Natural Foraging for Sea Lions

Matt O’Leary, from the Zoological Society of London, briefed us on the opportunities to develop hunting enrichment for Californian sea lions.  In captivity, training provides important mental stimulation for sea lions but it doesn’t provide the experience of foraging and hunting down prey. Matt and other zoo professionals are keen to find ways to reduce the animal’s focus on keepers for food, and to encourage animals’ natural foraging behaviour. Ideally sea lions would be engaged in foraging for extended periods of time, needing to pursue prey at high speed, like they would in the wild.

 Enrichment for sea lions at ZooJam 2016 from Fiona French on Vimeo.

The team working on this challenge proposed an enrichment system consisting of a ‘countercurrent swimming machine’ or ‘endless pool’ installation (which creates a current to swim against) so that the sea lions can swim for extended periods in a relatively small tank. Secondly, an automated feeder located behind the swimming machine apparatus would be used to dispense small fish (e.g. a sprat) into the current. The position at which the fish is dispensed, and the time interval between dispensing, would be variable and could be pre-programmed or remotely controlled. The dispenser mechanism might (after initial introduction) be configured to work only if the sea lion is actively swimming at speed.

 

A key challenge is to design and construct a dispenser for fresh fish. This might include a conveyor-belt mechanism. Requirements include an easy-to-clean interior, weatherproofing (allowing outdoor use) and some way of keeping the contents cool for a few hours (either electric refrigeration or, for prototyping, cool blocks and insulation). 

Visitors might have the opportunity to remotely control where and when the fish is released for the sea lion to catch.