Understanding the behavioural ecology of Nycticebus menagensis is vital in conducting best-practice releases for those that are rescued from the illegal pet trade. In releasing protected species such as slow lorises, whose wild populations are severely affected by the wildlife trade, it is necessary to ensure wild survival and facilitate sustainable wild populations. Two important factors determining adaptation to wild conditions and natural habitat are consuming a natural diet and appropriate feeding behaviours (Cheyne, 2006; Grundmann and Didier, 2000). If they are to survive in the wild, it is important that the diets and feeding schedules of slow lorises undergoing rehabilitation meet the nutritional needs of the individuals while mirroring natural feeding behaviours.

The first primate-like mammals to appear in the fossil record date to the earliest Palaeocene (Clemens, 2004; Fox and Scott, 2011; Silcox and López-Torres, 2017; Van Valen and Sloan, 1965), and the first primates of modern aspect (euprimates) do not appear until the latest Palaeocene/earliest Eocene (Morse et al., 2019; Ni et al., 2013; Rose et al., 2012; Sigé et al., 1990; Silcox et al., 2017; Smith et al., 2006). However, the most recent molecular estimates for the last common ancestor (LCA) of all living primates suggest that the order originated at some point between the late Cretaceous and the early Palaeocene (approximately between 60 and 70 Mya; Andrews et al., 2016; Herrera and Dávalos, 2016; Seiffert et al., 2018). Later, between 42 and 55 Mya (according to the same sources for molecular dates), Strepsirrhini split into the progenitors of the infraorders Lemuriformes and Lorisiformes (throughout this chapter we use the taxonomy established by Grubb et al., 2003). The Lemuriformes went on to radiate into the vast array of morphologically diverse living and extinct lemurs located on the island of Madagascar, and the lorisiforms split into two families: Lorisidae (pottos, angwantibos, slender lorises and slow lorises) and Galagidae, the bushbabies (Covert, 2002; Martin, 1990; Rasmussen and Nekaris, 1998).

For many wild animals under human care, detailed nutritional requirements are not yet established. In these cases, we must use the existing knowledge of domestic species as models. The nearest model to lorisiforms is the common marmoset Callithrix jacchus, which is not a domestic species but has been used in laboratories since the 1970s and its nutritional requirements have been well described (NRC, 2003). Unfortunately, the marmoset is not a perfect model because of its differing basal metabolic rates (Ross, 1992), high vitamin D requirements (Abbott et al., 2003) and differing proportions of food items within its natural diets (Cabana et al., 2018b). Therefore, many parameters must be estimated based on the wild loris’ feeding ecology and feeding trials under human care (Baer et al., 2010). The stakes are much higher today, since we know that diets are not only responsible for supplying optimal concentrations of nutritional components, but also for supporting the animal’s welfare through appropriate food presentation methods (Scott et al., 1999). Providing more natural diets may help in doing the latter, but it does not guarantee a balanced diet. Even a diet consisting entirely of insects is not necessarily nutritionally appropriate for insectivorous animals as the insects commonly fed in captivity such as mealworms and crickets lack many micronutrients (Finke, 2013).

The Internet has revolutionised our lives, transforming the way in which we communicate and carry out business (IFAW, 2005). As a result of the development of the Internet and ultimately social networking sites (SNS), biodiversity conservation is facing new threats. Wildlife trade and online exotic pet trade is flourishing due to the provision of a medium via which illegal trade can occur more easily and discreetly (Creamer and Philips, 2005; Engler and Parry-Jones, 2007; IFAW, 2005; Morgan, 2015). At the same time, wildlife tourism is becoming increasingly popular. Wildlife tourism attractions make up an estimated 20–40 per cent of the global tourism industry, drawing in approximately 110 million people annually; yet 80 per cent of participants are unable to recognise the negative impacts on animal welfare (World Animal Protection, 2016). Many Westerners who contribute substantially to wildlife tourism live in relative isolation from nature and wild animals. Consequently, interaction with wildlife is considered a vital part of their modern tourism experiences (Cohen, 2009).

Primary data like occurrence, distribution range and size and ecological characteristics of the population are essential for the conservation and management of any species (Caughley, 1977; Williams et al., 2002). Population size or demographic changes can be used as an indicator when evaluating management success (Caughley, 1977; Williams et al., 2002). Therefore, understanding the different parameters of a population for a species is crucial for conservation action. Appropriate field techniques need to be employed to generate such data and need to be adapted to survey the target species.

This book started as a conversation in New Orleans back in 2016. A morphologist and a primatologist were sitting at the American Association of Physical Anthropologists annual meeting, bemoaning the scant presentations on lorises (slow lorises, slender lorises, angwantibos and pottos) relative to galagos, lemurs, monkeys and apes. Not only where were the talks on these primates, but where were the books on lorisids? After a few minutes of this talk, we decided it was time to see to it ourselves. Using a cocktail napkin and later a more respectable legal pad, we started sketching out what we would each want to see in a collected, edited volume devoted to what we know about lorises, some of the least understood primates living today. What resulted from that afternoon in a New Orleans bar is this edited volume. The scope is intentionally broad and is primarily divided into sections on evolution and morphology, behaviour and conservation. We also purposefully focused on soliciting short contributions, set as boxes within the text, from young authors doing fieldwork in Asian range countries, places where scientific study and conservation efforts on Loris and Nycticebus, the Asian lorises, is producing previously unknown data on population density and specific challenges to conservation efforts.

The African lorisid subfamily Perodicticinae includes the slow-moving angwantibos (Arctocebus) and the pottos (Perodicticus) (Lambert, 2014), the focal taxon of this chapter. The distinguishing physical features of this subfamily include their short tails and vestigial manual second digit (Charles-Dominique, 1977a). Perodicticus potto, first described by Bosman in 1704 and further characterised by Müller in 1776 (Bosman, 1705; Müller, 1773; Smeenk et al., 2006), was originally placed in the genus Nycticebus by Geoffroy, but the subsequent rediscovery of the animal in Sierra Leone by Bennett in the early nineteenth century became the basis for his naming the genus Perodicticus (Bennett, 1831; Hill, 1953a; Smeenk et al., 2006).

Inspiring people to value their local wildlife is vital to promoting the conservation of native fauna (Padua, 2010; Savage et al., 2010). Conservation education has historically tended to focus on enhancing people’s knowledge about animals and the threats to their survival as a means of promoting pro-conservation behaviours. Educators have identified that people need both factual knowledge and an emotional affinity for animals as precursors to developing positive attitudes and behaviours towards them (Cheng and Monroe, 2012; Jacobson, 2010; Kuhar et al., 2010). There is a growing recognition that initiatives using positive messages to highlight nature’s positive aspects are more inspiring than negative communication about loss of species that can instead make people feel helpless (IUCN-CEC, 2010). A key component to inspiring people to care for wildlife is building empathy and pride (McCauley, 2006; van der Ploeg et al., 2011).

Direct observations are the main method employed to collect animal behaviours, although providing reliable data for wild animals is frequently challenging (Brown et al., 2013). In fact, direct observations require a habituation period that varies depending on the species and may last for years (Crofoot et al., 2010; Jack et al., 2008). The observer is rarely undetectable, and even habituated animals may still change their natural behaviour in latent ways (Caine, 1990). Direct observations are also biased by inter-subject methodological differences (Altmann, 1974). Furthermore, many animal species are cryptic and the amount of data collectable via behavioural observations may be very limited (Chimienti et al., 2016).

Social media is a phenomenon that offers a host of challenges and opportunities for conservationists. The sector is rapidly evolving, with an increasing variety of platforms and social networking sites (SNS) that gain and lose popularity at unprecedented rates (Livingstone and Brake, 2010). These sites are frequently used to spread images of animals and this has a potentially devastating impact on species conservation, particularly with respect to charismatic mammals such as Lorisiformes (Vázquez et al., 2016).

Primates are often distinguished from other mammals by their greater emphasis on vision relative to other senses (Cartmill, 1992; Kirk, 2013). Many of the defining traits of early primates are adaptations of the visual system, such as a postorbital bar, greater orbital convergence and larger eyes (Heesy, 2008; Kay and Kirk, 2000; Kirk, 2013; Ross and Kirk, 2007). In comparative studies of extant mammals, primates are typically characterised by higher estimates of visual acuity (i.e. the ability to resolve fine details) and greater variation in colour vision and opsin genes (Jacobs, 2008, 2013; Kirk and Kay, 2004; Veilleux 2016; Veilleux and Kirk, 2009, 2014). Consequently, most hypotheses of primate evolutionary origins involve identifying ecological factors that selected for this increased visual performance in early primates. Given that most of these hypotheses propose a nocturnal niche (e.g. Cartmill, 1992; Rasmussen, 1990a; Sussman, 1991), identifying and understanding variation in visual function and ecology among nocturnal primates is particularly important.

Studies on the behaviour of the African lorisiforms are scarce, but there are clear morphological, ecological and behavioural differences between the robust pottos (Perodicticus spp.) and the smaller, gracile angwantibos (Arctocebus spp.). Pottos have a wide distribution across the African rainforest zone, while angwantibos are restricted to the forests of western equatorial Africa.

Global trade in slow lorises (Nycticebus spp.) has risen precipitously in recent decades (Nijman et al., 2017), and slow lorises are poached for use as bushmeat, traditional medicine, photo props and pets (Nekaris et al., 2010b). The pet trade has been particularly lucrative since slow lorises became popular in ‘cute’ viral videos and photos on social media sites like YouTube (Nekaris et al., 2013a). International trade in the genus Nycticebus is prohibited by Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) (Nekaris and Nijman, 2007). Greater slow lorises (Nycticebus coucang) are also protected in Indonesia, but are still openly traded in large numbers in Indonesian wildlife markets (Shepherd, 2010). Effective enforcement of wildlife protection laws requires seizing and confiscating illegally traded animals. As a result, enforcement efforts increase the number of animals living in sanctuaries and rescue centres, which now are strained past capacity (Moore et al., 2014; Nekaris and Jaffe, 2007).