Environmental Enrichment Project – sea turtle rehabilitation
Our ongoing behavioural study is progressing well. We introduced a series of novel environmental enrichment devices (EEDs) into the pools of our long-term (unreleasable) turtle patients, and filmed their subsequent behaviours. Different objects acted as ‘toys’ (frame, ball, brush) to stimulate each animal’s curiosity to novel objects and for tactile stimulation. To stimulate foraging/hunting behaviours, food was delivered on a rotational schedule using different strategies (fish ‘popsicles’, PVC pipes, floating lid). We also continued our regular ocean swims with each patient, out in the Resort’s lagoon.
For the next stage, we need to characterise the behaviours of the turtles both with and without the enrichment. Twenty-minute video clips were recorded for all four patients, without enrichment, and again with 6 different devices in turn.
Ethograms (behaviour catalogues) were created to evaluate the effectiveness of the enrichment devices. Using continuous sampling, the footage was evaluated by timing the different behaviours:
- repetitive pattern swimming,
- focused/oriented behaviour (interaction with the device and grooming),
- random swimming around the pool,
- resting on the water surface.
- Without enrichment, the turtles spent most time ‘pattern swimming’ (75%) and ‘resting’ (20%), and very little time ‘oriented’ (<1%).
- With enrichment, ‘pattern swimming’ (40%) and ‘resting’ (1%) were much reduced as expected, with more time spent ‘oriented’ (40%) towards the devices and ‘random swimming’ (20%). This behaviour shift was consistent for all 4 turtle patients, although variations in behaviours towards the different enrichment devices was recorded, due to their different personalities.
The results of our pilot study show that environmental enrichment can be effective in increasing activity and exploratory behaviours in captive sea turtles. A changing environment provides turtles with the opportunity to make behavioural choices based on the assimilation of new information, and the ability to satisfy curiosity about new stimuli. Because of this, it is important to maintain novelty, which can be achieved by providing enrichment for short periods in rotation (as inquisitive initial behaviours may lessen with familiarity). The varied responses seen between the turtles serves to highlight the importance of tailoring enrichment devices to each turtle’s preferences.
Overall, positive behavioural changes were seen in all four turtles, so we will continue to develop and implement enrichment devices to improve the psychological and physiological well-being of our rehabilitation patients.
Pictured below, interacting with their environmental enrichment ‘toys’: Frisbee – Varu – Thaku – April