How to train your stingray
Published: Feb 22, 2017Fish are clever, which means you can use positive reinforcement training to change their behaviours and improve welfare.
At Living Coasts we have two species of stingray in our Mysterious Mangrove exhibit. There are three female blue spotted stingrays (Neotrygon kuhlii), which are also known as masked rays, and six blue-spotted ribbontail rays (Taeniura lymma) (four females and two males).
The species live in the same type of habitat in the wild – among the coral reefs and mangroves of the tropical Indian and Western Pacific Oceans where the seabed is sandy and flat. They therefore co-exist in our tank quite nicely - most of the time!
The ribbontail rays are a more dominant presence in the tank and can be a little greedy at feeding times and not share the food fairly with the masked rays. They are all fed three times a day with a scatter feed, which is where the food is distributed all over the tank to encourage natural foraging behaviours. The ribbontail rays will often chase the masked rays away from the most favourable pieces of food, leaving them with the least favourable.
This is where the training comes in. I have been doing some behavioural observations on all of our stingrays in order to determine which rays are the most dominant in the hope that training these individuals first will solve the problem. From my observations, I discovered that there were certain ribbontail rays responsible for chasing away the masked rays. These were three of the four females - Sandy, Alex and Holly.
Once I’d identified these individuals, the training began. I chose to start with Sandy because she is the most dominant and showed the most instances of chasing the other inhabitants of the tank. My observations allowed me to determine where Sandy spent most of her time in the lead up to feeds and also which food item she preferred - this turned out to be sprats. This was useful information, as I decided to start training in that area of the tank and commence the first few sessions with her favourite food. I used a training target which is basically a black and white chequered circle on a pole.
To begin with, I lowered the target into the tank in the area where Sandy spent most of her time, so that she and the others could get used to it being in their environment. Luckily, the target didn’t seem to bother them too much and they happily swam around it or just ignored it. During the next session, I placed the target in the same location as previously and when Sandy swam near, I dropped a piece of food next to it. Eventually, she began to associate the presence of the target with food. Sandy started to approach the target and press herself against it for her food reward.
It only took three sessions to perfect the behaviour, which shows just how intelligent rays really are! Now, Sandy will follow the target, no matter where in the tank it is and will press herself against the target for the reward, move away and come back for the next piece of food.
Since starting the training, Sandy has been chasing the others less often and the masked rays are getting a fairer share of the scatter feed. The work is not done, however. I will continue to train Sandy so that she doesn’t slip back into old habits; and I have just made a new target for Alex so that I can commence training with her. If the success with Sandy is anything to go by, Alex will be trained in no time and I can start working with Holly!
Meg Davitt is a student at the University of Surrey, where she is studying Veterinary Biosciences.