Study on the distribution, habitat and ecology of Flores Hawk-eagle Spizaetus cirrhatus floris in Lombok, Sumbawa, Flores, Komodo and Rinca Islands, Nusa Tenggara, Indonesia低地熱帯林の生態系指標としてのカワリクマタカ(Spizaetus cirrhatus)に関する調査
―スンバワ島、コモド島、フロレス島に生息する亜種を対象として―

Authors著者名

Wahyu Raharjaningtrahワーユ・ラハルジャニントゥラ1), Zaini Rahmanザイニー・ラフマン1)

Affiliations著者所属

  1. 1) YPAL (Indigenous Nature Conservation Society) Jl. Paledang 21, Cibeureum, Bandung 40184 West Java, INDONESA

ABSTRACT要約

The Flores Hawk-eagle Spizaetus cirrhatus floris, possibility to bring it into distinct species (Gjershaug et al. 2003, in prep) is distributed at all part of main islands of Lombok, Sumbawa and Flores, which Mountain Rinjani in Lombok as the Western and Mountain Lewetobi in Flores as the Eastern part of distribution of this species. It was also found at satellite islands i.e., Satonda Island (Sumbawa) and Komodo and Rinca Island (Flores). The Flores Hawk-eagle is dependent on forest area, especially lowland forest as most of the contacts were happened at Lowland forest. The occupation of the Hawk-eagle to Sub-montane and Montane forest were only seen at Ruteng area, Flores Island, so this species is the most suitable to be an indicator of the forest (lowland) existence. The home range size of this species estimated as 38.5 km2 and then all population estimated is 73~75 pairs, and it has been as CRITICAL status according to the IUCN category. The occurrence of this species has been seriously threatened by human activities, such as forest encroachment was happened almost in all surveyed sites and hunting and poaching for trade was not only done by local people also people come from Java and Bali.


カワリクマタカ(Spizaetus cirrhatus)の亜種で、学説によっては独立の種として扱うこともあるS.c.florisについて、分布域の調査を行った。その結果、本種はロンボク島、スンバワ島、フロレス島のほぼ全域にわたって生息することが明らかとなった。調査 では、ロンボク島のRinjani山が分布域の最西端、フロレス島のLewetobi山が同最東端であった。また、スンバワ島沖合のSatonda島、Flores島沖合のKomodo島 、Rinca島などの小島でも本種の生息が確認された。本種の生息が確認された地点の多くが低地熱帯林であって、本種が森林、特に低地熱帯林の依存種であることが確認された。フロレス島のRuteng地区では本種が亜高山帯、高山帯にも生息することが確認されたが、亜高山帯以上の地点で本種が記録されたのはこの地区だけであり、やはり本種は十分に低地熱帯林の指標種足り得ると考えられる。本種一つがいのなわばりは約38.5km2と推定され、この数値から計算すると 、地球上に残された本種の生息数はわずか73~75つがいとなる。これは、他の観察結果と合わせると、IUCNのレッドリストカテゴリー上絶滅危惧IA類に該当する。今回調査を行った地点の多くで森林伐採が進んでおり、本種の生息にとって大きな脅威となっている。また、土地の人々ばかりでなく、ジャワ島やバリ島 からもハンターや密猟者が流入してくることが、大きな問題となっている。

(推薦者:乾由布子)

1. INTRODUCTION

Nusa Tenggara (Lesser Sunda) Islands are stretch in the most south Wallacea region that are biodiversity poorly known. Most of the natural researches were done in 18th century to the early 1900’s (Monk et al. 1997), and for the first time in 1990’s several researches on biodiversity were conducted; such as research in Ruteng by Department of Forestry and LIPI, and research on bird by Bird Life International-Indonesia Program.

Nusa Tenggara Islands are a group of medium to small islands that extend from Lombok in the west to the Tanimbar Is. in the east (Coates et al. 1997). Although the topography varied, some types of landscape related to the distribution of rocks still exist. Nusa Tenggara Islands are a widespread grasslands and scrub with a low tree density (Timor, Sumba and East Flores) and most of the forest are semi-deciduous monsoon forest (Coates et al. 1997). After Monk et al. 1997, Nusa Tenggara Islands are dominated by Mixed Savanna (62% coverage), Lowland rain forest (19%), Limestone forest (10%), Sub-montane rain forest (5.5%) and coastal forest and tidal, mangrove, montane forest, riparian and ultrabasic forest are the rest. Unfortunately, there were no forest size calculation which based on field surveys, most were estimated through satellite images calculation. Only the conservation forest areas have a precise forest size but most of the protection forest status is not and that's land cover is 10% only.

Monsoon forest is the most sensitive and vulnerable forest in the tropical forest formation. It is very easily lost. The natural monsoon forest in Nusa Tenggara has extensively changed into savanna and grasslands. From generation to generation people burn the forest for hunting and shifting cultivation, and it become worst with the increasing of people population and the activities of some commercial development such as agriculture and forestry (Monk et al. 1997). The rain forest is not the most threatened of the major forest formations. The tropical dry forests (monsoon forest) hold this honor (Janzen 1988 in Monk et al. 1997).

Study on the hawk-eagles in Nusa Tenggara are very poor, especially the study on certain type of sub-species. One of research conducted in this sites was done by Bird Life International IP and the study is pretty general for all kind of birds.

The study on the Flores Hawk-eagle Spizaetus cirrhatus floris as an indicator for the lost of tropical rain forest that occurs rapidly in most of the sub-species distribution sites (Lombok, Sumbawa, Flores, Komodo and Rinca) is necessary because: (1) There are not enough data to estimate the situation in the lowland rain forest in those islands, except a few from Flores Island. (2) Based on habitat and territorial behavior, Flores Hawk-eagle is compatible for studying the habitat changes. (3) Flores Hawk-eagle is one of the least studied sub-species among others, because there are not enough research conducted in Nusa Tenggara and also there are only a few specimen collected in the world's museums, and only the juvenile known, the adult is still unknown.

(1) Flores Hawk-eagle Spizaetus cirrhatus floris

There are 398species of birds recorded in Nusa Tenggara area and amongst of it 22species are raptors (Andrew 1992), with the additional record for Grey-faced buzzard Butastur indicus and Crested serpent-eagle Spilornis cheela bido (Coates et al. 1997). As one of the raptor species, Spizaetus cirrhatus flores has attracting many raptors researcher, and its status is still the subject of debate since it has different taxonomy in the color and feather type with other S. cirrhatus in Asia. Genetically, Flores Hawk-eagle S. c. floris almost similar to the others and it has close relation with S. c. limnaetus, but Gjershaug et al. (2003, in prep) show the possibility to bring it into distinct species and if it is happen then this bird will probably be the most threatened raptor in the world.

In general, the color of the feathers of an adult Flores Hawk-eagle is similar to the immature bird of other sub-species (Amadon 1953). This sub-species has a greatest size among other Spizaetus cirrhatus sub-species (Ferguson et al. 2001). The upper body is dark brown, white below, including under wing-coverts (Coates et al. 1997). No crest found, white colored body ended at thigh and black stripes in the wing tip (Ferguson et al. 2001).

Collar et al. (1994) recommended Spizaetus cirrhatus as vulnerable species according to the IUCN category. Distributed in the west part of Nusa Tenggara; Sumbawa, Flores and Paloe (Coates et al. 2000), Komodo and Rinca (Agista 2000 in Trainor & Lesmana 2000). Uncommon species, inhabits montane forest, occasionally ranging over the lowlands. Recorded at 400~1,000+ m in Sumbawa and lowlands to 1,700m in Flores (Coates et al. 1997). Rare and uncommonly observed from sea level to 2,100m (Trainor & Lesmana 2000). Mostly seen in cultivated hills and woodland from sea level to 1,000m (Verhoeye & Holmes 1998 in Trainor & Lesmana 2000).

2. METHODS

(1) Identification of Species

The study was conducted to identify the species of Flores Hawk-eagle Spizaetus cirrhatus floris through literatures study. Field observation was then conducted to ensure the morphological type of the bird especially the color type and behavior.

Vantage Point Method (Thiollay 1996, Bibby 2000) is used in this survey and conducted at the upper hills or in the forest edge or in an open area. The selection of the sites was concentrated on the sites that estimated to have access or great probability of Flores Hawk-eagle presence and it was done to obtain more description of this sub-species. Study continued by sites sampling that represent any types of forest.

(2) Study period and Selection of Sites

Field observations were done for 3 times i.e.: August~October 2002, December 2002~February 2003 and June~July 2003. The first field observation was not supported by Pro Natura Fund but its data is compiled and compared to the second and third observations in this report. Two first surveys were conducted at rainy season while the last survey was conducted at dry season. The conditions of the forest are different drastically on those 2 seasons.

The first field observation was conducted from August 25th 2002 to October 3rd 2002. Due to the limitation of time and accessibility, duration of observation was maximized to obtain much more time of observation. The observation was done for 31days in some sites in Flores. The second survey was done on December 23~24 of February 2003 at Lombok and Sumbawa islands for 42days and the final survey was done on June~July 2003 at Lombok, Sumbawa, Komodo and Flores, respectively for 25days. The total of the observation time was 609hours in all sites. All observation time were varied from 2 to 10 hours depending on accessibility, sites area and climate and especially based on the presence of the Hawk-eagle.

Data collected are: species present, types of forest, behavior and other data considering to the reporting needs such as site altitude, site name, other raptor species present, local name for the Hawk-eagle etc. The sites were selected by considering its condition and the probability of observing the birds directly, unless it had a wide range of point of view.

The selected sites were also referring to the presence of conservation area with the assumption that the forest is still in good condition. The selected sites were Rinjani Mountain National Park (Lombok), Dora Maria Mt., Tambora Mt., Batulanteh Mt., Ropang Mt. and Satonda Island (Sumbawa Island); Ruteng Nature Recreation Park, Mbeliling Protection Forest, Sano Nggoang Protection Forest, Ndeki-komba Protection Forest, Kelimutu National Park, Repok Mountain Protection Forest, Egon Ilimudu Protection Forest (Flores) and Rinca and Komodo Island in Komodo National Park.

(3) Types of Forest

During the field observation, types of forest were divided based on the altitude as lowlands (0~900m asl), sub-montane (901~1,500m), and montane (>1,500m) forest (Monk et al. 2000, Trainor et al. 2000).

The forest condition on rainy season is pretty green and extensive. Oppositely on the dry season most of the trees were fallen its leaves, it was seen buff and very dry, the forest looks green near water pool or streams only, mostly at the gorges.

Map1 Survey sites at Lombok, Sumbawa and Islands

Map1 Survey sites at Lombok, Sumbawa and Islands

To estimate the population of Spizaetus cirrhatus floris, the home range of the Hawk-eagle was counted then it was extrapolated to the size of the forest surveyed.

3. RESULT

(1) Identification of Flores Hawk-eagle

Most of Flores people are Manggarai tribe who mostly recognize any kinds of eagles. They named Flores Hawk-eagle as Ntangis. They also named a small number of eagles such as Jumburiang for Bonelli's Eagle Hieraetus fasciatus and Lawang ntangis for Brahminy Kite Haliastur Indus. Throughout Manggarai, west part of Flores, Flores Hawk-eagle is considered as totem or empo, human ancestor, and was not persecuted, killed, or captured (Trainor & Lesmana 2000).

In general, Flores Hawk-eagle has white colored feather in all over its body, including head, breast, and belly to the lower part, and black stripes in the side of the under belly. When perched, the white color of the bird is conspicuous and seen contrast with the surrounding area as observed in Golo Desat, Mbeliling Protection Forest and Kolorongo, Kelimutu National Park.

Amadon (1953) stated that the feather color of an adult bird is more like the color of immature bird of other sub-species which Ferguson (2001) named it as monomorphic. It is very difficult to differ the species by age since the color of an adult and the juvenile almost look similar. So, to identify the age of the bird in the field is through its behavior. As seen at Kolorongo village, west side of Kelimutu National Park, seen one individual of the eagle flapping the wing instabily. Then this eagle flew move from one tree to another, but when it decided to stay in one tree, the eagle seems little doubt. When it finally perched, the body position was upside down and while flapping its wing the bird straighten out its position. It happened repeatedly. After a while, one other bird flew around the area and then they flew together heading to the other side of the hill. By comparing those 2 eagles we can make assumption that the first Hawk-eagle is a juvenile and probably still learning how to fly, but it was still not easy to differ those 2 birds since the patterns of the feather color was almost similar.

The team identified the Hawk-eagle also when flying, the under parts appears white from head to thigh and there is a window-like formed from white bright feather pigment on the under part of the wing. There is a black contrast line on the tip of the wing and on the tail clearly seen some black band especially because the contrast white colored tail tip.

Table1. Important Characteristics on Identifying Flores Hawk-eagle in the Field
  Reference Field Identification
Variation of an Adult Color In general, the feather color of an adult bird is more like the color of immature bird from other sub-species (Amadon,1953) The color of an adult and a juvenile almost look similar. However the behaviour of the adult and juvenile/immature are different.
Upper parts Dark brown (Coates, dkk. 2000) Mantle, light brown on the back (Agista, pers.comm.) Dark brown on the back, the white vent sometime appears when flying.
Under parts White colored body to thigh (Ferguson et al, 2001) White under parts and under wing coverts (Coates. Dkk.2000) White breast, belly, and thigh (Agista, Personal Obs.) White clean feather color on the lower parts, Few slight black lines on the lower belly which was not documented before will be a good indicator to identify of Flores Hawk-eagle.
Head No crest (Ferguson et al, 2001) Crown (White upper head) with a thin light brown irregular spots. Grey forehead, dark grey beak, white nape, neck, cheek and throat (Agista, Personal Obs.) No crest at all.
Wing Black lines on the tip of the wing (Ferguson et al, 2001) Longer and narrower wing (Coates et al.2000) Dark brown primary and secondary feather (Agista, Personal Obs.) White under wing with window-like formed from white bright feather pigment is also good cap to identify this bird but it need some experiences to see this. A thin black stripes in the under wing.
Tail Less conspicuously barred tail (Coates dkk 2000) Dark brown tail with 4 black bands, the lower band wider than the rest (Agista, pers.comm.) As literate, but black band on the tip of tail often seen clear.

Some similar species:There are 2 species can be alternate of the Flores Hawk-eagle, they are Short-toed Eagle Circaetus galicus and Bonelli's Eagle Hieraaetus fasciatus. Based on the color patterns, Short-toed Eagle appears similar to Spizaetus except for the black circle around the Eagles'neck that easily observed in the field. The upper parts of the Bonelli's Eagle appears similar to Spizaetus, except for the white spot on the back of an adult Bonelli's eagle that sometimes appears in a young Bonelli's Eagle as well.

(2) Distribution of Flores Hawk-eagle

1) Lombok Island

White and Bruce (1986) stated that the distribution of Flores Hawk-eagle is at Sumbawa and Flores Is., the distribution of this Hawk-eagle in Lombok was questioned. This survey was ensuring that the Hawk-eagle is also present at Lombok Island, especially at Rinjani Mountain National Park.

Mount Rinjani straight up from 0~3,300m above sea level, but its forest extent from 300~2,400m asl, its comprises all forest categories i.e. lowland, sub-montane and montane forest. The survey were done at 2 categories (lowland and sub-montane) because after 2,000m altitude most forest are contains small trees and open areas, and from 3 sides of the area i.e.: west, east and north. The locations surveyed were Sesoat, Pusuk, Jeruk Manis (first survey), Senaru, Pidana, Sesoat, Pidana, Jeruk Manis (second survey) and Pusuk, Senaru, Semabalun, and Pidana (third survey). During the 3 surveys, Flores Hawk-eagle were found at 4 locations i.e. Sesaot, Senaru, Pidana and Pusuk, all at altitude less then 900m asl.

The location where Flores Hawk-eagle present on both rainy and dry seasons is Pidana at 845m asl. Contact at Sesaot and Senaru only on rainy season and Pusuk on dry season only.

2) Sumbawa and Satonda Islands

28 observational points on 8 sites at Sumbawa were surveyed, the Flores Hawk-eagle were found at 10 observation points on 6 sites, i.e. Kalate and Jalamba (Dora Maria Mt.), Sonae (Tambora Mt.), Tongoloka and Township (PT Newmont Nusa Tenggara concession area, including in Selalu Legini PF according to this report), Satonda Island, Marente and Batulanteh (Batulanteh Mt.) and Ropang and Takan (Ropang Mt.). All contacts were happened at lowland forest areas on 800m asl and below. During 2 surveys conducted at Sumbawa, 4 contacts were happened on rainy season and the rest on dry season. No single observation points where Flores Hawk-eagle present on both season but at Dora Maria Mt. with different observational points.

3) Flores Island, Komodo and Rinca Is.

28 observational points on 11 sites at Flores, Komodo and Rinca Islands were surveyed, the Flores Hawk-eagle found at 15 observational points on 7 sites, i.e. Rinca Island, Golodesat, Melo, Nunang (Mbeliling), Golo Lusang, Carep, Ranaka, Ranamese, Leda (Ruteng), Kisol and Nangarawa (Poco Ndeki), Kolorongo (Kelimutu), Blidit (Egon Ilimudu), Lewetobi and Duri (Lewetobi). Contacts with Flores Hawk-eagle on both rainy and dry seasons were happened at Golodesat, Kisol and Ranamese, while contacts on rainy season were at Carep, Gololusang, Kolorongo, Leda, Melo, and Puarlolo. And on dry season contacts were happened at Blidit, Duri, Lewetobi, Moni, and Poco Ranaka. All contacts were mostly at lowland area, except at Ruteng area were between sub-montane and montane, higher than 1,200m asl.

Lombok Island as the most western area of Wallacean region, previously was overlooked as a distribution area of Flores Hawk-eagle. Actually by these surveyed we ensure that the most western part of this Hawk-eagle distribution is Lombok and only at Rinjani National Park as the last forest refugee in Lombok Island. The presence of this eagle in the main island of Flores was distributed widely from the west part to the east, however its presence mainly on the west part of Flores where the forest and the forest cover relatively in good condition and the climate relatively wetter than on the eastern part. The most western part where Flores Hawk-eagle recorded is Mbeliling Protection Forest area, and the most eastern distribution of this Hawk-eagle found in Egon Ilimudu Mt. near Larantuka. Trainor & Lesmana (2000) had recorded this Hawk-eagle in Egon Ilimudu Mt. After that, there were no any contact recorded eastern of Egon Ilimudu including in some satellite island, as well as our last surveyed proved that this Hawk-eagle is not extent to the eastern part of Egon Ilimudu.

4) Bali Island

In Bali Island, survey was conducted at 2 main mountains area Mt. Agung and Mt. Seraya on East Bali Island on 20~21 January 2003. This survey proposed to determine any possibilities overlapping distribution with the other sub-species of Changeable Hawk-eagle. During this survey in both of 2 mountains areas, there is no record of Spizaetus cirrhatus floris only a record of an individual S.c.limnaetus a dark morph. In addition, any records of S.c.limnaetus at Bali were confirmed and supported the other references and field record from the other ornithologist who was visited Bali. This survey was carried out the present result that distribution of Flores Hawk-eagle is not including the Island of Bali.

(3) Forest Condition

As stated on the introduction that very difficult to classifying forest conditions at Lesser Sunda, both western and eastern parts, even its' area sizes. Because of these reason, we selected the sites are visited based on the information we can compile and collect from Forestry Department which are cited on few references and most are conservation areas such as National Park (NP), Natural Reserve (NR), Nature Recreation Park (NRP), and also Protection Forest (PF), however protection forest is managed by Dinas Kehutanan Propinsi (Province Forest Body) which is separate from Directorate General of PHPA (Forest Protection and Nature Conservation). According to the Indonesian forestry law, protection forest can be changed to other land-use if local province government sees it less valuable for their local original assets.

We classified simply the forest type into Lowland, Sub-montane and Montane forest by the reason of ease to the data analysis, although there is another forest classification such as Ultrabasic, Limestone, Riparian forest etc., but the first classification is straightforward with the purpose of this survey.

(4) Distribution of Flores Hawk-eagle based on Forest Types

1) According to the altitude

A. Lombok Island

Rinjani Mountain National Park is the last forest refuge in Lombok, however it comprises 3 type of forest i.e.: Lowland, Sub-montane and Montane forest. The Flores Hawk-eagle were found at lowland forest only which is distributed at 0~900m above sea level 4 individual were found from 3 surveys conducted.

Fig1 Flores Hawk-eagle Presence at Lombok Island

Fig1 Flores Hawk-eagle Presence at Lombok Island

B. Sumbawa and Satonda Islands

From 10 observation points of 6 sites the Flores Hawk-eagle found, all at lowland forest, actually all the sites visited were lowland forest as almost Sumbawa forest are lowland forest. 14 Hawk-eagles were found from 2 surveys conducted at Sumbawa Island and 1 individual was found at Satonda Island at January 2003.

Fig2 Flores Hawk-eagle Presence at Sumbawa Island

Fig2 Flores Hawk-eagle Presence at Sumbawa Island

C. Flores, Komodo and Rinca Islands

A bit different with the western islands, the Flores Hawk-eagle found at Flores were much more variable on forest type, it found not only at lowland forest but also at Sub-montane and Montane forests, however lowland was the most Hawk-eagle found with 15 individual, Sub-montane 6 individual and Montane 2 individual only. All sub-montane and montane individual found were at Ruteng areas, within and outside the Ruteng Nature Recreation Park.

Fig3 Flores Hawk-eagle Presence at Fiores, Komodo and Rinca Islands

Fig3 Flores Hawk-eagle Presence at Fiores, Rinca and Komodo Islands

2) According to the Season

Although the influence of the season at tropical region is not as strong as at temperate region, however in the last decade the season especially dry season was quite influencing to the tropical environment. On the other hand, theoretically, when studying a species or environment it is better if conducted for both seasons, rain and dry.

Contact with Flores Hawk-eagle at Lombok and Sumbawa Islands were mostly happened at dry season comparing at rainy season, with comparison of 4 to 1 at Lombok Island, 17 to 9 at Sumbawa, however oppositely happened at Flores with comparison of 16 to 24.

As explained before that the eastern part of Nusa Tenggara is dryer than the western part, so the extensive wet forests of Lombok and Sumbawa were smaller in sizes at the dry season so the Hawk-eagle were concentrated and more easier to contacted at that time, but oppositely to Flores, the rainy season made the Hawk-eagle more conspicuous because rainy season seems forced them to showed up for territorial occupation. However, the first survey conducted at Flores actually at the end of dry season when they just hatched the eaglet.

(5) The Ecological and Conservation Aspects of Flores Hawk-eagle

1) Population estimation

The population of a species is not easy to counted, especially by the direct method, so some approach were described to estimate the population of species, one of the approach is home range or territorial approach which is based on the home range of a pair within a certain area. Although there is variation within a different sites but extrapolation is allowed to genoralise 1 species home range, the counting was done at Ruteng Nature Recreation Park on August 2002.

Started from Golo Lusang Mt. in the west to Poco Ranaka Mt. in the distance of 10km, the survey team found 3 different pair of Flores Hawk-eagle. The farthest distance of 1 of these 3 mates was around 7km. If this distance is predicted as the Hawk-eagle diameter of its home range and the home range is (usually) in circular shape, then we can predict that the home range of this raptor is around 38.5 km2, derived from π(1/2d)2 (Gjershaugh et al. 2003, in prep). So, if the forest areas surveyed are known (Table2) we can then estimate the population of the Hawk-eagle at every island forests surveyed are: Lombok = 10 pairs; Sumbawa = 38 pairs and Flores = 27 pairs.

Gjershaugh et al. (2003, in prep.) and Thiollay (2003, pers. comm.) are pretty sure that the Flores Hawk-eagle which is put as a sub species of Spizaetus cirrhatus as a distinct species even by its morphology so with the population estimation above, means that the species with has a critical status according to the IUCN category of population is the most threatened raptor in the world.

2) Threats

Most currently identified threats to raptors are related to habitat destruction. Other classical threats including poaching, trade or pesticide are of local occurrence and it is often not significant (Thiollay 1999). In Nusa Tenggara Islands, forest clearance for timber, agriculture and cultivation area are high especially at Sumbawa and Flores Islands (personal observation). Approved by the frequent contacts of the team with trucks full of logs from the forest areas and forest clearance by fires. Forest fragmentation caused by logging leads to the formation of small separated patches of forest.

A. Forest encroachment

Forest encroachment happened almost in all surveyed sites, mainly at forest boundaries that people used for cultivation. Forest damaged had also accelerated by shifting cultivation. People, usually, growing their crops on the dry forest of lowland area, they selected such area for their easiness on managing their garden. The forest were slashed and burnt at the end of the dry season before they changed it into cultivation area in wet season. If they thought that the area was no longer fertile, they moved to another area.

B. Hunting

People hunted birds including raptors for local trade, as occurred in Ilimudu, they also shipped it to Bali. 2 stuffed birds were also sold in Ruteng (Trainor & Lesmana 2000). We found Spizaetus cirrhatus floris wing hanging on the house wall in Melo village, it was captured and killed 2 weeks before we arrived because they found it hunting for chicken. The Flores Hawk-eagle was also found at Lombok local bird market for sale, according to the bird seller, the Hawk-eagle origin was from Sumbawa.

The reason for hunting the birds was because it attacks cattle and most of them did it for hobby. Hunting was not only done by local people, mostly the outsider who was also took part in hunting the birds for trade come from Java and Bali.

Table2 The size and types of forest surveyed
Location Size (km) Obs.point Altitude (m) Forest type
Lowland
(0-900)
Sub-montane
(900-1500)
montane
(up to 1500)
Rinjani 400 Sesoat 420 1    
    Pusuk 300 1    
    Jeruk Manis 900 1    
    Senaru 1100   1  
    Pidana 790 1    
    Semabalun 800 1    
Batu lanteh 380 Pelita 215 1    
    Marente 600 1    
    Utan 320 1    
    Batulanteh 600 1    
Ropang   Ranan 715 1    
    Labangkar 725 1    
    Ropang 800 1    
    Takan 730 1    
Tambora 300 KM.16 515 1    
    Sumber Urip 500 1    
    Pancasila 545 1    
    Mada oi 50 1    
    Oi penihi 160 1    
    Sonae 180 1    
Dora maria   Jalamba 800 1    
    Kalate 760 1    
    Sambu 790 1    
Satonda 40 Satonda 50 1    
Selalu Legini 750 GPS 14 <500      
    SG7        
    Brang nangka        
    Concentrator        
    Tongoloka        
    Township        
    Chrusher        
    SG1        
Subtotal 1470          
Mbeliling 184.2 Golo desat 790 1    
    Puarlolo 900 1    
    Melo 800 1    
    Nara 790 1    
Sanongoang 50 Nunang 800 1    
Ruteng 322 Golo lusang 1590     1
    Carep 1310   1  
    Rana mese 1200   1  
    Tenda 1300   1  
    Leda 1330   1  
    Ponglao 975   1  
    Ranaka 1600     1
Repok 150   Desu 970 1    
Poco Ndeki 23   Kisol 190 1    
    Muting 100 1    
    Nangarawa 50 1    
Irenie 80 Bena 995   1  
Kelimutu 50 Kolorongo 790 1    
    Woloara 800 1    
    Puncak 1560 1    
Egon Inimudu 150 Blidit 340 1    
             
Lewetobi 42 Lewetobi 210 1    
    Duri 300 1    
Komodo NP 173,3 Rinca 50 1    
    Komodo 120 1    
Subtotal 1051          

4. CONCLUSION

Lowland forest are dominating the Sumbawa and Flores forests, surprisingly Sumbawa forest is quite extensive from western to the eastern part, but mostly at the southern part of the island, except Mount Tambora area. The submontane and montane forest are limited to Rinjani Mountain National Park (Lombok), Ruteng area and Kelimutu Mountain National Park (Flores). Monk et al. (1998), stated that 62% of Nusa Tenggara forest type is Mixed Savanna, but by the field surveys that type of the forest are showed clearly at the dry season and mostly at lowland area which much more dry than the upper altitude area.

Flores Hawk-eagle is distributed evenly at all part of the islands from west to the east, although there were no contacted at several observation points in between. They were found from Mount Rinjani National Park of Lombok Island to Mount Egon Ilimudu Protection Forest at Larantuka, Flores. It was also found at a couple of satellite islands i.e., Satonda Island (Sumbawa) and Rinca Island (Flores). The home range of the Hawk-eagle is estimated as wide as 38.5km2 and then the population was extrapolated with the result is Lombok island (10pairs), Sumbawa (38pairs) and Flores (27pairs). With that population Flores Hawk-eagle has a CRITICAL status according to the IUCN category.

Naturally, Flores Hawk-eagle is dependant on forest area, especially lowland forest as most of the contacts were happened at Lowland forest including on Lombok. The occupations of the Hawk-eagle to sub-montane and montane forest were only seen at Ruteng area, Flores Island. Although there are other raptor species, Rufous Billied Eagle Hieraaetus kienerii and Bonelli's Eagle Hieraaetus fasciatus, are occupied the lowland forest, but because of Flores Hawk-eagle confined area status so this Hawk-eagle is the most suitable to be an indicator of the forest (lowland) existence. On the other hand, the population fluctuation on the rainy and dry season, where the forest changed drastically, also showed that this raptor is also good indicator of habitat change.

He occurrence of Spizaetus cirrhatus floris has been seriously threatened by human activities, such as forest clearance for timber, vasting shifting cultivation and mine concession (at Sumbawa), unfair agricultural system, and hunting practice by local people because the raptor is known as predator to their chicken. When the bird is declared as the distinct species and as consequences to be the most endangered raptor in the world, it will be the most wanted raptor by the collectors as happened to Javan Hawk-eagle.

The study was conducted at rain and dry season, however according to the limited fund, caused to the team limited field survey accommodation. The limited time survey causing to the limited data collected especially to the ecological data including its behavior. As the most endangered raptor in the world, poor knowledge of this raptor is handycapped and will be regrettable in the future due to the habitat change in Nusa Tenggara area.

The distribution of the Flores Hawk-eagle is found generally, but due to the data compilation and as indicator of lowland forest, it is extremely needed to know the detail distribution to achieve Nusa Tenggara forest management.

Forest status is very important tool to protect the forest itself including habitat to preserve for Flores Hawk-eagle. Protection forest is not ensuring the above statement because it still can change into other land uses if the local government considers them more valuable for local original assets. Considering that only 10% of Nusa Tenggara land are conservation area, so the need to its adding is essential, both in conservation issues as well as social issues if we agree that forest is the people life's resources.

In a cliche′way, law enforcement on environmental issues, have to be enforced which will be need much more efforts than others.

ACKNOWLEDGEMENTS

Many people helped to this project since its preparation until this report writing although many things have to be developped.

We are indebted to our friends and colleagues to accompanied during the surveys, Dani Heryadi, Dadan Ramdhan (YPAL), Jan Ove Grejshaugh, Nills Rov (NINA-Norwegia), Jean-Marc Thiollay (Laboratoire d'Ecologie, ENS, France), Oni Purwoko Besuki, Ni Nyoman Sumarlita, M. Jeri Irmansyah, Deni Purwandana, Ardiansyah, Ketut Adi, Meriyanti (KPB Kokokan), and Usep Suparman (FFI Indonesia Program) which their assistances and their sharing feeling with so much difficulties. We are also very grateful to the locals, which is too many people if we are citing here, who help us at the survey locations.

We are grateful to Pak Adi Susmianto, the Director of PHPA (Forest Protection and Nature Conservation) to process the permission letters for us. We are grateful too to YPAL Director Pupung F Nurwatha, Idah Faridah and Titis Endang Widuri for their patience of our fussiness; Dian Agista (BirdLife-Indonesia) which provide us maps and other information.

We are especially grateful to Yuko Inui for her encourages, so all the things were happened, for her patience on our late report and her effort on proposal submitting and report translation to Japanese. The last but not least to Pro Natura Fund which funded most of the survey trips for us.

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