Report of yellow-cheeked crested gibbon (Nomascus gabriellae) survey in Dong Nai Nature Reserve, Dong Nai province, Vietnam

The Vinh Cuu Nature Reserve and Historical Relics now called Dong Nai Nature Reserveand referred as such throughout this document was established in 2004 by Dong Nai’sProvincial People C

Report of yellow-cheeked crested gibbon (Nomascus

gabriellae) survey in Dong Nai Nature Reserve, Dong

Nai province, Vietnam

Nguyen Manh Ha

Centre for Natural Resources and Environmental Studies (CRES)

Nguyen Hoang HaoTran Duc DungNguyen Manh DiepPham Van Nong

Dong Nai Nature Reserve

Citation: Nguyen Manh Ha, Nguyen Hoang Hao, Tran Duc Dung, Nguyen Manh Diep,

Pham Van Nong, Report of yellow-cheeked crested gibbon (Nomascus gabriellae) survey in Dong Nai Nature Reserve, Dong Nai province, Vietnam.

Fauna & Flora International/Conservation International, Hanoi, Vietnam

Centre for Natural Resources and Environmental Studies (CRES)

Nguyen Hoang Hao Tran Duc Dung Nguyen Manh Diep Pham Van Nong

Dong Nai Nature Reserve

Reviewed by: Dr Ben Rawson and Paul Isua-Cao

Funded by: Arcus Foundation, The Rufford Small Grants for Nature Conservation, and

the SeaWorld & Busch Gardens Conservation FundCover photo: The forest of Dong Nai Nature Reserve / Nguyen Manh Ha

Table of Contents

Acknowledgements 1

1 Introduction 2

2 Background information of biodiverisy and primate studys in Dong Nai NR 5

3 Goal and objectives 6

4 Survey method and timing 6

5 Results 9

5.1 Gibbon records in Dong Nai NR 9

5.1.1 Results of interview survey 9

5.1.2 Results of listening post survey 9

5.1.3 Results of transect 13

5.2 Distribution of gibbons in Dong Nai NR 15

5.3 Records of other primates in Dong Nai NR 16

5.4 Conservation issues 19

5.4.1 Illegal hunting and trapping of wild animals 19

5.4.2 Non-timber forest product collection 19

5.4.3 Cattle grazing and forest fire 20

4.4.4 Habitat fragmention 20

5 Discussion 21

6 Conservation recommendations 22

References 23

Appendix 24

Appendix 1: Detailed information on gibbon records in Dong Nai NR 24

Appendix 2: Result of transect surveys 28

Appendix 3: Records of other primates 36

Appendix 4: Records on human impacts 40

Appendix 5: Records of other endangered species 44

Acknowledgements

This study was made possible with important financial support from ARCUSFOUNDATION, The Rufford Small Grants for Nature Conservation, and the SeaWorld &Busch Gardens Conservation Fund and technical Support from Fauna & FloraInternational/Conservation International

We would like to express our thanks to the Management Board of Dong Nai NatureReserve, especially Mr Nguyen Hoang Hao and the staff of Vinh Cuu for the great help ofthe research team during our research in this protected area

We would also like to express our thanks to the local community and local field assitants inthe Vinh Cuu district who provided important support for our team in the field

1 Introduction

Dong Nai Nature Reserve (NR) is one most important conservation areas in Vietnam as thereserve is one of the largest in terms of area and biodiversity richness The Nature Reservecovers an area of 68,370 ha, and 87% of the area is covered by natural forest Thelandscape of the nature reserve is dominated by lowland semi-evergreen forest with anelevation range of 100-340 m above sea level (asl) The reserve is one of the mostimportant strategic watershed forests of the Dong Nai River and Tri An hydropower damwhich provides drinking water for the second most populated and industrial area ofVietnam

During a working group meeting on gibbon status in Vietnam held in 2009, it wasconcluded that the Vinh Cuu-Cat Tien forest complex is one of the most importantconservation areas for the yellow-cheeked gibbon in Vietnam Besides its rich biodiversityand significant conservation value, Dong Nai NR is also identified as an illegal wildlifetrade hot-spot where gibbons and other primates are sourced for illegal trade However,there is no study so far to provide accurate information on the primate population in thisimportant nature reserve

The Vinh Cuu Nature Reserve and Historical Relics (now called Dong Nai Nature Reserveand referred as such throughout this document) was established in 2004 by Dong Nai’sProvincial People Committee based on the area of three state forest enterprises andHistorical War Sector D’ Management Board and Centre for Fishery of Dong Nai Thetotal area of the nature reserve is 100,303 ha, include: 67,903 forest land and 32,400 ha ofwater of the Tri An reservoir

The nature reserve is located on the northern side of Dong Nai river and spans 11communes and towns of five districts in Dong Nai province The coordinates of the reservefall within:

The reserve falls in the transition area between Bao Loc-Lam Dong plateau to flatter areas

of the Vietnam South-Eastern geographical region The terrain in the area typicallyconsists of gentle hills or flat areas The highest hill in the reserve is 368 m ASL and thelowest area is 20 m above sea level (ASL) with an average altitude of 100 - 120 m asl

(1) dry season is a period of six months from November to April During this time

the area has almost no rain Total rainfall during the dry season is only 10-15%

of total annual rainfall of the area with an average evaporation rate of 64-67%

of total evaporation per annum

(2) rainy season runs from May to October when the rainfall is most intense, with

90% of total annual rainfall in the area falling ion this period

Biodiversity resources

Recent biodiversity surveys conducted in Dong Nai NR confirmed the richness ofbiodiversity in the area There are 1,401 species of plant belong to 589 genera, 156families, 92 orders and 10 phyla Typical forest types are: evergreen, semi-evegreen andmixed bamboo forest and grassland There are 1,729 species of insect belong 238 families

so far identified (VCNR, 2009a) Surveys also confirm the existence of 85 species ofmammal belong to 27 families including 36 which are endemic and endangered in Vietnamand Southeast Asia and 26 species listed in IUCN Red List of threatened species (VCNR,2009a) There are 259 species of bird belonging to 52 families, among those 12 species arelisted in the Vietnam Red Data Book and 11 species are listed in IUCN Red List ofthreatened species

A total of 64 reptile species have also been confirmed in the reserve with an additional 33species listed in IUCN Red List and 21 species listed in the Vietnamese Red Data Book.There are also 99 fresh water fish species confirmed in the reserve

Map 1 Location of Dong Nai Nature Reserve

2 Background information of biodiverisy and primate studys in Dong Nai NR

Dong Nai NR is believed to home of up to seven taxa of primate, including the

yellow-cheeked crested gibbon (Nomascus gabriellae), black-shanked douc (Pygathrix nigripes) and Indochinese silvered langur (Trachypithecus margarita) which are all globally

threatened species The reserve is also a key conservation site for other endangered

mammals in Vietnam such as the Asian elephant (Elephas maximus) and gaur (Bos gaurus) In additon, Dong Nai NR has similar habitat and is contiguous with Cat Tien

National Park which is the best known area for yellow-cheeked crested gibbonconservation in Vietnam Therefore Dong Nai NR is likely to contain a significantpopulation of yellow-cheeked crested gibbons

Beside it’s biodiversity richness, Dong Nai NR was identified as an illegal hunting andtrade hot-spot for wildlife Recent data on illegal wildlife trade in Vietnam’s LowerMekong Region confirmed that gibbons and other primates were commonly illegallyhunted, smuggled and traded from this reserve Illegal hunting and trade is considering asthe primary threat to the survival of gibbons in this area and indeed, hunting and trade hasemerged as a real threat to the survival of much of the terrestrial fauna of this importantnature reserve

Despite this fact there is not many detail biodiversity survey have been carried out for thisnature reserve There is also no specific study on gibbons and other endangered primatepopulations in this important nature reserve Some key biodiversity surveys so farconducted Dong Nai NR include the following:

1 Bird survey for three state forest enterprises (Hieu Lien, Ma Da, Vinh An)conducted in 2002

2 Study to analyse the impacts of Agent Orange on biodiversity and the change ofecosystems in Ma Da area

3 Specimen collection of the sites forest, wild fauna and flora conducted by Dong Nai

NR, IEBR, Southern Sub-Institute of Forest Planing and Inventory and Institute ofFishery Research and Breeding (2007-2009)

These surveys and studies have confirmed the existence of at least seven taxa of primate in

the nature reseve including: pygmy loris (Nycticebus pygmaeus), bear macaque (Macaca arctoides), long-tailed macaque (Macaca fascicularis), pig-tailed macaque (Macaca leonina), silvered langur (Trachypitecus margarita), black-shanked douc (Pygathrix nigripes) and the yellow-cheeked crested gibbon (Nomascus gabriellae) Again the

population and status of these taxa is unknown due to the lack of specific survey andresearch on these groups of animals in the reserve

3 Goal and objectives

The overall goal of this survey was to provide information on the population of cheeked crested gibbons in Dong Nai NR and to raise conservation capacity of Dong Nai

yellow-NR staff concerning endangered primate study and monitoring

Specific objectives

- Undetake a one day training for Dong Nai NR staff in gibbon survey techniquesand reporting;

- Undertake a field survey for gibbons in Dong Nai NR;

- Produce a report on the gibbon population in Dong Nai NR and associated threatsand conservation issues;

- Based on survey results, to produce recommendations for future conservation ofgibbons in Dong Nai NR

4 Survey method and timing

The survey followed standard gibbon survey methods that have been widely used inVietnam and successfully used for gibbon survey and monitoring in Quang Nam, ThuaThien Hue and Quang Tri province Listening post surveys was the key method usedduring the survey Additionally, transect lines and observation posts were also used indaytime surveys wherever forest type and terrain were favorable, such as in areas thatgibbon were suspected to occur in, in order to maximize data collection andopportunistically observe gibbons in the forest

An archival study was also conducted, with all reports and related studies on mammals andprimates in Dong Nai NR and adjacent areas collected and analysed The informationprovided our team with a good background for field surveys and to select focal surveyareas

An interview survey was conducted in Ly Lich, Ma Da, Hieu Lien and Phu Ly communesand in all forest ranger stations of Dong Nai NR to collect information on gibbons beforethe field survey In total, 25 local people, including five hunters, 10 technical staff and 15rangers of the nature reserve were interviewed

Based on the interview results and consultation meetings with Dong Nai NR forest rangers,the reserve was divided into three sectors and the number of listening posts in each sectordetermined based on the collected information and habitat type of the area Evergreen and

- Ma Da sector is located further in the southern part of the reserve and is atransistion area between the most undisturbed to the most disturbed forest.Interview results indicated that gibbons do not occur in this area, and as such onlysix listening posts were surveyed here .

- Hieu Liem sector is in the southernmost part of the reserve and no information ongibbons occurring in this area was collected during interview surveys This areaalso represents the most disturbed area of the reserve with the entire forest area inthis sector consisting of secondary and regenerated forest Five listening posts weresurveyed in this sector

The listening posts and transects were selected by combining secondary data from archivalresearch and interview information with topography and forest cover maps of Dong Nai

NR In total, 34 listening posts were selected for the whole nature reserve The posts werelocated in different type of habitats and represented all major forest types in the areaincluding evergreen-broadleaf forest, semi-evergreen forest, dipterocarp deciduous forestand mixed bamboo forest (see Map 2)

The minimum distance between listening post was 1,2 km with a maximum of 3.0 km.Each listenting post was surveyed on two consecutive days Survey time for each listeningpost was from 04:30 to 10:00 Average listening post survey time was 6 hours per day Intotal 69 days were spent for this listening post survey with aproximaetly 414 survey hours The following data were collected and noted in a standard listening post datasheet (seeAppendix 1) for each listening post:

- time of gibbon singing (beginning and end);

- weather the night before and at the time of survey;

- compass bearing to calling gibbon group;

- distance to the gibbon group(s);

- gibbon group(s) composition: male, female, juvenile, infant (if possible)

- brief description of forest types;

- human impacts;

- tape recording of the singing and photograph (if possible)

From each listening post, one transect was created that started from the listening post andwent in one direction for approximately 2 to 4 km in length The transect walk wasselected depending on the terrain and vegetation type, and in general the team often chose

to walk in undisturbed woodland areas rather than bamboo or disturbed forest (i.e.transects were non-ramdom) The survey time on transects was from 10:00 to 12:00 Oneach transect information on gibbon occurance and other primates and other speciessighted was also noted in detail in data sheets (see Appendix 2 and 3) In total 33 transectswere established during the survey Total transect walking distance was 91.9 km and totaltime for transect surveys was 84 hours

From 14:00 to 17:00 the team spent time to locate the next listening post and transect forthe following survey day

Gibbon calls, wherever possible, were recorded stored for future usage No DNA samplefrom gibbon (hair, tissue, skin, bone, dung) was taken during the survey

Information on human impacts such as hunting, logging or non-timber forest productcollection was also collected for reporting and analysis of the human impact on the reserve.For each listenting post and transect, a brieft description of habitat type and generalcondition of forest and terrain was made in order to provide basic information on gibbonpreferred habitat for analysis

Some key equipment that was used during the survey included:

- Binoculars (Carl Zeiss 10x40),

- Cameras (Nikon D90, Canon 50D, Lens 70-300mm, 17-85mm)

Timing of the survey

- the interviewing survey was conducted in May and June 2010

- training was conducted on 21 July 2010

- field survey was conducted from 22 July to 30 October 2010

- data analysed and reporting from August to December 2010

5 Results

5.1 Gibbon records in Dong Nai NR

5.1.1 Results of interview survey

Interview survey results indicated that gibbons only occur in the north-west corner (Vinh

An and Ma Da sectors) of Dong Nai NR These areas consist of approximately 20,000 ha

of contiguous evergreen and semi-evergreen forest This area also is the least disturbedforest of Dong Nai NR and importantly connects with Cat Tien National Park, creatingfavorable conditions for the dispersal of gibbon and gene flow between these two protectedareas These conditions combined suggest that these areas are the most suitable habitat forgibbons in the reserve

There is no information on gibbons in the Hieu Lien sector Consulation with the Dong Nai

NR Management Board and forest rangers resulted in the conclusion that this southernmost sector of the reserve was heavily logged when it was an area of Hieu Lien StateForest Enterprise Addionally most of the areas are close to roads and Tri An reservoirtherefore they have been more heavily impacted from logging and agriculture than otherareas In addition, the area of Hieu Liem is currently cut into many fragmented patched byroads and agriculture lands reducing its suitability for gibbons and other large mammals.During this time (under the state forest enterprise) there was no control of hunting,therefore gibbons and other large animals had move to other area such as Vinh An and Ma

Da where the forest was less disturbed It is likely that gibbons were hunted to extinction inthis area

5.1.2 Results of listening post survey

In total, 69 survey days were spent surveying 34 listening post and 34 transects (map 2) Atotal of 15 groups of gibbon were confirmed in Dong Nai NR 31 individual gibbons werecounted, including 13 males, 10 females and 8 juveniles, identified by their distinctivecalls

This information only gives a minimum gibbon population size in Dong Nai NR becausethe survey was able to cover only 40% the size of the area that is suspected as the coregibbon distribution area in the reserve (mostly in Vinh An sector)

Gibbons were heard from 44.1% of listening posts The highest number of gibbon groupscounted from one listening post was two groups Most of the groups were recorded in Vinh

An sector (14 groups) with Ma Da (1 group) and Hieu Liem (0 group) sectors having avery low density of gibbons

Due to the relatively flat terrain in Dong Nai NR listening distance is probably about 1.5 to

2 km from calling gibbon groups The low gibbon density in the nature reserve made thesurvey less difficult in term of distinguishing gibbon groups heard from more than one postwhere there was overlap in suvey area, increasing the accuracy of group estimation in eachsurvey area

Map 2 Location of listening posts surveyed in Dong Nai NR

Results of survey effort in Vinh An sector

A total of 23 listening posts were surveyed in Vinh An sector with 47 consecutive surveydays in August and September 2010 A total of 14 groups with 30 individuals include 13males, 10 females and 7 immature individuals were identified

During the survey, our team determined that some group of gibbons changes their sleepingtrees as identified by the change of compass bearing of the morning calls over consecutivedays while still remaining in the same general area For instance, in Vinh An, at least threegroups were identified to display this phenomenon during the survey period

Among those 14 groups confirmed in Vinh An, 11 groups were found in mixed evergreen forest The forest here still has canopy connectivity formed by dipterocarp treesand other evergreen plants Gibbons also utilise the evergreen forest patches that arelocated within the mixed forest The contiguous canopy provides suitable conditions forthe movement of gibbons as well as facilitating the dispersal of gibbon between Cat Tien

bamboo-NP and Dong Nai NR The area where the 11 groups were recorded in Vinh An are largelylocated next to Cat Tien NP

In this sector, there were three group of gibbon recorded in the semi-evergreen forest at theborder with Ma Da sector, the second most disturbed area in the reserve, despite localinterviewees saying gibbons had been extirpated in Ma Da and Hieu Liem sectors due toheavy logging and hunting in pervious years (1985-2003) The occurrence of gibbongroups in this area probably indicates a recent extension of the population into these moredisturbed areas Dong Nai NR technical department reports that other species, including

Asian elephant (Elephas maximus), gaur (Bos gaurus) and black shanked douc (Pygathrix nigripes) have also been reported to be extending their range in to more southerly sections

of the reserve The reason for this extension is likely due to more effective management ofrangers is Dong Nai NR in last five years resulting in a reduction in illegal logging and therecovery of the forest and ecosystem

Results of survey effort in Ma Da sector

A total of six listening posts were surveyed over two consecutive days per post (12 days intotal) in Ma Da sector Only one group (group number 14 at listening post 24) alsoincluding one immature individual was recorded in this sector

As indicated in the methods section, the Ma Da and Hieu Liem was given lower priority aswell as fewer listening posts due to the lack of information on gibbon presence in this area

In addition, assessment of forest cover maps and detailed consultation with themanagement board of Dong Nai NR showed that the majority of the forest in this sector isregenerating forest after intense logging Moreover, the southeastern area of this sectorconnects with Tri An reservoir and inter-district road (provincial road number 761) withhigh traffic, therefore animals often avoid activities in this area And within this area thereare some agriculture land and plantations that currently separates the contiguous naturalforest which also creates a less favorable condition for wild animals especially gibbonswhich generally require good quality natural forest

The interview information in this area also indicated that there was almost no confirmedpresence of gibbons in the southern part of this sector in the previous five years and withonly one provisional record of one group of gibbon in northern part (area Trung Ung Cucand Bau Dien ranger stations)

The only group of gibbon in this sector was recorded near Rang Rang ranger station Thisarea is located next to the border with Binh Phuoc province and is heavily disturbed byhumans Hunting pressure and non-timber forest product collection is very high, the area isalso separated by two roads (no 322 and 761) with plantations in the corridor and most ofthe main forest canopy was destroyed by previous selective logging by Ma Da State ForestEnterprise All these conditions together make it the second most disturbed forested area inthe reserve

Nevertheless, this area is the transition area between Vinh An and southern part of thenature reserve, therefore in next few decades when the forest would gradually recovergibbons could possibly extend their distribution from Cat Tien NP and Vinh An andreoccupy this area In addition, the nature reserve is seizing all plantation and agriculturalland in this sector to convert to indigenous forest This plan, if successfully implemented,could possibly reconnect the remaining forest patches in the area and once again become aappropriate habitat for gibbon

Results of survey effort in Hieu Liem sector

A total of five listening posts were surveyed over 10 days in Hieu Liem sector; however nogibbons were confirmed to exist in this area during our survey Our listening posts werelocated in the most undisturbed forest of the sector which were likely the most suitablehabitat for gibbons, however no signs of gibbon were confirmed Interview surveys alsoindicated that there is no information on gibbons in this sector in the last five years.However, it is probable that gibbons inhabited this sector once when forest was not cut andimpacted by the state forest enterprise activity

Hieu Liem sector is located in the triangle of the provincial borders of Binh Duong, DongNai and Binh Phuoc provinces The sector is also bordered by two rivers, the Be and Ma

Da rivers Forests in both Binh Duong and Binh Phuoc have been completely cleared forrubber plantation therefore placing pressure for logging and non-timber forest productextraction from these two provinces on to this area in Dong Nai NR

In general, this sector is the most disturbed by current pressure from surrounding localcommunities In addition when this area was under Hieu Lien State Forest Enterprise all ofits forests were heavily logged As a result, presently only secondary and regeneratedforest remain in this sector Moreover, the logging trail system in the area is still used bylocal people, increasing disturbance to the forest

The nature reserve has launched an indigenous forest recovery program, which ifsuccessful will allow forest recovery to a condition sufficient to support gibbons andpermit an extension of the gibbon population southward from Vinh An and Ma Da,allowing the Hieu Liem sector to be recolonised

5.1.3 Results of transect surveys

Beside the listening post survey, the team also undertook transect surveys in the same areawhere listening posts were established Because the area of Dong Nai NR is so vast(68,000 ha) only areas that had listing posts were selected for transect surveys Transectswere conducted on existing trails in mixed bamboo forests and on steep terrain and cutthrough the forest following a random compass direction in woodland areas In total, 33transects were established with a total length of 91.9 km and 82 survey hours for the wholesurvey area in Dong Nai NR

Vinh An sector

In total 19 transects with a total length of 46.9 km with an average lengtgh of 2.5 km(range of 0.4 km - 7.7 km) were walked in the Vinh An sector No gibbons were observedduring transect surveys, likely due to the dense vegetation which limited viewing distanceand required the team to make lots of noise moving through the forest, probably alertinggibbons to our presence

Nevertheless, a number of black-shanked doucs, pig-tailed macaques, bear macaques andlong-tailed macaques were observed during our survey In addition, traces and foot-prints

of a number of other endangered species were identified along transect such as: Asian

elephant (Elephas maximus), gaur (Bos gaurus), Siamese f ireback p heasant (Lophura diadi), great hornbill (Buceros bicornis), Bengal monitor (Varanus bengalensis) and many

common ungulate species

Ma Da sector

A total of eight transects with a total length of 26.6 km was surveyed, with an averagelength of 3.3 km (range 2.1 - 4.6 km) One group of gibbons were observed along transects(transect MD 2 to Ven Ven hill), consisting of one male and one female, however thegibbon was aware of the team presence and moved away quickly

The team also obsevered other endangered primates on transects including black-shanked doucs, pig-tailed macaques, bear macaques and long-tailed macaques Track and sign of

gaur, Asian elephant, sambar deer (Cervus unicolor), muntjac (Muntiacus muntjak), mouse-deer (Tragulus javanicus) and wild boar (Sus crofa) were also detected, especially

in forest unit number 93 and 96 where the team identified a group of eight gaur were active

in the area

During the survey a lot of human activity in Ma Da area was observed including forestplanting and land preparation for the agriculture These noises may have alerted gibbonsand animals and hence perhaps reduced the opportunity to observe animals during oursurvey

Hieu Liem sector

A total of six transects were surveyed in Hieu Liem sector with a total length of 18.4 km(range 1.1 - 4.7 km).No gibbons were observed in this area and few individuals of black-shanked douc, bear macaque, and long-tailed macaque were observed on these transects.The occurrence of humans encounters in the forest of Hieu Lien sector were morefrequently than in Vinh An and Ma Da sector

Map 3 Transect survey effort in Dong Nai NR

5.2 Distribution of gibbons in Dong Nai NR

Based on the survey results and preliminary observations on gibbons’ preferred habitat inDong Nai NR, gibbons are distributed only in Vinh An and Ma Da sectors, but mostly inVinh An The area that gibbons occur in in Dong Nai NR is approximately 33,000 ha andconsists of evegreen forest, semi-evergreen forest and mixed woodland and bamboo forest.However the predominant habitat for gibbon based on our records is mixed woodland andbamboo forest (17,000 ha) In the woodland area, only three groups were recorded

With an assumed average accurate listening distance from each listening post being 1.5km,the average area surveyed at each post was 7.07 km2 Therefore, appropriate 240.32 km2

(34 listening posts) was surveyed in Vinh Cuu which included some overlap portions areasbetween listening post

An explanation for the finding that gibbons occur mostly in the mixed bamboo forest ratherthan other habitats in Dong Nai NR is that, firstly the bamboo forest in Vinh An and Ma

Da sector received little impact from logging therefore the forest still has the main forestcanopy intact which suits the typical arboreal movement of gibbons Conversely, the othersectors of Hieu Liem and the southern part of Ma Da, the canopy has been largelydestroyed and not well connected Secondly, the human impact in Hieu Lien and thesouthern part of Ma Da is very high with logging, hunting and agricultural land preparationsurrounding and within forested areas, disturbing gibbons Thirdly, the areas of Vinh Anand Ma Da are connected with Cat Tien NP which is considered to be one of the mostimportant conservation sites for yellow-cheeked crested gibbon in Vietnam Thisconnection perhaps facilitates the dispersal of some gibbon groups from Cat Tien NP toDong Nai NR and may explain why gibbon records in this border area are more numerousthan any other parts of the nature reserve Whether Dong Nai NR has been in the past, orcontinues to be in the present, a sink population for gibbons in Cat Tien NP remains to bedetermined

It’s also believed that gibbons are possibly spreading into the more southerly areas of DongNai NR however determination of this apparent trend will need more time to evaluate.Only with increased forest recovery, improved forest canopy connectivity and a significantreduction in human activity in the area can southerly gibbon dispersal occur in Dong Nai

NR

5.3 Records of other primates in Dong Nai NR

Black shanked douc (Pygathrix nigripes)

Four groups of douc were recorded during the survey with 21 individuals (4 males, 1female, 2 infants and 14 unidentified) Three groups were recorded in Vinh An and one inHieu Liem Several other groups were likely observed, however due to the densevegetation observation and counting of individuals/groups proved difficult and additionalgroups were only confirmed by their call (and are not listed in this report) Based on ourobservations and the reports of local interviewees, doucs seem to still have a reasonablyhigh abundance in Dong Nai NR, however they suffer from illegal hunting for thebushmeat trade

Long tailed macaque (Macaca fascicularis)

A total of six groups of long-tailed macaque, with 40 individuals were observed duringtransect surveys, including two groups in Vinh An, three in Ma Da and one in Hieu Liem.Long-tail macaques seem to be the most common primate in Dong Nai NR They wereobserved mostly in areas close to water sources such as streams and small lakes Thespecies is also hunted by local people for food and for the bushmeat trade

Pig tailed macaque (Macaca leonina)

A total of five groups of pig-tailed macaques were recorded in Dong Nai NR with 38individuals (6 males, 12 females, 3 infants and 17 unidentified individuals) Three groupswere recorded in Vinh An and two in Ma Da

Interviews with local people indicated that the pig-tailed macaque population in the areahas suffered badly from hunting as their meat is considered to taste good In addition, asinformed by local people and from a previous trade survey of local restaurants in Phu Lycommune, the species meat is still served in restaurants (Nguyen Manh Ha, 2008) Theircapture is facilitated by the fact that the species often visits agricultural areas and fruit treesand hence can be easily targeted by hunters with improvised huting guns or snare traps

Bear macaque (Macaca arctoides)

One group of 10 animals was observed near Suoi Rang ranger station This group visitsSuoi Rang stream every 2-3 days, and they were observed at least three times while theteam undertook gibbon surveys in Vinh An sector Sharing the same threats as pig-tailedmacaques, bear macaques are often hunted by local hunters as they are reported to tastegood and can easily be sold to local bush meat restaurants

Map 4 Records of other primates in Dong Nai NR

Table 1 Records of other primates in Dong Nai NR

Survey area

5.4 Conservation issues

5.4.1 Illegal hunting and trapping of wild animals

Illegal hunting and trapping of wild animals is a critical issue for wildlife protection inVietnam In Dong Nai NR this issue is also posing lots of threat to terrestrial animalsespecially in areas that are close to residential areas

During our gibbon trade survey in Dong Nai province we confirmed that live gibbons fromDong Nai NR was the key location for supplying the pet and zoo collections in Ho ChiMinh City and Binh Duong province It is estimated that annually around five gibbons arepurchased from hunter in Dong Nai NR

During the survey we heard gun shots in Vinh An at least 7 times and one hunter with agun was seen at listening post number 7 As informed to us by forest rangers in Suoi Rang,the forest in Vinh An sector is the best in the reserve, therefore there are more animals inthe area and as a result Vinh An has become a target area for hunting

The worst areas for hunting pressure are Ma Da and Hieu Liem sectors which aresurrounded by local residential areas of Binh Duong, Binh Phuoc and Dong Nai provinces.Forest rangers in these areas struggle with hunters coming in from from Binh Duong andBinh Phuoc who visit this area every day

During the survey, hundreds of wild animal traps were observed and removed in the field.Areas such as waterholes and mineral licks are most commonly targeted for trapping bylocal hunters

Our observations in Phu Ly and Ly Lich communes (in the middle of Dong Nai NR)suggest bush meat restaurants are still very active in these two communes Meat fromprimates and ungulates is always available in the restaurants, more over they were clearlyindicated in restaurant menus

In summary, hunting is still the most serious threat to animals in Dong Nai NR If this cannot be effectively controled, soon not only endangered animals but common species willbecome rarer from this illegal hunting and trade

5.4.2 Non-timber forest product collection

Dong Nai NR has suffered greatly from non-timber forest product (NTFP) collection,

bamboo shoot and the “hat ươi” Scaphium lychnophorum collector These two seasonal

NTFPs attract a large number of local people into the forest In some instances, the

Scaphium lychnophorum tree is cut down by the collector; this destructive practice

seriously threatens this speices in the area

Honey, rattan, orchid and ornamental tree (Ochna integerrima) collection also create a lot

of disturbance to the forest With a large nunber of people searching the forest for NTFPs,this makes the forest and animal habitats seriously disturbed and unstable Especially

during the bamboo shoot and “hat ươi” season, 500-1000 local people visit the forest every

day With this number of people in the forest, tremendous disturbance is created that couldimpact animal species distributions within Dong Nai NR

19

5.4.3 Cattle grazing and forest fire

There are several grassland areas in Dong Nai NR, either naturally created or by humansafter logging activities that are currently being used by local people as grazing areas The occurance of domestic cattle and other livestock in the reserve could pose someserious threat to wildlife including disease transmission and food competition to wildbovids In addition, in some areas local people intentionally create forest fires in thegrasslands for grazing purposes This activity creates a serious threat to the reserveespecially during the dry season Forest in Dong Nai NR consists of a large extent ofbamboo forest and deciduous forest and once forest fires occur, they can easy expand anddestroy forest

Hence this activity should be prohibed and all cattle and livestock grazing in the forestshould be completely eradicated

4.4.4 Habitat fragmentation

The central and southern part of Dong Nai NR is currently facing the serious issue ofhabitat fragmentation resulting from the allocation of many areas to local people formaking plantations, planting agricultural crops and fruit trees These allocated areas arelocated right in the middle of the reserve which has formed an area that makes the forestbecome disconnected and islolated

In addition, old logging trails are often used by local people to access plantations In someareas frequent motocycle and truck travel to plantations has widened roads which furtherfragments forest and may create difficulties for aboreal animals to move between areas.Issues of habitat fragmentation, even minor fragmentation, are especially significant forgibbon which requires canopy closure due to their strictly arboreal nature

5 Discussion

Due to the limited time, not all the reseve was surveyed however key areas for gibbonoccurence in the reserve was studied by our team A total of 15 groups and 34 individual ofthe endangered yellow-cheeked crested gibbon were recorded in Dong Nai NR, the largestprotected area of Vietnam

The 15 groups of gibbon were mostly recorded in Vinh An Sector, and one was recored in

Ma Da sector In the southern part of the reserve, Hieu Liem, we did not record anygibbons during the field survey or during inteview surveys with local people in this sector

It is possible that the area was so disturbed by logging and hunting pressure while it was anarea of Hieu Liem State Forest Enterprise, that gibbons perhaps moved out of the area orwere completly hunted out in this area

Despite the fact that gibbons occupy only the northern part of the reserve, if the reserve iseffectively managed in the future, it is probable that the southern part will be a potentialarea for the expansion southward of the gibbon population

During the survey, we also observed and reconfirmed the presence of six of the sevenspecies of primate in this nature reserve, with Indochinese silver langur the only primatespecies that was not observed during our survey In addition, a number of other endangeredspecies were also confirmed during the survey such as Asian elephant, gaur, Siamesefireback pheasant and great hornbill These records again express the biodiversity richness

of the reserve as well as their conservation role

Illegal hunting and wildlife trade is still the most serious threat to the terestrial mammals inthe nature reserve Primates including gibbons are still a target for local hunters Illegaltrade in live gibbons from Dong Nai NR to other provinces was documented and represents

a key threat to the survival of this endangered primate in the reserve Hence, not only goodconservation management is required but also effective law enforcement on illegal huntingand trade is needed to facilitate the recovery and development of gibbon and othermammal populations in the reserve

Wildlife conservation and cessation of illegal hunting in the reserve will give a brightchance for the recovery and development of a significant gibbon population in Dong NaiNR

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6 Conservation recommendations

- To date, hunting is the most serious threat to the survival of gibbons and otherendangered species in Dong Nai NR, hence it is important to have a wildlife tradeanalysis that focuses on the hunting and trade in primates The assessment will beimportant to figure out the level of hunting and trade as well as the key huntingareas for better law enforcement patrols and monitoring in key gibbon andendangered species distribution areas

- To date, this is the only primate survey ever undertaken in Dong Nai NR, hence theinformation on other endangrered primates is still unclear Therefore, it is important

to have a comprehensive primate survey in this reserve to provide betterinformation on species status, distribution and pressures This importantinformation will be vital for long-term primate conservation and monitoring in thereserve Local involvement in primate monitoring and law enforcement patroling isalso crucial for better awareness raising as well as the future involvement of localcommunities in conservation management of the reserve

- A training is needed for Dong Nai NR staff on primate and endangered speciesmonitoring and conservation Up to date, there have been no training everundertaken for the reserve This knowledge will be very important for futureconservation activity in the reserve

- Currently the reserve is implementing the indigenous tree program to fill gaps inforest cover between forest patches This programe could give a good chance toconnect gibbon habitats and eventually increase the pace of recovery of forestquality and habitats for wildlife The recovery of the forest could also giveopportunities to gibbons in Dong Nai NR to extend their distribution to southernareas of the reserve in the future

- NTFP collection is another serious threat to gibbon habitat and the biodiversity ofthe reserve, therefore the Management Board of Dong Nai NR should have anappropriate management programe for NTFP collection, such as a timetime ofharvest, open and strictly protected areas Especially in the gibbon andendangered species’ habitats, harvesting should be limited to a minimum to avoidany disturbance to key conservation areas

- There have been no conservation awareness activities ever launched in the reservefor gibbons and other endangered species Therefore a gibbon conservationawareness campaign is strongly recommended for the communes surrounding thereserve to raise the knowledge on gibbons and nature