are chemical messengers that are responsible for a wide range of effects like mood swings and hunger. Hormones also control the reproductive cycle. Dr. Tubbs uses fecal samples such as the ones he is holding to determine how much of a given hormone an animal is producing. This enables him to determine where an animal may be within her reproductive cycle or if she is pregnant.

Hormones are chemical messengers that are responsible for a wide range of effects like mood swings and hunger. Hormones also control the reproductive cycle. Dr. Tubbs uses fecal samples such as the ones he is holding to determine how much of a given hormone an animal is producing. This enables him to determine where an animal may be within her reproductive cycle or if she is pregnant.

One of the most important hormones Dr. Tubbs monitors is called progesterone, which signals the brain to release or withhold eggs from the uterus and controls the shedding of the uteran lining. Therefore, raised levels of this hormone can be specifically indicative of ovulation and pregnancy.

One of the most important hormones Dr. Tubbs monitors is called progesterone, which signals the brain to release or withhold eggs from the uterus and controls the shedding of the uteran lining. Therefore, raised levels of this hormone can be specifically indicative of ovulation and pregnancy.

Interns got to play a game of “Who dung it?” in which we had to guess whose poop belonged to who! Examining the fecal material (poop) of Zoo and Safari Park animals is one of the easiest ways of monitoring hormone levels. As you can imagine, blood and saliva samples are considerably more difficult to collect, especially on a regular basis.

Fecal matter and urine samples are rich sources of information regarding the diet and health of an animal. Samples are preserved in a refrigerator and are kept for the duration of the animal’s research.

Interns were given an activity to test mock-samples for progesterone levels. We had to analyze what might be happening to the animal’s reproductive cycle. There were twelve samples of mock progesterone in test tubes labeled with sequential dates. We mixed each sample with a solution, which would turn the sample a different color. The darkness of the color would determine the relative strength of progesterone in our subject animal.

Interns were given an activity to test mock-samples for progesterone levels. We had to analyze what might be happening to the animal’s reproductive cycle. There were twelve samples of mock progesterone in test tubes labeled with sequential dates. We mixed each sample with a solution, which would turn the sample a different color. The darkness of the color would determine the relative strength of progesterone in our subject animal.

In reality, data received from the tests is not quick in coming. However, once researchers achieve precise data the hormone levels are graphed with respect to time. These graphs show trends in hormone levels and reveal what’s going on beneath the surface of these complex animals. In our experiment, the results were virtually immediate and Joseph is seen here recording his initial findings.

As the interns presented their findings in the form of large colored graphs, it became clear that our mock-data actually matched that of real animals. Trends such as the “flatline” just after the beginning of intern Haley’s graph are typical of animals who are not ovulating or pregnant.

As the interns presented their findings in the form of large colored graphs, it became clear that our mock-data actually matched that of real animals. Trends such as the “flatline” just after the beginning of intern Haley’s graph are typical of animals who are not ovulating or pregnant.

Haley’s data was similar to that of real progesterone levels in a pregnant rhino, shown here. Unfortunately, rhinos are one of the most difficult animals to monitor, since their irregular hormone levels frequently baffle researchers. Dr. Tubbs’s work in deciphering the chemical signals of animals gives an element of predictability to the reproduction of animals in zoos. This allows zookeepers and medical staff to plan for and protect the offspring of these animals, boosting the populations of endangered species.

Laura, Photo Team
Week Five, Fall Session 2013

 

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