7 Days at Sea

As we wrap up our second week of observation, which involved observing the otters interacting with the raft we made, I feel good about the results. We won't have actual data until Wednesday, however when I observed the otters on Wednesday and Thursday last wee they really took to the raft. It was cool because at first they were extremely curious about it and would push and pull it from one side of the exhibit to the other, chewing and smelling it intently. Once they were more familiar with it though, they seemed to like to use it as a place to recline on the water.

Louie lounging on the raft.

And they would actually wrestle in a king of the hill type skirmishes over who had rights to use it.

Louie watching as Benny tries to climb aboard.

My most recent observations lead me to believe that it draws them out of the back of the exhibit and into the public eye, so it seems successful. Surprisingly enough, even the 'old men' of the group (Delmar, Digger, and Louie) took to the raft as energetically as their younger counterparts. The groups were mixed up this time around, so it may be due to the youthful spirit of the others they were in with yet they would often go check it out by themselves as well. But they are not the only ones who were curious about the new raft as many people stopped and asked me questions about what it was since I was wearing an aquarium name tag. They seemed genuinely interested and even those who did not stop and talk to us remarked how they like to watch the otters play and lounge about the raft. However, it seems that the otters still tire near the end of their shifts, so I am uncertain what amount of change was actually made to their behavior. I will have a better idea when we compare the data next time we meet, and after that I will be able to publish my results but until then I think that we have achieved our goal. I will admit that the raft may have to be repaired or rebuilt every few moths because the otters love to chew on the rope, especially when they are floating about. The way to solve this would be to use a stronger, polymer based rope, however this would be more likely to harm the otters so I think it is out of the question. Considering the reactions of the aquarium staff, I think that they will continue this practice for a little while so I am sure they will find a more than adequate solution.

The Maiden Voyage of the S.S. Why I Otter

Tomorrow will be the maiden voyage of the S.S. Why I Otter, or the raft that we finally completed. As we wrap up our first week of observation, in which we have observed the otters to establish a baseline for their behavior, we completed a raft that we now plan to put into the exhibit for the otters to play on.

The S.S. Why I Otter moments after completion.

As you can see, we ended up having to make the raft out of bamboo. It is lightweight and its closed sections make it naturally buoyant, making it easy to carry in and out of the exhibit and be pulled by the otters. Despite bamboos' origins, it grows very well in Tennessee and can be found many places out in the wild so it is not as exotic as it may seem. However it was not our first choice since we originally wanted to make the raft out of wood that is indigenous to Tennessee but one of the logs that we had was already waterlogged to the point that it could no longer float and the other simply weighed too much. After working with the wood for about a week, we decided that it was time to find a different material that would be viable. Sarah Farnsley (the enrichment coordinator at UTC) found some bamboo that we could use, already cut into equal lengths. This material ended up being superior for several reasons; We did not have to do much sanding (just at the ends) because bamboo is naturally smooth, lashing it together with rope allowed us to easily add a rope undertow for the otters without having to drill holes in the wood which would increase the possibility of it getting waterlogged, and the otters are less likely to chew on the wood (not meaning that they will not chew on the rope). Today we presented the finished raft to the aquarium and it will 'set sail' tomorrow at 9 a.m. EST, kicking off our second week of observation. After observing the otters for a week, my compatriots and I seem to reach the conclusion that it is really only one of the groups of otters that exhibit the problematic behavior. We divided the exhibit into 9 sections (shown below) where we can report the otters presence at the time of observation (30 second intervals for 90 minutes).

The youngest, Benny, is very active in sections 1 and two of the exhibit, often swimming laps or playing with other otters.

Benny diving to the bottom of the large pool (1).

He is grouped with his sister, Maya, and another young otter named Hunter. They tend to remain active for most of their time in the exhibit and when they choose to lay about it is often still in visible areas (4 & 5).

Benny and Maya doing laps with each other.

The reclusive otters (Delmar, Digger, and Louie) are all older males who are less vocal than the other otters. They are bigger as well, which could lead to them tiring faster and losing interest in the exhibit. Hopefully We will get the chance to see if their group responds well to the raft as it will be supervised within the exhibit, for the first little while anyway. I think that the raft will attract both groups of otters, but the older ones may not play on it as much as they use it as a pool bed.

Background and Raft Ideas

This summer I have had the chance to be part of an animal enrichment project, sponsored by UTC, at the Chattanooga aquarium. Initially, we met with the enrichment director of the aquarium, Sara Carlton, who explained to us what we would be doing and what animals we would be working with. The options were macaws, crows, alligators, penguins, and otters, each with their own behavioral issues that the aquarium wanted to work to adjust. After a few visits to the aquarium we had our options narrowed down to the crows, alligators, and otters as both types of birds we not on active display and would be harder to observe without distracting them. We met as a group a few more times with the professors and decided that the otters would be the most practical to work with, because of the behaviors they exhibited and because of a higher chance that enrichment would actually affect these behaviors. The otters at the aquarium tend to play in their exhibit for a little while after they are rotated in (they are put into the exhibit in interchangeable groups of three, in shifts) but then they retreat to the door in the back where the keepers come in, also where they are not visible. The aquarium mentioned that they would prefer the enrichment we implemented to attempt to get the otters down into the visible part of the exhibit for the majority of their shift. 

The main pool where they want the otters to play.

A smaller pool at the end of a waterslide that the otters can land in.

Initially we thought about hiding food in different places when the otters were fed, but they already do this as a public enrichment activity in the middle of each shift. So we came up with the idea that we eventually presented to the aquarium staff, that of a wooden raft or rafts that could be put into the pools at the bottom. The idea was to put holes that they could climb through, nooks that food could be hidden in, and to provide a place for the otters to relax in the visible portion of the exhibit. They approved the idea and gave us a list of materials we could use to complete our rafts, including types of wood and methods of building that would not disturb the exhibit. Currently we have the wood (pictured below), and we have begun construction on the rafts.

The cedar logs that will eventually become the raft, partially hollowed.

Initially we thought that we could hollow them out to make something that the otters could climb or chase each other through, however as we found today there is simply too much woo on the interior for it to be able to float. So we went back to earlier designs and plan to cut the logs up and make a raft out of the pieces so it will be much lighter and more buoyant. This also allows us to add an undertow that the otters may use to pull the raft where they want it to go, and maybe even include holes for food to be hidden in but the design will become clearer as we work with the wood. We also start observation this week (my day is Sunday) where we will observe the otters behavior and create a baseline by which we can see the difference, or lack thereof, in the inclusion of the raft in the exhibit.