Will work for fish

Rice engineering students develop fish-rewarding enrichment device for sea lions at Houston Zoo

Cali, Jonah, Kamia and Rockie are the Houston Zoo’s resident California sea lions – and they absolutely love fish.

One of the Houston Zoo’s sea lions interacts with the Sea Lion Enrichment Device developed by Rice engineering students. Photo credit: Jeff Fitlow. 

They’re also highly intelligent, inquisitive mammals capable of mastering and engaging in intricate behaviors, and they enjoy frequent mental and physical stimulation. This is why the zoo recruited a group of six Rice engineering students enrolled in Introduction to Engineering Design (ENGI 120) to develop a new enrichment device for the sea lions to use during breaks from training sessions, shows and exploring their habitat at the zoo.

The students – Amelia Brumwell, Matthew Chagnot, Cody Davis, Jeremy Palmer, Brady Taylor and Jasmine Zhou – began developing the Sea Lion Enrichment Device (S.L.E.D.) in fall 2015 under the supervision of Ann Saterbak, associate dean of engineering education and professor in the practice of bioengineering education, and Matthew Wettergreen, a lecturer at the Oshman Engineering Design Kitchen (OEDK). The team worked with Houston Zoo trainers to understand the needs of the sea lions and what the trainers were looking for in an enrichment device.

“Throughout the fall semester, we went through the design process, figured out what was going to work, narrowed down our ideas and built our final prototype to give to them at the end of the semester,” Palmer said.

The S.L.E.D. is constructed from PVC pipes and consists of four pieces that can be fitted together as one or two devices. Each section has a hole covered by a rotating collar, which the sea lions must use their problem-solving skills to open. When they use their noses to push these pieces around, they can line up the holes to release fish, ice or toys from the wells.

The trainers introduced the sea lions to the device with the holes exposed, so they would learn that treats and toys were inside. Eventually the trainers closed the holes, and the sea lions learned to manipulate the device to release the items.

“Our primary concern with our design, since we’re working with the zoo and live animals, is … the animals’ safety,” Chagnot said. “Right away, that knocked out a lot of potential materials.”

“The idea whenever we make enrichment is that it satisfies a specific goal, and in this instance, it is foraging and problem-solving,” said Heather Crane, a sea lion trainer at the zoo. “The students had to make sure the device would float, and we wanted it to have four arms so that each of our four sea lions could be involved at the same time if we wanted.”

On April 21 the students had their first opportunity to watch the sea lions interact with the device, something Zhou described as an “interesting experience” for the team.

Her fellow team member, Brumwell, said that all of the interesting places around Rice – including the zoo – and the many opportunities because of these surroundings factored into her decision to come to the university.

“I love going to the zoo,” she said.

Crane called it “extremely rewarding” to have this partnership with Rice University and to be able to fuse the science of engineering and the mental engagement of the sea lions.

“For me personally, (it’s about) reaching out to the students and teaching them the safety aspects of building these types of enrichment devices and what is the goal,” she said. “It’s not just about making a toy; it’s actually about encouraging natural responses from our sea lions.”

For more information on other design projects at the OEDK, visit http://oedk.rice.edu/.