豐富化設施與表演對圈養海豚行為的影響

Abstract

許多的動物園與水族館為了評估圈養動物的福利而投入很多心力來發展不同的方式與工具。當動物對於環境中的壓力因子感到無法應付時，動物表現出的行為是最明顯的指標能讓我們得知動物的狀況。本論文主要分為兩個章節，第二章探討空間、食物、觀賞遊客與表演這些環境中的壓力因子對於圈養海豚的行為影響；第三章則是透過人造設施來測試環境豐富化(Environmental enrichment)的影響。研究是從2012年七月到2013年三月在台灣的花蓮遠雄海洋公園進行實驗。在第二章中，行為與聲音上的資料都有記錄並根據表演前後進行比較，特別是刻板行為(Stereotypic behavior)的部分。行為是利用瞬間掃描取樣的方式，而聲音則是透過放置水下麥克風進行收集。研究發現有在進行表演的海豚鮮少表現出刻板行為，而觀賞的遊客對於海豚似乎是中立性的影響。另外當時間越接近表演的開頭時，有一半的海豚會減少共游行為而增加獨立游泳的行為，且在表演結束後的聲音多樣性也高於表演前的狀態，這可能與牠們期待參與這項活動有關。此外，花蓮海洋公園所提供給海豚的空間與食物對比於其他的參考文獻，這些物理條件都略高於平均水準。因此，我認為這些環境的壓力因子並不會帶給圈養海豚太顯著性的影響。在第三章，我利用豐富化設施去測試瓶鼻海豚(Tursiops truncatus)與瑞氏海豚(Grampus griseus)刻板行為的變化，結果顯示透過給予豐富化物體，海豚可以減少67.6±14.4%的刻板行為。且有40%的個體在物體形狀上有角形的偏好，而此結果則是與牠們如何去操作物體有相關性。

Zoos and aquarium have put many efforts on developing tools for assessing the welfare of captive animals. Animal behavior is often the most obvious way to indicating if an animal is unable to cope with environmental stress. There are two major parts of this thesis. The first part investigated the effect from the environmental stressors from performance as well as from space and food support. The second part tested environmental enrichment effect by providing artificial devices. Study was executed at Far Glory ocean park, Hualien, Taiwan, from July 2012 to March 2013. In the first part (chapter 2), the changes of dolphins’ behaviors and sound, especially the stereotypic behavior were recorded and compared before and after performance. Behavioral sampling followed instantaneous and scan sampling, and sound data was recorded by underwater hydrophone. I found that dolphins with performance seldom showed stereotypic behaviors. Visitors’ crowdness seem had neutral effect with dolphins. When the time was closing to show start, 50% of dolphin individuals increase solitary swimming and decrease synchronous swimming, while dolphins’ whistle types showed siginificantly higher diversity after the performance in the afternoon, and could be related with dolphins’ expectating the performance. In addition, comparing the space dimension and regular diet records of Far Glory ocean park with reference of other aquaria, I found this park’s physical condition is slightly over the world average standards. So, I conclude that the stressors from the performance as well as food and space should not bring significant impact on these captive dolphins. In the second part, I used enrichment devices to test the changes on stereotypic behavior of bottlenose dolphin (Tursiops truncatus) and Risso’s dolphin (Grampus griseus). I found that by giving enrichment devices, dolphins could significantly reduce 67.6±14.4% of stereotypic behavior. And 40% of individuals showed a preference to the devices with angled shapes, it was related to the way how they manipulated the devices.