Red Slender Loris EDGE Conservation Programme


The project ultimately aims to better understand the past and current threats facing the loris, its current status (in terms of population and distribution) and its conservation needs.

Sri Lanka, an island off the southern-most point of India, is known as a global biodiversity hotspot for its high number of species in a relatively limited area. The island's amphibian diversity illustrates this point: despite covering only 0.013 percent of the world's land surface, Sri Lanka is home to more than 2 percent of the world's known amphibian species. The island is also home to nearly a thousand species of endemic plants and overall, about 27 percent of the Sri Lankan flora and 22 percent of its vertebrate fauna are endemic. The islands' isolation from the mainland, two bi-directional monsoons and three disparate mountainous regions have created a variation in climate and therefore ecology which is normally found at the continent scale. Sri Lanka (together with the Western Ghats) is amongst the eight biodiversity hyper-hot spots in the world. Sri Lanka has the second highest human population growth in the Asia region putting its resources at extraordinary risk.
Map & Range
Project actions

The primary objectives for addressing the main conservation concerns are:


Reliable data on occurrence and extent of the Loris tardigradus complex appears very limited despite a decade of research engagement. Conservation management demands more reliable and systematic survey to verify the distribution boundaries of the Loris tardigradus complex for the identification of spatial conservation units. In addition, robust trend data capable of demonstrating changes in species circumstances is an essential component to any competent species conservation management plan. Loris habitat use and preference is also still ill-defined for certain critical ecotypes such as home gardens and montane forest. A well designed monitoring programme which focuses primarily on repeat surveys recording presence or absence should be able to deliver robust baseline data within one year. Habitat patches will be monitoring in primary, secondary and home garden ecotypes. This is a precursor to establishment of a monitoring programme design and analysis procedure and robust baseline data. Monitoring sites must conform to specific criteria and can be established whilst collecting data for the distribution study.
1. Current distribution of slender loris in the wet and intermediate zone
2. Establish sites for long-term monitoring of Loris in protected and non-protected sites including montane forest, primary rainforest, secondary rainforest and home garden ecotypes
3. Provide training in occupancy monitoring methodologies and analysis techniques to core project personnel and local biometricians
4. Develop estimates of detection probability in different habitat types
5. construct a data set and analysis outputs that are capable of addressing the question of whether proportional occupancy of habitat patches is influenced by ecotype and/or environmental variables


Species and subspecies boundaries remain confused within the Loris tardigradus complex and Sri Lankan researchers suggest that cryptic taxa may be included within the current four described subspecies due to regionally specific polymorphisms observed. It has been suggested that L.t.nycticeboides may be distinct species in its own right and if this is the case then this species is likely to be considered critically endangered, and requiring of further conservation attention.
1. Investigate systematics of L. tardigradus complex and prepare capacity to continue work to include other Sri Lankan loris taxa
2. Should L.t.nycticeboides prove to be a good species or achieve a new taxonomic status then publication of findings in primate taxonomy literature
3. Develop a diagnostic key for species and subspecies in Sri Lanka

Awareness programmes will be conducted where the opportunity arises during the field programme to advocate the conservation of slender loris and habitat. This will be conducted through community workshops, school education programmes, and close involvement with local schools and science/environmental education teachers. A focused effort will also be made to achieve greater understanding of loris biology, ecology and conservation need amongst DWC and DF planning and field staff.

All wildlife should fall under a management plan of some form. It is increasingly becoming the case, especially amongst habitat sensitive species and vertebrates, that a species specific management plan is necessary for the security of those species and to enable governments to fulfil and act upon the . Through the expert working group formed to review this proposed programme, existing literature and the findings of research as described here, we will deliver a conservation action plan (CAP) for slender loris by the end of this programme that may initiate the formation of a species management and/or recovery programme for some or all of the taxa involved. Should specific resource management methods be necessary to safeguard loris in Sri Lanka or to facilitate their recovery if taxa are confirmed as in imminent peril of extinction then the CAP and following recovery plan must be governmentally endorsed (through appropriate resource management agencies) and include a focus on mechanisms to achieve sustainable environmental management and investment.

Notable successes to date, include:

The establishment of a national association of experts and authorities, with the primary objective of determining priority action areas for research, conservation and education.

Rediscovery of the virtually unknown Horton Plains slender loris (Loris tardigradus nycticeboides). Originally documented in 1937, there have only been four known encounters in the past 72 years. The rediscovery and capture by the team (working under the ZSL EDGE programme) has resulted in the first detailed physical examination of this sub-species.

The Horton Plains slender loris is evidently extremely rare and was only found after more than 200 hrs of nocturnal transect surveys in the known habitat. The red slender loris is a focal EDGE species, and the rarity of L. t. nycticeboides resulted in it being listed as one of the world’s 25 most endangered primates.

Related Media
The Montane Evergreen Forests (MEF) of Sri Lanka is beginning to expand. This is great news for the Horton Plains slender loris (HPSL), a subspecies which is endemic to Sri Lanka and rest...
The Montane Evergreen Forests (MEF) of Sri Lanka will soon be expanding. This is great news for the Horton Plains slender loris (HPSL), a subspecies which is endemic to Sri Lanka and res...
You may not be aware that we are currently in the midst of loris awareness week (, an event that is being promoted by the Little Firefac...
The Loris Field Team
Looking for loris
Expert working group
Taking morphometric data