Dr Magdalena Svensson

In a mountainous area of northwest Namibia, known as the Northern Highlands, community game guards have many years of experience in monitoring local wildlife. But until our study there had been no published research specifically on the elephants in the Northern Highlands. The area is highly remote, and the steep, rocky landscape makes traditional monitoring methods difficult for this small population of elephants, both in terms of on-the-ground tracking and aerial surveys. We identified that an alternative approach of estimating the size of the elephant population could be to gather local ecological knowledge of game guards. From this method, we estimated that there are between 78 and 212 elephants in the Northern Highlands, with a best estimate of 128. We identified how the method could be improved and conclude that it would be applicable for longer-term ecological monitoring of trends in population. This cost-effective approach would supplement other approaches such as aerial surveys that can only provide a snapshot of the population estimate once every five years, because of the high costs. The long-term monitoring would be important to inform the planning of adaptive strategies for the protection of elephants, an endangered species.

A growing global human population, habitat conversion, and the indiscriminate exploitation of natural resources have created unsustainable demands on nature, resulting in widespread biodiversity loss. Primates, which represent the third most specious Order of mammals, are facing an extinction crisis. Currently, 69% of primate species are listed by the IUCN as threatened (Vulnerable, Endangered, or Critically Endangered) and 94% have declining populations. Here, we examine two primary threats to primate population persistence, namely the commercialized hunting and capturing of wild primates and their body parts for food, traditional medicine, pets, and use in biomedical research. Both the legal wildlife trade and illegal wildlife trafficking represent multibillion-dollar industries that contribute to primate population decline, a reduction in genetic diversity, and local extirpation. Trade and trafficking also can lead to the emergence of infectious diseases, increasing biosecurity risks to humans. Between 2015 and 2021, CITES reported 337,511 live primates representing at least 99 species were legally traded, with 6.5% sourced directly from the wild. The recent indictment of Cambodian officials for allegedly laundering wild-caught long-tailed macaques into the U.S. by labelling them as captive-bred, highlights the need for greater transparency and accountability. Comprehensive data on the illegal trafficking of primates are extremely difficult to obtain. However, between 2009 and 2017, primates accounted for 20% of all seizures of illegally traded mammals in the air transport sector. International wildlife trafficking is dominated by criminal networks, corruption, and driven by the demands of Frontiers in Conservation Science wealthy consumers. In addition, the internet has expanded international opportunities to connect buyers and sellers of wild-caught primates and their body parts. Despite explicit bans on selling endangered primates, social media sites continue to do so. Moreover, data on the global food security index (GFSI) indicate that as the international demand for wild live primates, their meat, and other body parts has continued to increase, the majority of people in primate range nations have remained food insecure. Given that almost 70% of primate species are negatively impacted by hunting and trapping, we offer a set of recommendations to reduce the trade and trafficking of wild primates.

quirrels traded for pets or consumption have the potential to be vectors for zoonotic disease transmission and to establish themselves as invasive species. Callosciurus spp. (Greek for beautiful squirrel) are popular in the pet trade due to their medium size and many colour variants, though several feral populations have established themselves in various parts of the world and these wild-caught individuals can carry and spread infectious diseases. Here, we investigate the live trade in Prevost’s squirrels (C. prevosti) in Indonesia where they are naturally found on the islands of Sumatra, Bangka and Borneo. Between 2016 and 2024, we recorded 284 Prevost’s squirrels for sale, viz., 115 in the physical markets and 169 online. We detected the species for sale in Sumatra (13 individuals), Bangka (7) and Borneo (3), i.e. within their natural range, but also on Java (242) and Bali (4). The mean asking price per individual was US$63, and younger individuals commanded higher prices than older ones. Asking prices were not higher in cities further away from the species’ native range nor in cities with higher purchasing power. All individuals were wild-caught, and with a domestic quota of five individuals allowed to be traded as pets per year (45 over the study period) most of this trade is illegal under Indonesian law. This is distinctly different from trade in Prevost’s squirrels in for instance Europe or the USA where legally captive-bred individuals are offered for sale. In Indonesia the illegal trade happens in the open and despite the risk of the spread of zoonotic diseases wherever it is traded there appears to be little incentive on the side of the authorities to curb this trade. Their widespread availability on Java and Bali risks the accidental or deliberate introduction on these two islands. Better coordination is needed between the Indonesian authorities, online sales sites, pet traders and consumers to stop the sale of illegally obtained Prevost’s squirrels to limit the risk of them becoming invasive species or contributing to the spread of emerging infectious diseases.

Wildlife trade, both legal and illegal, is increasingly recognized as a key factor in the rise of emerging viral infectious diseases, and this is especially apparent in Asia, where large numbers of wildlife are openly offered for sale in bird markets. We here focus on the risk of Psittacosis becoming a zoonotic disease in the wildlife markets of Java and Bali, Indonesia. Psittacosis is particularly prevalent in parrots (hence the name), and the trade in parrots was instrumental in the Great Parrot Fever Pandemic in 1929/1930. Between 2014 and 2023, we conducted 176 surveys of 14 bird markets, during which we recorded 4446 largely wild-caught parrots for sale. On average, each market had nine genera on offer, and the diversity of genera increased with the increasing presence of parrots (up to 16 genera). For most of the bird markets during each survey, parrots from different genera and originating from different parts of the world, were offered for sale alongside each other. Genera offered for sale together did not cluster into natural (geographic) groups. We found no temporal difference in the sale of parrots. We conclude that the omnipresence of wild-caught parrots from various geographic regions in large numbers within the same bird markets increases the risk that psittacosis is present and that this poses a real risk for the zoonotic spread of avian chlamydiosis to humans.

Conservation funding is currently limited; cost-effective conservation solutions are essential.We suggest that the thousands of field stations worldwide can play key roles at the frontline of biodiversity conservation and have high intrinsic value.We assessed field stations’ conservation return on investment and explored the impact of COVID-19. We surveyed leaders of field stations across tropical regions that host primate research; 157 field stations in 56 countries responded. Respondents reported improved habitat quality and reduced hunting rates at over 80% of field stations and lower operational costs per km2 than protected areas, yet half of those surveyed have less funding now than in 2019. Spatial analyses support field station presence as reducing deforestation. These “earth observatories” provide a high return on investment; we advocate for increased support of field station programs and for governments to support their vital conservation efforts by investing accordingly.

Conservation funding is currently limited; cost-effective conservation solutions are essential. We suggest that the thousands of field stations worldwide can play key roles at the frontline of biodiversity conservation and have high intrinsic value. We assessed field stations’ conservation return on investment and explored the impact of COVID-19. We surveyed leaders of field stations across tropical regions that host primate research; 157 field stations in 56 countries responded. Respondents reported improved habitat quality and reduced hunting rates at over 80% of field stations and lower operational costs per km2 than protected areas, yet half of those surveyed have less funding now than in 2019. Spatial analyses support field station presence as reducing deforestation. These “earth observatories” provide a high return on investment; we advocate for increased support of field station programs and for governments to support their vital conservation efforts by investing accordingly

In the Anthropocene, primate conservation can only take place when considering human culture, perspectives, and needs. Such approaches are increasingly important under the growing impact of anthropogenic activities and increasing number of threatened primates. The Amazon rainforest, rich in cultural and biological diversity, where indigenous people play a crucial role in primate conservation, provides ample opportunity to study human–primate interactions and the sociocultural context in which they occur. Human activities threaten the Amazon’s fragile ecosystems and its primates, which play a key role in its maintenance and regeneration. This study focuses on one of the largest indigenous groups in the Peruvian Amazon: the Shipibo. Interviews and participant observation were used to investigate local perceptions of animal presence and depletion, food preferences, and how primates are incorporated into daily life and culture. Since time immemorial and still today, primates remain important in Shipibo culture, mythology, and subsistence. Local Shipibo participants consistently identified the presence of 13 species of primate. Primates were among the preferred species for consumption, pet keeping, and held a fundamental role in mythology, traditional knowledge, and storytelling. Large-bodied primates were often mentioned as being locally extinct, with reports and observations suggesting increasing consumption of smaller-bodied primates. Commonly perceived reasons for primate depletion include noise disturbance, hunting, and population growth, often in parallel. This study sheds light on the cultural context of an area rich in biodiversity, where primates, essential for ecological balance and integral to Shipibo lives and identity, are being depleted. We highlight the need for an inclusive ethnoprimatological approach to conserving primates and preserving indigenous heritage while improving local livelihoods.

Population viability analyses (PVAs) have become a useful tool in wildlife conservation because of their
ability to assess the relative impact of threats on populations and identify the most effective management scenarios for endangered species. The Raffles’ banded langur (Presbytis femoralis) is classified as Critically Endangered, with populations occurring in Peninsular Malaysia and the island of Singapore. In Singapore, as of 2021, 68 individuals remain, up from approximately 40 in 2010. A key goal listed in a recent species action plan was to increase the population size. In this study, a PVA was conducted to model the integrated effects of deterministic and stochastic factors on estimated growth trajectories. VORTEX software was used to model the relative impact of threats (habitat loss and low genetic diversity) and management scenarios (increased habitat connectivity, translocation of conspecifics from Malaysia) on population growth rates within a 50-year period. Our modelled results estimated the probability of extinction to be 0% in every scenario and the baseline predicted a population of 244 individuals by 2071 with current population growth rates. The impacts of inbreeding on the population were low, with minimal variation from the baseline scenario. The primary constraint to future population growth is habitat availability, with the population having the potential to reach carrying capacity within the next 40–50 years even if improved habitat connectivity allows increased access to neighbouring forest fragments. With this study, we provide further support for the top management priorities of habitat protection and connectivity identified in the species action plan. There is an urgent need to identify other suitable habitats for the species within Singapore to support future population expansion towards numbers consistent with long-term demographic and genetic viability, with the positive impact of translocations likely to be minimal unless carrying capacity can be increased. With populations of most primate species decreasing and cities playing an increasingly crucial role as a refuge for remaining wildlife populations, this study also demonstrates the potential for populations to recover with effective management, with population growth in the Singapore Raffles’ banded langur population demonstrated in all threat scenarios modelled. Conservationists can utilise the strategies employed in Singapore to safeguard similar primate populations in fragmented habitats.

As road infrastructure networks rapidly expand globally, especially in the tropics, previously continuous habitats are being fragmented, resulting in more frequent wildlife–vehicle collisions (WVC). Primates are widespread throughout many sub-/tropical countries, and as their habitats are fragmented, they are increasingly at risk of WVC. We created the Global Primate Roadkill Database (GPRD), the largest available standardized database of primate roadkill incidents. We obtained data from published papers, un-published and citizen science databases, anecdotal reports, news reports, and social media posts. Here, we describe the collection methods for the GPRD and present the most up-to-date version of the database in full. For each primate roadkill incident, we recorded the species killed, the exact location, and the year and month the roadkill was observed. At the time of publication, the GPRD includes 2862 individual primate roadkill records from 41 countries. As primates range in more than twice as many countries, the absence of data from these countries is not necessarily indicative of a lack of primate vehicular collisions. Given the value of these data for addressing both local and global research questions, we encourage conservationists and citizen scientists to contribute to the GPRD so that, together, we can better understand the impact road infrastructure has on primates and evaluate measures which may help mitigate risk-prone areas or species.

Illegal and/or unsustainable trade is a major obstacle to effective primate conservation. The wildlife trade in the European Union (EU) and the United Kingdom (UK) is significant, but for many species, such as primates, the trade is poorly understood and sparsely reported. All EU countries are Party to the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES); all primates are listed on Appendix I or II of CITES and are included on Annex A or B of Regulation (EC) No 338/97. We here combine data from several databases (CITES, UN Comtrade, TRAFFIC WiTIS) and seizure reports, to provide a narrative of the trade in primates into and within Europe. The legal import of live primates (2002–2021) amounted to 218,000–238,000 individuals (valued at US$ 869 million), with France, the UK, and Spain as the main importers and Mauritius, Vietnam, and China as the main exporters. Over 21,000 primate parts (trophies, skulls, bodies) were imported mainly from African countries, and UN Comtrade data suggests that ~ 600 tonnes of primate meat was imported mainly from Asia. The vast majority of live primates are either captive-born or captive-bred, and this proportion has increased over time. Reports of the illegal primate trade are far from complete, but the illegal trade of specific species or primate meat can have negative impacts of wild populations of already imperiled species. Stronger policies and more effective enforcement in consumer countries, such as the EU, would also aid in, and garner support for, better protecting primates in primate range states.

Social media is known to influence consumers’ attitudes and to increase demand for wild animals
as pets, when depicted online. We investigate the online presence of the nocturnal primates gala-
gos, on TikTok and Instagram, and its influence on followers’ attitudes and desire to keep galagos
as pets. We monitored activity June – December 2020 and conducted sentiment analysis on 21976
comments. We assessed trends in Google searches and estimated the international trade of live
galagos using CITES reports. Post views increased up to 472% within the study period. Posts were
mostly from Japan, Thailand, and Russia, with comments in 43 different languages. Of the com-
ments, 95% were positive, e.g., “cute” and “I want one”. Google searches of the term “galago pet”
increased over time, as did the number of live galagos exported. Southeast Asia is having a boom
in exotic pet trade. Viral videos of other nocturnal primates previously led to increased demand for
pets, and we hope our findings provide data to guide policy and conservation intervention

Our understanding of the transmission of anthropozoonotic diseases between humans and non-human primates, particularly great apes due to their close genetic relationship with humans, highlights a serious potential threat to the survival of these species. This is particularly the case at tourism sites where risk of disease transmission is increased. We focus on the interaction between tourists and the Critically Endangered Sumatran orangutan (Pongo abelii) at Bukit Lawang in the Gunung Leuser National Park, Indonesia, before and after the park was closed due to the threat of COVID-19 in April 2020. Through analysis of posts on Instagram we determine the extent of compliance by visitors with the rule to keep a minimum distance of 10 m from orangutans and assess the positional behaviours of the orangutans. Of the 2,229 photographs we assessed between November 2019 and July 2020, 279 depicted one or more orangutans. Forty-two of these contained both a human and an orangutan, and of these all showed inappropriate behaviours (direct contact, feeding orangutans, close proximity

In January 2021, the International Union for the Conservation of Nature’s Primate Specialist Group Section for Human Primate Interactions (IUCN PSG SHPI) published best practice guidelines on the use of non-human primate imagery online. This paper explores the contribution of professional primate keepers to the detrimental online sharing of images involving humans and primates, and their knowledge and opinions towards this subject. A total of 421 primate keepers responded to an online questionnaire shared in March 2021, providing information about their use of primate imagery on social media platforms and sharing their understanding of scientific studies on this topic. Over half (56%) of primate keepers admitted to sharing images online of themselves and primates, that could be considered irresponsible. A complementary review of posts shared on Instagram™ under the hashtag #primatekeeper revealed that 64% of 128 images surveyed depicted primates in situations which prior research has shown to have negative consequences for primate conservation, in addition to affecting the way the public perceives the conservation status of species in such imagery. Of the respondents, 53% had not heard of the IUCN PSG SHPI, and 67% of primate keepers were unaware of the new guidelines published by the group. It is recommended that the best practice guidelines are disseminated to zookeepers directly through appropriate forums to ensure primate keepers are acting in line with the recommendations in the best practice guidelines, and that further research is conducted regarding human-primate two-shot images to better guide decisions made by primatologists and others working both in and ex situ with primates.

Pig-tailed macaques are used by coconut farmers in Southeast Asia to harvest coconuts. We assessed the welfare of northern pig-tailed macaques Macaca leonina involved in coconut harvesting in southern Thailand. We interviewed 89 coconut farmers in three provinces focusing on quantifying basic demographics of this trade, i.e., species, where the macaques were sourced, diet, sex, and age. Independent from the interviews, we assessed the welfare of 158 working macaques through direct observations using the ‘five domains’ criteria. Based on our scoring system, the mean welfare score of 4.8 out of the maximum 12 points indicates a need for improvement. Overall, we found good agreement between the interviews data and the welfare assessments. The most important individual welfare modifications required for working macaques to obtain a good level of welfare that benefits both the farmers and macaques include: providing access to conspecifics, adding opportunities to hide from stressors, and increasing the freedom of movement. This study highlights the individual welfare concerns and necessity of legislative changes regarding working macaques and other working animals of wild origins.  

Primates are traded yearly in the tens of thousands for reasons such as biomedical research, as trophies and pets, for consumption and to be used in traditional medicine. In many cases, this trade is illegal, unsustainable and considered a major impediment to primate conservation. Diurnal primates make up the vast majority of this trade, but recent studies have found that the trade in nocturnal primates is more common than previously thought, and among them are the galagos. There are currently 19 galagos recognized but there is still a dearth of research on these species and subspecies. The purpose of our study was to provide a more comprehensive picture of the trade in galagos within and across their African range countries, to help determine whether it is illegal or its sustainability needs to be assessed, and to provide baseline data and management recommendations to better regulate this trade, including strengthening policy, enforcement and conservation interventions. We gathered information on trade and use of galagos using an online questionnaire (May–August 2020), and on country-specific legislation relating to wildlife trade, hunting and legal protection of galagos, and looked at each range country’s Corruption Perception Index score to gain an understanding of the obstacles in the way of effective law enforcement. We received 140 responses to our online questionnaire, from 31 of the 39 galago range countries. Respondents from 16 of these countries reported on first-hand observations of galagos being traded or used. Out of these, 36% reported seeing galagos sold or used for consumption, 33% as pets and 25% had observed them sold or used for traditional practices (including medical and magical purposes and for witchcraft). Most reports came from West Africa followed by Central Africa, East Africa and Southern Africa. We found that the number of reports on galagos being traded was higher in countries with higher numbers of galago species. Countries with more restrictive legislation experienced a higher number of reports of trade. Galagos observed in the pet trade was more common in East Africa, whilst reports of them in the bushmeat trade were more common in Central and West Africa. Galagos observed in the trade for traditional practices was by far most common from West Africa. We found that all galago range countries have some level of legal protection for some or all of their native galago species. It is evident that use and trade of galagos occurs throughout their range, albeit localized to certain areas. We urge galago range countries to adequately protect all species and to ensure legal trade is effectively regulated. Range countries that prohibit the use and trade in galagos must ensure legislation is adequately enforced. Further research into the drivers behind the use and trade of galagos should be initiated in countries with high levels of use and trade to further inform conservation and policy actions and to catalyze enforcement actions against poaching and illegal trade.

1. Mountain gorilla Gorilla beringei beringei trekking is a substantial source of revenue for the conservation of this threatened primate and its habitat. Trekking, however, may pose a threat of human-to-gorilla disease transmission that could have disastrous effects on wild gorillas.

2. We used 858 photographs posted on Instagram in 2013–2019 to analyse the proximity of tourists visiting mountain gorillas in the wild. We classified photographs of the encounters according to the distance between the closest gorilla and human, the age class of the gorilla, the trekking location and presence of a surgical face mask on the tourist. We ran a generalised linear mixed model to test whether these variables influenced the distance between the human and the wild gorillas in the photographs, and to test whether these distances have changed over time.

3. Most sampled photographs (86%) showed tourists within a critical 4 m of the gorillas, with 25 incidents of physical contact between a tourist and a gorilla, and only 3% at the recommended distance of 7 m or more. We only were able to record face mask use in the Democratic Republic of Congo, where these were present in 65% of uploaded photos.

4. Tourists and immature gorillas tended to get closer to each other than tourists and adult gorillas, and this is more pronounced in female tourists than male tourists. The mean distance between human and wild gorillas decreased by ~1 m between 2013 and 2019.

5. The results indicate that existing rules are not enforced and raise attention to this unsustainable aspect of mountain gorilla trekking as it is practiced today. These ever-growing tourist attractions in the range countries pose risks of disease transmission in both directions between tourists and wildlife. The popularity of photograph-based social media may stimulate closer contacts and influence people into risky behaviours.

6. We advocate the establishment and reinforcement of regulations relating to the distance between animals and tourists in any in situ wildlife ecotourism context,as well as campaigns to raise awareness regarding the risks of anthroponosis, and fines applied in case of non-compliance.

Understanding the repertoire of hunting techniques used by traditional peoples in tropical forests is crucial for recognizing the role of traditional knowledge in hunting activities, as well as assessing the impact of harvests on game species. We describe the hunting techniques used across Amazonia by Indigenous and non-Indigenous peoples for hunting yellow-footed tortoises (Chelonoidis denticulatus), one of the most consumed species in the biome. We interviewed 178 local people in 25 communities living in seven study areas in the Peruvian and Brazilian Amazon. We used a Principal Coordinate Analysis (PCoA) and Analysis of Similarity (ANOSIM) to compare the hunting techniques between ethnic groups and the ages of the interviewees. Four different techniques were reported: (1) trapping with bait (46%; n = 122); (2) hunting with dogs (35%; n = 92); (3) active searching (14 %; n = 37); and (4) visiting fruiting trees (5%; n = 14). Trapping with bait was alleged to be the most cost-effective technique by 67% of the interviewees. Among the baits used, 93% involved the use of wild species as rotten meat. Hunting with dogs was also frequently cited and involved eight different methods of training. The hunting techniques recorded were not significantly different among ethnic groups or generations. The consonance among the technique repertoire likely reflects a shared knowledge still in use across different cultural groups. There is a potential for applying the hunting techniques to large scale community-based monitoring and management programs, but the impact on additional species affected, such as species intentionally captured to be used as bait, should be considered. Local assessments and community-based management plans that incorporate traditional ecological knowledge are recommended to guarantee the maintenance of livelihoods and ensure the species' conservation in Amazonia.

Seizures of hundreds of jaguar heads and canines in Central and South America from 2014 to 2018 resulted in worldwide media coverage suggesting that wildlife traffickers are trading jaguar body parts as substitutes for tiger parts to satisfy the demand for traditional Asian medicine. We compiled a data set of >1000 seized wild cats (jaguar [Panthera onca], puma [Puma concolor], and ocelot [Leopardus pardalis]) from 19 Central and South American countries and China. We ran generalized additive mixed models to detect trends in wild-cat seizures from 2012 to 2018 and assess the effects of socioeconomic factors of source countries and between those countries and China on the number of wild cats seized. Jaguar seizures increased over time, and most of the seized jaguar pieces were canines (1991 of 2117). Around 34% (32 of 93) of the jaguar-part seizure reports were linked with China, and these seizures contained 14-fold more individuals than those intended for domestic markets. Source countries with relatively high levels of corruption and Chinese private investment and low income per capita had 10-50 times more jaguar seizures than the remaining sampled countries. The number of Chinese residents in Central and South America was not significantly related to the number of jaguars seized. No socioeconomic factors influenced the seizures of puma and ocelots. Legal market chains may provide structure for the illegal chain; thus, the influx of illegal jaguar products is potentially a side effect of the economic partnership between Central and South American countries and China. Poverty and high levels of corruption in the source countries may motivate local people to engage in illegal activities and contribute to the growth of this trade. Supply-side interventions to curb this threat to Neotropical wild cats may include improved training for officials and promotion of governance and the value of protecting these animals to local people.

Vocalizations are a vital form of communication. Call structure and use may change depending on emotional arousal, behavioral context, sex, or social complexity. Pithecia chrysocephala (golden-faced sakis) are a little-studied Neotropical species. We aimed to determine the vocal repertoire of P. chrysocephala and the influence of context on call structure. We collected data June–August 2018 in an urban secondary forest fragment in Manaus, Amazonian Brazil. We took continuous vocal recordings in 10-min blocks with 5-min breaks during daily follows of two groups. We recorded scan samples of group behavior at the start and end of blocks and used ad libitum behavioral recording during blocks. We collected 70 h of data and analyzed 1500 calls. Lowest frequencies ranged 690.1–5879 Hz in adults/subadults and 5393.6–9497.8Hz in the only juvenile sampled. We identified eight calls, three of which were juvenile specific. We found that, while repertoire size was similar to that of other New World monkeys of similar group size and structure, it also resembled those with larger group sizes and different social structures. The durations of Chuck calls were shorter for feeding contexts compared to hostile, but frequencies were higher than predicted if call structure reflects motivation. This finding may be due to the higher arousal involved in hostile situations, or because P. chrysocephala use Chuck calls in appeasement, similar to behavior seen in other primates. Call structures did not differ between sexes, potentially linked to the limited size dimorphism in this species. Our findings provide a foundation for further investigation of Pithecia vocal behavior and phylogeny, as well as applications for both captive welfare (stress relief) and field research (playbacks for surveys).

Stone tools in the prehistoric record are the most abundant source of evidence for understanding early hominin technological and cultural variation. The field of primate archaeology is well placed to improve our scientific knowledge by using the tool behaviours of living primates as models to test hypotheses related to the adoption of tools by early stone-age hominins. Previously we have shown that diversity in stone tool behaviour between neighbouring groups of long-tailed macaques (Macaca-fascicularis) could be explained by ecological and environmental circumstances (Luncz et al., 2017b). Here however, we report archaeological evidence, which shows that the selection and reuse of tools cannot entirely be explained by ecological diversity. These results suggest that tool-use may develop differently within species of old-world monkeys, and that the evidence of material culture can differ within the same timeframe at local geographic scales and in spite of shared environmental and ecological settings.

Like other nocturnal primates, many species of galago (Galagidae) are phenotypically cryptic, making their taxonomic status difficult to resolve. Recent taxonomic work has disentangled some of the confusion. This has resulted in an increase in the number of recognised galago species. The most widespread galago species, and indeed the most widespread nocturnal primate, is the northern lesser galago (Galago senegalensis) whose geographic range stretches >7,000 km across Africa. Based on morphology, 4 subspecies are currently recognised: G. s. senegalensis, G. s. braccatus, G. s. sotikae and G. s. dunni. We explore geographic and subspecific acoustic variation in G. senegalensis, testing three hypotheses: isolation by distance, genetic basis, and isolation by barrier. There is statistical support for isolation by distance for 2 of 4 call parameters (fundamental frequency and unit length). Geographic distance explains a moderate amount of the acoustic variation. Discriminant function analysis provides some degree of separation of geographic regions and subspecies, but the percentage of misdesignation is high. Despite having (putative) parapatric geographic ranges, the most pronounced acoustic differences are between G. s. senegalensis and G. s. dunni. The findings suggest that the Eastern Rift Valley and Niger River are significant barriers for G. senegalensis. The acoustic structures of the loud calls of 121 individuals from 28 widespread sites are not significantly different. Although this makes it unlikely that additional unrecognised species occur within G. senegalensis at the sites sampled, vast areas of the geographic range remain unsampled. We show that wide-ranging species do not necessarily exhibit large amounts of variation in their vocal repertoire. This pattern may also be present in nocturnal primates with smaller geographic ranges.

Comparative behavioural research reveals both intra- and inter-species diversity among primates. Few long-term behavioural studies have been conducted on African nocturnal primates. Here we describe and compare behavioural and ecological observations on two species of pottos (Perodicticus ibeanus and P. edwardsi) across ten sites. We observed a total of 51 P. edwardsi and 28 P. ibeanus. We recorded all 21 postures within an established lorisid ethogram, as well as 42 of 50 behaviours. Eating, locomotion, freezing, resting and sniffing were the most common behaviours. We recorded behaviours not previously described for perodicticines, including bark chewing and unique vocalisations. Three species of pottos are now recognised, with potentially more species to be revealed within this cryptic and nocturnal genus. Although there are similarities among potto species, we show that unique ecological adaptations and behaviours may further elucidate their diversity.