How active are Dolphins?

Hello, I’m Dr. Melinda Conners and I’m so excited to introduce a new research project looking at the health and welfare of our group of bottlenose dolphins right here at Brookfield Zoo.
A Healthy 2016 for All
Active animals at Brookfield ZooAt Brookfield Zoo, we are committed to providing stimulating and enriching environments for all of the animals under our care.

We’re only a few months into 2016, which means we’ve still got an eagle eye focused on keeping our New Year’s Resolutions, right? I’d bet that many of those resolutions include exercising more and getting healthy. Here at the Chicago Zoological Society, we’re invested in ensuring that all the species living at Brookfield Zoo are getting a healthy dose of physical activity every day.

How active is a Dolphin?

We know our dolphins at Seven Seas are active, but now we have a tool to measure just how active they are throughout a day, along with differences in activity and behavior between individuals, so that we can ensure each individual is thriving.

Measuring just how active a species can be is much trickier than you might think! How can we go about measuring how much a dolphin swims in a day? Dolphins are very active species; they don’t simply swim in straight lines- they move continuously through varying depths using acrobatic movements, like spins, glides, and jumps. All of this motion is important for us to measure when considering how active a dolphin is throughout a day. 

“D-TAG”: A Fit-Bit© For Dolphins
To understand the activity and movements of our dolphins, we’re partnering with Alex Shorter, a biomechanical engineer from the University of Michigan, and with scientists from Woods Hole Oceanographic Institute. Brookfield Zoo’s marine mammal care team are working with our dolphins to get them comfortable wearing a special device called a “D-tag”, short for “Digital Acoustic Recording Tag”. D-tags are a type of bio-logging device used to track and monitor the movements, behavior and physiology of animals. The simplest way to understand what a D-tag does is to think of it as a “special-edition” Fit-Bit© designed specifically for dolphins and whales. They are about the size and shape of a computer mouse and stay on the back of the animals with four small suction cups.

Image on Left: For a size comparison, here you can see a D-tag on Tapeko, a 34 year old female dolphin at Seven Seas, next to my hand sporting my own activity logger! Note, the suction cups on the bottom of the tag and the hydrophones (the two small yellow bumps) at the front of the tag. The suction cups that are used to keep the tag attached to the dolphins have been examined thoroughly by engineers and biologists to be safe for the dolphins: they suction firmly, but not so firmly that they could damage the skin. Center Image: Spree wears her tag while swimming throughout the Seven Seas habitat. Note the placement of the tag behind her blowhole but in front of her dorsal fin, and aligned with the center axis of her body. Image on Right: Here, Melissa Zabojnik, a senior marine mammal care specialist at Seven Seas, works with Spree to familiarize her to the feel of the D-tag. Just like wearing a ring on your finger can feel a little unusual for the first few days, so can wearing a suction cup device. The animal care team at Seven Seas tailors the training process to each individual dolphin, so that all the dolphins are calm and comfortable with the tags before wearing them. 

Bundled up into the device is an orientation sensor, a compass, and two mini underwater microphones called hydrophones. These sensors allow us to understand how the animals are moving and communicating. By recording when and how deep they dive, how they move underwater, and the vocalizations they make to communicate to each other, we can begin to create a detailed picture of the dolphins’ underwater lives.

What’s inside a D-tag? D-tags contain a suite of sensors designed to record information on 1) the vocalizations of the animals (recorded by two hydrophones), 2) the acceleration of the animals on three different axis (roll, pitch, and yaw: just like sensors on an airplane), and 3) the swimming and diving depths of the animals (recorded by a pressure sensor). Additionally, the tags used at Brookfield Zoo will soon incorporate tiny velocity sensors, which, combined with data from the motion sensors, can be used to reconstruct an animal’s path underwater. Cool, right?! 

At Brookfield Zoo, we’re in a unique situation where we can work with all of the dolphins at Seven Seas to ensure they’re comfortable wearing the tags by using a technique called positive reinforcement training. This means that our group of eight dolphins are gradually introduced to the tags and then, over time, increase the time they spend wearing the tag, while getting rewarded with their favorite reinforcement items (like fish and jell-o). The dolphins at Seven Seas are making great progress, becoming increasingly comfortable wearing their tags. Tapeko, Allie and Magic are already wearing their tags during “Dolphins-in-Action” presentations at Brookfield Zoo, so be sure to come see their progress in person!

Spree, a 13 year old female bottlenose dolphin, wearing her tag and interacting with senior marine mammal care specialist Mairim Martinez, at Seven Seas.

We hope that soon each of the dolphins will be wearing their individual D-tags as part of their daily routine, so that we can monitor their behavior, movements, and vocalizations. We’ll revisit this in a few months to share the dolphins’ progress and all the data we’ve been able to collect!
So, now I leave you with a question: How much have YOU exercised today?
-Melinda C

Posted: 3/8/2016 3:53:26 PM by Bryan Todd Oakley

CZS & Brookfield Zoo

Since the opening of Brookfield Zoo in 1934, the Chicago Zoological Society has had an international reputation for taking a cutting-edge role in animal care and conservation of the natural world. Learn more about the animals, people, and research that make up CZS here at our blog.


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