Foraging-Based Enrichment Promotes More Varied Behaviour in Captive Australian Fur Seals (Arctocephalus pusillus doriferus)

During wild foraging, Australian fur seals (Arctocephalus pusillus doriferus) encounter many different types of prey in a wide range of scenarios, yet in captive environments they are typically provided with a narrower range of opportunities to display their full repertoire of behaviours. This study aimed to quantitatively explore the effect of foraging-based enrichment on the behaviour and activity patterns displayed by two captive Australian fur seals at Melbourne Zoo, Australia. Food was presented as a scatter in open water, in a free-floating ball device, or in a static box device, with each treatment separated by control trials with no enrichment. Both subjects spent more time interacting with the ball and static box devices than the scatter feed. The total time spent pattern swimming was reduced in the enrichment treatments compared to the controls, while the time spent performing random swimming behaviours increased. There was also a significant increase in the total number of bouts of behaviour performed in all three enrichment treatments compared to controls. Each enrichment method also promoted a different suit of foraging behaviours. Hence, rather than choosing one method, the most effective way to increase the diversity of foraging behaviours, while also increasing variation in general activity patterns, is to provide seals with a wide range of foraging scenarios where food is encountered in different ways.

野生觅食期间，澳州海狗（Arctocephalus pusillus doriferus）会在多种场景中接触到各类不同的猎物；但在圈养环境下，它们通常仅能获得有限的机会来展现其完整行为库。本研究旨在定量探究基于觅食的丰容（foraging-based enrichment）对澳大利亚墨尔本动物园内两只圈养澳州海狗的行为与活动模式的影响。实验中将食物以三种方式投放：开放水域散置、自由漂浮球装置、静态箱装置，且各处理组之间设置无丰容的对照试验作为间隔。两只受试个体与球装置和静态箱装置的互动时长均高于散置投喂模式。相较于对照组，丰容处理组的定向游泳总时长有所减少，而随机游泳行为的时长则有所增加。同时，三种丰容处理组的行为总回合数均较对照组有显著提升。每种丰容方式还可诱导出不同的觅食行为组合。因此，若要提升觅食行为的多样性，同时增加整体活动模式的丰富度，最有效的方式并非仅选用单一丰容手段，而是为海狗提供多样化的觅食场景，使其能以不同方式获取食物。