December 01, 2016

By Liz Irwin, Saint Louis Zoo Keeper, Rivers Edge 

Asian elephants Asian elephants

Animals are communicating across the zoo!  Many animal care areas across the Saint Louis Zoo are now collaborating to collect and share digital audio clips of different species vocalizing.  We are playing these tapes for animals that might never hear these sounds otherwise.  

Sometimes the animals we tape or the animals that listen to the tapes live on opposite sides of the Zoo and are naturally from completely different continents.  We are using sound as a type of environmental enrichment to elicit natural behaviors from the animals hearing these new sounds. 

Sound communication is extremely important for many species.  Throughout the Zoo, we hear a multitude of sounds from almost all the species we care for—from the Asian elephants to the dwarf mongoose.  They can range from low grunts to very high frequency sounds that humans sometimes cannot hear. 

The Zoo’s Audiovisual Department was an important ally when it came to collecting sounds.  This tiny staff of two was kind enough to supply a simple sound recorder, commonly used in meetings and lectures.  This turned out to be a great choice because with it, we could pick up the low and high frequency vocalizations of our animals, while cancelling out much of the background noise.  After much discussion, the staff in Rivers Edge decided to set the recorder up during the day as well as overnight, making sure we collected those sounds that animals may only make during the nighttime hours. 

We began the sound enrichment project by simply collecting some of the many noises our multi-generational elephant family makes.  In the wild, animals may communicate throughout the day and night.  Depending on the species, animals use sounds to communicate to their family members, mates or even their enemies.  The sounds we hear at the Zoo can be in response to one another or even other stimuli, such as an airplane flying overhead or a squirrel running across their habitat.  Vocalizations can be directed toward another elephant, a keeper or no one at all.  The sounds elephants make can range from roars and trumpets to squeaks and clucks and can differ from one individual to another. 

After collecting sounds from the elephants, we decided to move on to the other animals under our care. We used the same guidelines: collecting sounds during the day and overnight and in response to different stimuli. Once we collected sounds, we uploaded them to a program called Audacity to edit them into short 60-second sound clips. The edited clips were then added to an excel database that is easily accessible to any keeper on Zoo grounds. This database provides information about the clip, including the species, sound, age, location and other information about the animal and the environment. This gives keepers all the information they may need about any clip.

Black rhinoceros Black rhinoceros

The recorder is currently being used in several areas throughout the Zoo, including the ungulate (hooved animal) and bird departments.  In the future, we will continue to build an extensive database of noises from across the Zoo that all keepers can have access to. 

One additional goal would be to use the sounds in educational programs for both adults and children to hear and learn about animals.  This is yet another way we can encourage people to connect with the animals that so desperately need their help in the wild.   

So, please keep your ears open as you are walking through the Saint Louis Zoo you may hear some of the many amazing sounds we are working to collect!