Sikundur Monitoring Post Annual Report for 2015

James Askew

SUMATRAN ORANGUTAN CONSERVATION PROGRAMME

Contents I. Introduction ...... 2 II. Climatological & Phenological Monitoring ...... 4 III. Habitat Monitoring ...... 7 IV. Orangutan Observations ...... 10 V. Student Projects from 2015 ...... 19 -Habitat Structure ...... 19 -Orangutan/Primate Vocalizations ...... 20 -Gibbon, Siamang, and Leaf Monkey Surveys ...... 21 -Orangutan Nest Surveys ...... 22 -Liana Use by Orangutans at Sikundur ...... 23 VI. Ongoing Projects ...... 24 -Camera Trap Study of Biodiversity ...... 24 -Unmanned Aerial Vehicle (UAV) Technology ...... 25 VII. Coming Up In 2016 ...... 26 VIII. References Cited ...... 28 IX. How to Get Involved ...... 30

I. Introduction

Throughout their range, Sumatran orangutans are threatened by two often related factors, habitat loss and poaching/hunting. Deforestation in Sumatra, a product of ongoing human extractive industries (e.g., development of infrastructure, expansion of large-scale agriculture, logging concessions, mining, and small-scale localized encroachment), is primarily attributed to inadequate cross-sectorial land use planning, desire for short-term economic growth, and a lack of environmental law enforcement (Wich et al. 2011a). Most worrisome is that Sumatra’s lowland and swamp forests, areas known to house the highest densities of orangutans (Wich et al. 2008, in press), also have the highest rates of deforestation in Indonesia (Laumonier et al. 2010; Margono et al. 2012). While more difficult to quantify (i.e., relative to forest loss), poaching/hunting is an additional threat to the survival of Sumatran orangutans, and is largely associated with access to forested areas, a byproduct of deforestation/habitat fragmentation and population growth (Wich et al. 2011a).

Interestingly, virtually all long-term monitoring studies of Sumatran orangutans, and indeed all data in recent population viability analyses of the species (Marshall et al. 2009), have utilized ‘high-density’ orangutan populations situated in primary peat- swamp forest (Suaq Balimbing, Aceh Province) and primary lowland rainforest (Ketambe, Aceh Province). These two sites are regarded as “prime habitats” for Sumatran orangutans (Husson et al. 2009) and historically have suffered relatively lower levels of human disturbance. Accordingly, we lack knowledge of Sumatran orangutans in less productive and/or more degraded landscapes, and thus also lack a complete grasp of their behavioral, demographic, ecological, and physiological variability, factors vital to understanding their future population viability (Marshall et al. 2009).

The Sikundur Monitoring Post is located in the Langkat District of North Sumatra Province, within the Gunung Leuser National Park (TNGL) and larger Leuser Ecosystem National Strategic Area [Fig. 1]. It consists of previously logged lowland dipterocarp tropical rainforest, and even so, is one of the few remaining lowland areas that still maintains suitable forest habitat for the Critically Endangered Sumatran orangutan. As such, the importance of the Sikundur Monitoring Post and its relevance to long-term Sumatran orangutan conservation must be underscored. The Sumatran Orangutan Conservation Programme (SOCP) started orangutan and habitat monitoring at Sikundur in the second half of 2012 and is now in its fifth year of operation there.

Building off of 2014’s successes, the 2015 field season at Sikundur was full of many new developments and a tremendous amount of progress. These include an increase in orangutan follows and new focal individuals, additions to the long-term climatological and phenological datasets, more intensified habitat monitoring efforts, and a continuation of ongoing projects (e.g., camera trapping, Unmanned Aerial Vehicle [UAV] studies, and student research projects). The purpose of this short report will be to highlight some of these activities and emphasize Sikundur’s importance to orangutan conservation and also the conservation of Sumatra’s unique biodiversity.

Fig. 1. The location of the Sikundur Monitoring Post in relation to the Gunung Leuser National Park and the Leuser Ecosystem National Strategic Area.

II. Climatological & Phenological Monitoring

At the Sikundur Monitoring Post, the average monthly rainfall during August 2013 – December 2015 was 251.7 mm, with a monthly range of 12.4-535.4 mm [Fig. 2]. Average yearly rainfall at Sikundur is 2,895.9 mm, albeit this only includes data points for 2014 and 2015. In general, higher levels of rainfall occur during May, August- October, and December, whereas low levels of rainfall occur during January-April, June- July, and November. Both February and March have recorded rainfall levels below 100 mm, indicating extreme rainfall lows.

Average monthly temperatures from within the field station were 27.4° C, with a monthly range of 26.1-29.7° C [Fig. 2]. During the observation period, temperature highs were recorded for the months February-July, whereas temperature lows were recorded for the months of January and August-December. In general, there is a correlation between monthly temperature and rainfall, with increases in temperature correlating with rainfall after a lag of two months.

Fig. 2. The average monthly rainfall and temperature for the Sikundur Monitoring Post from August 2013 – December 2015.

The average percent of liana and tree stems (>10 cm diameter at breast height) that were bearing fruit in our 20 phenological plots was 2.8% for the period of June 2013 – December 2015, with a range of 0.3-13.0% [Fig. 3-4]. High fruiting values were generally observed during May-October; however, consistent levels of high fruit productivity were most apparent during August and September. Conversely, consistent

fruit lows are present during January-April and then again during November-December [Fig. 3-4]. Extreme high fruiting values were observed for June-September 2014. We are hesitant to suggest that a masting event occurred during this period, given that the phenology dataset included in this study encompasses only 31 months; however, the aforementioned period is above Wich and van Schaik’s (2000) masting requirement of 1.96 standard deviations above the mean. The range of fruiting values observed from 2013-2015 indicates that there is a considerable level of fruiting variability at the Sikundur study site.

It is interesting to note that the average fruiting score for Sikundur (i.e., 2.8%) falls nearest the percent fruiting score range of a number of Bornean field sites (3.0-6.8%); however conversely, it is well outside the published range of percent fruiting scores of two Sumatran (6.9-30.57%) sites, Ketambe and Suaq Balimbing (Wich et al. 2011b). Even when two additional unpublished Sumatran station data points (i.e., Batang Toru, 6.6% and Jantho, 4.9%) are added to these values, Sikundur has one of the lowest fruit productivity values for both Borneo and Sumatra [Fig .5]. Thus, the Sikundur Monitoring Post has lower fruit productivity than that of previously studied Sumatran orangutan field sites, indicating that Sumatra is far less homogeneous than currently thought and that a portion of remaining orangutan habitat in Sumatra is far less productive than previously thought. This is clearly visualized in Fig. 5, where the Bornean trend line is relatively flat, compared to the steep trend incline of that of the Sumatran sites.

Fig. 3. The average monthly rainfall and percent of liana/tree stems with fruit for the Sikundur Monitoring Post from June 2013 – December 2015.

Fig. 4. The average monthly percent of liana/tree stems with fruit for the Sikundur Monitoring Post from June 2013 – December 2015, including the mean (black dashed line) and +1 (blue line) / +2 (red line) standard deviations from the mean.

Fig. 5. A comparative look at fruit productivity at a number of Bornean and Sumatran field stations. All data are from Wich et al. (2011b), except for that of SOCP’s unpublished data from the Sumatran sites of Batang Toru (6.6%), Jantho (4.9%), and Sikundur (2.8%),

III. Habitat Monitoring

The Sikundur area, previously the Sikundur Reserve (est. 1938) prior to the formation of the TNGL (est. 1980) was selectively logged starting in the late 1960s, which continued and progressively intensified in some areas until the 1980s (Cribb, 1988; Wind, 1996). Following the establishment of the TNGL, logging in the Sikundur area continued primarily at the park border. Currently, illegal logging and in some cases complete land clearing are still present near the southeastern boundary of the Sikundur Monitoring Post at the TNGL border, in addition to more generalized illegal human extractive activities (e.g., bird trapping, damar resin extraction, and fishing). As a major part of SOCP’s activities in the Sikundur area, we conduct monthly habitat monitoring (field/UAV patrols and geospatial analyses). Data generated from these activities are compiled in our long-term database and allow us to make detailed analyses of habitat loss, which form the basis for conservation planning and habitat protection.

Of greatest concern are the extensive levels of forest loss that continue to appear at the boundary of the Sei Betung area of the TNGL, all of which is within the Leuser Ecosystem National Strategic Area [Fig. 6]. Nevertheless, relative to 2014, forest loss at the Sikundur Monitoring Post was minimal in 2015, with encroachers coming briefly into the area of the field station in early 2015. After a number of months of forest disturbance, national park staff conducted a patrol that finally eradicated the illegal encroachers. A recent Google Earth image from June 2015 shows that the southeastern portion of the Sikundur field site, the area logged and burned in 2014 and again briefly disturbed in 2015, has started to regrow, following only a number of months without any further disturbances [Fig. 7]. This unfortunate situation serves to highlight that early detection, immediate response from the proper authorities, and adequate follow-up activities are required to curb forest loss. Our observations also indicate that the threat of deforestation to orangutans is ongoing and that in some cases, protected areas will likely not be enough to preserve orangutan habitat, if the proper authorities are unable to adequately enforce the law.

Fig. 6. Forest loss from 2000-2014 in the Sei Betung area of the Gunung Leuser National Park (TNGL), nearest the Sikundur Monitoring Post. Forest loss data from Hansen et al. (2013).

Fig. 7. The Sikundur Monitoring Post from a recent Google Earth image taken in June 2015. As compared to 2014, there was limited encroachment and the southeastern portion of the transect area (yellow ellipse) has begun to grow back, following clear cutting of the area in 2014 and further disturbance in early 2015.

IV. Orangutan Observations

The 2015 field season was tremendously successful, with a total of 239 focal follows being conducted by student researchers and SOCP staff [Fig. 8; Table 1]. In addition, there were two new adult male orangutans that were contacted and followed in 2015. This has brought our total of habituated animals to 17, including 5 adult females, 8 adult males, and 4 infants [Fig. 9-11].

Results from all orangutan follows >3 hours duration suggest that on average (n=31 months) adult orangutans at Sikundur were found to feed 53.9% of the time [Fig. 12], followed by rest ( x =27.3%), travel ( =16.9%), and other ( =1.9%). During periods of fruit scarcity (n=22 months), adult orangutans were observed to feed 58.5% of the time, followed by rest ( =24.0%), travel ( =15.8%), and other ( =1.7%). Conversely during periods of fruit abundance (n=6 months), adult orangutans were observed to feed 40.9% of the time, followed by rest ( =35.1%), travel ( =20.8%), and other ( =3.1%). Thus, the primary differences were more feeding during fruit scarce periods, with greater emphasis on all other behaviors during fruit abundant periods.

During the observation period, adult orangutans were observed to feed primarily on fruit ( =59.7%), followed by leaves ( =14.2%), bark ( =13.6%), piths/stems ( =5.9%), invertebrates ( =4.0%), flowers ( =2.2%), and other ( =0.4%) [Fig. 13]. When fruit was scarce, adult orangutans were observed to feed on fruit ( =53.65%), leaves ( =14.8%), bark ( =18.0%), piths/stems ( =6.8%), invertebrates ( =4.1%), flowers ( =2.4%), and other ( =0.3%). When fruit was abundant, adult orangutans were observed to feed on fruit ( =81.9%), leaves ( =7.1%), piths/stems ( =4.8%), invertebrates ( =3.4%), bark ( =0.7%), flowers ( =1.1%), and other ( =0.9%). The primary differences are the significant amount of fruit feeding during fruit abundant periods and the significant amount of feeding on lower quality food resources (e.g., bark and leaves) during fruit scarce periods.

These differences in activity budgets are likely related to a greater handling time needed for lower quality resources in the fruit scarce months, and an emphasis on travelling to higher quality resources during fruit abundant months, plus the energetic freedom to utilize time for rest and social behaviors. These results are quite different from that of previously published Sumatran orangutan populations, and indicate that orangutans in Sikundur are impacted seasonally by fruit availability. These results also suggest that Sikundur orangutans utilize a feeding/foraging strategy that is intermediate between Bornean and Sumatran orangutans, making the division between Bornean and Sumatran orangutans more enigmatic (Morrogh-Bernard et al. 2009). Given that this is the first study to conduct orangutan research on the eastern portion of the Bukit Barisan Mountain Range, a known climatological barrier, these results have important conservation implications for the remaining orangutan population in the eastern portion of the Leuser Ecosystem National Strategic Area. This, in combination with our analyses of fruiting seasonality, highlights that we are just starting to understand

Sumatran orangutan population variability and that these and future results will be vital to our current and future viability analyses and conservation strategies.

A total of 13,800 15-minute GPS waypoints were also collected during 2013-2015 focal animal follows. We have started to analyze these in greater detail and present an initial analysis here in the form of cell counts within 100 x 100 m sized grid cells [Fig. 14]. From the figure, it is clear that while orangutans were observed throughout the station transect area, orangutans at Sikundur are being observed extensively (orange to red colored grid cells) in areas along the Besitang River, especially on the small peninsula that has recently been the site of a considerable amount of illegal encroachment/logging [see above; Fig. 6-7]. There are a number of reasons that might explain these observations, including greater productivity along the course of the Besitang River and/or orangutans are easier to find and follow in this area. Nevertheless, SOCP will be attempting to evaluate these results by testing whether food productivity is higher in riverine areas and also if and how orangutan travel at Sikundur corresponds to seasonality.

Fig. 8. SOCP staff members discussing an orangutan follow.

Fig. 9. Photographs of two adult female orangutans at Sikundur. A) Suci sharing food with her infant Siboy; B) Madeline with her infant Malala. Photographs courtesy of James Askew.

Fig. 10. Photographs of two adult flanged male orangutans at Sikundur. A) Mat Pangkor; B) Ompung. Photographs courtesy of James Askew.

Fig. 11. Photographs of a semi-flanged male orangutan at Sikundur. A) Bendot; B) Bendot walking on the ground. Photographs courtesy of James Askew.

Fig. 12. Activity budgets of adult orangutans at the Sikundur Monitoring Post, comparing between two seasonal periods.

Fig. 13. Diet of adult orangutans at the Sikundur Monitoring Post, comparing between two seasonal periods.

Fig. 14. A map of the trail system at the Sikundur Monitoring Post, with time spent in 100 x 100 m grid cells overlaid using a colored gradient of grid cells. Red indicates extensive use during the observation period, whereas yellow indicates lower levels of use.

V. Student Projects from 2015

SOCP has been fortunate to establish collaborations with Bournemouth University (UK), Liverpool John Moores University (UK), Medan Area University (Indonesia), and University of Southern California (USA). These collaborations have allowed for the development of some very interesting projects, which were undertaken by undergraduate and graduate students from the aforementioned universities in 2014- 2015. The focus of these projects is a detailed look at habitat structure, primate surveys, primate vocalizations, and orangutan liana use.

-Habitat Structure Two Master’s students from Bournemouth University (Helen Slater & Rosanna Consiglio) and one PhD student from Liverpool John Moores University (John Abernethy), guided by Drs. Amanda Korstjens, Ross Hill, and Serge Wich, completed a detailed look at habitat structure at the Sikundur Monitoring Post.

Fig. 15. A map highlighting the 30 transects utilized during surveys of habitat structure.

For this particular project, 10 transects from each of three main micro-habitat types (alluvial, plain, and hill forest) were surveyed by the three graduate students [Fig. 15].

During the surveys, the students collected various habitat structural data, which will eventually be linked to primate densities, primate behavior, and will also serve as an important component in future UAV analysis.

-Orangutan/Primate Vocalizations Graduate PhD student James Askew from the University of Southern California, directed by Drs. Craig Stanford and Roberto Delgado, is seeking to better understand orangutan social behavior and reproductive strategies, with an emphasis on how orangutans respond to male long calls. For his observations, Mr. Askew utilized long call playbacks and then evaluated how focal orangutans responded to the playback experiments [Fig. 16]. This project hopes to give us a better understanding of Sumatran orangutan social behavior, as few researchers have attempted a study like this on Sumatran orangutans.

Fig. 16. Graduate researcher from University of Southern California, James Askew, undertakes a playback experiment at the Sikundur Monitoring Post. Photo courtesy of John Abernethy.

In addition to the playback experiments, Mr. Askew is also attempting to record primate vocalizations, in order to better understand their function and also survey some of the more unique primates within the area. For instance, white-handed gibbons (Endangered), siamangs (Endangered), and Thomas’ leaf monkeys (Vulnerable) regularly vocalize, most often nearest sunrise. Using audio recorders that are fitted with a real time clock and GPS unit [Fig. 17], Mr. Askew surveyed the three aforementioned

primates, and then using spatial capture-recapture methods will eventually estimate their densities. This project will also serve as a comparative dataset for the fixed count vocal surveys that student researchers Helen Slater and Rosanna Consiglio conducted on the same three species (see below).

James has recently completed his Sumatran field study and is set to travel to Sabangau (Kalimantan) to collect comparative data from a population of Bornean orangutans, though he may return to Sumatra for a late 2016 field season. A detailed look at Mr. Askew’s research and his journey through Indonesia can be accessed via his Scientific American Expeditions blog – (blogs.scientificamerican.com/expeditions).

Fig. 17. Two of SOCP’s assistants help to setup one of the audio reorders that were used during audio surveys of gibbons, siamangs, and Thomas’ leaf monkeys. Photo courtesy of James Askew.

-Gibbon, Siamang, and Leaf Monkey Surveys In addition to their analyses of habitat structure at Sikundur, Helen Slater and Rosanna Consiglio were also interested in evaluating the densities of three key primate species, the white-handed gibbon, siamang, and Thomas’ leaf monkey. Using the fixed point call count methodology established by Brockelman & Ali (1987) and Brockelman & Srikosamatara (1993), Ms. Slater and Ms. Consiglio conducted surveys at three listening arrays, each comprised of three listening posts [Fig. 18]. The three arrays were set up in each of the three micro-habitat types. Data recorded for each listening post

included the time of the group call, the species, the compass bearing, and the estimated distance. Via triangulation, these data can be used to estimate primate group densities and these densities will eventually be evaluated relative to forest structure. These data will also serve a comparative dataset for the audio survey data discussed above. This will be the first time that a comparison of these survey methods will be undertaken for these primate species.

Fig. 18. A map of the three fixed point vocal arrays that will be surveyed by Helen Slater and Rosanna Consiglio, in their analyses of gibbon, siamang, and Thomas’ leaf monkey densities.

-Orangutan Nest Surveys John Abernethy, a PhD student from Liverpool John Moores University, directed by Dr. Serge Wich, conducted a detailed orangutan nest survey, which will allow him to calculate orangutan density estimates and then link the survey results to that of habitat structure [Fig. 19]. Orangutan nest surveys rely on the fact that orangutans construct nests daily, which are used at night and also sometimes during the day for resting (van Schaik et al. 1995). Using nest counts instead of live encounters with orangutans is often preferred due to the low density of orangutans, making density estimates based on live encounters a very time consuming exercise. It also allows researchers to

systematically do repeat monitoring of a given area. This was the first time that the Sikundur area was surveyed since the initial surveys in early 2000s (Knop et al. 2004).

As the Sikundur area was previously logged, Mr. Abernethey’s analyses are a key component to understanding the behavioral strategies of orangutan populations in Sumatra’s degraded forest areas. Furthermore, given that the majority of lowland areas housing orangutans in Sumatra are either completely deforested or highly degraded, this project is highly important to current and future conservation strategies of Sumatran orangutans.

Fig. 19. A photograph of John Abernethy and a few of SOCP’s assistants undertaking orangutan nest surveys. Photo courtesy of James Askew.

-Liana Use by Orangutans at Sikundur Lastly, Amri, an undergraduate from Medan Area University, conducted and completed a study of liana use by orangutans at Sikundur [Fig. 20]. From SOCP’s long-term database, roughly 14.4% of all food items and 25.9% of all fruit items that orangutans at Sikundur consume come from liana species. Thus, lianas are a key group of species utilized on a regular basis by orangutans. Amri is currently analyzing the data that he

collected during his study and will then be finishing his undergraduate thesis, which will help us to better understand how these woody species allow the orangutans at Sikundur to sustain themselves, even during periods of fruit scarcity, similar to that observed during 2015.

Fig. 20. A photograph of Amri collecting orangutan observational data. Photo courtesy of Suprayudi.

VI. Ongoing Projects

-Camera Trap Study of Biodiversity Via a small crowd funding grant which was received through experiment.com, SOCP’s Biodiversity Monitoring Unit, along with two graduate student researchers James Askew (University of Southern California) and John Abernethy (Liverpool John Moores University) developed a site wide camera trap survey of the Sikundur Monitoring Post. Using a randomized grid of 30 camera traps, the survey sought to analyze the distribution of animal species across the three main habitat types (i.e., alluvial, hill, and plain forest) at the Sikundur Monitoring Post. The results from 2,700 camera trap nights has thus far yielded a list of at least 31 animal species from 19 families [Table 2]. From this list, eight are identified as Vulnerable (VU) by the IUCN, with three being identified as Critically Endangered (CR). The Critically Endangered species include the Sumatran elephant, orangutan, and tiger. These data are currently being analyzed and within 2016 a publication will be ready for submission.

Table 2. Animal Species Detected on Camera Traps in the Sikundur Monitoring Post Class Family Species Common Name IUCN Status Aves Bucerotidae Berenicornis cornatus White-crowned hornbill NT Aves Bucerotidae - - - Mammalia Cercopithecidae Macaca fascicularis Long-tailed Macaque LC Mammalia Cercopithecidae Macaca nemestrina Pig-tailed Macaque VU Mammalia Cercopithecidae Presbytis thomasi Thomas's Leaf Monkey VU Mammalia Cercopithecidae - - - Mammalia Cervidae Muntiacus muntjac Red Muntjac DD Mammalia Cervidae Rusa (Cervus) unicolor Sambar Deer VU Mammalia Cervidae - - - Aves Columbidae Chalcophaps indica Emerald Dove LC Aves Columbidae - - - Mammalia Elephantidae Elephas maximus sumatranus Asian Elephant CR Mammalia Elephantidae - - - Mammalia Erinaceidae Echinosorex gymnurus Moonrat DD Mammalia Erinaceidae - - - Mammalia Felidae Catopuma temminckii Asiatic Golden Cat NT Mammalia Felidae Neofelis diardi Sunda Clouded Leopard VU Mammalia Felidae Pardofelis marmorata Marbled Cat VU Mammalia Felidae Felis bengalensis Leopard Cat DD Mammalia Felidae Panthera tigris sumatrae Sumatran Tiger CR Mammalia Felidae - - - Mammalia Herpestidae Herpestes brachyurus Short-tailed Mongoose LC Mammalia Herpestidae - - - Mammalia Hominidae Homo sapiens Human LC Mammalia Hominidae - - - Mammalia Hystricidae Hystrix sumatrae Sumatran Porcupine LC Mammalia Hystricidae - - - Mammalia Mustelidae Martes flavigula Yellow-Throated Martin LC Mammalia Mustelidae - - - Aves Phasianidae Rollulus rouloul Crested Partridge NT Aves Phasianidae - - - Mammalia Pongidae Pongo abelii Sumatran Orangutan CR Mammalia Pongidae - - - Reptilia Pythonidae Python reticulatus Reticulated Python NE Reptilia Pythonidae - - - Mammalia Sciuridae Ratufa bicolor Black Giant Squirrel NT Mammalia Sciuridae Sundasciurus hippurus Horse-tailed Squirrel NT Mammalia Sciuridae - - - Mammalia Suidae Sus scrofa Wild Boar LC Mammalia Suidae - - - Mammalia Tragulidae Tragulus javanicus Lesser Mouse Deer DD Mammalia Tragulidae Tragulus napu Greater Oriental Chevrotain LC Mammalia Tragulidae - - - Mammalia Ursidae Helarctos malayanus Sun Bear VU Mammalia Ursidae - - - Mammalia Viverridae Arctictis binturong Binturong VU Mammalia Viverridae Arctogalidia trivirgata Small-toothed Palm Civet LC Mammalia Viverridae Hemigalus derbyanus Banded Civet VU Mammalia Viverridae Paradoxurus hermaphroditus Common Palm Civet LC Mammalia Viverridae - - -

Total 19 31 - -

-Unmanned Aerial Vehicle (UAV) Technology The Sikundur Monitoring Post remains one of SOCP’s main sites for the development of our UAV program. Since the station’s opening in late 2012, a number of studies utilizing UAV technology have been conducted in collaboration with Conservation Drones (conservationdrones.org) and university partners (Bournemouth University and

Liverpool John Moores), including both orangutan nest (December 2014 – January 2015) and phenological surveys (November 2013), analysis of forest structure (2013- present), and detailed habitat monitoring of the TNGL and Leuser Ecosystem National Strategic Area boundaries in the vicinity of the Sikundur Monitoring Post (2013-present). These projects are all ongoing and will no doubt aid in our understanding of the local ecology at Sikundur, but also offer new methods for surveying orangutans and monitoring habitat loss.

VII. Coming Up In 2016

Given the successes of the 2015 field season, we are very much looking forward to the 2016 field season. In addition to SOCP’s regular habitat and orangutan monitoring activities, there are a number of new student projects from both Bournemouth University and Liverpool John Moores University that will be started 2016. Many of these will have a focus on local habitat structure and will attempt to utilize the new technologies (e.g., UAVs) that we have been trying to develop over recent years.

Over the past three years, the Sikundur Monitoring Post has slowly started to receive an increasing number of researchers and visitors each year. As such, SOCP’s current station house, which only has three small rooms, is no longer sufficient for growing demand. Provided funding is available in 2016, one of our biggest priorities is to build an additional station house, so that our staff and our guests can better enjoy the wonders that the Sikundur Monitoring Post has to offer. An example of the proposed station house is pictured in Fig. 21.

Given that the Langkat District is one of the most deforested areas in the Leuser Ecosystem National Strategic Area and also one of the areas with the highest incidences of human-orangutan conflict and poaching, the SOCP also seeks to develop a greater capacity for conservation education, conflict mitigation, and local capacity building in the Langkat area over the coming years. Our aims are to: 1) conduct local village/school visits with relevant educational presentations; 2) enhance human- orangutan conflict mitigation protocols; and 3) provide greater support for local Indonesian university students seeking to complete their degrees.

Lastly, with all of the projects that have been undertaken during 2013-2015, we at SOCP are working diligently on a number of key publications that will help to get the word out about this unique lowland Sumatran rainforest habitat. We thank you for your continued support and ask that you keep your eye out for these exciting future publications.

Fig. 21. Photographs of planned camp changes. A) Current station house; B) An example of a newly proposed station house.

VIII. References Cited

Brockelman WY, Ali R. 1987. Methods of surveying and sampling forest primate populations. In: Marsh CW and Mittermeier RA (eds.), Primate Conservation in the Tropical Rain Forest, Alan R Liss, New York, pp 23-62. f Brockelman WY, Srikosamatara S. 1993. Estimation of Density of Gibbon Groups by Use of Loud Songs. American Journal of Primatology, 29, 93-108.

Cribb R. 1988. The politics of environmental protection in Indonesia. Centre of Southeast Asian Studies, Monash University, Melbourne, Australia.

Hansen et al. 2013. High-resolution global maps of 21st-Century forest cover change. Science, 342, 850-853.

Husson et al. 2009. Orangutan distribution, density, abundance, and impacts of disturbance. In: Wich SW et al. (eds.), Orangutans: Geographic variation in behavioural ecology and conservation, Oxford University Press. Oxford, pp 77-96.

Knop et al. 2004. A comparison of orang-utan density in a logged and unlogged forest on Sumatra. Biological Conservation, 120,183-188.

Laumonier et al. 2010. Eco-floristic sectors and deforestation threats in Sumatra: identifying new conservation area network priorities for ecosystem-based land use planning. Biodiversity Conservation, 19, 1153-1174

Margono et al. 2012. Mapping and monitoring deforestation and forest degradation in Sumatra (Indonesia) using Landsat time series data sets from 1990 to 2010. Environ Res Lett, 7, doi:10.1088/1748-9326/7/3/034010.

Marshall et al. 2009. Orangutan population biology, life history, and conservation. In: Wich SW et al. (eds.), Orangutans: Geographic variation in behavioural ecology and conservation. Oxford University Press, Oxford, pp 311-326.

Morrogh-Bernard et al. 2009. Orangutan activity budgets and diet. In: Wich SW et al. (eds.), Orangutans: Geographic variation in behavioural ecology and conservation. Oxford University Press, Oxford, pp 119-133.

Wich SA, van Schaik CP. 2000. The impact of El Nino on mast fruiting in Sumatra and elsewhere in Malesia. J Trop Ecol, 16(4), 563-577.

Wich et al. 2008. Distribution and conservation status of the orang-utan (Pongo spp.) on Borneo and Sumatra: How many remain? Oryx, 42(3), 329-339.

Wich et al. in press. Land-cover changes predict steep declines for the Sumatran orangutan (Pongo abelii). Science Advances.

Wich et al. 2011a. Orangutans and the economics of sustainable forest management in Sumatra. UNEP/GRASP/PanEco/YEL/ICRAF/GRID-Arendal, Indonesia.

Wich et al. 2011b. Forest production is higher on Sumatra than on Borneo. PLos ONE, 6(6), e21278. doi:10.1371/journal.pone.0021278

Wind, J. 1996. Gunung Leuser National Park: History threats, and options. In: van Schaik C and Supriatna J (eds.), Leuser: A Sumatran Sanctuary. Yayasan Bina Sains Hayati Indonesia, Indonesia, pp 4-27. van Schaik et al. 1995. Population estimates and habitat preferences of orangutans based on line transects of nests. In: Nadler RD et al. (eds.), The Neglected Ape. Plenum Press, New York, pp 129-147.

IX. How to Get Involved

If you would like to make a donation or would like further information about our Sikundur project, please contact us:

Matthew G. Nowak Director of Biodiversity Monitoring (SOCP) Email: [email protected]

Dr. Ian Singleton Director SOCP Email: [email protected]

Donations can also be made via Paypal online at: www.sumatranorangutan.org/research

Follow all of our developments online at: www.sumatranorangutan.org