Comparative Study of Released Javan Hawk-Eagle (Nisaetus bartelsi) And Changeable Hawk-Eagle (Nisaetus cirrhatus) Based On Satellite Tracker Data

Abstract

The release of a rehabilitated raptor, defined as an effort to release the raptor back into nature, have been done in Indonesia; however, only about 2% were monitored for more than one year. This is because long time intensive monitoring using simple observation equipment is difficult to do because of limited resources. Thus, more modern equipment – oneof which is satellite radio used in this research – needs to be used. The use of satellite radio to monitor the movement of rehabilitated raptors was carried out for the first time in 2018 for juvenile male Javan hawk-eagles (N.bartelsi) and adult female Changeable hawk-eagles (N.cirrhatus). The results of the monitoring of these two types of raptors showed that they mostly used forested areas close to water sources. Both types of eagles had the farthest flight distance with an average distance of ± 1,000 m / day occurring at week 4. Thus, it can be concluded that the rehabilitation efforts for these eagles were successful and that they had adapted to their new habitats as wild raptors.

First report on daily activity and feeding behavior of Javan hawk-eagle (Nisaetus bartelsi) in the protected forest of Kondang Merak Beach, Malang, Indonesia

“…The difference in encounter time in this observation compared to previous research was because the male Javan hawk-eagle was actively hunting for prey in the morning. The male parent did not immediately bring the prey due to human disturbances around the nest site (Gunawan et al 2016). When the conditions were calm, the male parent brought the prey to the nest during midday and the near evening.…”

Vocal Activity Patterns of the Changeable Hawk-Eagle (Nisaetus cirrhatus) in Peninsular Malaysia during Mid-Breeding Season

“…Of the ten Nisaetus species around the world, a total of nine species have been recorded from the Southeast Asian region (Gjershaug 2006). Within the Southeast Asian region, a plethora of ecological studies have been conducted on the Javan Hawk-Eagle ( Nisaetus bartelsi ; Nijman et al 2000, Nijman and van Balen 2003, Gjershaug et al 2004, Prawiradilaga 2006, Kaneda et al 2007, Gunawan et al 2016, Prawiradilaga et al 2016, Septiana et al 2020, Suyitno and Syartinilia 2020) and Mountain Hawk-Eagle ( Nisaetus nipalensis ; Iida et al 2006, Sun et al 2009, Huang et al 2021, Nishibayashi et al 2022). Likewise, other lesser known hawk-eagles have gained interest from researchers over the past two decades (e.g., Flores Hawk-Eagle [Raharjaningtrah and Rahman 2004, Syartinilia and Setiawan 2021, Worho et al 2022] and North Philippine Hawk-Eagle [ Nisaetus philippensis ; Gan et al 2022]).…”

“…Apart from brief records on its predation habits (Fam andNijman 2011, Najmuddin et al 2019), information on the species' behavior in Malaysia is limited to basic biology (Ferguson-Lees andChristie 2001, Wells 2007a). Elsewhere, studies have been conducted covering its nesting ecology (Gokula 2000, Gunawan et al 2017, Senanayake et al 2017, Aldy and Zainun 2019, Sentanu et al 2019, Rodrigues et al 2020, Boer et al 2021, predation habits (Gokula 2000, Sirdesai et al 2013, Pierce et al 2014, home-range (Widiana et al 2017, Gunawan et al 2021), habitat selection (Nijman 2004), distribution (Rodrigues et al 2020), vocalization (Gjershaug et al 2020), genetics (Zein 2018, Pharmawati and Yuni 2020, Krisdayana et al 2021, phylogeny (Haring et al 2007, Rifaldo et al 2020, sex determination (Annisa et al 2021), and gastrointestinal infection (Kurniawan et al 2010).…”

Conservations Javan Hawk Eagle (Nisaetus bartelsi) in Gunung Picis Ponorogo Nature Reserve

“…Although each diurnal raptor is protected by law [15], most of its trade occurs on the black market [11]. In 2015 there were 2471 diurnal raptor individuals offered through Facebook (FB) social media, and of them, there were 127 Javan Hawk Eagles [8,10].…”