Oh, the stress of it all… Tanya explains
Tanya Lama, a Masters student from the University of Massachusetts, spent June to August living at EWB’s Conservation Ecology Research Station in the Okavango Delta. As a researcher on the elephant stress hormone project, she worked alongside the Abu herd as well as re-introduced and wild elephants in NG26 collecting fecal samples for stress hormone analysis. Here’s what she had to say about her first experience in Botswana and with EWB:
I’ve never been to Africa before, so stepping off of a tiny plane in the middle of the Okavango Delta absolutely astounded me. On the brief ride to the research camp, the landscape, the steady flow of the incoming floods, the vegetation, an occasional giraffe or a zebra caught my eye among the foreign scenery. The following morning I was introduced to the handlers and the Abu herd. I joined them under the blazing sun while the elephants browsed and munched, wrapping grasses around their muscular trunks and ripping the roots up from the sandy soil. Flat brown teeth in straight rows; mashed and ground together in slow succession while their trunks gathered the next fistful of spikey acacia branches, of hard round palm fruits, of dry three-horn thatching grasses.
These days offered a lot of firsts and a lot of questions. I welcomed the knowledge and expertise of the elephant handlers who have shared so many hours with this herd under the hot October sun, November rains, and Christmas mornings. They helped me piece together the history of each individual, their complex herd dynamics and most importantly helped me monitor behavioral and physiological markers that would be essential to my study.
People think my job is pretty glamorous until they find out I spent all summer picking up elephant feces. It turns out feces can provide us with a wealth of biological data and is relatively easy to collect. As herbivores, elephants tend to defecate frequently (depending on sex, age, diet and other factors like season), and provide a really non-invasive method of collecting biological data (versus blood, tissue or hair collection). Collection of feces for a stress hormone study provides a really different picture than would a series of blood samples. Stress hormone (cortisol in humans and other mammals) spreads rapidly through the blood as a response to environmental stimulus, and these metabolites are reflected in the feces after a stressful event. Therefore a blood sample is kind of like a snapshot, whereas a fecal sample is more of an overview of the past 24 hours of activity for an individual. I was able to go out on a daily basis, find a known individual, observe him or her from a safe distance and then collect any feces that were left behind.
For the Abu herd, I was able to observe them all day long and make note of any potentially stress inducing circumstances (mating with a wild bull, interactions with other herds, threats) and the behavioral response of the individual to these circumstances. These samples were then homogenized, and the fecal matter was extracted (stripped of the fibrous material) and sterilized, resulting in a dry, odorless sample.
The objective of my project is to evaluate stress hormone levels of semi-captive (Abu herd), released and wild African elephants living in NG26. I collect biweekly fecal samples from several members of the Abu herd and put those samples in context of the previous 24 hours of activity of that individual. Behaviorally, I recorded the frequency of interaction with Abu guests (meet and greets, elephant back safaris) as well as the handler that accompanied that elephant and any potentially stress inducing events. Physiologically, I collect whatever biological data is available to me including height and weight, periods of estrus or physical injury. I also gather fecal samples weekly from the three reintroduced individuals who were previously members of the Abu herd. Gika, Naya and Nandipa are also fitted with telemetry collars which record their GPS location hourly. I will be putting the collection of their samples in context of their movements, their proximity to the Abu herd and human settlements, such as lodges. I am not able to continuously observe their behavior, but I am able to perform additional sampling under special circumstances such as a new birth or an injury. This helps me to better construct an endocrine “profile” (the range of stress hormone levels exhibited) for each individual. I collect fecal samples from three wild females from different herds on a weekly basis. I was able to deploy one telemetry collar on a wild individual in NG26, and will be comparing her movements to the movements of Gika, Naya and Nandipa.
I have managed to collect and extract 150 fecal samples thus far and will be analyzing them using radio immunoassay (RIA) at the San Diego Zoo Institute for Conservation Research later this year. These preliminary analyses will give me an idea of how consistent my extraction method was, as well as the range of stress hormone per sample both under normal circumstances and under stress.
My final weeks in the delta were focused on sample extraction and training our research assistants, Kabo and Ronnie, who will take over the sampling of released and wild individuals while I begin analyses and coursework at UMass towards the completion of my Masters. I’m sad to have left the delta, but reading the handler’s daily reports keeps me up to date on the elephant’s activities. The main objectives of my next trip to the delta are to refine my sample extraction method and hopefully finally get to spot a leopard!
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