Blog: Center for the Science of Animal Care and Welfare

Going the Distance to Monitor Dolphin Welfare

Hello again!

Melinda here. Last time I wrote to you, we were just getting started with our dolphin welfare project at Brookfield Zoo. Over the past few months, we’ve made some exciting headway.

Today’s story revolves around one central question: How far does a dolphin swim in a day?

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Here, Allie and her young daughter Maxine are swimming together. Dolphins are commonly seen swimming in pairs or in small groups, often using parallel movements, a behavior called “synchronous swimming.”

Similar to what you may experience at school or work, our dolphins’ activity levels change throughout a day. While you may run and jump during recess and P.E., or go for a jog after work, you are probably sitting and resting (but hopefully not sleeping!) during math and grammar lessons or while at your desk. Likewise, if you visit our Seven Seas dolphin habitat, you will see that our dolphins’ behavior is continuously switching between resting, exploring, playing, and interacting with animal care staff.

What is a footstep to a dolphin?
Animals who move on land, like us humans, do so typically by propelling themselves forward with their feet or paws. Feet are less useful in the water than they are on land … so, many animal species that swim in the ocean evolved to have flukes instead of feet. Flukes are like two feet fused together to create one big, strong water paddle!

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Our youngest dolphin, Maxine, shows off her powerful fluke! Note the similarity in her fluke with the flippers you put on your feet when you swim or snorkel in the ocean. Flukes are important for swimming, but also have many other purposes, such as acting as a tool to hit and stun fish while hunting and even as a communication tool used between dolphins by slapping the surface of the water and creating a loud sound.

So, instead of looking at footsteps in dolphins, we count fluke strokes! By keeping track of each individual fluke stroke, we can begin to piece together just how each individual dolphin swims in its environment. 

How do we look at dolphin fluke strokes?
As described in a previous post, we are using DTAGs to measure dolphin activity. Inside these tags is a motion sensor that measures animal acceleration. By watching animal behavior through video-recordings, we can match specific animal behaviors with acceleration patterns. One of our goals is to describe the behavior of an individual dolphin solely by looking at DTAG data.

Here are some examples:
The following picture shows a typical fluke stroke pattern of a dolphin swimming slowly and steadily. Each peak in the pattern represents a single fluke-stroke (where the dolphin moves its tail up and down one time).

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Now, compare that to the following fluke stroke pattern of a dolphin who took off swimming super-fast!! I call these patterns “BURST FLUKES” for obvious reasons! I usually see these when our dolphins are playing rambunctiously with each other or are interacting with their favorite enrichment items! 

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Going the distance
Well, now I’ve shown you how to identify fluke patterns when a dolphin is swimming through the water, but how do we measure how much a dolphin travels in a day?

In a partnership with scientists and students from Dr. Kenneth Shorter’s biomechanics lab at the University of Michigan, we have just installed an overhead video recording system at the Seven Seas stadium. Using two very powerful video cameras, we are now able to record detailed movements of individual dolphins across the pool surface. Dr. Shorter’s students, Annika and Joaquin, recently used some of the video data to recreate a movement track of our dolphin Magic at Seven Seas during a training session. Check out this really cool animation of Magic’s track created by Dr. Shorter’s team using the video data!

 

 

The moving red “worm” is actually the reconstructed movement path of our two-and-a-half-year-old dolphin, Magic, swimming around the stadium pool during a Dolphins-In-Action show! While Magic can swim pretty darn fast, the speed of this animation was sped up so that you could see his full movement track more quickly.

The next step will be to combine this surface tracking data from the video cameras with the motion sensor data collected by the DTAGs to reconstruct three-dimensional paths of our animals in their Seven Seas habitat!  

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And, once we recreate these three-dimensional paths of our dolphins we can finally answer our sought after question: how far does a dolphin at Seven Seas swim in a day?

Stay tuned for more updates on the dolphin welfare project at Chicago Zoological Society. In the meantime, come say hello to all of our eight dolphins and to our highly-skilled animal care staff at Seven Seas who make this project possible!

Melinda Connors
Postdoctoral Fellow

Posted: 9/20/2016 10:43:42 AM by


Center for the Science of Animal Care and Welfare

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