September 8, 2016
What Do Tiger's Varied Sounds Mean? A Woman Investigates
By Andrea Bruner
The Batesville Daily Guard
Batesville, AR (AP) - In 2008, Courtney Dunn was volunteering with a sanctuary when she started noticing the different sounds tigers would make with one another as well as the sounds they made when she talked to them.
Dunn started thinking about the tigers’ communication and began recording them, according to The Batesville Daily Guard (http://bit.ly/2ccaRCv ).
Today, her research work has been nationally recognized and Dunn is at the forefront of a movement to save the tiger population for generations to come.
Even in high school, Dunn always knew she wanted to go into biology, although she was unsure of which specific area she wanted to study.
Dunn, who was an honor student at Midland and graduated in 2008, can’t remember a time when there weren’t animals around.
``My first dog was a border collie named Patch,’’ she recalled, and they also had an orange tabby cat named Oliver.
Meredith Pennino, a volunteer for the project and keeper at Big Cat Rescue, records Bengali as part of the ex-situ study. (Photo Credit: Michael Kennedy)
``We lived on a farm in Denmark, Arkansas, so I also grew up around a herd of cattle, horses, ducks, chickens, rabbits - any kind of farm animal you could imagine,’’ she continued. ``I tried to help my father around the farm as much as I could.’’
While in school, Dunn volunteered several years at the Bald Knob Veterinary Clinic and had become interested in veterinary medicine, but it was not until she was in her last year of studying for her bachelor’s degree that she decided to switch from becoming a zoo veterinarian to a conservation biologist.
``I had been gaining experience at various animal facilities throughout college, including an internship at the Memphis Zoo with their African penguins, African elephants, white rhino, and various species of tropical birds,’’ she said.
Her goal was to gain experience with a variety of animals so she would have ``diverse knowledge’’ going into her veterinary school applications.
But when she began an internship at the National Tiger Sanctuary in Chestnutridge, Missouri - and met a rehomed Bengal tiger named Tina - Dunn’s focus changed from veterinary medicine to the conservation research she now does.
The sanctuary is also home to mountain lions, African lions and leopards. Dunn said besides caring for the big cats, she also led guided educational tours for the public and taught visitors about the plight of these animals in the wild.
``Oddly enough, there are actually more tigers in the state of Texas alone than there are anywhere in the wild,’’ Dunn said. ``Tina happened to come from this state where she initially relocated from someone who had her as a pet.’’
Through her ``unique personality and vocalizations,’’ Tina sparked Dunn’s interest in tiger conservation and in turn, led her to pursuing her master’s degree as well as eventually founding The Prusten Project.
As Dunn worked with Tina, she started noticing the different sounds she would make with other tigers vs. with her. Dunn thought there might be a way of studying how they communicate with each other, so she started recording them and analyzing their sounds.
``One of the most interesting sounds tigers make is a greeting noise, called chuffing, which tigers use to say hello. There is really no easy way to describe the sound, but the tiger produces it by keeping its mouth closed and blowing through its nostrils, producing a breathy snort.
``Another friendly sound tigers make sounds very close to a cow mooing. In reality, it is probably the closest thing a tiger has to a meow but just sounds very deep as they are obviously a much larger animal,’’ Dunn said.
The sound Dunn specifically studies, however, is something known as ``a long call,’’ which can travel upwards of three miles away. It is a very deep, resonating call that tigers use to communicate with other tigers they cannot necessarily see.
Because tigers are friendly to their keepers, some people might have the misconception that they are safe to be around, but Dunn stresses that tigers are still very much a wild animal despite living in a zoological facility.
``As anyone probably knows, domestic cats are very stealthy and like to pounce and scratch when they are playing with you. Now, imagine that domestic cat weighing approximately 400 pounds - it could definitely do quite a bit of damage! Which is why, I always let people know that just because a tiger is talking friendly to us, it does not make them safe,’’ Dunn said.
Dunn also said that while some think of white tigers as ``a unique, endangered species,’’ in reality the white tiger is merely a genetic variation of the Bengal tiger. ``The white coloration occurs as a recessive genetic mutation on only very rare occasions in the wild. The reason we see so many in captivity is people have selectively bred for that white coloration.’’
The Prusten Project (www.theprustenproject.org) started out as a research project in August 2012 but became a nonprofit organization in January 2016. Dunn said it began as a way to ``define what makes an individual tiger’s call unique in hopes of developing non-invasive acoustic monitoring.’’ If human ears were able to make that distinction, what could a software program pick up?
The monitoring would entail analyzing the social vocal communications of tigers by using microphones strategically over the tiger’s home ranges, not only as a tool for conservation censusing but also anti-poaching efforts.
Dunn set up recorders around zoos and animal sanctuaries in the U.S. to record. Dunn wanted to determine if tigers have unique vocalizations per sex age or individual.
``I wanted to find a way to improve current protection methods for wild tiger populations while providing an easier tool to study and monitor forests as a whole. Not only would acoustic monitoring provide information about tigers but, since it is recording every sound in the forest, it can also provide information about other vocal mammals like bats, birds, amphibians and even human activity in the area. This is a method known as soundscape monitoring which has shown great promise in other areas of the world,’’ she said.
She sent her research on The Prusten Project to a contest called Think for Tigers sponsored by Oxford University’s Wild Conservation Research Unit in England.
Think for Tigers (www.thinkfortigers.org) was trying to find an innovative idea product or solution that will help researchers and rangers locate track or monitor the last 3,200 tigers in the wild to better study and protect them. With their camouflage, stealth and large territories - tigers are often difficult to spot.
Dunn won the contest, and she and researchers from the University of Oxford’s WildCRU and staff members from World Animal Protection went to India for 10 days in April and May this year to locate tigers.
This kitty in the Milwaukee Zoo is in the Prusten Project
``It (India) was a very beautiful country with very friendly people,’’ Dunn remarked. ``The forests are not the way people often picture jungles with tigers. They are usually dry with a lot of tall, dry grasses and thinned out patches of trees.’’
Dunn said they would look for pawprints (or ``pug marks’’) in the dirt and followed these in their jeep.
``We also listened to the forest . and all of the vocalizations the other animals are making. When certain animals see a tiger, like sambar deer or langurs (a type of monkey), they make a very specific vocalization. Once we would hear another animal call, `Tiger! tiger!’ and we would follow that sound until we reached one.’’
Dunn said the group is planning to go back to India in December to explain their findings and present their plan.
She currently works at the Dallas World Aquarium as a zookeeper with giant anteaters, Hoffman’s two-toed sloths, golden-headed lion tamarins, and several species of tropical birds.
She has just started her Ph.D. this month at the University of Texas at Arlington and will be continuing her work with bioacoustics, applying her knowledge to protecting other types of animals, not just tigers.
After completing her Ph.D., she hopes to work as a post-doc at the San Diego Zoo Institute for Conservation Research.
It’s important to Dunn to get the word out that there is a need in helping to save the tiger population for generations to come, especially as the international wildlife poaching and trafficking scene runs rampant (it’s a multibillion-dollar-per-year global criminal activity) and habitats are being lost.
Today, only six subspecies of nine remain, and all remaining six subspecies are endangered, according to The Prusten Project. Six years ago, there were about 3,200 tigers (all subspecies combined) left in the wild, but those numbers have actually gone up - according to the most recent data from World Wildlife Fund, around 3,890 tigers now exist in the wild.
But with the work of The Prusten Project, Oxford and World Animal Protection - she hopes the future is bright.