Haemadipsid leeches are ubiquitous inhabitants of tropical and sub-tropical forests in the Indo-Pacific region. They are increasingly used as indicator taxa for biomonitoring, yet very little is known about their basic ecology. For example, to date no study has assessed the occurrence and distribution of haemadipsid leeches across naturally occurring gradients within intact habitats. We analyzed a long-term data set (2012-2020) on the closely related tiger (Haemadipsa picta) and brown (Haemadipsa spp.) leech species to investigate if and how abiotic and biotic factors influence their occurrence across a gradient of forest types at an undisturbed tropical rainforest site in Indonesian Borneo. We compared a series of negative binomial mixed models and found that, of the abiotic factors, soil moisture had the largest positive effect on encounter rates of both leech species. Among biotic factors, forest type had differential effects on counts of the two species: while tiger leech counts were greater in low elevation forest types, brown leech counts were greater in high elevation forest types. Additionally, we found that the presence of one species had a positive effect on the presence of the other species. Finally, our results show that the tiger leech has a narrower distribution, being restricted to lower elevation forest types with higher water retention, suggesting that the tiger leech could be more sensitive to lower soil moisture levels. Abstract in Indonesian is available with online material.

The Bengal slow loris Nycticebus bengalensis is a nocturnal prosimian that inhabits the forests of northeastern India. As with many nocturnal prosimian species, little is known about its behavior or ecology; even less information is available on its distribution and population status in northeastern India. We conducted a survey of forest patches in the state of Meghalaya, in northeast India, in order to assess its distribution. A secondary aim of our study was to estimate the severity of threats that may affect the long-term survival of the slow loris in Meghalaya. We surveyed sixteen sites in six districts. Slow lorises were seen in only two sites; however, information obtained through secondary sources indicated that they were present in a number of other forest patches across the state. Many of the forests surveyed were severely affected by logging, poaching and forest fires; it is imperative that conservation measures, aimed at protecting existing forest patches, be implemented in order to ensure the long-term survival of the slow loris and other mammals in the state.

In this study we estimated the extent of exudativory in Nycticebus bengalensis and examined whether exudates can be considered as fallback foods. This study was carried out in Trishna Wildlife Sanctuary, northeastern India, in winter (December-February) and summer (March and April). We estimated time-activity budget using instantaneous sampling and used continuous focal animal sampling to record all instances and durations of feeding, over a total of 177 hr. Feeding accounted for 22.3+/-2.2% of the activity budget, with no seasonal difference. Bengal slow lorises fed on exudates, nectar, fruit, bark, invertebrates and avian eggs. In addition to scraping they also obtained exudates by gouging holes into the bark of trees. In winter, lorises almost exclusively fed on exudates (94.3% of winter feeding time). In summer, exudates (67.3%) and nectar from one species (22.3%) dominated the diet. This study identifies the Bengal slow loris as the most exudativorous loris. Exudates rather than being a staple fallback food, seem to be a preferred, patchily distributed and common food in the diet of the Bengal slow loris. Exudativory in this species is characterized by high selectivity among species and seasonal variation, which may be related to variations in productivity of exudates and their chemical composition. An understanding of these factors is necessary for predicting the response of this species to human disturbance such as logging. This study also underscores the importance of protecting some of the common species such as Terminalia belerica on which the loris feeds during periods of scarcity.