Nycticebus Javanicus Research Articles

Interactions between Javan slow lorises (Nycticebus javanicus) and domestic and wild carnivores in an anthropogenic landscape in Java, Indonesia.

With increasing replacement of native forests with agriculture, it is important to understand the factors allowing non-human primates to persist, including interactions with potential predators. For small-bodied nocturnal primates, smaller carnivores and domestic dogs that often characterise agroforestry landscapes may be a particular threat, especially for primates like slow lorises, which rely on canopy connectivity and are particularly vulnerable on the ground. We present data collected over 12 years in Indonesia. During a long-term study on Javan slow lorises, we used ad libitum sampling to record 703 instances of slow lorises in proximity to wild small carnivores (Javan palm civets, small Indian civets, Sunda leopard cats, Javan ferret badgers) and interactions with small carnivores (62) and domestic dogs (58) respectively. Most of these interactions were neutral or affiliative, including sharing canopy bridges and sleeping sites. Two negative interactions occurred between lorises and wild carnivores; five potential predation events were linked to dogs. Lorises were less active and more vigilant when carnivores were present. AWhatsApp® group facilitated data collection, increasing detail of observations, especially on interactions with domestic dogs. We saw an overall decline in small carnivores, especially nearer to the village, which could be linked to competition with domestic dogs. Abetter understanding of the role of dogs in this changing landscape is vital.

Vegetation characteristics of the Javan slow loris habitat in Mount Masigit Kareumbi Protected Area, West Java, Indonesia

Abstract. Allasselcida A, Sumarga E, Sofiatin. 2024. Vegetation characteristics of the Javan slow loris habitat in Mount Masigit Kareumbi Protected Area, West Java, Indonesia. Biodiversitas 25: 2512-2520. Habitat loss and degradation are major threats to the conservation of endemic wildlife in Indonesia, owing to the high rates of deforestation over the past decades. Most of these endemic animals are now at risk of extinction. Javan slow loris (Nycticebus javanicus) is a primate endemic to Java Island and is currently classified as critically endangered by the IUCN. This study analyzes four key aspects of the loris' habitat in Mount Masigit Kareumbi Protected Area (MMKPA), West Java: plant diversity, vegetation community structure and composition, plant species as food sources, and canopy density. A vegetation survey was conducted in three research sites using 41 nested plots measuring 20x20 m for trees, 10x10 m for poles and shrubs, 5x5 m for saplings, and 2x2 m for herbaceous plants. Data on plant species, diameter at breast height (DBH), and abundance (number of individuals) were collected within each plot. Forest Canopy Density (FCD) was mapped using Landsat 8 RAW Imagery and Landsat 8 TOA Reflectance Imagery, involving calculating several indices: Advanced Vegetation Index (AVI), Bare Soil Index (BI), Shadow Index (SI), and Thermal Index (TI). This study identified 104 plant species from 40 families across the three studied sites with dominant tree species were Pinus merkusii, Schima wallichii, Actinodaphne procera, Pinanga coronata, Miconia crenata, and various Setaria species. The diversity index at the three locations ranged from 3.02 to 3.41. This study found 35 species, including the dominant tree species, which served as food sources for slow lorises. The primary food sources available to slow lorises are sap (92.4%), followed by fruit (3.9%) and flowers/nectar (3.7%). The results of FCD analysis indicated that 83% of MMKPA has a "high" category, suggesting the presence of a continuous branch network that facilitates the easy movement of Javan slow loris. This information can be used to develop strategies for improve habitat management in the area, such as enriching fruit-bearing crops to increase food diversity.

From masks to muscles: Mapping facial structure of Nycticebus.

Facial musculature in mammals underlies mastication and nonverbal communicative facial displays. Our understanding of primate facial expression comes primarily from haplorrhines (monkeys and apes), while our understanding of strepsirrhine (lemurs and lorises) facial expression remains incomplete. We examined the facial muscles of six specimens from three Nycticebus species (Nycticebus coucang, Nycticebus javanicus, and Nycticebus menagensis) using traditional dissection methodology and novel three-dimensional facial scanning to produce a detailed facial muscle map, and compared these results to another nocturnal strepsirrhine genus, the greater bushbaby (Otolemur spp.). We observed 19 muscles with no differences among Nycticebus specimens. A total of 17 muscles were observed in both Nycticebus and Otolemur, with little difference in attachment and function but some difference in directionality of movement. In the oral region, we note the presence of the depressor anguli oris, which has been reported in other primate species but is absent in Otolemur. The remaining muscle is a previously undescribed constrictor nasalis muscle located on the lateral nasal alar region, likely responsible for constriction of the nares. We propose this newly described muscle may relate to vomeronasal organ functioning and the importance of the use of nasal musculature in olfactory communication. We discuss how this combined methodology enabled imaging of small complex muscles. We further discuss how the facial anatomy of Nycticebus spp. relates to their unique physiology and behavioral ecology.

Identifying Important Areas for the Release of Five Endemic Species in a Mountainous Landscape: Inference from Spatial Modeling Techniques

Efforts to release animals resulting from evacuation and rehabilitation into their natural habitats are important practices in wildlife conservation. Before releasing the animals, it is important to assess the habitat suitability of the areas to support the existence of the animals in the long run. Yet, there is limited study of habitat suitability assessment on national parks as release locations for wild animals. This study aimed to assess the suitable habitat of five charismatic animal species, i.e., Panthera pardus melas, Hylobates moloch, Prinonailurus bengalensis, Nycticebus javanicus, and Nisaetus bartelsi, in Gunung Halimun Salak National Park using Maxent, and to determine potential locations for releasing animal’s species. Models for the P. p. melas show 47,619 ha and 21,391 ha, respectively, suitable as habitat and potential release location, for H. moloch, each is 57,537 ha and 33,471 ha, for P. bengalensis, each is 25,460 ha and 17.189 ha, for N. javanicus, each is 29,848 ha and 15,578 ha, and for N. bartelsi, each is 44,426 ha and 25,660 ha. Our study shows that a suitable habitat can be critical in choosing a wildlife release site. Further consideration of conflict mitigation and practicalities is required to achieve the long-term existence of released species.

Goal-Directed Travel in the Nocturnal Javan Slow Loris (Nycticebus javanicus)

An animal’s ability to navigate its home range in search of essential resources is a key aspect of its ecology. To reach these resources, animals employ varying navigational processes depending on their exocentric or egocentric view of their environment. The goal of this study was to determine if the Javan slow loris (Nycticebus javanicus), a nocturnal arboreal primate found in southeast Asia, uses some form of cognitive map and spatial memory while navigating their environment. Using behavioural and GPS data of six males and seven females collected at the Little Fireface Project field station based in West Java, Indonesia, we measured their frequency of revisiting important feeding trees, route overlap, and points where individuals significantly changed directions. We found that all individuals predominantly used four tree species while feeding and foraging. The lorises also displayed a high level of route overlap, leading us to conclude that they likely utilize a route-based cognitive map where certain landmarks are integral to their nightly movement. Few studies have specifically focused on strepsirrhine spatial cognition in the wild; here, we show the navigational mechanism used by the Javan slow loris to reach distant/out-of-sight resources. The evident reliance on spatial cognition in a strepsirrhine species suggest that it could be an important selective pressure for primates at the earliest stages of primate cognitive evolution. In addition to the importance of spatial memory in theoretical discourse, understanding slow loris movement has practical applications to conservation, particularly regarding the numerous translocations undertaken by individuals rescued from the illegal wildlife trade. We discuss the importance of considering soft release training and monitoring in such releases.

Habitat Suitability Modeling of Javan Slow Loris (Nycticebus javanicus) in the Forest Cluster of Gunung Halimun Salak

Javan slow loris (Nycticebus javanicus) is one of the endemic wildlife on Java Island. This species owns particular characteristics, including arboreal, solitary, and nocturnal natures. The species is threatened due to habitat loss and illegal trafficking. Nevertheless, their current geographic distribution remains unclear and environmental factors impact on these species is mostly unknown. This study aims to predict the habitat suitability of javan slow loris in the Conservation Management Forest Unit area of Mount Halimun Salak Forest Group. The study employs a species distribution modeling approach using Maximum Entropy. The presence data of javan slow loris was collected from the radio-telemetry devices used in post-release monitoring. The modeling utilizes elevations, distance from the settlements, slopes, and land covered as its environment variables. The result shows that 52% of the study areas, or 54,669 ha are suitable as the habitat of N. javanicus. Since as the largest protected area on Java Island, Gunung Halimun Salak National Park is one of the natural habitats that are pivotal for this species. This study provides essential documentation for developing management strategies within protected areas. Hence, the result of the study could serve as one of the factors in the determination of animal release location in the future.

TEETH CLIPPED-OUT IN JAVANESSE SLOW LORIS AND ITS PRESERVATION THROUGH ROOT CANAL TREATMENT

Nycticebus javanicus or often called the Javan slow loris is one of Indonesia's endemic primates whose status is now in the critically endangered category because their numbers are decreasing. The illegal trade often causes serious problems for the health and survival of slow lorises in their natural habitat. There is a wrong perception that the teeth of slow lorises are poisonous, which makes illegal traders cut or even pull out the teeth of slow lorises indiscriminately. Slow lorises (Nycticebus spp.) are obligate exudativators that gouge at tree bark with their teeth. In addition to functioning for the process of eating, slow loris teeth also function for defense mechanism and allogrooming. Amputation of dental crowns or crown fractures in slow lorises can be a serious problem. Slow lorises do not survive either slowly in rehabilitation centers due to changes in diet or even faster in their natural habitat when being released. Root canal treatment as an effort that can be taken to maintain the damaged or broken teeth, so as to prevent tooth from infection and maintain the function of slow loris teeth to survive in its natural habitat. The method of root canal treatment involves three fundamental components: root canal shaping, disinfection and obturation. Teeth restoration to be performed after obturation, using composite. Teeth that have been successfully treated provide an opportunity for slow lorises to express their natural behavior as well as in surviving in their natural habitat.

Habitat Use, Terrestriality and Feeding Behaviour of Javan Slow Lorises in Urban Areas of a Multi-Use Landscape in Indonesia

Urban areas are rapidly expanding into natural habitats worldwide. When species are threatened with habitat loss, it is vital to understand how they will respond or adapt to the change in their environment. One primate species threatened by habitat loss is the fully arboreal Javan slow loris (Nycticebus javanicus). This non-leaping species not only relies on canopy continuity but is also subject to capture for illegal wildlife trade, especially in anthropogenic landscapes where they are easier to catch. We examine the use of urban areas by Javan slow lorises in terms of habitat use as well as feeding and terrestriality behaviours in the municipality of Cipaganti in West Java, Indonesia. For this study, we observed Javan slow lorises from May 2018 to April 2020 for two dry periods and two wet periods. We combined home ranges and core areas with a land cover classification of the area to understand the composition of the loris habitat. We also included feeding and terrestriality data to determine the ratio of these activities within each land cover class. We found that approximately half of their territory falls into natural areas (bamboo patches: 45–60%), and the other half is in human land use areas (agriculture, shade gardens, urban areas, and fallow land). Urban areas ranged from 0 to 54% of an individual loris’s habitat, with the proportion of urban land cover being higher in some individuals’ core areas than in their home ranges. Only urban areas showed a variation between periods, with p-values of 0.06 and 0.002 for home ranges and core areas, respectively, showing a significant increase usage during dry periods. Of all feeding observations, 4% occurred in urban areas with nectar being the most common feeding item. We recorded thirteen different food species in urban areas with Calliandra calothrysus being the most frequent. We found that 7% of terrestriality events occurred in urban areas. The findings from this study show that human land use areas cover a significant portion of the Javan slow lorises habitat in this region, further emphasising the need to consider the needs of these Critically Endangered primates when developing natural habitats into those of human managed landscapes. The same principles are true for the large number of species that are able to persist in urban areas in a world increasingly dominated by humans.

Nature Club Activity: Knowledge Exploration on Javan Slow Loris (Nycticebus javanicus) and Protected Endemic Animals in Conservation Education Program

Conservation education can increase knowledge about endangered animals, one of which is the Javan slow loris (Nycticebus javanicus), and protected endemic animals in Indonesia, and this can be done through the nature club activity as one of the conservation education programs. However, most students are indifferent to conservation or science education. This individual influence is the characteristics and dispositions students bring to learning, such as interest, effort, values, and perceived abilities. This study aims to determine the effectiveness of conservation education programs through nature club activities on students' knowledge of Javan slow loris and protected endemic animals. The research method is the experimental method, with the research design used as one group pretest-postest design; the data collection technique is done by test and observation. The results showed that the activities carried out were effective on students' knowledge of Javan lorises and protected endemic animals, as evidenced by the calculation of the N-gain score indicating that the average N-gain score (mean) was 0.614.ABSTRAK: Pendidikan konservasi dapat menambah ilmu mengenai hewan yang terancam punah salah satunya yaitu Kukang Jawa (Nycticebus javanicus) serta hewan endemik yang dilindungi yang ada di Indonesia, hal ini dapat dilakukan melalui program klub alam yang ada pada pendidikan konservasi. Akan tetapi mayoritas siswa belum mendapatkan pendidikan konservasi dan hanya menjadi bagian kecil dari pendidikan sains. Penelitian ini bertujuan untuk mengetahui efektivitas pendidikan konservasi melalui kegiatan klub alam terhadap pengetahuan siswa mengenai kukang jawa dan hewan endemik yang dilindungi. Metode penelitian yang digunakan yaitu metode eksperimen, dengan desain penelitian yang digunakan adalah one group pretest-posttest design, teknik pengumpulan data dilakukan dengan tes dan observasi. Hasil penelitian menunjukkan bahwa kegiatan yang dilakukan efektif terhadap pengetahuan siswa mengenai kukang jawa dan hewan endemik yang dilindungi, dibuktikan dari hasil perhitungan N-gain score menunjukkan bahwa rata-rata skor N-gain (mean) adalah 0,614

Mammals Community in Ranggawulung Urban Forest, Subang

Ranggawulung urban forest as one of the remaining vegetated sites in Subang city has the potential to be a strategic location for biodiversity that needs to be managed sustainably. Biodiversity studies in Rangawulung urban forest need to be conducted periodically to assess and control the impact of urban development. This study was conducted to assess biodiversity in Subang City, especially mammals community ini Ranggawulung Urban Forest as an indicator of biological management in urban areas. There were eight species of mammals found in the Ranggawulung City Forest area from five families. Diversity (H'), richness (Dmg), and evenness (E') indices of the area species were 1,09, 1,6, and 0,84. One of the species found, the Javanese slow loris (Nycticebus javanicus), is a protected animal in PermenLHK Number P.106 / MENLHK / SETJEN / KUM.1 / 12/2018. The species is also categorized as CITES Appendix I and Critical Endangered according to the IUCN red list. Ranggawulung Urban Forest is considered important as an animal habitat in Subang City and needs to be managed properly and sustainably.

Mammals Diversity in Ranggawulung Urban Forest, Subang, West Java

Ranggawulung urban forest is one of the remaining vegetated sites in Subang. That place needs to be managed sustainably because of its potential to be a strategic location for biodiversity. Biodiversity studies in Rangawulung urban forest need to be conducted periodically to assess and control the impact of urban development. This study was undertaken to evaluate biodiversity in Subang City, especially Ranggawulung Urban Forest as an indicator of biological management in urban areas. There were ten species of mammals found in the Ranggawulung City Forest area from six families. One of the species found, the Javanese slow loris (Nycticebus javanicus), is a protected animal in Minister of Environment and Forestry regulations (PermenLHK Number P.106/2018). The animal is categorized as CITES Appendix I and Critical according to the IUCN red list. Diversity (H'), richness (Dmg), and evenness (E') indices of the area species were 2.03, 2.06, and 0.92, respectively. Ranggawulung Urban Forest is considered important as an animal habitat in Subang City and needs to be managed properly and sustainably.

Local farmers’ attitudes towards artificial wildlife bridges in a fragmented agroforestry environment

Abstract Fragmentation of tropical forests has severe consequences for global biodiversity. The island of Java, Indonesia has a long history of deforestation and outside the protected area system, the island contains a patchwork of small forest fragments among expanding agricultural land, human settlements, and infrastructure. The arboreal Javan slow loris’ (Nycticebus javanicus) remaining habitat largely occurs in these anthropogenic landscapes. Arboreal canopy bridges have proven to be a successful conservation intervention for Javan slow lorises but must be built on the private land of farmers. Here, we describe the process of collaborating with local farmers to construct and maintain canopy bridges over their farms to aid in connecting habitat for Javan slow lorises. We held non-structured conversations with ten farmers to understand their perceptions of the bridges. We found an overall positive attitude towards slow lorises, as well as acknowledgement of the economic importance of the bridges. Farmers also recommended improvements, including ensuring equity of the bridges in the community and increased financial commitment from the conservation project. There is growing appreciation amongst conservationists that trust and collaboration with local communities are essential for carrying out successful initiatives. We recommend regular discussions with community members in similar interventions to ensure the long-term trust and involvement of local people.

Influence of Moon Luminosity, Seasonality, Sex and Weather Conditions on the Activity Levels of the Nocturnal Javan Slow Loris

The activity patterns of mammals depend on environmental changes (e.g., moon luminosity, food availability, weather) and endogenous rhythms. Behavioral observations are traditionally used to estimate the activity patterns of animals, but low visibility and the cryptic nature of some species entail that, in certain conditions, the animal is visible only for around 60% of the time. Recent advances in technology allow automatic data collection on the activity levels of animals. We used five years of data collected via accelerometers to understand how moon luminosity, seasonality, sex, and weather conditions influence the activity levels of the nocturnal and cryptic Javan slow loris. We collected 9589 h on six females and 7354 h on six males. Via Generalized Additive Mixed Models, we found that lorises are lunarphobic; they reduce activity levels during cold nights, they have higher activity levels when the relative humidity is close to 100%, and they have high peaks of activity between December and February and between June and August. The activity levels are thus influenced by avoidance of predators, food availability, consumption of insects and nectar, physiological, and behavioral adaptations to cold temperatures and energy requirements during reproductive stages. We highlight the importance of using bio-loggers for cryptic animals as with behavioral observations only, and the observer might underestimate active behaviors and overestimate inactivity.

The Influence of Sex and Weather on the Activity Budget of Javan Slow Lorises (<i>Nycticebus javanicus</i>) in Garut Regency, West Java

The Javan slow loris (Nycticebus javanicus) is a nocturnal primate endemic to Java. Previous studies on slow loris activity are limited to general daily activity, and there is a lack of research on the potential sex differences in slow loris activity. This study aims to analyze differences in the daily activity of the Javan slow loris based on sex. From August to December 2018, the daily activity of six wild Javan slow lorises was recorded using behavioral observations with instantaneous point sampling at 5-minute intervals. Differences in male and female slow loris activity were analyzed using the Generalized Linear Mixed Model (GLMM). We set sex and weather as fixed factors and individuals as random effects. The results of this study showed that females spent more time feeding and less time resting than males. In addition, the Javan slow loris behavior was affected by temperature and humidity like other slow loris species.

The sticky tasty: the nutritional content of the exudativorous diet of the Javan slow loris in a lowland forest.

Plant exudates are an important food source for many primates. The Critically Endangered Javan slow loris (Nycticebus javanicus) was previously found to prefer Acacia decurrens exudate in an anthropogenically disturbed site, while its feeding habits in secondary natural forest remain unknown. Knowledge of the chemical characteristics of the plant exudates that Javan slow lorises consume is limited, especially with respect to those that they feed on in natural forests. As plant exudates may contain plant secondary metabolites (PSM), which are considered unpalatable in high concentrations, differences in PSM composition may drive feeding preferences. This research aims firstly to confirm exudate consumption by the Javan slow loris in a lowland tropical forest in Central Java, and secondly to identify the chemical characteristics of the exudates consumed. We followed wild slow lorises in Kemuning Forest, Central Java and observed their behaviour. We investigated the gum-producing trees that were utilized by the slow lorises by tapping the exudates and examining their nutritional and PSM contents. We found that exudates are the predominant food source for the Javan slow loris in this lowland forest, and that their nutritional contents are similar to those of exudates consumed by lorises in anthropogenically disturbed areas. Significant differences in polysaccharide and flavonoid contents were found between consumed and unconsumed exudates. Knowledge of the diet of the Javan slow loris is crucial to its conservation, and our findings confirm the importance of exudates in its diet. We also highlight the need to preserve natural slow loris habitat, and to manage the diets of these species in captivity. The results of this study indicate that plant exudates should constitute a significant portion of the diet of captive slow lorises, and that the presence of exudate-producing trees is vital in areas into which slow lorises are to be translocated.

SEBARAN DAN KELIMPAHAN KUKANG JAWA (Nyticebus javanicus) DI TAMAN WISATA ALAM GUNUNG TAMPOMAS

The observation of distribution and abundance of Javan slow loris (Nycticebus javanivus) was carried out in Sumedang district area (West Java), which includes at TWA Gunung Tampomas. The objective of the research is to investigate the distribution and abundance of Javan slow loris at side and outside of protected forest in support the conservation management of slow loris. Observation location was between protected forest and agricultural area an altitude of 600 to 900 m above sea level. The result only on the three lines transect Javan Slow loris were found with total 11 individual. The population is less than the population outside the site research. Twenty-six individuals of Javan slow loris were found in community’s plantation which vegetation dominated by bamboo trees and agriculture plantation.

Sebaran Keberadaan Kukang Jawa (Nycticebus javanicus) di Kawasan Taman Buru Masigit Kareumbi

According to previous observations, the distribution of habitat and population of slow lorises in Indonesia shows that slow lorises are found mostly in plantation habitats, agricultural land, and community forests where the available feed supply is in the form of fruits, insects and small reptiles. Taman Buru Masigit Kareumbi is one of the areas that has a level of vulnerability to the illegal hunting of slow lorises outside the forest area that enters the community land area. One of the habitats for the Javan slow loris is the Masigit Kareumbi Hunting Park (TBMK). Observations in the study used the line transect method (line transect) combined with the spot lighting method and GPS mapping, with a sampling intensity of 1% in accordance with P.67 /Menhut-II / 2016 regarding criteria and forest inventory standards for sampling intensity. The survey was carried out by walking slowly at an average speed of 1 km / hour and systematically looking for and observing the presence of slow lorises on the forest floor, lower canopy, middle canopy and upper canopy. The existence of slow lorises in Taman Buru Masigit kareumbi is spread across utilization blocks in 3 locations, namely Bagus, Hadun, and Cimulu, and 5 Javan slow lorises were found directly in the field during the research.

Impact of weather conditions, seasonality and moonlight on the use of artificial canopy bridges by nocturnal arboreal mammals

Natural and artificial canopy bridges can be used to mitigate the effects of habitat fragmentation. Understanding the ecological factors that influence bridge use is imperative to the effective design and placement of this potential conservation intervention. Moonlight, seasonality and weather may influence the cost and risk of using bridges, potentially reducing their effectiveness. We installed five artificial waterline bridges and, between 2017 and 2019, monitored via camera trapping their use by Javan palm civets Paradoxurus musanga javanicus and Javan slow lorises Nycticebus javanicus. We used a weather station to record microclimate data (temperature and relative humidity) and calculated the illumination percentage of the moon. We tested the influence of moon luminosity, relative humidity, seasonality (Julian day) and temperature on the frequency of bridge use via Generalised Additive Models. Camera traps captured 938 instances of bridge use by civets, which was significantly lower than the reference value at moon luminosity > 90%, temperatures > 20 °C, humidity > 90%, and during the drier period (May–July). Camera traps captured 1036 instances of bridge use by lorises, which was significantly lower than the reference value during the drier period and higher than the reference value at temperatures > 20 °C. Lorises showed peaks in bridge use close to sunset and sunrise whereas civets showed peaks around 2 h after sunset and 2 h before sunrise. Our study illustrates the utility of simple-to-construct bridges by two sympatric nocturnal mammals facing severe habitat loss, with bridge use differing between those species according to abiotic factors. In particular, less use by both taxa during the drier season could suggest modifying placement of bridges or providing another intervention during that time. Camera traps were an excellent mechanism to record these differences and to validate the importance of the bridges, including during inclement weather and dark nights, when observations would be more difficult for human observers. By understanding the influence that abiotic factors have on the use of artificial bridges, we can improve bridge placement and construction to encourage use by a variety of species, particularly those threatened by habitat fragmentation.

Aposematic signaling and seasonal variation in dorsal pelage in a venomous mammal.

In mammals, colouration patterns are often related to concealment, intraspecific communication, including aposematic signals, and physiological adaptations. Slow lorises (Nycticebus spp.) are arboreal primates native to Southeast Asia that display stark colour contrast, are highly territorial, regularly enter torpor, and are notably one of only seven mammal taxa that possess venom. All slow loris species display a contrasting stripe that runs cranial‐caudally along the median sagittal plane of the dorsum. We examine whether these dorsal markings facilitate background matching, seasonal adaptations, and intraspecific signaling. We analyzed 195 images of the dorsal region of 60 Javan slow loris individuals (Nycticebus javanicus) from Java, Indonesia. We extracted greyscale RGB values from dorsal pelage using ImageJ software and calculated contrast ratios between dorsal stripe and adjacent pelage in eight regions. We assessed through generalized linear mixed models if the contrast ratio varied with sex, age, and seasonality. We also examined whether higher contrast was related to more aggressive behavior or increased terrestrial movement. We found that the dorsal stripe of N. javanicus changed seasonally, being longer and more contrasting in the wet season, during which time lorises significantly increased their ground use. Stripes were most contrasting in younger individuals of dispersal age that were also the most aggressive during capture. The dorsal stripe became less contrasting as a loris aged. A longer stripe when ground use is more frequent can be related to disruptive colouration. A darker anterior region by younger lorises with less fighting experience may allow them to appear larger and fiercer. We provide evidence that the dorsum of a cryptic species can have multimodal signals related to concealment, intraspecific communication, and physiological adaptations.

Blood Biochemistry Reference Values of Javan Slow Loris (Nycticebus javanicus) in Rehabilitation Center

The Javan slow loris (Nycticebus javanicus) is an endemic primate species to Java Island, Indonesia. Currently, their conservation status is critically endangered due to habitat loss and the illegal wildlife trade. As a consequence of the pet trade, wild-caught slow lorises are confiscated or handed over to centers like IAR Indonesia Rescue Center. Rescued lorises present multiple health issues following stress, trauma, and miss-treatment after being kept as pets. During the medical evaluation, besides physical examination, blood biochemistry provides valuable diagnostic information. However, data on physiological values are unavailable and therefore interpretation of results is difficult. The objective of this study was to establish blood biochemistry reference values for wild, rehabilitant healthy adult Javan slow lorises in captivity. We anesthetized 20 individuals of Javan slow loris (10 males and 10 females) for pre-release check-up procedures. Blood samples were collected for blood biochemistry analysis on an in-house Vetscan VS2 (Zoetis), after which the results were statistically analyzed for mean and standard deviation. Results showed different values between the male and female group, however, they were not significant (p>0,05). Comparison with available biochemistry data (ZIMS) for other loris species in captivity: Nycticebus pygmaeus and Nycticebus coucang, did not show significant differences. Although the sample size of this study was limited, this study provides the first preliminary reference ranges for healthy adult wild, rehabilitant Javan slow loris in captivity. Further data collection is necessary for more accurate ranges and will be done during the future pre-release health check.