Study Correlation Daily Behavior and Bioacoustics in Captive Javan Hawk-Eagle (Nisaetus bartelsi) at Taman Safari Indonesia Bogor

Abstract

The Javan hawk-eagle (Nisaetus bartelsi) is an endemic bird of prey species found in Java Island, Indonesia with an IUCN ‘endangered’ status. This study aims to analyze behaviors and sounds produced by Javan hawk-eagle. This study employs behavioral observation using ad libitum sampling method for a duration of 15 days, with a total observation time of 103.5 hours. A pair of captive javan hawk-eagles from Taman Safari Indonesia were studied. From the behavioral observations, seven types of behaviors were found that are commonly performed daily. These types of behaviors are then presented in the form of hourly probabilities of behavior occurrence during observations. Sound samples were analyzed with Audacity^® and Raven Pro 1.6^®. The study results indicate that male eagle exhibit higher activity levels compared to female. Seven behavior types were identified: basking (♂ 3.4%, ♀ 4.1%), preening (♂ 3.7%, ♀ 6%), flying (♂ 76.4%, ♀ 64.7%), feeding (♂ 5.4%, ♀ 6.6%), mating (♂ 5.4%, ♀ 9.6%), interaction (♂ 5.1%, ♀ 9%), and water-bathing (♂ 0.6%, ♀ 0%). Basking and preening are often observed between 08:00-11:00, while flying behavior is consistently observed throughout the observation period. Vocalizations included high-pitched call, alarm call, mating call, and trill which the highest frequency calls were recorded from the female eagle. High-pitched calls, alarm calls, and trills were frequently recorded during landing or perching.